International Fuel Gas Code Companion

INTERNATIONAL FUEL GAS CODE COMPANION: INTERPRETATION, TACTICS, AND TECHNIQUES About the Author R. Dodge Woodson is a...

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INTERNATIONAL FUEL GAS CODE COMPANION: INTERPRETATION, TACTICS, AND TECHNIQUES

About the Author R. Dodge Woodson is a seasoned builder of as many as 60 single-family homes a year, a master remodeler, a master plumber, and a master gasfitter with over 30 years of experience. He opened his first business in 1979 and is now the owner of The Masters Group, Inc., in Brunswick, Maine. In addition to operating this contracting company, Mr. Woodson has taught both code and apprentice classes in the technical college system in Maine. Well known as a prolific author of many McGraw-Hill titles, his reputation and experience come together to offer readers a real-life view of professional practices.

Copyright © 2008 by The McGraw-Hill Companies, Inc. Click here for terms of use.

INTERNATIONAL FUEL GAS CODE COMPANION: INTERPRETATION, TACTICS, AND TECHNIQUES

R. Dodge Woodson

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Copyright © 2008 by The McGraw-Hill Companies, Inc. All rights reserved. Manufactured in the United States of America. Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher. 0-07-159625-9 The material in this eBook also appears in the print version of this title: 0-07-149896-6. All trademarks are trademarks of their respective owners. Rather than put a trademark symbol after every occurrence of a trademarked name, we use names in an editorial fashion only, and to the benefit of the trademark owner, with no intention of infringement of the trademark. Where such designations appear in this book, they have been printed with initial caps. McGraw-Hill eBooks are available at special quantity discounts to use as premiums and sales promotions, or for use in corporate training programs. For more information, please contact George Hoare, Special Sales, at [email protected] or (212) 904-4069. TERMS OF USE This is a copyrighted work and The McGraw-Hill Companies, Inc. (“McGraw-Hill”) and its licensors reserve all rights in and to the work. Use of this work is subject to these terms. Except as permitted under the Copyright Act of 1976 and the right to store and retrieve one copy of the work, you may not decompile, disassemble, reverse engineer, reproduce, modify, create derivative works based upon, transmit, distribute, disseminate, sell, publish or sublicense the work or any part of it without McGraw-Hill’s prior consent. You may use the work for your own noncommercial and personal use; any other use of the work is strictly prohibited. Your right to use the work may be terminated if you fail to comply with these terms. THE WORK IS PROVIDED “AS IS.” McGRAW-HILL AND ITS LICENSORS MAKE NO GUARANTEES OR WARRANTIES AS TO THE ACCURACY, ADEQUACY OR COMPLETENESS OF OR RESULTS TO BE OBTAINED FROM USING THE WORK, INCLUDING ANY INFORMATION THAT CAN BE ACCESSED THROUGH THE WORK VIA HYPERLINK OR OTHERWISE, AND EXPRESSLY DISCLAIM ANY WARRANTY, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. McGraw-Hill and its licensors do not warrant or guarantee that the functions contained in the work will meet your requirements or that its operation will be uninterrupted or error free. Neither McGraw-Hill nor its licensors shall be liable to you or anyone else for any inaccuracy, error or omission, regardless of cause, in the work or for any damages resulting therefrom. McGraw-Hill has no responsibility for the content of any information accessed through the work. Under no circumstances shall McGraw-Hill and/or its licensors be liable for any indirect, incidental, special, punitive, consequential or similar damages that result from the use of or inability to use the work, even if any of them has been advised of the possibility of such damages. This limitation of liability shall apply to any claim or cause whatsoever whether such claim or cause arises in contract, tort or otherwise. DOI: 10.1036/0071498966

This book is dedicated to Adam and Afton, the two brightest stars in my life. Leona, Sadie, Ben, and Megan make up the rest of my universe.

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CONTENTS

Acknowledgments Introduction

xv xvii

CHAPTER 1: ADMINISTRATION

1.1

Piping Systems Gas Utilization Equipment Exceptions Other Fuels Minimum Standards Existing Installations Maintenance Additions Change in Occupancy Historic Designation Relocated Buildings Code Officer Appointment Liability Authority Rules Applications and Permits Entry Records Approval Modifications Alternative Options Testing Permits Permit Application Permit Issuance Approved Construction Documents Validity Expiration Extensions Retention of Documents Working Without a Permit Inspections Underground Inspections vii

1.2 1.2 1.2 1.4 1.4 1.4 1.5 1.5 1.5 1.6 1.7 1.7 1.7 1.7 1.8 1.8 1.8 1.9 1.9 1.9 1.10 1.10 1.10 1.11 1.11 1.11 1.12 1.12 1.12 1.13 1.13 1.13 1.14

viii

INTERNATIONAL FUEL GAS CODE COMPANION

Rough-In Inspections Final Inspections Heating Equipment Prefabricated Construction Follow-up Inspections Approval Violations Punishment Stop-work Order Unsafe Conditions Condemned Installations Disconnection Reconnection Appeal Membership of Board of Appeals Qualifications Board Organization

1.14 1.14 1.14 1.15 1.15 1.16 1.16 1.17 1.17 1.17 1.18 1.18 1.18 1.18 1.18 1.19 1.19

CHAPTER 2: DEFINITIONS

2.1

CHAPTER 3: GENERAL REGULATIONS

3.1

Labeling Plumbing Fuel Types Vibration Repair Wind Flooding Seismic Resistance Ducts Rodents Structural Safety Penetrations Cutting, Notching, and Boring Wood Joists Studs Bored Holes Trusses Steel Structural-steel Framing Cold-formed Steel Framing Nonstructural Steel Prohibited Appliance Locations Outdoor Locations Pit Locations Combustion, Ventilation, and Dilution Air

3.1 3.2 3.2 3.2 3.2 3.2 3.2 3.3 3.3 3.3 3.4 3.4 3.4 3.4 3.4 3.5 3.5 3.5 3.5 3.5 3.6 3.6 3.7 3.7 3.8

CONTENTS

Makeup Air Indoor Air Combined Spaces Outdoor Combustion Air Combination Air Mechanical Combustion-air Supply Louvers and Grilles Combustion-air Ducts Fumes and Gases Installation Elevation of Ignition Source Parking Garages Public Garages Private Garages Grade Clearance Combustible Construction Access and Service Attic Installations Under-floor Appliances Roofs and Elevated Structures Permanent Ladders Sloped Roofs Guards Condensate Disposal Clearance Reduction Air-conditioning Equipment Furnace Plenums Supply Ducts Boilers and Furnaces CHAPTER 4: GAS PIPING INSTALLATIONS Identification Pipe Sizing Branch Length Hybrid Pressure Pressure Drop Operating Pressure LP Systems Sizing Tables Piping Materials Anodeless Risers Workmanship Threads Corrosive Action Joints and Fittings Metallic Fittings Plastic Pipe Joints

ix

3.8 3.8 3.9 3.9 3.10 3.11 3.11 3.11 3.12 3.13 3.13 3.14 3.14 3.14 3.15 3.15 3.15 3.15 3.16 3.17 3.17 3.18 3.18 3.18 3.20 3.20 3.20 3.21 3.21 4.1 4.1 4.2 4.4 4.4 4.4 4.5 4.5 4.5 4.62 4.63 4.64 4.64 4.64 4.65 4.65 4.66

x


Flanges and Flange Gaskets Piping-system Installation Pipe Protection Solid Floors Above-ground Outdoor Piping Corrosion Outside Appliances Beneath Buildings Outlet Locations Plastic-pipe Limitations Tracers Changes in Direction Testing Test Pressure and Duration Servicing a System Pipe Support Wet Gas Shutoff Valves Flow Controls Manufactured-home Connections Connector Length Gas-connector Prohibitions Motor-vehicle Facilities LP-gas Fuel-dispensing Facilities Dispensing Devices Private Fueling Compressed-natural-gas Fuel-dispensing Facilities Location Exceptions Residential Applications Private Fueling Facilities Emergency Shutdown Closed Transfer System Vent Tube Air or Oxygen under Pressure Interconnections Support Intervals Overpressure Protection Settings Unauthorized Operation Vents Size

4.66 4.67 4.67 4.68 4.68 4.69 4.69 4.70 4.70 4.71 4.71 4.71 4.72 4.73 4.74 4.74 4.75 4.76 4.77 4.78 4.78 4.79 4.79 4.79 4.79 4.80 4.80 4.80 4.81 4.81 4.82 4.82 4.82 4.83 4.83 4.83 4.83 4.86 4.86 4.87 4.87

CHAPTER 5: CHIMNEYS AND VENTS

5.1

Single Booster-type Automatic Instantaneous Water Heaters Requirements of Nonvented Appliances Residential and Low-heat Appliances Category I Appliances

5.2 5.2 5.3 5.4

CONTENTS

Existing Chimneys and Vents Vents Insulation Shields Protection Venting Mechanical Draft Systems Above-ceiling Systems Masonry Chimneys Chimney Termination Chimney Sizing Limitations Chimney Inspections Liquid-fuel-burning Appliances Combination Appliances Cleanouts Combustion Air Gas Vents Terminating Gas Vents Vents for Category I Appliances Offsets Multistory Buildings Sizing Connectors Labeling Single-Wall Pipe Roof Penetration Installation Rules Single-wall Pipe Size Venting Termination Locations Category II and IV Appliances Unconditioned Areas Residential-type Appliance Connectors Low-heat Equipment Medium-heat Equipment Multiple Draft Hoods Multiple Appliances Joints Connector Length Chimney Connections Wall Penetration Vented Appliances Draft Hoods Table Definitions Venting Tables Minimum Size Vent Offsets High Altitudes Multiple Inputs Liner Sizing Vent Area and Diameter Chimney and Vent Locations

xi

5.4 5.5 5.5 5.5 5.6 5.6 5.7 5.7 5.8 5.8 5.10 5.10 5.10 5.11 5.11 5.12 5.12 5.13 5.13 5.14 5.14 5.15 5.15 5.15 5.16 5.16 5.17 5.18 5.18 5.18 5.19 5.19 5.20 5.21 5.21 5.21 5.22 5.22 5.23 5.24 5.25 5.26 5.26 5.26 5.27 5.27 5.27 5.27 5.27

xii


Component Commingling Conversion Accessories Vent Obstructions Connector Length Manifolds Fittings Vent Height Multistory Offsets Vertical Vent Maximum Size Liner Sizing and Connections Connector Maximum and Minimum Sizes Commercial Cooking Appliances Factory-built Chimneys CHAPTER 6: SPECIFIC APPLIANCES Decorative Appliances Fireplaces Vented Gas Fireplaces Vented Wall Furnaces Furnaces Floor Furnaces Walls Thermostats Clearance Duct Furnaces Air Heaters Nonrecirculating Direct-fired Industrial Air Heaters Atmospheric Vents Relief Openings Recirculating Direct-fired Industrial Air Heaters Air Supply Clothes Dryers Exhaust Systems Duct Penetrations Exhaust Installation Makeup Air Domestic Ducts Commercial Clothes Dryers Sauna Heaters Air Intakes Controls Ventilation Forced-air Warm-air Furnaces Prohibited Sources Unit Heaters Unvented Heaters Cooking Appliances

5.28 5.28 5.28 5.29 5.29 5.29 5.29 5.30 5.31 5.31 5.31 5.32 5.32 6.1 6.1 6.2 6.2 6.2 6.3 6.3 6.3 6.3 6.4 6.4 6.4 6.4 6.5 6.5 6.5 6.6 6.6 6.6 6.7 6.7 6.7 6.8 6.8 6.9 6.9 6.10 6.10 6.10 6.10 6.12 6.13 6.14

CONTENTS

Water Heaters Refrigerators Air Conditioning Refrigeration Coils Boilers Illuminating Appliances Infrared Radiant Heaters Boiler Standards Chimney Dampers CHAPTER 7: GASEOUS HYDROGEN SYSTEMS Generating and Refueling Operations Ventilation Types Natural Ventilation Garage Openings Louvers and Grilles Mechanical Ventilation Design Pressure Relief Devices Valves Installation Sizing Protection Configuration Piping Identification Protection Outdoor Piping Joints Components Shutoffs Containers Inspections Testing Time Pressure Test Disconnection Leaks Service Operation Vent Outlets Suitable Locations INDEX

xiii

6.15 6.15 6.15 6.16 6.17 6.17 6.18 6.18 6.19 7.1 7.1 7.2 7.2 7.3 7.3 7.3 7.4 7.4 7.4 7.4 7.5 7.5 7.6 7.6 7.7 7.8 7.8 7.9 7.10 7.10 7.10 7.11 7.11 7.11 7.12 7.12 7.12 7.12 7.13 7.13 I.1


ACKNOWLEDGMENTS I would like to thank the International Code Council, Inc. for its cooperation and permission to reprint certain illustrations and tables. This material was taken from material published by the International Code Council, Inc. Each appearance of the material is noted with appreciation.

xv Copyright © 2008 by The McGraw-Hill Companies, Inc. Click here for terms of use.


INTRODUCTION R. Dodge Woodson has over 30 years of experience in the construction trades. He has built up to 60 single-family homes a year, has remodeled countless homes and buildings, and is licensed as a master plumber and master gasfitter. As a seasoned author, Woodson is well known throughout the professional community. His writing style and ability to turn complicated tasks into easy-to-understand terms makes him and this book your guide to getting your code questions answered with less stress. Here is your ticket to simplifying the cryptic code that you work with on a daily basis. The code is large and can be complicated. Woodson translates it into easy-to-use terms for people in the field. See the code as a real-world guide instead of some foreign language that only some people can begin to sift through. This is your chance. How important is understanding the code? It is essential for professionals in the trade. Working without code compliance is an expensive mistake. Many good gas workers mean well and still stray from the code. This is often due to the code being difficult to understand and follow. Not anymore. This book will walk you through the code requirements chapter by chapter. Laid out in the same basic sequence as the code book, this book can be used in conjunction with your code book. While this book is not a replacement for your code book, it is a strong enhancement to it. Use the books together as resources to make your job or your business more productive. Thumb through the pages here. Notice the code alert boxes. You will find that some key components of the code are highlighted in the alert boxes. Go ahead, take a peek. While you are at it, pick a few topics that you are either familiar with or confused about, and look them up. See for yourself how easy this book makes it to put your mind at ease on code issues. You might find another book that attempts to do what this one does, but it was not written by R. Dodge Woodson. Another book might be a fine piece of work, but Woodson has a long-standing reputation as a best-selling author of coderelated books for McGraw-Hill. If you are looking for one guide to the code that you can trust, this is it.

xvii Copyright © 2008 by The McGraw-Hill Companies, Inc. Click here for terms of use.


CHAPTER 1

ADMINISTRATIVE PROCEDURES

The administration of a compliance code is often overlooked by people in the trades. Since this aspect is not usually dealt with by field installers, the elements of administration are sometimes ignored. While this can sometimes work in the field, it is not advisable to turn your back on any code requirement. If you are wondering what the administration of a code involves, you are about to find out. Our goal is to gain a full understanding of the International Fuel Gas Code. We will do this chapter by chapter. Administration is our primary focus in this chapter. If you don’t already have an official code book, get one. You will need a code book to use in conjunction with this book. Be aware that every code jurisdiction is permitted to amend the basic code requirements to meet local needs. Don’t overlook this fact. If you have any doubts about your local code requirements, check with your local code-enforcement officer for clarification of the full code requirements in your region. What does the International Fuel Gas Code apply to? Is it the same as the plumbing code? The gas code is not the same as the plumbing code. Areas covered under the fuel-gas code include the following: • The installation of fuel-gas piping systems • Fuel-gas utilization equipment • Gaseous-hydrogen systems • Related accessories There is an exception to the above. Detached one- and two-family dwellings and multiple single-family dwellings such as townhouses that are not more than three stories high and that have separate means of egress, together with their accessory structures, must comply with the International Residential Code.

1.1 Copyright © 2008 by The McGraw-Hill Companies, Inc. Click here for terms of use.

1.2


PIPING SYSTEMS Natural-gas piping with an operating pressure of 125 pounds per square inch gauge (psig) or less is covered under this code. Liquid petroleum (LP) gas with an operating pressure of 20 psig or less is also covered by this code. Requirements of the code apply from the point of delivery of gas to the outlet of the equipment shutoff valve for gas distribution. Piping-system requirements include: • Design • Materials • Components • Fabrication • Assembly • Installation • Testing • Inspection • Operation • Maintenance

GAS UTILIZATION EQUIPMENT Requirements for gas-utilization equipment and related accessories are covered under the gas code. Such requirements include: • Installation • Combustion • Ventilation air • Venting • Connections to piping systems

EXCEPTIONS There are a number of situations where the fuel-gas code does not apply. Remember to check your local code requirements if there is any doubt in your mind about the applicable requirements. These are the exceptions: • Portable LP-gas equipment of all types that is not connected to a fixed fuel-piping system • Installation of farm equipment such as brooders, dehydrators, dryers, and irrigation equipment


1.3

• Raw material (feedstock) applications except for piping to special atmosphere generators • Oxygen-fuel gas cutting and welding systems • Industrial gas applications using gases such as acetylene and acetylenic compounds, hydrogen, ammonia, carbon monoxide, oxygen, and nitrogen • Petroleum refineries, pipeline compressor or pumping stations, loading terminals, compounding plants, refinery tank farms, and natural-gas processing plants • Integrated chemical plants or portions of such plants where flammable or combustible liquids or gases are produced by or used in chemical reactions • LP-gas installations at utility gas plants • Liquefied-natural-gas (LNG) installations • Fuel-gas piping in power and atomic-energy plants • Proprietary items of equipment, apparatus, or instruments such as gas-generating sets, compressors, and calorimeters • LP-gas equipment for vaporization, gas mixing, and gas manufacturing • Temporary LP-gas piping for buildings under construction or renovation that will not become part of the permanent piping system • Installation of LP-gas systems for railroad-switch heating • Installation of hydrogen-gas, LP-gas, and compressed-natural-gas (CNG) systems on vehicles • Except as referenced in Section 401.1.1 of the code, gas piping, meters, gas pressure regulators, and other appurtenances used by the serving gas supplier in the distribution of gas other than undiluted LP gas • Building design and construction, except as specified in the code • Piping systems for mixtures of gas and air within the flammable range with an operating pressure greater than 10 psig • Portable fuel-cell appliances that are neither connected to a fixed piping system nor interconnected to a power grid

! Codealert A dwelling unit is a single unit providing complete, independent living facilities for one or more persons, including permanent provisions for sleeping, eating, cooking, and sanitation.

1.4


?

Did you know

Did you know that provisions found in appendices of the code shall not apply unless they are specifically adopted by a jurisdiction? It is a fact.

OTHER FUELS The requirements for the design, installation, maintenance, alteration, and inspection of mechanical systems operating with fuel other than fuel gas are regulated by the International Mechanical Code.

MINIMUM STANDARDS The code is used to establish minimum standards to protect life, limb, health, safety, property, and public welfare. This is done by controlling the design, construction, installation, material quality, location, operation, and maintenance or use of fuel-gas systems. Without code requirements the installation of gas systems would likely pose far greater risks.

EXISTING INSTALLATIONS Existing installations are typically grandfathered. This simply means that code requirements rarely force a person to bring existing conditions into a form that will pass modern code requirements. However, for this rule to apply, existing installations must have complied with the code in use at the time the installation occurred.

Tradetip If a section, subsection, sentence, clause, or phrase of the code is for any reason deemed to be unconstitutional, this decision will not affect the validity of the remaining portions of the code.


1.5

Tradetip Additions, alterations, renovations, or repairs related to building or structural issues are regulated by the International Building Code.

MAINTENANCE Proper maintenance is required for all installations, both new and existing. The operating condition of a system must be maintained in accordance with the original design and in a safe manner. This applies to devices and safeguards that are required by code. Who is responsible for required maintenance? Is it the installer? Are primary contractors responsible for maintenance? No. The maintenance required for a system is the responsibility of the property owner or the owner’s designated agent. It is within the rights of a code official to require an installation to be reinspected.

ADDITIONS Additions, alterations, renovations, or repairs to installations must conform to the requirements of a new installation. This is not to say that existing portions of the system must be updated. The requirements of the modern code apply only to the new work being done, so long as the original installation was in code compliance at the time of installation. Any work done to alter, repair, or add to an existing system must be performed in a manner that will not render the system unsafe, hazardous, or overloaded. What happens if you have a minor repair to make to an existing system? Does that repair have to meet current code requirements? There are two answers. The short answer is that the work must meet current code requirements. However, there is an exception. When minor alterations, repairs, renovations, or additions are made to an approved existing system, the work may be done in the same manner and arrangement as was allowed in the existing system so long as the work does not render the system hazardous.

CHANGE IN OCCUPANCY Be careful when working with a building where there will be a change in occupancy. When a change of occupancy is desired, the change must be approved

1.6


! Codealert

Relocated buildings generally must meet present code requirements. There are, of course, exceptions. In general, a building that is moved into or within a jurisdiction is required to comply with the provisions for new installations. This sometimes fools even experienced workers, so remember the rule well.

by a code official. Failure to seek approval before making such a change is unlawful. Assuming that the building meets the intent of the provisions governing building construction for the proposed change in occupancy without any risk of creating a hazard to public health, safety, or welfare, the change should be approved.

HISTORIC DESIGNATION How does the historic designation of a building affect the enforcement of this code? Historic buildings receive different treatment under the code requirements. To be considered a historic building, the building must be designated as historic by a state or local jurisdiction. A code officer must be consulted to determine if a historic building is safe and in the public interest of health, safety, and welfare in its present condition following any work done to the building. If these conditions are met, a code officer can waive normal code requirements for work to be done on historic buildings.

?

Did you know

Did you know that a code officer can determine requirements that are not specified in the code? Code officers must make rulings pertaining to public safety, health, and general welfare.


1.7

RELOCATED BUILDINGS Relocated buildings generally must meet present code requirements. There are, of course, exceptions. In general, a building that is moved into or within a jurisdiction is required to comply with the provisions for new installations. This sometimes fools even experienced workers, so remember the rule well.

CODE OFFICER APPOINTMENT Code-officer appointment is done by the chief appointing authority of a jurisdiction. A code official cannot be removed from office except for cause and after a full opportunity to be heard on specific and relevant charges by and before the appointing authority. A code official has the authority to appoint a deputy code official, other related technical officers, inspectors, and other employees. Liability How does liability affect code officers? Code officials, code officers, and employees charged with the enforcement of the code, while acting for the jurisdiction, cannot be rendered liable personally. They are relieved from all personal liability for any damage accruing to persons or property as a result of an act required or permitted in the discharge of official duties. If a lawsuit is instituted against any officer or employee because of an act performed by that officer or employee in the lawful discharge of duties and under the provisions of the code, the suit shall be defended by the legal representative of the jurisdiction until the final termination of the proceedings. Code officials and subordinates must not be made liable for costs in an action, suit, or proceeding that is instituted in pursuance of the provisions of the code. Any officer of the Department of Inspection who is acting in good faith and without malice will be free of liability for acts performed under any of its provisions or by reason of any act or omission in the performance of official duties in connection therewith. Authority How much authority does a code official have? Plenty, when it comes to code enforcement. The code official is responsible for all aspects of enforcing code requirements. The following is a list of powers within the grasp of a code official: • Rule-making authority • Applications and permits • Inspections

1.8


• Right of entry • Identification • Notices and orders • Department records Rules When the rules of the code are involved, the code official is the ruler. Code officials have full authority, as is necessary for public health, safety, and general welfare, to adopt and promulgate rules and regulations. The interpretation and implementation of rules are within the control of a code official. However, a code official cannot rule in a way that will waive structural or fire performance requirements specifically provided for by the code. Applications and Permits Who is responsible for receiving applications and issuing permits? The code official is. Alterations covered by the code, inspection of premises where permits have been issued, and enforcement of compliance are also the responsibility of the code official. Entry Code officials have plenty of power to enter a premise. Entry must be provided to a code official whenever it is necessary to make an inspection to enforce the provisions of the code. When a code official has reasonable cause to believe that any conditions or violations of the code that make a structure unsafe, dangerous, or hazardous in a building or on a premise exist, the code official shall have the authority to enter the building or premise at all reasonable times to inspect or to perform the duties imposed upon the code official by the code. When a code official feels the need to enter an occupied structure, the official is required to show credentials to the occupant and request entry. Unoccupied buildings that are in need of being entered require the code official to make an attempt to locate the property owner or person in charge of the property. If entry for a code official is refused, there are options for the code official to seek remedy.

?

Did you know

Code officials are required to carry proper identification when inspecting structures or premises in the performance of duties under the code requirements.


1.9

! Codealert

Code officials are required to issue all necessary notices or orders to ensure compliance with the code.

Obtaining a proper inspection warrant or other remedy provided by law to secure entry will get the code official into a building. Records Code officers are required to keep accurate records. Some of the items that code officers are responsible for include: • Applications received • Permits • Certificates issued • Fees collected • Reports of inspections • Notices issued • Orders issued The records retained are to be kept as long as the building or structure to which they apply remains in existence, unless otherwise provided for by other regulations.

APPROVAL Approval is another part of the job description for code officials. Most workers in the trades think of inspectors when they think of code requirements. This is common and on target. Let’s discuss some of the approval issues to be considered by code officials. Modifications Practical difficulties can result in a code official’s decision to make a modification in code requirements. Prior to such modification, a code official is required to find that a special individual reason makes the strict letter of the code impractical. Any

1.10


modification must be in compliance with the intent and purpose of this code and must not lessen health, life, and fire safety requirements. All details of any action granting modifications are required to be entered in the files of the Department of Inspection. Alternative Options Alternative options for methods and materials are allowed by code-enforcement officers. However, the options must be approved. As long as the option is intended to deliver the same intent of the code in an equal or better manner or quality, a code official may approve the alternate course. Testing Testing can be required by a code official when there is insufficient evidence of compliance with the provisions of the code. Test methods shall be as specified in the code or other recognized test standards. If there are no recognized and accepted test methods, the code official shall approve a testing procedure. All tests shall be performed by an approved agency. All reports of tests shall be retained by the code official for the period required for retention of public records.

PERMITS Permits are required in most instances for any type of new work. Property owners, authorized agents, or contractors who plan to erect, install, enlarge, alter, repair, remove, convert, or replace an installation regulated by the code or to cause such work to be done require a permit. There is an exception: Where equipment replacements and repairs are required to be performed in an emergency situation, the permit application shall be submitted within the next working business day of the Department of Inspection. Permits are not required for portable heating appliances. The replacement of any minor component of equipment that does not alter the prior approval of such equipment or make such equipment unsafe does not require a permit. When a per-

Tradetip If there are no recognized and accepted test methods, the code official shall approve a testing procedure. All tests shall be performed by an approved agency.


1.11

?

Did you know

Materials, equipment, and devices shall not be reused unless such elements have been reconditioned, tested, placed in proper working condition and approved.

mit is not required, work performed must remain in compliance with the code and the laws or ordinances of the jurisdiction. Permit Application Permit application requires a fee. The application and fee are filed with a code official on an official form provided for that purpose. The forms are available from local code-enforcement offices. Applications must be signed by the property owner or an authorized agent. The proposed occupancy of all parts of a building must be described in the permit application. Unless waived by a code official, construction documents are required when a permit is applied for. Construction documents, engineering calculations, diagrams, and other data may be required prior to the issuance of a permit. These documents are generally required to be prepared by registered design professionals. Permit Issuance Code officials are required to issue permits when all application matters are complied with. Common requirements for the issuance of a permit include: • Permit application • Construction documents • Diagrams • Engineering calculations • Related pertinent data • Application fee Approved Construction Documents When a code official issues a permit for which construction documents are required, the construction documents shall be endorsed in writing and stamped "APPROVED." Once the documents are approved and stamped, they may not be changed in any way without approval from the code official. All work performed must be done in accordance with the approved plans.

1.12


?

Did you know

Code officials shall have the authority to issue a permit for the construction of part of an installation before the construction documents for the entire installation have been submitted or approved. There is, however, no guarantee that a permit for the entire project will be issued until all application documents are in and approved. Acting with a partial permit is risky in the event that the full project is not authorized.

Validity The issuance of a permit or approval of construction documents shall not be construed to be a permit for or an approval of any violation of any of the provisions of the code or of other ordinances of the jurisdiction. A permit presuming to give authority to violate or cancel the provisions of the code shall be invalid. If an error is made in the issuance of a permit by a code official, the code official has the right to correct any mistake that was made. A stop-work order can be issued by the code official if the mistake is of such a type to warrant such drastic action. Expiration Permits come with time limits. Work must commence under the permit within 180 days. If it does not, the permit will become null and void. Be aware that once work starts, it must continue. If the work being done under a permit is suspended or abandoned for a period of 180 days or more at any time once the work has started, this can result in the loss of the permit. If a permit does expire, a new permit will be required to resume work. Usually, the fee for the renewal permit is one-half the cost of the original permit. There are two exceptions: If work has been stopped for more than a year, the process of obtaining a permit goes back to the normal procedure of getting a new permit; and,when work will deviate from the original plans and specifications, a new permit process is required. Extensions Active permits that require more time for the completion of work can be used to apply for an extension. An extension may be approved for an additional 180 days if there is reasonable cause for the request. Extensions are limited to a one-time event. Fees for extensions tend to be half the cost of a new permit.


1.13

! Codealert

Code officers are required to revoke permits or approvals issued under the provisions of the code in cases where false information or facts in the application or construction documents were provided.

?

Did you know

A permit shall not be issued until the fees required by the code are paid. If an amendment to a permit is requested, it must not be issued until the required fee is paid.

Retention of Documents One set of construction documents shall be retained by the code official until final approval of the work covered therein. One set of approved construction documents shall be returned to the applicant, and said set shall be kept on the site of the building or work at all times during which the work authorized thereby is in progress. Working Without a Permit Working without a permit when a permit is required is not good business. At the very least, a person caught beginning work without a required permit is going to have to pay a fee of 100 percent of the cost of a permit plus the cost of a permit. In other words, you will pay twice as much for a permit when you get one. Don’t begin work without a required permit. The refunding of permit fees may occur up to 180 days after a permit fee is paid. Percentage amounts for the refunds vary from jurisdiction to jurisdiction. Check with your local code enforcement office for details on refund amounts.

INSPECTIONS A permit holder is required to notify a code official when work is ready for a required inspection. When a code official conducts a required inspection, the offi-

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Tradetip The code official shall accept reports of approved agencies, provided that such agencies satisfy the requirements as to qualifications and reliability.

cial must either allow work to proceed or identify violations that must be corrected before work progresses. There are three types of inspections required: underground inspections, rough-in inspections, and final inspections. Underground Inspections Underground inspection shall be made after trenches or ditches are excavated and bedded and piping is installed and before backfill is put in place. When excavated soil contains rocks, broken concrete, frozen chunks, and other rubble that would damage or break the piping or cause corrosive action it must not be used. Clean backfill shall be on the site. Rough-In Inspections Rough-in inspections are made after the roof, framing, fireblocking, and bracing are in place and components to be concealed are complete and prior to the installation of wall or ceiling membranes. Final Inspections Final inspections take place upon the full completion of all work.

HEATING EQUIPMENT Heating equipment installed to replace existing equipment serving an occupied portion of a structure can be treated as an emergency action and does not require a permit to be obtained prior to work being done, in the event that a request for inspection of such heating equipment has been filed with the department not more than 48 hours after replacement work is completed and before any portion of such equipment is concealed by any permanent portion of the structure. Remember, though, that you must apply for all applicable permits within 48 hours of completing the work.


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Tradetip New installations and parts of existing installations that have been altered, extended, renovated or repaired must be tested as prescribed by the code to disclose leaks and defects.

PREFABRICATED CONSTRUCTION Prefabricated construction has become very popular. Since this type of construction is done off the construction site and much of the work that would normally be inspected is concealed prior to placement on a building lot, how do you account for the inspection requirements? The process is actually quite simple. A manufacturer of prefabricated construction must provide a code official with detailed submittals for consideration. Once the documents are reviewed and approved, a permit can be issued. Several factors may be included in the submittals, some of which include: • Evaluation report • Complete installation details • A description of systems and components • The basis upon which the system is being evaluated • Test results • Other data as specifically required Follow-up Inspections Follow-up inspections can be required, unless there is ready access provided to installations, service equipment, and accessories. Code officials are required to con-

Tradetip When an evaluation service is required, a code official shall designate the service of an approved agency and review the agency’s evaluation report for adequacy and conformance to the code.

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Did you know

Where any work or installation does not pass an initial test or inspection, the necessary corrections shall be made so as to achieve compliance with the code. Once corrections are made, the work must be resubmitted to the code official for inspection and testing.

duct in-plant inspections as frequently as necessary to ensure performance complies with an approved evaluation report. At the discretion of a code official, an independent inspection agency may be appointed by the code official. When an independent inspection is done, a report of inspections must be furnished to the code official upon request. Additionally, a label permanently affixed to the system indicating that factory inspections have been performed is required. Required test and inspection records must be made available to code officials at all times during the fabrication of an installation and the erection of a building. Records required by a code official must be filed. Approval Once all required testing and inspection are done and prove the work to be in compliance with code requirements, a code official approves the work. This approval is done in writing and filed. Temporary connection to sources of energy can be approved by a code official to allow the testing of an installation. It is also possible to obtain a temporary certificate of occupancy at the discretion of a code official.

VIOLATIONS Violations of code requirements can bring big trouble. The code is not to be taken lightly. It is a violation of law for a person, firm, or corporation to perform coderegulated work in violation of code requirements.

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Did you know

Testing required by the code is done by the permit holder and observed by a code official. Apparatus, instruments, materials, and labor required for testing an installation or part thereof shall be furnished by the permit holder.


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! Codealert

What is the punishment for a code violation? It may be a simple fine, but some code violations can result in imprisonment. In some cases, a fine and imprisonment may both be handed out as a punishment. Each day that a violation continues after due notice has been served shall be deemed a separate offense.

When a code violation is discovered, a code official is required to serve notice on the appropriate party that a code violation exists. The official order must direct the discontinuance of the illegal action or condition and the abatement of the violation. The recipient of a violation notice must take corrective action promptly. If this does not occur, a code official is required to press the matter with legal counsel of the jurisdiction being served. All remedies allowed by law may be brought to bear in an attempt to abate the code violation. Punishment What is the punishment for a code violation? It may be a simple fine, but some code violations can result in imprisonment. In some cases, a fine and imprisonment may both be handed out as a punishment. Each day that a violation continues after due notice has been served shall be deemed a separate offense. Stop-work Order If a code official issues a stop-work order, all work must cease immediately. The notice must be in writing and given to the property owner, the owner’s agent, or the person doing the work. A stop-work order must define the conditions under which work is authorized to resume. In the event of emergency circumstances, a code official is not required to provide written notice prior to stopping work. Failure to comply with a stop-work order is likely to result in a fine. Unsafe Conditions Unsafe conditions surrounding work are considered to be conditions in which the work is unsafe, constitutes a fire or health hazard, or is otherwise dangerous to human life. Unsafe installations are considered to be a public nuisance that must be abated by repair, rehabilitation, demolition, or removal.

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Condemned Installations A code official can condemn a site when there is reasonable belief on the part of the official that any installation or portion thereof regulated by the code becomes hazardous to life, health, or property. When a site is condemned, a written notice is presented that outlines what is required to abate the situation. The notice must include a time limit for compliance to take place. A person shall not use or maintain a defective installation after receiving such notice. If an installation is to be disconnected, written notice must be given. In cases of immediate danger to life or property, such disconnection shall be made immediately without such notice. Disconnection Code officers have the authority to have utilities disconnected from buildings and structures when emergency conditions exist. If this is to be done, the utility server must be notified. An attempt will be made to notify the property owner. If a property owner cannot be notified prior to disconnection, the property owner shall be notified in writing as soon as is practicable thereafter. Reconnection A person must not make energy-source connections to installations regulated by the code that have been disconnected or ordered to be disconnected by the code official. The use of an energy-source connection that has been shut down or ordered shut down, until approved by a code official, is prohibited. In the event that compliance is not provided to an official order, the code official shall institute appropriate action to prevent, restrain, correct, or abate the violation.

APPEAL A person has a right to appeal a decision made by a code official. This process begins with an application for appeal. The request must state that the appeal is based on a claim that the true intent of the code or rules legally adopted under the code has been interpreted incorrectly. An application for appeal must be filed on a form obtained by a code official within 20 days after the notice was served. Membership of Board of Appeals The board of appeals consists of five members. They are appointed by the chief appointing authority. The members are appointed for staggered terms. The details are as follows: • One for five years


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• One for four years • One for three years • One for two years • One for one year • Thereafter, each new member shall serve for five years or until a successor has been appointed Qualifications What are the qualifications needed to hold a place on the membership board? The five individuals who sit on the board must come from five different walks of life. Rules call for the following requirements: • One member must be a registered design professional who is a registered architect, builder, or superintendent of building construction. Ten years of experience are required. Half of this experience must have been gained as the person in charge of work. • One member must be a registered design professional with structural-engineering or architectural experience. • One member must be a registered design professional with fuel-gas and plumbing-engineering experience or a fuel-gas contractor with at least 10 years of experience, with half of that experience gained while in charge of work. • One member must be a registered design professional with fire-protection-engineering experience or a fire-protection contractor with at least 10 years of experience, with half of that experience gained while in charge of work. Board Organization The board is required to select one of its members to serve as chairman once a year. Members must not hear an appeal in which the members have a personal or professional interest in the proceeding. Selection of a qualified clerk to serve as

! Codealert

The chief appointing authority shall appoint two alternate members, who shall be called by the board chairman to hear appeals during the absence or disqualification of a member. Alternate members shall possess the qualifications required for board membership and shall be appointed for five years or until a successor has been appointed.

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secretary to the board is made by the chief administrative officer. Compensation for members is determined by law. The board shall meet upon notice from the chairman within 10 days of the filing of an appeal or at stated periodic meetings. Hearings before the board shall be open to the public. Anyone affected by an appeal has an opportunity to attend an open hearing. The board must adopt and make available to the public through the secretary procedures under which a hearing will be conducted. The procedures shall not require compliance with strict rules of evidence but shall mandate that only relevant information be received. An appeal hearing can be postponed if fewer than five board members are present. It takes a concurring vote of at least three board members to modify or reverse a decision made by a code official. The decision of an appeal board must be by resolution. Certified copies shall be furnished to the appellant and to the code official. It is then up to the code official to take immediate action in accordance with the decision of the board. Any person, whether or not a previous party to an appeal, shall have the right to apply to the appropriate court for a writ of certiorari to correct errors of law. Application for review shall be made in the manner and time required by law following the filing of the decision in the office of the chief administrative officer. Well, there you have it. We are done with the administration section of the code. Understanding definitions is next on our list, so let’s turn to Chapter 2 and get a clear understanding of the words, terms, and phrases used in the code.

CHAPTER 2

DEFINITIONS

Definitions are important when interpreting the code. If you don’t have a clear understanding of what words and phrases mean, you are going to have a rough ride trying to read the code properly. This chapter is going to review the meaning of terms as they are defined by the code. When dealing with the code, words used in the present tense include the future tense. Words in masculine gender include the feminine and neuter genders. A single number includes a plural number, and a plural number also indicates a single number. Terms that are not specifically defined in this section have ordinarily accepted meanings as the context implies. Terms defined in other codes carry the meanings in those codes. Definitions don’t require a lot of interpretation.. Don’t skip this chapter. I know it may seem senseless to put a lot of effort into learning definitions. However, you will not be able to do your best work with the code if you don’t understand the definitions. ACCESS (TO): That which enables a device, appliance, or equipment to be readily reached or by a means that first requires the removal or movement of a panel, door, or similar obstruction. AIR CONDITIONER, GAS-FIRED: A gas-burning, automatically operated appliance for supplying cooled and/or dehumidified air or chilled liquid. AIR CONDITIONING: The treatment of air so as to control simultaneously the temperature, humidity, cleanness, and distribution to meet the requirements of a space. AIR, EXHAUST: Air being removed from any space or piece of equipment and conveyed directly to the atmosphere by means of openings or ducts. AIR-HANDLING UNIT: A blower or fan used for the purpose of distributing supply air to a room, space, or area. AIR, MAKEUP: Air provided to replace air being exhausted. 2.1 Copyright © 2008 by The McGraw-Hill Companies, Inc. Click here for terms of use.

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ALTERATION: A change in a system that involves an extension, addition, or change to the arrangement, type, or purpose of the original installation. ANODELESS RISER: A transition assembly in which plastic piping is installed and terminated above ground outside of a building. APPLIANCE, AUTOMATICALLY CONTROLLED: Appliances equipped with an automatic burner ignition, safety shutoff device, and other automatic devices that accomplish complete turn-on and shutoff of the gas to the main burner or burners and graduate the gas supply to the burner or burners, but do not affect complete shutoff of the gas. APPLIANCE (EQUIPMENT): Any apparatus or equipment that utilizes gas as a fuel or raw material to produce light, heat, power, refrigeration, or air conditioning. APPLIANCE, FAN-ASSISTED COMBUSTION: An appliance equipped with an integral mechanical means to either draw or force products of combustion through a chamber or heat exchanger. APPLIANCE, LOW-HEAT (RESIDENTIAL): Any appliance in which the products of combustion at the point of entrance to the flue under normal operating conditions have a temperature of 1,000 degrees F. APPLIANCE, MEDIUM-HEAT: Any appliance in which the products of combustion at the point of entrance to the flue under normal operating conditions have a temperature of more than 1000 degrees F, but not greater than 2000 degrees F. APPLIANCE, UNVENTED: An appliance designed or installed in such a manner that the products of combustion are not conveyed by a vent or chimney directly to the outside atmosphere. APPLIANCE, VENTED: An appliance designed and installed in such a manner that all of the products of combustion are conveyed directly from the appliance to the outside atmosphere through an approved chimney or vent system. APPROVED: Acceptable to the code official or other authority having jurisdiction. APPROVED AGENCY: An established and recognized agency that is acceptable to the code official and regularly engaged in conducting tests or furnishing inspection services. ATMOSPHERIC PRESSURE: The pressure of the weight of air and water vapor on the surface of the earth, approximately 14.7 pounds per square inch (psi) at sea level. AUTOMATIC IGNITION: Ignition of gas at the burner(s) when the gas-controlling device is turned on, including reignition if the flames on the burner(s) have been extinguished by means other than by the closing of the gas-controlling device. BAFFLE: An object placed in an appliance to change the direction of or retard the flow of air, air-gas mixtures, or flue gases. BAROMETRIC DRAFT REGULATOR: A balanced damper device at-

DEFINITIONS

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tached to a chimney, vent connector, breeching, or flue-gas manifold to protect combustion equipment by controlling chimney draft. A double-acting barometric draft regulator is one whose balancing damper is free to move in either direction to protect combustion equipment from both excessive draft and back draft. BOILER, HOT-WATER-HEATING: A boiler in which no steam is generated, from which hot water is circulated for heating purposes and then returned to the appliance and that operates at water pressures not exceeding 160 pounds persquare-inch gauge (psig) and at water temperatures not exceeding 250 degrees F at or near the outlet. BOILER, HOT-WATER-SUPPLY: A boiler completely filled with water that furnishes hot water to be used externally and that operates at water pressures not exceeding 160 psig and at water temperatures not exceeding 250 degrees F at or near the outlet. BOILER, LOW-PRESSURE: A self-contained appliance for supplying steam or hot water. BOILER, STEAM-HEATING: A boiler in which steam is generated and that operates at a steam pressure not exceeding 15 psig. BRAZING: A metal-joining process wherein coalescence is produced by the use of a nonferrous filler metal having a melting point above 1000 degrees F but lower than that of the base metal being joined. The filler material is distributed between the closely fitted surfaces of the joint by capillary action. BROILER: A general term including salamanders, barbecues, and other appliances cooling primarily by radiated heat, excepting toasters. BTU: Abbreviation for British thermal unit, which is the quantity of heat required to raise the temperature of one pound of water 1 degree F. BURNER: A device for the final conveyance of a gas or a mixture of gas and air to the combustion zone. BURNER, INDUCED-DRAFT: A burner that depends on draft induced by a fan that is an integral part of the appliance and is located downstream from the burner. BURNER, POWER: A burner in which gas, air, or both are supplied at pressures exceeding, for gas, the line pressure,, and, for air, atmospheric pressure, with this added pressure being applied at the burner. CHIMNEY: A primarily vertical structure containing one or more flues for the purpose of carrying gaseous products of combustion and air from an appliance to the outside atmosphere. CHIMNEY, FACTORY-BUILT: A listed and labeled chimney composed of factory-made components, assembled in the field in accordance with manufacturer’s instructions and the conditions of the listing. CHIMNEY, MASONRY: A field-constructed chimney composed of solid ma-

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sonry units, bricks, stones, or concrete. CHIMNEY, METAL: A field-constructed chimney made of metal. CLEARANCE: The minimum distance through air measured between the heatproducing surface of the mechanical appliance, device, or equipment and the surface of the combustible material or assembly. CLOTHES DRYER: An appliance used to dry wet laundry by means of heated air. CLOTHES DRYER, TYPE 1: A factory-built package in multiple production, primarily used in family living environments; usually the smallest unit physically and in function output. CLOTHES DRYER, TYPE 2: A factory-built package in multiple production, used in public Laundromats; not designed for use in individual family living environments. CODE: Regulations, subsequent amendments thereto, or any emergency rule or regulation that the administrative authority having jurisdiction has lawfully adopted. CODE OFFICIAL: The officer or other designated authority charged with the administration and enforcement of a code or a duly authorized representative. COMBUSTION: In the context of this code, the rapid oxidation of fuel accompanied by the production of heat or heat and light. COMBUSTION AIR: Air necessary for complete combustion of a fuel, including theoretical air and excess air. COMBUSTION CHAMBER: The portion of an appliance within which combustion occurs. COMBUSTION PRODUCTS: Constituents resulting from the combustion of a fuel with the oxygen of the air, including inert gases but excluding excess air CONCEALED LOCATION: A location that cannot be accessed without damaging permanent parts of the building structure or finish surface. Spaces above, below, or behind readily removable panels or doors are not considered to be concealed. CONCEALED PIPING: Piping that is located in an inaccessible location. CONDENSATE: The liquid that condenses from a gas, including flue gas, caused by a reduction in temperature or an increase in pressure. CONNECTOR, APPLIANCE (FUEL): A rigid metallic pipe and fittings, semirigid metallic tubing and fittings, or listed and laved device that connects an appliance to the gas-piping system. CONNECTOR, CHIMNEY OR VENT: The pipe that connects an appliance to a chimney or vent. CONSTRUCTION DOCUMENTS: All of the written, graphic, and pictorial documents prepared or assembled for describing the design, location, and physical characteristics of the elements of the project necessary for obtaining a permit.

DEFINITIONS

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CONTROL: A manual or automatic device designed to regulate the gas, air, water, or electrical supply to or operation of a mechanical system. CONVERSION BURNER: A unit consisting of a burner and its controls for installation in an appliance originally utilizing another fuel. COUNTER APPLIANCES: Appliances such as coffee brewers and any appurtenant water-heating equipment, food and dish warmers, hot plates, griddles, waffle bakers, and other appliances designed for installation on or in a counter. CUBIC FOOT: The amount of gas that occupies 1 cubic foot at a temperature of 60 degrees F, saturated with water vapor and under a pressure equivalent to that of 30 inches of mercury. DAMPER: A manually or automatically controlled device to regulate draft or the rate of flow of air or combustion gases. DECORATIVE APPLIANCE, VENTED: A vented appliance wherein the primary function lies in the aesthetic effect of the flames. DECORATIVE APPLIANCE, VENTED FIREPLACE: A vented appliance designed for installation within the fire chamber of a vented fireplace, wherein the primary function lies in the aesthetic effect of the flames. DEMAND: The maximum amount of gas input required per unit of time, usually expressed in cubic feet per hour or BTU/h. DESIGN-FLOOD ELEVATION: The elevation of the design flood including wave height, relative to the datum specified on the community’s legally designated flood hazard map. DILUTION AIR: Air that is introduced into a draft hood and mixed with the flue gases. DIRECT-VENT APPLIANCES: Appliances that are constructed and installed so that all air for combustion is derived directly from the outside atmosphere and all flue gases are discharged directly to the outside atmosphere. DRAFT: The pressure difference existing between the equipment or any component part and the atmosphere, which causes a continuous flow of air and products of combustion through the gas passages of the appliance to the atmosphere. DRAFT HOOD: A nonadjustable device built into an appliance or made as part of the vent connector from an appliance, designed to (1) provide for ready escape of the flue gases from the appliance in the event of no draft, back draft, or stoppage beyond the draft hood; (2) prevent a back draft from entering the appliance; and (3) neutralize the effect of stack action of the chimney or gas vent upon operation of the appliance. DRAFT, MECHANICAL OR INDUCED: The pressure difference created by the action of a fan, blower, or ejector that is located between the appliance and the chimney or vent termination. DRAFT, NATURAL: The pressure difference created by a vent or chimney due to

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its height and the temperature difference between the flue gases and the atmosphere. DRAFT REGULATOR: A device that functions to maintain a desired draft in the appliance by automatically reducing the draft to the desired value. DRIP: The container placed at a low point in a system of piping to collect condensate and from which the condensate is removable. DRY GAS: A gas having a moisture and hydrocarbon dew point below any normal temperature to which the gas piping is exposed. DUCT FURNACE: A warm-air furnace normally installed in an air-distribution duct to supply warm air for heating. This definition shall apply only to a warm-air heating appliance that depends for air circulation on a blower not furnished as part of the furnace. DUCT SYSTEM: A continuous passageway for the transmission of air that, in addition to ducts, includes ducts fittings, dampers, plenums, fans, and accessory air-handling equipment. DWELLING UNIT: A single unit providing complete, independent living facilities for one or more persons, including permanent provisions for living, sleeping, eating, cooking, and sanitation. EQUIPMENT: See “Appliance.” FIREPLACE: A fire chamber and hearth constructed of noncombustible material for use with solid fuels and provided with a chimney. FIREPLACE, FACTORY-BUILT: A fireplace composed of listed factory-built components assembled in accordance with the terms of listing to form the completed fireplace. FIREPLACE, MASONRY: A hearth and fire chamber of solid masonry units such as bricks, stones, listed masonry units, or reinforced concrete, provided with a suitable chimney. FIRING VALVE: A valve of the plug and barrel type designed for use with gas and equipped with a lever handle for manual operation and a dial to indicate the percentage of opening. FLAME SAFEGUARD: A device that will automatically shut off the fuel supply to a main burner or group of burners when the means of ignition of such burners becomes inoperative and when flame failure occurs on the burner or group of burners. FLOOD HAZARD AREA: The greater of the following two areas: (1) the area within a flood plain subject to a 1 percent or greater change of flooding in any given year or (2) the area designated as a flood hazard area on a community’s flood hazard map or otherwise legally designated. FLOOR FURNACE: A completely self-contained furnace suspended from the floor of the space being heated, taking air for combustion from outside such space and with means for observing flames and lighting the appliance from such space.

DEFINITIONS

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FLOOR FURNACE, FAN TYPE: A floor furnace equipped with a fan that provides the primary means for circulating air. FLOOR FURNACE, GRAVITY-TYPE: A floor furnace depending primarily upon circulation of air by gravity. This classification also includes floor furnaces equipped with booster-type fans that do not materially restrict free circulation of air by gravity flow when such fans are not in operation. FLUE, APPLIANCE: The passage(s) within an appliance through which combustion products pass from the combustion chamber of the appliance to the drafthood inlet opening equipped with a draft hood or to the outlet of the appliance on an appliance not equipped with a draft hood. FLUE COLLAR: That portion of an appliance designed for the attachment of a draft hood, vent connector, or venting system. FLUE GASES: Products of combustion plus excess air in appliance flues or heat exchangers. FLUE LINER: A system or material used to form the inside surface of a flue in a chimney or vent for the purpose of protecting the surrounding structure from the effects of combustion products and for conveying combustion products without leakage to the atmosphere. FUEL GAS: A natural gas, manufactured gas, liquefied-petroleum gas, or mixtures of these gases. FUEL-GAS-UTILIZATION EQUIPMENT: See “Appliance.” FURNACE: A completely self-contained heating unit that is designed to supply heated air to spaces remote from or adjacent to the appliance location. FURNACE, CENTRAL: A self-contained appliance for heating air by transfer of the heat of combustion through metal to the air and designed to supply heated air through ducts to a space remote from or adjacent to the appliance location. FURNACE, DOWN-FLOW: A furnace designed with air-flow discharge vertically downward at or near the bottom of the furnace. FURNACE, ENCLOSED: A specific heating or heating and ventilating furnace incorporating an integral total enclosure and using only outside air for combustion. FURNACE, FORCED-AIR: A central furnace equipped with a fan or blower that provides the primary means for circulation of air. FURNACE, FORCED-AIR WITH COOLING UNIT: A single-package unit, consisting of a gas-fired forced-air furnace combined with an electrically or fuelgas-powered summer air-conditioning system contained in a common casting. FURNACE, GRAVITY WITH BOOSTER FAN: A furnace equipped with a booster fan that does not materially restrict free circulation of air by gravity flow when the fan is not in operation. FURNACE, GRAVITY-TYPE: A central furnace depending primarily on circulation of air by gravity.

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FURNACE, HORIZONTAL FORCED-AIR: A furnace with air flow through the appliance essentially in a horizontal path. FURNACE, MULTIPLE-POSITION: A furnace designed so that it can be installed with the air-flow discharge in the up-flow, horizontal, or down-flow direction. FURNACE PLENUM: An air compartment or chamber to which one or more ducts are connected and that forms part of an air-distribution system. FURNACE, UP-FLOW: A furnace designed with air-flow discharge vertically upward at or near the top of the furnace. This classification includes “highboy” furnaces with the blower mounted below the heating element and “lowboy” furnaces with the blower mounted beside the heating element. GAS CONVENIENCE OUTLET: A permanently mounted, manually operated device that provides the means for connecting an appliance to and disconnecting and appliance from the supply piping. The device includes an integral manually operated valve with a nondisplaceable valve member designed so that disconnection of an appliance only occurs when the manually operated value is in the closed position. GAS PIPING: An installation of pipe, valves, or fittings installed on a premise or in a building and utilized to convey fuel gas. GAS-UTILIZATION EQUIPMENT: An appliance that utilizes gas as a fuel, raw material, or both. HAZARDOUS LOCATION: Any location considered to be a fire hazard for flammable vapors, dust, combustible fibers, or other highly combustible substances. The location is not necessarily categorized in the building code as a highhazard group. HOUSE PIPING: See “Piping system.” IGNITION PILOT: A pilot that operates during the lighting cycle and discontinues during main burner operations. IGNITION SOURCE: A flame, spark, or hot surface capable of igniting flammable vapors or fumes. Such sources include appliance burners, burner igniters, and electrical switching devices. INCINERATOR: An appliance used to reduce combustible refuse material to ashes and manufactured, sold, and installed as a complete unit. INDUSTRIAL AIR HEATERS, DIRECT-FIRED, NONRECIRCULATING: A heater in which all the products of combustion generated by the burners are released into the air stream being heated. The purpose of the heater is to offset building heat loss by heating only outdoor air. INDUSTRIAL AIR HEATERS, DIRECT-FIRED RECIRCULATING: A heater in which all the products of combustion generated by the burners are released into the air stream being heated. Such heaters are of either the vented or unvented type.

DEFINITIONS

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INFRARED RADIANT HEATER: A heater that directs a substantial amount of its energy output in the form of infrared radiant energy into the area to be heated. Such heaters are of either the vented or unvented type. JOINT, FLANGED: A joint made by bolting together a pair of flanged ends. JOINT, FLARED: A metal-to-metal compression joint in which a conical spread is made on the end of a tube that is compressed by a flare nut against a mating flare. JOINT, MECHANICAL: A general form of gas-tight joint obtained by the joining of metal parts through a positive-holding mechanical construction, such as a flanged joint, threaded joint, flared joint, or compression joint. JOINT, PLASTIC ADHESIVE: A joint made in thermoset plastic piping by the use of an adhesive substance that forms a continuous bond between the mating surfaces without dissolving either one of them. JOINT, PLASTIC HEAT-FUSION: A joint made in thermoplastic piping by heating the parts sufficiently to permit fusion of the materials when the parts are pressed together. JOINT, WELDED: A gas-tight joint obtained by the joining of metal parts in a molten state. LABELED: Devices, equipment, appliances, or materials to which have been affixed a label, seal, symbol, or other identifying mark of a nationally recognized testing laboratory, inspection agency, or other organization concerned with product evaluation that maintains periodic inspection of the production of the abovelabeled items and by whose label the manufacturer attests to compliance with applicable nationally recognized standards. LIMIT CONTROL: A device responsive to changes in pressure, temperature, or level for turning on, shutting off, or throttling the gas supply to an appliance. LIQUEFIED-PETROLEUM GAS (LPG): A gas composed predominantly of propane, propylene, butanes or butylenes, or mixtures thereof that is gaseous under normal atmospheric conditions but is capable of being liquefied under moderate pressure at normal temperatures. LISTED: Equipment, appliances, or materials included in a list published by a nationally recognized testing laboratory, inspection agency, or other organization concerned with product evaluation that maintains periodic inspection of production of listed equipment, appliances, or materials and whose listing states either that the equipment, appliance, or material meets nationally recognized standards or has been tested and found suitable for use in a specified manner. The means for identifying listed equipment, appliances, or materials may vary for each testing laboratory, inspection agency, or other organization concerned with product evaluation, some of which do not recognize equipment, appliances, or materials as listed unless they are also labeled. The authority having jurisdiction shall utilize the system employed by the listing organization to identify a listed product.

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LIVING SPACE: Space within a dwelling unit utilized for living, sleeping, eating, cooking, bathing, washing, and sanitation purposes. LOG LIGHTER: A manually operated solid-fuel-ignition appliance for installation in a vented solid-fuel-burning fireplace. LUBRICATED PLUG-TYPE VALVE: A valve of the plug and barrel type provided with a means for maintaining a lubricant between the bearing surfaces. MAIN BURNER: A device or group of devices essentially forming an integral unit for the final conveyance of gas or a mixture of gas and air to the combustion zone and on which combustion takes place to accomplish the function for which the appliance is designed. METER: The instrument installed to measure the volume of gas delivered through it. MODULATING: Also known as throttling, the action of a control from its maximum to minimum position in either predetermined steps or increments of movement as caused by its actuating medium. OCCUPANCY: The purpose for which a building or portion thereof is utilized or occupied. OFFSET (VENT): A combination of approved bends that makes two changes in direction, bringing one section of the vent out of line but into a line parallel with the other section. ORIFICE: The opening in a cap, spud, or other device whereby the flow of gas is limited and through which the gas is discharged to the burner. OUTLET: A threaded connection or bolted flange in a pipe system to which a gas-burning appliance is attached. OXYGEN-DEPLETION SAFETY SHUTOFF SYSTEM (ODS): A system designed to shut off the gas supply to the main and pilot burners if the oxygen in the surrounding atmosphere is reduced below a predetermined level. PILOT: A small flame that is utilized to ignite the gas at the main burner or burners. PIPING: A pipe, tubing, or both. Pipe is a rigid conduit of iron, steel, copper, brass, or plastic. Tubing is a semirigid conduit of copper, aluminum, plastic, or steel. PIPING SYSTEM: All fuel piping, valves, and fittings from the outlet of the point of delivery to the outlets of the equipment shutoff valves. PLASTIC, THERMOPLASTIC: A plastic that is capable of being repeatedly softened by increase of temperature and hardened by decrease of temperature. POINT OF DELIVERY: For natural gas systems, the outlet of the service-meter assembly or of the service regulator or service shutoff valve where a meter is not provided. Where a value is provided at the outlet of the service-meter assembly, such valve shall be considered to be downstream of the point of delivery. For undiluted liquefied-petroleum-gas systems, the point of delivery shall be considered to be the outlet of the first regulator that reduces pressure to 2 psig or less.

DEFINITIONS

2.11

PORTABLE FUEL-CELL APPLIANCE: A fuel-cell generator of electricity that is not fixed in place. A portable fuel-cell appliance utilizes a cord and plug connection to a grid-isolated load and has an integral fuel supply. PRESSURE DROP: The loss in pressure due to friction or obstruction in pipes, valves, fittings, regulators, and burners. PRESSURE TEST: An operation performed to verify the gas-tight integrity of gas piping following its installation or modification. PURGE: To free a gas conduit of air, gas, or a mixture of gas and air. QUICK-DISCONNECT DEVICE: A hand-operated device that provides a means for connecting and disconnecting an appliance or an appliance connector to a gas supply and that is equipped with an automatic means to shut off the gas supply when the device is disconnected. READY ACCESS (TO): That which enables a device, appliance, or equipment to be directly reached without requiring the removal or movement of any panel, door, or similar obstruction. REGISTERED DESIGN PROFESSIONAL: An individual who is registered or licensed to practice a respective design profession as defined by the statutory requirements of the professional registration laws of the state or jurisdiction in which the project is to be constructed. REGULATOR: A device for controlling and maintaining a uniform supply pressure, either pounds-to-inches water column (MP regulator) or inches-to-inches water column (appliance regulator). REGULATOR, GAS APPLIANCE: A pressure regulator for controlling pressure to the manifold of equipment. REGULATOR, GAS APPLIANCE, LIMITED-ADJUSTMENT: A spring type limited adjustment in which the regulating force acting upon the diaphragm is derived principally from a spring, the loading of which is adjustable over a range of not more than 15 percent of the outlet pressure at the midpoint of the adjustment range. REGULATOR, GAS APPLIANCE, MULTISTAGE: A regulator for use with a single gas whose adjustment means is capable of being positioned manually or automatically to two or more predetermined outlet pressure settings. Each of these settings shall be adjustable or nonadjustable. The regulator may modulate outlet pressures automatically between its maximum and minimum predetermined outlet pressure settings. REGULATOR, GAS APPLIANCE, NONADJUSTABLE, SPRING TYPE: A regulator in which the regulating force acting upon the diaphragm is derived principally from a spring, the loading of which is not field-adjustable. REGULATOR, GAS APPLIANCE, SPRING TYPE, STANDARD ADJUSTMENT: A regulator in which the regulating force acting upon the diaphragm is derived principally from a spring, the loading of which is adjustable.

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The adjustment means shall be concealed. REGULATOR, GAS APPLIANCE, WEIGHT TYPE: A regulator in which the regulating force acting upon the diaphragm is derived from a weight or combination of weights. REGULATOR, LINE GAS-PRESSURE: A device placed in a gas line between the service pressure regulator and the equipment for controlling, maintaining, or reducing the pressure in that portion of the piping system downstream of the device. REGULATOR, MEDIUM-PRESSURE (MP): A line pressure regulator that reduces gas pressure from the range of greater than 0.5 psig and less than or equal to 5 psig to a lower pressure. REGULATOR, PRESSURE: A device placed in a gas line for reducing, controlling, and maintaining the pressure in that portion of the piping system downstream of the device. REGULATOR, SERVICE PRESSURE: A device installed by the serving gas supplier to reduce and limit the service line pressure to delivery pressure. RELIEF OPENING: The opening provided in a draft hood to permit the ready escape to the atmosphere of the flue products from the draft hood in the event of no draft, back draft, or stoppage beyond the draft hood and to permit air into the draft hood in the event of a strong chimney updraft. RELIEF VALVE, DEVICE: A safety valve designed to forestall the development of a dangerous condition by relieving either pressure, temperature, or vacuum in the hot-water-supply system. RELIEF VALVE, TEMPERATURE, RESEATING OR SELF-CLOSING TYPE: A resealing or self-closing automatic valve that opens and closes a relief vent, depending on whether the temperature is above or below a predetermined value. RELIEF VALVE, TEMPERATURE, MANUAL RESET TYPE: A valve that automatically opens a relief vent at a predetermined temperature and that must be manually returned to the closed position. RELIEF VALVE, VACUUM: A valve that automatically opens and closes a vent for relieving a vacuum within the hot-water-supply system, depending on whether the vacuum is above or below a predetermined value. RISER, GAS: A vertical pipe supplying fuel gas. ROOM HEATER, UNVENTED: See “Unvented room heater.” ROOM HEATER, VENTED: A free-standing heating unit used for direct heating of the space in and adjacent to that in which the unit is located. ROOM, LARGE, IN COMPARISON WITH SIZE OF EQUIPMENT: A room having a volume equal to at least 12 times the total volume of a furnace or air-conditioning appliance and at least 16 times the total volume of a boiler. Total

DEFINITIONS

2.13

volume of the appliance is determined from its exterior dimensions and is to include fan compartments and burner vestibules when used. When the actual ceiling height of a room is greater than 8 feet, the volume of the room is figured on the basis of a ceiling height of 8 feet. SAFETY SHUTOFF DEVICE: See “Flame safeguard.” SHAFT: An enclosed space extending through on or more stories of a building, connecting vertical openings in successive floors or to a floor and the roof. SLEEPING UNIT: A room or space in which people sleep; it can also include permanent provisions for living, eating, and either sanitation or kitchen facilities but not both. Such rooms and spaces that are also part of a dwelling unit are not sleeping units. SPECIFIC GRAVITY: As applied to gas, the ratio of the weight of a given volume to that of the same volume of air, both measured under the same condition. STATIONARY FUEL-CELL POWER PLANT: A self-contained package or factor-matched package that constitutes an automatically operated assembly of integrated systems for generating electrical energy and recoverable thermal energy and is permanently connected and fixed in place. THERMOSTAT, ELECTRIC-SWITCH TYPE: A device that senses changes in temperature and controls electrically, by means of separate components, the flow of gas to the burner(s) in order to maintain temperatures between predetermined limits and in which the thermal actuating element is an integral part of the device. THERMOSTAT, GRADUATING: A thermostat in which the motion of the valve is approximately in direct proportion to the effective motion of the thermal element induced by temperature change. THERMOSTAT, SNAP-ACTING: A thermostat in which the thermostatic valve travels instantly from the closed to the open position and vice versa. TRANSITION FITTINGS, PLASTIC TO STEEL: An adapter for joining plastic pipe to steel pipe. The purpose of this fitting is to provide a permanent, pressure-tight connection between two materials that cannot be joined directly. UNIT HEATER, HIGH-STATIC PRESSURE TYPE: A self-contained, automatically controlled, vented appliance having integral means for circulation of air against 0.2 inch or greater static pressure. Such an appliance is equipped with provisions for attaching an outlet air duct and, where the appliance is for indoor installation remote from the space to be heated, is also equipped with provisions for attaching an inlet air duct. UNIT HEATER, LOW-STATIC PRESSURE: A self-contained, automatically controlled, vented appliance, intended for installation in the space to be heated without the use of ducts, having integral means for circulation of air. Such units are allowed to be equipped with louvers or face extensions made in accordance with the manufacturer’s specifications.

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UNLISTED BOILER: A boiler not listed by a nationally recognized testing agency. UNVENTED ROOM HEATER: An unvented heating appliance designed for stationary installation and utilized to provide comfort heating. Such appliances provide radiant or convection heat by gravity or fan circulation directly from the heater and do not utilize ducts. VALVE: A device used in piping to control the gas supply to any section of a system of piping or to an appliance. VALVE, AUTOMATIC GAS-SHUTOFF: A valve used in conjunction with an automatic gas-shutoff device to shut off the gas supply to a water-heating system. It can be constructed integrally with the gas-shutoff deice or a separate assembly. VALVE, AUTOMATIC OR SEMIAUTOMATIC: A device consisting essentially of a valve and operator that control the gas supply to the burner(s) during operation of an appliance. The operator shall be actuated by application of gas pressure on a flexible diaphragm, by electrical means, by mechanical means, or by any other approved means. VALVE, EQUIPMENT SHUTOFF: A valve located in the piping system, used to isolate individual equipment for purposes such as service or replacement. VALVE, INDIVIDUAL MAIN BURNER: A valve that controls the gas supply to an individual main burner. VALVE, MAIN BURNER CONTROL: A valve that controls the gas supply to the main burner manifold. VALVE, MANUAL MAIN GAS-CONTROL: A manually operated valve in the gas line for the purpose of completely turning on or shutting off the gas supply to the appliance, except to pilot or pilots that are provided with independent shutoff. VALVE, MANUAL RESET: An automatic shutoff valve installed in the gassupply piping and set to shut off when unsafe conditions occur. The device remains closed until manually reopened. VALVE, SERVICE SHUTOFF: A valve, installed by the serving gas supplier between the service meter or source of supply and the customer piping system, to shut off the entire piping system. VENT: A pipe or other conduit composed of factory-made components, containing a passageway for conveying combustion products and air to the atmosphere, listed and labeled for use with a specific type or class of appliance. VENT CONNECTOR: See “Connector.” VENTED APPLIANCE CATEGORIES: Appliances that are categorized for the purpose of vent selection into four categories. VENTED APPLIANCE, CATEGORY I: An appliance that is operated with a nonpositive vent static pressure and with a vent gas temperature that avoids excessive condensate production in the vent.

DEFINITIONS

2.15

VENTED APPLIANCE, CATEGORY II: An appliance that is operated with a nonpositive vent static pressure and with a vent gas temperature that is capable of causing excessive condensate production in the vent. VENTED APPLIANCE, CATEGORY III: An appliance that operates with a positive vent static pressure and with a vent gas temperature that avoids excessive condensate production in the vent. VENTED APPLIANCE, CATEGORY IV: An appliance that is operated with a positive vent static pressure and with a vent gas temperature that is capable of causing excessive condensate production in the vent. VENTED ROOM HEATER: A vented, self-contained, freestanding, nonrecessed appliance for furnishing warm air to the space in which it is installed directly from the heater without duct connections. VENTED WALL FURNACE: A self-contained vented appliance complete with grilles or the equivalent, designed for incorporation in or permanent attachment to the structure of a building, mobile home, or travel trailer and furnishing heated air circulated by gravity or by a fan directly into the space to be heated through openings in the casing. This definition excludes floor furnaces, unit heaters, and central furnaces. VENTING SYSTEM: A continuous open passageway from the flue collar or draft hood of an appliance to the outside atmosphere for the purpose of removing flue or vent gases. A venting system is usually composed of a vent or a chimney and a vent connector, assembled to form the open passageway. VENTING SYSTEM, FORCED-DRAFT: A portion of a venting system using a fan or other mechanical means to cause the removal of flue or vent gases under positive static vent pressure. VENTING SYSTEM, INDUCED DRAFT: A portion of a venting system using a fan or other mechanical means to cause the removal of flue or vent gases under nonpositive static vent pressure. VENTING SYSTEM, MECHANICAL DRAFT: A venting system designed to remove flue or vent gases by mechanical means, consisting of an induced draft portion under nonpositive static pressure or a forced draft portion under positive static pressure. VENTING SYSTEM, NATURAL DRAFT: A venting system designed to remove flue or vent gases under nonpositive static vent pressure entirely by natural draft. VENT GASES: Products of combustion from appliances plus excess air and dilution air in the vent connector, gas vent, or chimney above the draft hood or draft regulator. VENT PIPING, BREATHER: Piping run from a pressure-regulating device to the outdoors, designed to provide a reference to atmospheric pressure. If the device incorporates an integral pressure-relief mechanism, a breather vent can also serve as a relief vent.

2.16


VENT PIPING, RELIEF: Piping run from a pressure-regulating or pressurelimiting device to the outdoors, designed to provide for the safe venting of gas in the event of excessive pressure in the gas piping system. VENT, SPECIAL GAS: A vent listed and labeled for use with listed Category II, III, and IV appliances. VENT, TYPE B: A vent listed and labeled for use with appliances with draft hoods and other Category I appliances that are listed fur use with Type B vents. VENT, TYPE BW: A vent listed and labeled for use with wall furnaces. VENT, TYPE L: A vent listed and labeled for use with appliances that are listed for use with Type L or Type B vents. WALL HEATER, UNVENTED: A room heater of the type designed for insertion in or attachment to a wall or partition. Such a heater does not incorporate concealed venting arrangements in its construction and discharges all products of combustion through the front into the room being heated. WATER HEATER: Any heating appliance or equipment that heats potable water and supplies such water to the potable hot-water distribution system. We have now covered all of the definitions needed to use your code book. Our next topic pertains to general regulations, so let’s move to the next chapter and get started.

CHAPTER 3

GENERAL REGULATIONS

Appliances regulated by the code must be listed and labeled for the application in which they are used. An exception is if an appliance is otherwise approved. Who has the power to approve such a waiver in the code? The approval has to come from an acceptable engineering evaluation. The evaluation of appliances is to be done by an approved agency, which tests a representative sample to the relevant standard or standards. Records of the testing are required to be kept and maintained by the testing agency. All test records must provide sufficient detail to verify compliance with the test standard. Periodic inspection of appliances is required by the code. These inspections shall be in-plant if necessary. Inspections are done to verify that labeled appliances are representative of the appliances that were approved. Agencies to be approved must be objective and competent. To confirm its objectivity, the agency shall disclose all possible conflicts of interest. Approved agencies must have adequate equipment to perform all tests. Periodic calibration of equipment is required. Personnel employed by an approved agency must be experienced and educated in conducting, supervising, and evaluating tests.

LABELING Permanent, factory-applied name plates are required to be affixed to appliances that are approved. Legible lettering on the nameplate is required to include the following: • Manufacturer’s name or trademark • Model number • Serial number • Seal or mark of the testing agency


3.2


• The hourly rating in Btu/h • The type of fuel approved for use with the appliance • Minimum clearance requirements for the appliance

PLUMBING Plumbing connections to appliances, whether for potable water supply or building drainage, are regulated in accordance with the International Plumbing Code.

FUEL TYPES Appliances must be designed for use with the type of fuel gas that will be supplied to them. Converting appliances to utilize different types of fuel is not acceptable. However, conversions can be made if complete instructions are provided in the installation manual provided by the serving gas supplier or the appliance manufacturer.

VIBRATION There are times when appliances are installed in such a manner that vibration isolation is required. Under these circumstances, an approved means for support and restraint of that appliance shall be provided.

REPAIR When an appliance needs repair, it must be done with parts and practices that will preserve the original approval or listing.

WIND Appliances and supports that are exposed to wind shall be designed and installed to resist wind pressures as determined in the International Building Code.

FLOODING Flooding can create serious problems. Any structure that is located in a flood-haz-

GENERAL REGULATIONS

3.3

ard area is required to have appliances installed so that they are at or above the design flood elevation and comply with the flood-resistant construction requirements of the International Building Code. As is often the case with code requirements, there is an exception to the flood rule. Appliance, equipment, and system installations regulated by the code can be installed below the design flood-level elevation if they are designed and installed to prevent water from entering or accumulating within the components and to resist hydrostatic and hydrodynamic loads and stresses, including the effects of buoyancy, during an occurrence of flooding. Installations must comply with the flood-resistant construction requirements of the International Building Code.

SEISMIC RESISTANCE Earthquake loads have to be taken into consideration when working with the code. The International Building Code governs the requirements for earthquake loads. Supports must be designed and installed for seismic forces in accordance with this code.

DUCTS All ducts required for the installation of systems regulated by the gas code shall be designed and installed in accordance with the International Mechanical Code.

RODENTS Rodents can pose a threat to appliances. Precautions must be taken to protect appliances from rodent damage. The International Building Code dictates the requirements for rodent-proofing buildings and structures.

! Codealert Appliances, equipment, and systems regulated by the gas code must not be located in elevator shafts.

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STRUCTURAL SAFETY The installation of gas piping must not weaken the structural safety of a building. During the installation or repair of gas piping, structural safety must be maintained. Examples of elements to be protected are as follows: • Finished floors • Walls • Ceilings • Tile work • Other parts of the structure that are to be changed or replaced

PENETRATIONS Penetrations of floor, ceiling, and fire-resistance-rated assemblies are protected by the International Building Code.

CUTTING, NOTCHING, AND BORING WOOD There are a number of considerations to take into account when cutting, notching, or boring wood members. You must be aware of the type of wood that you are working with. For example, engineered-wood structures normally may not be cut, notched, or bored. This applies to trusses, structural composite lumber, structural glued-laminated members, and I-joists. Unless the manufacturer’s recommendation or a registered design professional’s design specifically allows modification to the wood members, consider engineered-wood products off limits for cutting. Joists Joists for ceilings and floors can be cut, drilled, or notched. But you must obey the rules set forth by the IBC code. These rules include the following: • Notching the ends of joist is allowed if the notching does not exceed one-fourth the joist depth. • Holes drilled in joists must not be within 2 inches of the top and bottom of the joist, and their diameter shall not exceed one-third the depth of the member. • Notches in the top or bottom of a joist must not exceed one-sixth the depth and shall not be located in the middle one-third of the span. Studs When you are cutting studs, the rules change depending on whether the walls are

GENERAL REGULATIONS

3.5

load-bearing or non-bearing. Exterior walls and bearing partitions can have their studs cut to a depth not exceeding 25 percent of the stud width. When cutting studs in non-bearing partitions, the cut cannot have a depth greater than 40 percent of the width of the stud. Bored Holes Bored holes that are not greater in diameter than 40 percent of a stud depth are allowed in any wood stud. Holes that are not greater than 60 percent of the stud depth are permissible in non-bearing studs. The 60-percent rule also applies in walls where each bored stud is doubled, provided not more than two such successive doubled studs are so bored. The edges of bored holes must not be nearer than 5/8 inch to the edge of a stud. Bored holes shall not be located at the same section of a stud as a cut or notch.

TRUSSES When working with trusses, you must not cut, drill, notch, splice, or alter them without written concurrence and approval of a registered design professional. This applies to truss members and components. The approved load rating for trusses must not be exceeded. For example, installing mechanical equipment that will be supported by trusses must be done only if the trusses are designed and approved for the load.

STEEL Structural-steel Framing A registered design professional must be consulted prior to cutting, notching, or boring holes in structural-steel framing. If such work is allowed, it must be done in compliance with the approved standards set forth by a registered design professional. Cold-formed Steel Framing The flanges and lips of load-bearing, cold-formed steel-framing members must not be cut or notched. Registered design professionals are responsible for establishing approved procedures for cutting holes in cold-formed steel framing. These holes are allowed in the webs of load-bearing, cold-formed steel framing members along the centerline of the web of the framing member so long as they do not exceed the dimensional limitations, penetration spacing, or minimum hole edge distance as determined by a registered design professional. If cutting or notching is

3.6


needed in steel floor or roof decking, a registered design professional must approve the procedure. Nonstructural Steel Nonstructural cold-formed-steel wall framing is allowed to have holes bored in it. Flanges and lips of nonstructural cold-formed-steel wall studs can be bored along the centerline of the web of the framing member. The holes shall not exceed 1 1/2 inches in width or 4 inches in length. A minimum spacing of 24 inches from center to center of holes is required. Holes must not be located less than 10 inches from the bearing end.

PROHIBITED APPLIANCE LOCATIONS There are exceptions, which we will go over shortly, but as a rule of thumb appliances are prohibited from the following locations: • Sleeping rooms • Bathrooms • Toilet rooms • Storage closets • Surgical rooms • Spaces that open only into locations noted above Now for the exceptions: Direct-vent appliances are allowed in prohibited locations when they are installed in complete accordance with the conditions of the listing and the manufacturer’s instructions. Section 304.5 of the code pertains to the required volume criteria for rooms that use vented appliances. If a room meets the requirements of Section 304.5, the following types of appliances may be installed in otherwise prohibited locations: • Vented room heaters • Wall furnaces

! Codealert Appliances are not allowed to be located in hazardous locations unless they are listed and approved for the specific installations.

GENERAL REGULATIONS

3.7

• Vented decorative appliances • Vented gas fireplaces • Vented gas fireplace heaters • Decorative appliances for installation in vented solid fuel-burning fireplaces A bathroom may have a single wall-mounted unvented room heater installed when the heater is equipped as specified in Section 621.6 of the code and has an input rating not greater than 6000 Btu/h. In addition to Section 621.6, the bathroom must meet the required volume criteria of Section 304.5 of the code. Bedrooms may have a single wall-mounted unvented room heater installed if the heater is equipped as specified in Section 621.6 of the code and has an input rating not greater than 10,000 Btu/h. Additionally, the bedroom must meet the required volume criteria of Section 304.5. Another exception allows an appliance to be installed in a room or space that opens only into a bedroom or bathroom if such a room or space is used for no other purpose and is provided with a solid, weather-stripped door that is equipped with an approved self-closing device. Combustion air must be taken directly from the outdoors in accordance with Section 304.6 of the code.

OUTDOOR LOCATIONS Equipment that is installed in outdoor locations must either be listed for outdoor installation or protected from outdoor environmental factors that influence the operability, durability, and safety of the equipment.

PIT LOCATIONS Appliances installed in pits or excavations must not come into direct contact with the surrounding soil. A minimum of 12 inches of clearance is required from the sides of a pit or excavation. The walls must be lined with concrete or masonry if the depth of the pit exceeds 12 inches in depth below the adjoining grade level. When a lining is required, it must extend a minimum of 4 inches above the adjoin-

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Did you know

Appliances must not be installed in a location where they may be impacted by vehicular damage, unless they are protected by an approved means.

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ing grade level. Any pit used to hold equipment must have sufficient lateral-loadbearing capacity to resist collapse. Flood protection of an approved type is also required for appliances located in pits or excavations.

COMBUSTION, VENTILATION, AND DILUTION AIR Air for combustion, ventilation, and dilution of flue gases used in appliances installed in building must be provided in accordance to Section 304.5 through 304.9 of the code. If these requirements are not met, outdoor air must be introduced in accordance with one of the methods detailed in sections 304.6 through 304.9. With the exception of Category I appliances, direct-vent appliances, gas appliances of other than natural draft design, and vented gas appliances must be provided with combustion, ventilation, and dilution air in accordance with the appliance manufacturer’s instructions. A Type 1 clothes dryer that is provided with makeup air in accordance with Section 614.5 of the code is exempt from the above. Makeup Air Makeup air requirements for the operation of exhaust fans, kitchen ventilation systems, clothes dryers, and fireplaces shall be considered in determining the adequacy of a space to provide combustion air requirements. Indoor Air Calculating indoor combustion air can be done in various ways. It is normally done by requiring a minimum required volume of 50 cubic feet per 1,000 Btu/h of the appliance’s input rating. When the air infiltration rate of a structure is known, the minimum required volume can be determined with the use of an equation: (Equation 3.1) Use this equation when calculating the required volume for appliances that are not fanassisted. For purposes of this calculation, an infiltration rate greater than 0.60 ACH shall not be used in Equations 3.1 or 3.2.

Tradetip Appliances must be located in such a way as not to interfere with proper circulation of combustion, ventilation, and dilution air.

GENERAL REGULATIONS

3.9

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Did you know

A draft hood or barometric draft regulator shall be installed in the same room or enclosure as the appliance served so as to prevent any difference in pressure between the hood or regulator and the combustion air supply.

(Equation 3.2) Use this equation when calculating the required volume for fan-assisted appliances. For purposes of this calculation, an infiltration rate greater than 0.60 ACH shall not be used in Equations 3.1 or 3.2.

The total required volume shall be the sum of the required volume calculated for all appliances located within the space. Rooms communicating directly with the space in which the appliances are installed through openings not furnished with doors and through combustion air openings sized and located in accordance with Section 304.5.3 of the code are considered to be part of the required volume. Combined Spaces When spaces are combined on the same story, each opening is required to have a minimum free area of 1 square inch per 1000 Btu/h of the total input rating of all appliances housed in the space but not less than 100 square inches. One opening shall commence within 12 inches of the top, and one opening shall commence within 12 inches of the bottom of the enclosure. The minimum dimension of air openings shall not be less than 3 inches. The rules differ when combining spaces on different stories. Volumes of spaces in different stories shall be considered as communicating spaces when such spaces are connected by one or more openings in doors or floor having a total minimum free area of 2 square inches per 1000 Btu/h of total input rating of all appliances. Outdoor Combustion Air Outdoor combustion air must be provided through openings to the outdoors. The minimum dimension of air opening shall be not less than 3 inches. One way of doing this is with two permanent openings, one that commences within 12 inches of the top and one commencing within 12 inches of the bottom of the enclosure. These openings are required to communicate directly or by ducts with the outdoors or spaces that freely communicate with the outdoors.

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In situations where openings communicate directly with the outdoors or where communication is achieved with vertical ducts, each opening is required to have a minimum free area of 1 square inch per 4000 Btu/h of total input ratings of all appliances in the enclosure. If horizontal ducts are used to communicate with the outdoors, each opening is required to have a minimum free area of not less than 1 square inch per 2000 Btu/h of total input rating of all appliances in the enclosure. When one permanent opening is used for ventilation, the opening must begin within 12 inches of the top of the enclosure. Clearance is required for appliances in these spaces. A minimum clearance of 1 inch is required from the sides and back of appliances. There must be a minimum of 6 inches of clearance in front of an appliance. The opening must communicate directly with the outdoors or through a vertical or horizontal duct to the outdoors or a space that freely communicates with the outdoors. A minimum free area of 1 square inch per 3,000 BTU/h of the total input rating of all appliances located in the enclosure is required. The minimum free area of the opening shall not be less than the sum of the areas of all vent connectors in the space. Combination Air The use of a combination of both indoor and outdoor combustion air is allowed under the requirements of the code in Sections 304.7.1 through 304.7.3. Indoor openings must meet the requirement of Section 304.5.3 of the code. Outdoor openings must be located in accordance with Section 304.6. We have already talked about these requirements. Now let’s discuss the required opening sizes for outdoor openings. When sizing an outdoor opening, you must determine the ratio of interior spaces. This ratio shall be the available volume of all communicating spaces divided by the required volume. The outdoor size-reduction factor is one minus the ratio of interior spaces. The minimum size of outdoor openings must be the full size of outdoor openings calculated in accordance with Section 304.6 of the code multiplied by the reduction factor. The minimum dimension requirement for air openings is 3 inches.

! Codealert Engineered combustion-air installations must provide an adequate supply of combustion, ventilation, and dilution air and must be approved.

GENERAL REGULATIONS

3.11

Mechanical Combustion-air Supply Mechanical combustion-air supply may provide all combustion air. When this is the case, the air must come completely from the outdoors at an established rate. The rate required is not less than 0.35 cubic feet per minute per 1000 Btu/h of the total input rating of all appliances located within the space. Makeup air must be provided to replace exhaust from exhaust fans. When multiple appliances use a main burner, the appliances must be equipped with an interlock. Each appliance shall be interlocked with the mechanical airsupply system to prevent main burner operation when the mechanical air-supply system is not in operation. When combustion air is provided by the building’s mechanical ventilation system, the system shall provide the specified combustion-air rate in addition to the required ventilation air. Louvers and Grilles The size of louver and grilles is based on the net free area of each opening. This provides combustion, ventilation, and dilution air. If the free area through louvers and grilles is not known, it must be calculated. To do this, you are allowed to assume that wood louvers have 24 percent free area and metal louvers and grilles have 75 percent free area. Screens used on louvers and grilles are to have a mesh with a size no smaller than 1/4 inch. A grill or louver that is not motorized must be installed in a fixed open position. Motorized louvers shall be interlocked with the appliance being served so that they are shown to be in the full open position prior to main burner ignition and during main burner operation. Safety devices are required to keep the main burner from igniting if the louvers fail to open during burner start-up. The system must be installed to shut down the main burner if the louver fails to open during operation. Combustion-air Ducts Galvanized steel, or a material having equivalent corrosion resistance, strength, and rigidity, is an acceptable material for the construction of air ducts. Dwelling

?

Did you know

Combustion-air intake opening located on the exterior of a building shall have the lowest side of each opening located not less than 12 inches vertically for the adjoining grade level.

3.12


units can use unobstructed stud and joist spaces for conveying combustion air, provide that not more than one required fire block is removed. Ducts must terminate in unobstructed spaces allowing free movement of combustion air to appliances. Only one enclosure may be served by a single duct. If ducts end in an attic space, they must not be screened. Ducts shall not serve both upper and lower combustion-air openings in locations where both such openings are used. The separation between ducts serving upper and lower combustion-air openings must be maintained to the source of combustion air. Horizontal upper combustion-air ducts are not allowed to slope downward toward the source of combustion air. Open air space around a chimney liner cannot be used to supply combustion air. The same is true of gas vents, special gas vents, or plastic piping that is installed within a masonry, metal, or factory-built chimney. There is an exception: Direct-vent, gas-fired appliances designed for installation in a solid fuel-burning fireplace and installed in accordance with the manufacturer’s instruction are allowed. Fumes and Gases Protection from fumes and gases must be provided. This requires the safe removal of fumes or gases in an approved manner. The types of gases and fumes may include any of the following: • Carbon monoxide • Hydrogen sulfide • Ammonia • Chlorine • Halogenated hydrocarbons Certain types of businesses generate corrosive or flammable products. Barber shop and beauty salons are examples of such businesses. The aerosol sprays used for hair care can produce dangerous fumes. Nondirect vent-type appliances shall be located in a mechanical room separated or partitioned off from other areas with provisions for combustion air and dilution air from the outdoors. Direct-vent appliances must be installed in accordance with the appliance manufacturer’s instructions.

Tradetip Horizontal upper combustion-air ducts shall not slope downward toward the source of combustion air.

GENERAL REGULATIONS

3.13

! Codealert Combustion-air intake openings located on the exterior of a building shall have the lowest side of such openings located not less than 1 foot vertically from the adjoining grade level.

INSTALLATION The installation of appliances must comply with the code and the manufacturer’s recommendations. A copy of the manufacturer’s instructions for installation of equipment must be available on the job site at the time of a code inspection. If you find discrepancies between the code and the manufacturer’s recommendations for installation and the code is less restrictive, what should you do? You must install the equipment in accordance with the manufacturer’s requirements. Elevation of Ignition Source Equipment and appliances installed in some locations must be installed so that the ignition source sits at least 18 inches above the floor level. The types of locations where this rule comes into play include the following: • Hazardous locations • Public garages • Private garages • Repair garages • Motor-fuel-dispensing facilities • Parking garages • Rooms or spaces that are not part of the living space of a dwelling unit and that communicate directly with a private garage through openings

?

Did you know

The manufacturer’s instructions for installation of equipment must be available on the job site at the time of a code inspection.

3.14


! Codealert Equipment and appliances that have an ignition source are not allowed to be installed in Group H occupancies or control areas where open use, handling, or dispensing of combustible, flammable, or explosive materials occurs.

An exception: Elevation of an ignition source is not required for appliances that are listed as flammable-vapor-ignition-resistant. Parking Garages Connection of a parking garage with any room in which there is a fuel-fired appliance shall be by means of a vestibule providing a two-doorway separation, except that a single door is permitted where the sources of ignition in the appliance are elevated in accordance with Section 305.3 of the code. Appliances that comply with Section 305.4 of the code are exempt from this ruling. Public Garages Appliances in public garages must be installed in a manner that will protect them from vehicle impact. Such appliances must be installed at least 8 feet above the finished floor level in certain types of buildings. Some of these buildings include the following: • Public garages • Motor-fuel-dispensing facilities • Repair garages • Areas frequented by motor vehicles When motor vehicles exceed 6 feet in height and are capable of passing under an appliance, the appliance must be installed at least 2 feet higher above the finished floor level than the height of the tallest vehicle. The only exception to the height requirements is if the appliances are protected from vehicle impact. Private Garages If appliances are installed in private garages, they must be at least 6 feet above the finished floor level. This rule does not apply if the appliance is protected from vehicle impact.

GENERAL REGULATIONS

3.15

Grade Clearance Grade clearance for equipment and appliances can be minimal if the unit is supported on a level concrete slab or other approved material extending above adjoining grade. When this is not the case, the equipment or appliance must be suspended a minimum of 6 inches above the adjoining grade. Combustible Construction Clearance for equipment and appliances from combustible construction must be maintained. The amount of clearance is typically established by the manufacturer of the equipment or appliance. See Section 308 of the code if you are seeking a reduction in clearance requirements. Devices such as door stops, limits, and closers are not allowed to provide required clearance. Some considerations for clearance requirements include the following: • Door swing • Drawer pull • Overhead projections • Shelving • Window swings

ACCESS AND SERVICE Adequate access must be provided for equipment and appliances to be serviced without removing elements of permanent construction or disabling the function of a required fire-resistance-rated assembly. The amount of clearance required must be adequate to allow for inspection, service, repair, or replacement of the equipment or appliance. Attic Installations Attic installations for appliances require access large enough to remove the appliance or equipment installed within the attic space. This access must not be less

! Codealert Boiler and furnace rooms must be protected in compliance with the International Building Code.

3.16


than 30 inches high and 22 inches wide and not more than 20 feet in length when measured along the centerline of the passageway from the opening of the equipment. Continuous solid flooring is required in the passageway. This flooring must not be less than 24 inches wide. A level service space that is not less than 30 inches deep and 30 inches wide must exist at the front or service side of equipment or appliances. Assuming that the appliance or equipment to be removed does not exceed the minimum measurements, the minimum measurement of clear access openings is 20 inches by 30 inches. As usual, there are some exceptions to access requirements in attic installations. The passageway and level service space are not required where the appliance is capable of being serviced and removed through the required opening. When the passageway is not less than 6 feet high for its entire length, the passageway shall be not greater than 50 feet in length. Under-floor Appliances Appliances may be installed under floors such as in crawl spaces. When this is the case, suitable access to the appliance is required. At a minimum, the access space must be large enough to allow the removal and replacement of the appliance or equipment installed beneath a floor. A minimum width of 22 inches is required. Maximum width must not exceed 20 feet when measured along the centerline of the passageway. The minimum height requirement is 30 inches. A level service space that is not less than 30 inches deep and 30 inches wide must exist at the front or service side of an appliance or equipment. When the depth of a passageway or a service space exceeds 12 inches below the adjoining grade, the walls of the passageway must be lined with concrete or masonry extending 4 inches above the adjoining grade and have sufficient lateral-bearing capac-

! Codealert Rooms containing appliances requiring access must be provided with a door and an unobstructed passageway measuring not less than 36 inches wide and 80 inches high. Dwelling units offer an exception to this rule. In such locations, the unobstructed passageway must be at least 24 inches wide and large enough to allow removal of the largest appliance in the space, provided that a level service space of not less than 30 inches deep and the height of the appliance but not less than 30 inches with the door open is present at the front or service side of the appliance.

GENERAL REGULATIONS

3.17

Tradetip A luminaire controlled by a switch located at the required passageway opening and a receptacle outlet must be provided at or near the equipment location in an attic as required by the ICC Electrical Code.

ity to resist collapse. Minimum access dimensions for openings are 22 inches by 30 niches, assuming that the opening is large enough to allow the removal of the largest component of the appliance or equipment. As you might expect, there are exceptions. A passageway is not required where a level service space is present when the access is open and the appliance is capable of being serviced and removed through the required opening. When the passageway is not less than 6 feet high for its entire length, the passageway shall not be limited in length. A luminaire controlled by a switch located at the required passageway opening and a receptacle outlet shall be provided at or near the equipment location in accordance with the ICC Electrical Code. Roofs and Elevated Structures It is not uncommon for appliances and equipment to be installed on roofs and elevated structures. If the appliance or equipment may require access and is installed on a roof or elevated structure that is more than 16 feet high, there are special access rules to be considered. Here are some of the key points: • Access must be provided by a permanent approved means of access. • The extent of the access shall be from grade or floor level to the appliance- or equipment-level service space. • The access must not require climbing over obstructions that are greater than 30 inches high or walking on roofs having a slope greater than 4 units vertical in 12 units horizontal. This amounts to a 33 percent roof slope. Permanent Ladders Permanent ladders may be used to provide access for rooftop and elevated equipment, but there are a number of factors that must meet minimum design criteria. Such factors include the following: • Side railings must extend above the parapet or roof edge by not less than 30 inches.

3.18


• Ladders are required to have rung spacing that does not exceed 14 inches on center. • Toe spacing for ladders shall not be less than 6 inches deep. • A minimum of 18 inches is required between ladder rails. • Ladder rungs must have a minimum diameter of 3/4 inch. • Ladder rungs must be capable of supporting a minimum load of 300 pounds. • When ladders extend more than 30 feet in height, they must be provided with offset sections and landings that are capable of withstanding a load of 100 pounds per square inch. • Ladders must be protected against corrosion by approved means. Catwalks installed to provide access shall not be less than 24 inches wide and must have railing as required for service platforms. Group R-3 occupancies are not required to abide by the regulations in this section. Sloped Roofs Appliances installed on roofs with a slope of 25 percent or more that have an edge more than 30 inches above grade must provide a level platform on each side of the appliance to which access is required for service, repair, or maintenance. The platform must have minimum dimensions of 30 inches in all directions. Guards are required around the platform. These guards are to extend at least 42 inches above the platform and shall be constructed so as to prevent the passage of a 21-inch-diameter sphere. The guards must meet the requirements set forth in the International Building Code. Guards When appliances or other components that require service and roof-hatch openings are located within 10 feet of a roof edge or open side of a walking surface and such edge or open side is located more than 30 inches above the floor, roof, or grade below, guards must be provided. The guard must extend not less than 30 inches beyond each end of any appliances, components, and roof-hatch openings, and the top of the guard shall be located not less than 42 inches above the elevated surface adjacent to the guard. Construction of the guard must be done to prevent the passage of a 21-inch-diameter sphere and shall comply with the loading requirements for guards specified in the International Building Code.

CONDENSATE DISPOSAL Condensate disposal is required for equipment and appliances containing evaporators and cooling coils in accordance with the International Mechanical Code.

GENERAL REGULATIONS

3.19

! Codealert An electrical receptacle outlet must be provided at or near the equipment location in accordance with the ICC Electrical Code.

Condensate drains must be trapped as required by the equipment or appliance manufacturer. Auxiliary drain pans are required for condensing appliances in Category IV if damage can be expected if the condensate drain becomes stopped up. Pans are not needed when the appliance is designed to shut down operation in the event of a stoppage in the condensate system. What does a condensate drain do? It collects and discharges the liquid-combustion byproducts of condensing appliances to approved plumbing fixtures. A condensate drain must be made of an approved corrosion-resistant material and shall never be smaller than the drain connection that it is attached to. Like normal drainage lines, condensate drains must be installed with a minimum grade, fall, or pitch. The minimum amount of grade allowable is a 1-percent slope. This amounts to 1/8 inch per foot of tubing or piping. Drainage pipes for condensate drains may be constructed of any of the following: • Cast iron • Galvanized steel • Copper • Polybutylene • Polyethylene • ABS • CPVC • PVC The minimum diameter for a condensate drain is 3/4 inch. Both pressure and temperature ratings must be considered when designing a condensate drain. It is not allowable to decrease the size of a condensate drain. It is acceptable to combine multiple condensate drains; however, the sizing of the drain must take into account the full flow requirements based on the number of connections to the drain.

3.20


! Codealert Electrical connections between equipment and the building wiring, including the grounding of the equipment, must comply with the ICC Electrical Code.

CLEARANCE REDUCTION There are times when the minimum required distance between an appliance and a combustible material can be reduced. These conditions are identified in Table 3.1. Reduction of clearances with specified forms of protection, courtesy of the 2006 International Fuel Gas Code. If you have a situation that is not covered in Table 3.1, there are alternatives. The reduced clearance can be determined by linear interpolation between the distances listed in the table. It is not acceptable to reduce clearances derived by extrapolation below the range of the table. Air-conditioning Equipment Air-conditioning equipment that is installed in locations that are not large in comparison with the size of the equipment must be listed for the type of installation being done. For example, if the equipment is being used in a small entry hall, the appliance must be rated for that use. Installation must be done in full accordance with the manufacturer’s recommendations. Listed clearances shall not be reduced by the protection methods described in the code, regardless of whether the enclosure is of combustible or noncombustible material. When air-conditioning equipment is installed in rooms that are large in comparison with the size of the appliance, it can be installed with reduced clearances to combustible material, provided the combustible material or appliance is protected as described in Table 3.1. Furnace Plenums Furnace plenums require clearance. A plenum that is adjacent to plaster on metal lath or noncombustible material attached to combustible material requires the clearance to be measured to the surface of the plaster or other noncombustible finish where the clearance specified is 2 inches or less.

GENERAL REGULATIONS

3.21

Supply Ducts Supply ducts for air-conditioning appliances must have clearance within 3 feet of a furnace plenum. At no time shall the clearance be less than what is listed for the appliance. Always check manufacturer’s recommendations before determining final clearance. Boilers and Furnaces Clearance for boilers and furnaces must be planned so as not to interfere with combustion air, draft-hood clearance and relief, and accessibility for servicing. All installations have to be done in compliance with the manufacturer’s instructions. This type of equipment has to be listed for the intended purpose of the installation. Front clearance must be sufficient for servicing the burner and the furnace or boiler. This concludes the review of general regulations. Now we are ready to talk about installations. Let’s move to the next chapter and get into the meat of the subject.

3.22


TABLE 3.1 Reduction of clearances with specified forms of protection.a through k TYPE OF WHERE THE REQUIRED CLEARANCE WITH NO PROTECTION PROTECTION FROM APPLIANCE, VENT CONNECTOR, APPLIED TO AND OR SINGLE-WALL METAL PIPE IS: (inches) COVERING ALL 36 18 12 9 6 SURFACES OF COMBUSTIBLE Allowable clearances with specified protection (inches) MATERIAL Use Column 1 for clearances above appliance or horizontal WITHIN THE connector. Use Column 2 for clearances from appliance, DISTANCE SPECIFIED AS THE vertical connector, and single-wall metal pipe. REQUIRED Sides Sides Sides Sides Sides CLEARANCE WITH NO PROTECTION Above and Above and Above and Above and Above and Col. 1 rear Col. 1 rear Col. 1 rear Col. 1 rear Col. 1 rear (See Figure 3.1) 1. 31/2-inch-thick 24 9 6 5 — 12 — — — masonry wall without — ventilated airspace 2. 1/2-inch insulation board over 1-inch 24 18 12 9 9 6 6 5 4 3 glass fiber or mineral wood batts 3. 0.024-inch (nominal 24 gage) sheet metal over 1-inch glass fiber or mineral wool 18 12 9 6 6 4 5 3 3 3 batts reinforced with wire on rear face with ventilated airspace 4. 31/2-inch-thick ma6 6 6 6 — 12 — — — — sonry wall without ventilated airspace 5. 0.024-inch (nominal 24 gage) sheet metal 18 12 9 6 6 4 5 3 3 2 with ventilated airspace 6. 1/2-inch insulation 12 9 6 6 4 5 3 3 3 board with ventilated 18 airspace 7. 0.024-inch (nominal 24 gage) sheet metal with ventilated airspace over 0.024-inch 18 12 9 6 6 4 5 3 3 3 (nominal 24 gage) sheet metal with ventilated airspace 8. 1-inch glass fiber or mineral wool batts sandwiched between two sheets 0.024-inch 18 12 9 6 6 4 5 3 3 3 (nominal 24 gage) sheet metal with ventilated airspace

GENERAL REGULATIONS

3.23

TABLE 3.1 Reduction of clearances with specified forms of protection.a through k (continued) For SI: 1 inch ⫽ 25.4 mm, °C ⫽ [(°F ⫺ 32)/1.8], 1 pound per cubic foot ⫽ 16.02 kg/m3, 1 Btu per inch per square foot per hour per °F ⫽ 0.144 W/m2 ⫻ K. a. Reduction of clearances from combustible materials shall not interfere with combustion air, draft hood clearance and relief, and accessibility of servicing. b. All clearances shall be measured from the outer surface of the combustible material to the nearest point on the surface of the appliance, disregarding any intervening protection applied to the combustible material. c. Spacers and ties shall be of noncombustible material. No spacer or tie shall be used directly opposite an appliance or connector. d. For all clearance reduction systems using a ventilated airspace, adequate provision for air circulation shall be provided as described [see Figure 3.1(2) and Figure 3.1(3)]. e. There shall be at least 1 inch between clearance reduction systems and combustible walls and ceilings for reduction systems using ventilated airspace. f. Where a wall protector is mounted on a single flat wall away from corners, it shall have a minimum 1-inch air gap. To provide air circulation, the bottom and top edges, or only the side and top edges, or all edges shall be left open. g. Mineral wood batts (blanket or board) shall have a minimum density of 8 pounds per cubic foot and a minimum melting point of 1,500°F. h. Insulation material used as part of a clearance reduction system shall have a thermal conductivity of 1.0 Btu per inch per square foot per hour per °F or less. i. There shall be at least 1 inch between the appliance and the protector. In no case shall the clearance between the appliance and the combustible surface be reduced below that allowed in this table. j. All clearances and thicknesses are minimum; larger clearances and thicknesses are acceptable. k. Listed single-wall connectors shall be installed in accordance with the manufacturer’s installation instructions.

FIGURE 3.1 Wall-protector clearance-reduction system, courtesy of the 2006 International Fuel Gas Code.

3.24


FIGURE 3.1 Wall-protector clearance-reduction system, courtesy of the 2006 International Fuel Gas Code. (continued)

GENERAL REGULATIONS

3.25

FIGURE 3.1 Wall-protector clearance-reduction system, courtesy of the 2006 International Fuel Gas Code. (continued)


CHAPTER 4

GAS PIPING INSTALLATIONS

The installation of gas piping is serious business. Mistakes made in the installation can result in death. Following code requirements is essential to good business and public safety. There are a number of rules and regulations to be considered when installing gas piping. This is our topic for the moment, so let’s get to it. When you consult your code book, you will see that the chapter on installations pertains to design, installation, modification, and maintenance of gas systems. The code covers work that begins at the connection point to an appliance or component to the point of gas delivery. Other codes do come into play with gas installations. For example, the International Building Code regulates utility service piping that is located within buildings. The International Fire Code and NFPA 58 cover the storage of liquefied-petroleum gas. All of the codes work together to maintain safe installations.

IDENTIFICATION Exposed gas piping, with the exception of steel piping, must be marked. This is done with a yellow label that displays the word “Gas” in black letters. The label

! Codealert When adding an additional appliance, the existing gas piping must be checked to confirm that it has adequate capacity for all the appliances served. Should the system be inadequate for the load, it must be upgraded to suitable specifications.


4.2


?

Did you know

When two or more gas meters are installed on the same premises to supply separate consumers, the piping systems shall not be interconnected on the outlet side of the meters. Piping from multiple meter installations must be marked with an approved permanent identification by the installer so that the piping system supplied by each meter is readily identifiable.

must appear along the piping at intervals of not more than 5 feet. There is an exception: Piping that is installed in the same room as the equipment being served is not required to be marked.

PIPE SIZING Pipe sizing must be done in a manner to provide adequate supply for all appliances serviced. This sizing must meet the maximum demand on the system without undue loss of pressure between the point of delivery and the appliance. The volume of gas to be provided, in cubic feet per hour, shall be determined directly from the manufacturer’s input ratings of the appliances served. In such cases when an input rating is not indicated, one must be derived by the use of tables in your code book, and there are a lot of them. Hourly loads on a gas system for all demands attached to the system shall be used for pipe sizing, assuming that all appliances may be operating at full capacity simultaneously. In other words, size and design systems to meet the maximum demands that may be put upon them. If a diversity of loads can be established, pipe sizing shall be permitted to be based on such loads. There are a few ways to size gas piping. The easy way, when it applies, is to use the sizing tables in your code book. Another way that is equally easy is to use the sizing tables provided by equipment manufacturers. When all else fails, you have to do the math. Or you can rely on an approved engineering design. There are equations that are used for sizing gas piping. Two of them are listed below:

(Equation 4.1)

4.3


(Equation 4.2)

These equations can be used in connection with tables. When the equations are used to size piping or tubing, the pipe or tubing must have a smooth inside wall and the length of the pipe shall be determined in accordance with Sections 402.4.1, 402.4.2, or 402.4.3 of the code.

TABLE 4.1 Approximate gas input for typical appliances, courtesy of the 2006 International Fuel Gas Code. APPLIANCE Space Heating Units Hydronic boiler Single family Multifamily, per unit Warm-air furnace Single family Multi-family, per unit

INPUT BTU/H (Approx.)

100,000 60,000 100,000 60,000

Space and Water Heating Units Hydronic boiler Single family Multifamily, per unit

120,000 75,000

Water Heating Appliances Water heater, automatic instantaneous Capacity at 2 gal./minute Capacity at 4 gal./minute Capacity at 6 gal./minute Water heater, automatic storage, 30- to 40-gal. tank Water heater, automatic storage, 50-gal. tank Water heater, domestic, circulating or side-arm

142,800 285,000 424,400 35,000 50,000 35,000

Cooking Appliances Built-in oven or broiler unit, domestic Built-in top unit, domestic Range, free-standing, domestic

25,000 40,000 65,000

Other Appliances Barbecue Clothes dryer, Type 1 (domestic) Gas fireplace, direct-vent Gas light Gas log Refrigerator

40,000 35,000 40,000 2,500 80,000 3,000

For SI: 1 British thermal unit per hour = 0.293 W, 1 gallon = 3.785 L, 1 gallon per minute = 3.785 L/m.

4.4


TABLE 4.2 C and Y values for natural gas and undiluted propane at standard

conditions, courtesy of the 2006 International Fuel Gas Code. EQUATION FACTORS

GAS

Cr

Y

Natural gas

0.6094

0.9992

Undiluted propane

1.2462

0.9910

For SI: 1 cubic foot = 0.028 m3, 1 foot = 305 mm, 1-inch water column = 0.249 kPa, 1 pound per square inch = 6.895 kPa, 1 British thermal unit per hour = 0.293 W.

Branch Length Pipe sizing for each section of the longest pipe run from the point of delivery to the most remote outlet shall be determined using the longest run of piping and the load of the section. The pipe size of each section of branch piping not previously sized shall be determined using the length of piping from the point of delivery to the most remote outlet in each branch and the load of the section. Hybrid Pressure Hybrid pressure has to do with higher-pressure gas piping. Sizing for this type of system is a little different. The sizing must be done from the point of delivery to the most remote line-pressure regulator. Then piping from the regulator to the most remote outlet served is used to determine the length for sizing. Pressure Drop Pressure drop must be factored into pipe sizing. The design pressure loss in a piping system under the maximum probable flow conditions for the point of delivery to the inlet connection of an appliance must be sized so that the supply pressure at the appliance is greater than the minimum pressure required for proper and nor-

! Codealert The pipe size of each section of gas piping shall be determined using the longest length of piping from the point of delivery to the most remote outlet and the load of the section.


4.5

mal operation. Clearly put, the pipe sizing must be large enough to allow for pressure drops that might affect the performance of an appliance. Operating Pressure Under normal conditions, the maximum operating pressure for a gas system inside a building is 5 psig. When certain conditions exist, this ruling may be changed. Examples of the types of circumstances that can change the maximum operating pressure include the following: • Welded piping systems • Piping that is located in a ventilated chase or otherwise enclosed for protection against accidental gas accumulation • Piping that is located inside buildings or separate areas of buildings used exclusively for industrial processing or heating • Piping that is located inside buildings or separate areas of buildings used exclusively for research • Piping that is located inside buildings or separate areas of buildings used exclusively for warehousing • Piping that is located inside buildings or separate areas of buildings used exclusively for boiler or mechanical rooms • Temporary piping for buildings under construction

LP SYSTEMS What is the maximum operating pressure of an undiluted LP-gas system? The correct answer is 20 psig. Temperature in a building can affect the use of an LP-gas system. For example, buildings with systems designed to operate below -5 degrees F or with butane or a propane-butane mix are required to have a design that will either accommodate liquid LP gas or prevent LP-gas vapor from condensing into a liquid. What is the exception? There is one. It involves buildings or separate areas of buildings constructed in accordance with Chapter 10 of NFPA 58. The space must be used exclusively to house industrial processes, research, and experimental laboratories or equipment or processing with similar hazards. Sizing Tables Your code book contains sizing tables that will make sizing gas systems easier. Please see the tables on pages 31 through 63 of the 2006 International Fuel Gas Code to illustrate the type of tables that you will be working with in your code book. Always make sure that your local code does not have changes that are not listed in standard code books.

4.6

TABLE 4.3 Schedule 40 metallic pipe, courtesy of 2006 International Fuel Gas Code.



4.7

4.8




4.9

4.10




4.11

4.12




4.13

4.14




4.15

4.16

TABLE 4.8 Semirigid copper tubing, courtesy of 2006 International Fuel Gas Code.



4.17

4.18




4.19

4.20




4.21

4.22




4.23

4.24




4.25

4.26




4.27

4.28




4.29

4.30

TABLE 4.15 Corrugated stainless-steel tubing (CSST), courtesy of 2006 International Fuel Gas Code.




4.31

4.32





4.33

4.34



TABLE 4.20 Polyethylene plastic pipe, courtesy of 2006 International Fuel Gas Code.


4.35

4.36



4.37


TABLE 4.22 Polyethylene plastic pipe, courtesy of 2006 International Fuel Gas Code. Natural

Gas Inlet Pressure

Less than 2.0 psi

Pressure Drop

0.3 in w.c. 0.60

Specific Gravity

Plastic Tubing Size (CTS) (in.) Nominal OD

1

/2

3

/4

Designation

SDR 7.00

SDR 11.00

Actual ID

0.445

0.927

Length (ft)

Capacity in Cubic Feet of Gas per Hour

10

54

372

20

37

256

30

30

205

40

26

176

50

23

156

60

21

141

70

19

130

80

18

121

90

17

113

100

16

107

125

14

95

150

13

86

175

12

79

200

11

74

225

10

69

250

NA

65

275

NA

62

300

NA

59

350

NA

54

400

NA

51

450

NA

47

500

NA

45

For SI: 1 inch ⫽ 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad. Notes: 1. NA means a flow of less than 10 cfh. 2. All entries have been rounded to three significant digits.

4.38




4.39

4.40


TABLE 4.24 Polyethylene plastic pipe, courtesy of 2006 International Fuel Gas Code. Natural

Gas Inlet Pressure

Less than 2.0 psi

Pressure Drop

0.5 in w.c. 0.60

Specific Gravity

Plastic Tubing Size (CTS) (in.) Nominal OD

1

/2

3

/4

Designation

SDR 7.00

SDR 11.00

Actual ID

0.445

0.927

Length (ft)


10

72

490

20

49

337

30

39

271

40

34

232

50

30

205

60

27

186

70

25

171

80

23

159

90

22

149

100

21

141

125

18

125

150

17

113

175

15

104

200

14

97

225

13

91

250

12

86

275

11

82

300

11

78

350

10

72

400

NA

67

450

NA

63

500

NA

59

For SI: 1 inch ⫽ 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad. Notes: 1. NA means a flow of less than 10 cfh. 2. All entries have been rounded to three significant digits.

4.41


TABLE 4.25 Polyethylene plastic pipe, courtesy of 2006 International Fuel Gas Code. Undiluted propane

Gas Inlet Pressure

11.0 in w.c.

Pressure Drop

0.5 in w.c. 1.50

Specific Gravity

Plastic Tubing Size (CTS) (in.) Nominal OD Designation Actual ID Length (ft)

1

/2

3

/4

SDR 7.00

SDR 11.00

0.445

0.927


10

121

828

20

83

569

30

67

457

40

57

391

50

51

347

60

46

314

70

42

289

80

39

269

90

37

252

100

35

238

125

31

211

150

28

191

175

26

176

200

24

164

225

22

154

250

21

145

275

20

138

300

19

132

350

18

121

400

16

113

450

15

106

500

15

100

For SI: 1 inch ⫽ 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

4.42

TABLE 4.26 Schedule 40 Metallic Pipe, courtesy of 2006 International Fuel Gas Code.



4.43

4.44




4.45

4.46




4.47

4.48




4.49

4.50




4.51

4.52




4.53

4.54




4.55

4.56

TABLE 4.33 Corrugated stainless-steel tubing, courtesy of 2006 International Fuel Gas Code.




4.57

4.58




4.59


4.60




4.61

4.62


TABLE 4.38 Specifications for threading metallic pipe, courtesy of 2006 International Fuel Gas Code. IRON PIPE SIZE APPROXIMATE LENGTH OF APPROXIMATE NUMBER (inches) THREADED PORTION (inches) OF THREADS TO BE CUT 1

3

10

3

/4

3

10

1

7

/2

/4 /4 /8

10

11/4

1

11

1

1

11

1 /2 2

1

11

21/2

11/2

12

3

1

1 /2

12

4

15/8

13

For SI: 1 inch ⫽ 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.

Now let’s enter into the realm of piping materials.

PIPING MATERIALS All piping materials must be in compliance with the code. Used materials cannot be used again except when they are free of foreign materials and are determined to be adequate for the service intended. Any material not covered by the code must be investigated and tested to determine suitability. Essentially, a manufacturer must say that the product is acceptable and a code official must approve its use. When steel pipe is used, it must be of standard weight, which is Schedule 40, and it must comply with either ASME B 36.10, 10M; ASTM A 53; or ASTM A 106. The same is true of wrought-iron piping. Copper and brass piping are limited in their use for gas. Threaded copper, brass, and aluminum-alloy pipe cannot be used with corrosive gases. No copper

?

Did you know

Cast-iron pipe cannot be used as a gas-pipe material.


4.63

or brass pipe shall be used if the gas being transferred contains more than an average of 0.3 grains of hydrogen sulfide per 100 standard cubic feet of gas. When aluminum-alloy pipe is used for gas-piping applications, the pipe must be coated to protect it against external corrosion where it is in contact with masonry, plaster, or insulation or subject to repeated wettings by such liquids as water, detergents, or sewage. This type of piping is not allowed for use in exterior locations or in underground installations. Copper and brass tubing that is used for gas piping must comply with Standard K or L of ASTM B 88 or ASTM B 280. These materials cannot be used for corrosive gases that contain more than 0.3 grains of hydrogen sulfide per 100 standard cubic feet of gas. Can plastic pipe be used to convey gas? Yes, as long as the plastic pipe and fittings are installed underground outdoors. The material must conform to ASTM D 2513. And the pipe must be marked as gas pipe and with the ASTM standard label. Anodeless Risers Plastic pipe, tubing, and anodeless risers must meet certain criteria. Manufacturers are required to recommend factory-assembled anodeless risers for the gas being used. The components must be tested for leaks. This testing has to be done within the parameter of the manufacturer’s recommendations. When a manufacturer produces a service-head adapter and field-assembled anodeless risers incorporating service-head adapters, the manufacturer must recommend the gas used and the design must be in compliance with one or more of the following: • Category I or ASTM D 2513 • U.S. Department of Transportation • Code of Federal Regulations • Title 49, Part 192.281 (e)

! Codealert Seamless copper, aluminum alloy, and steel tubing are not allowed to transport corrosive-gas materials.

4.64


! Codealert Corrugated stainless-steel tubing must be listed in accordance with ANSI LC 1/CSA 6.26.

WORKMANSHIP Workmanship is a consideration in code inspection. Pipe, tubing, and fittings used in gas systems must be free of cutting burrs and defects in structure or threading. They must be brushed. Chips and scales must be removed. If defects exist, they must be repaired. When repairing is not reasonable, replacement is required. Threads Metallic pipe threads and fittings must be taper pipe threads. The threads must comply with ASME B1.20.1. Pipe with threads that are stripped, chipped, corroded, or otherwise damaged shall not be used. Any weld that opens during the operation of cutting or threading makes the pipe unusable. Thread compounds, such as sealing tape or pipe dope, must be resistant to the action of liquefied-petroleum gas or to any other chemical constituents of the gases to be conducted through the piping. Corrosive Action Pipe and tubing must be protected against corrosive action. This is accomplished with protective coatings. The protective coating may be external or internal. The use of the protective coating is not to be considered as adding strength to the pipe.

?

Did you know

Plastic pipe, tubing, or fittings used in undiluted liquefied-petroleum-gas piping systems must be in accordance with NFPA 58.


4.65

! Codealert Plastic pipe, tubing, and fittings used to connect regulator vents to remote vent terminations shall be made of PVC that conforms to UL 651. PVC vent piping cannot be installed indoors.

JOINTS AND FITTINGS Joints and fittings used in gas piping have to meet tough requirements. They must be capable of withstanding maximum pressure and strength in the application. All joints must be tight and leakproof. Other requirements dictate that the piping, joints, and fittings must be able to withstand expansion, contraction, vibration, fatigue, and the weight of the pipe and its contents. Pipe joints are to be threaded, flanged, brazed, or welded. On occasions when nonferrous pipe is brazed, the brazing material must have a melting point in excess of 1000 degrees F. Phosphorus content in brazing materials must not exceed an amount of 0.05 percent. When working with tubing, the joints must either be made with approved gastubing fittings or brazed with a material having a melting pong in excess of 1000 degrees F. Again, the phosphorus contain must not exceed 0.05 percent. Nonferrous pipe and tubing can use flared joints, but the joints must be approved for the use. With metallic fittings there are numerous rules. Metallic Fittings Metallic fittings have to comply with a number of code requirements. To keep it simple, I am putting the rules in a list for you: • Unless special approval is retained, threaded fittings that are larger than 4 inches are prohibited. • The fittings used with steel or wrought-iron pipe must be made of steel, bronze, brass, malleable iron, or cast iron. • Copper, brass, or bronze fittings must be used when the piping is copper or brass. • Aluminum-alloy pipe requires the use of fittings that are of an aluminum alloy. • Flanges are allowed with cast-iron fittings. • Bushings are not allowed with the use of cast-iron fittings. • When flammable gas-air mixtures are in use, cast-iron fittings are not allowed.

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• Cast-iron fittings that are 4 inches or larger cannot be used indoors except where they are approved. • Cast-iron fittings in excess of 6 inches are not to be used unless they are specifically approved for the use. • Threads on aluminum-alloy fittings are not allowed to form a joint seal. • You cannot use zinc-aluminum-alloy fittings in systems that contain a flammable gas-air mixture. • There are special fittings that can be used. They include couplings, proprietarytype joints, saddle tees, gland-type compression fittings, and flared, flareless, or compression-type tubing fittings. These fittings must be used within the manufacturer’s pressure-temperature recommendations. The fittings must be used within the service conditions with respect to vibration, fatigue, and thermal expansion or contraction. They must be installed or braced to prevent separation of the joint by gas pressure or external physical damage, and they must be approved. Plastic Pipe Joints Plastic pipe joints, including plastic tubing joints, must be made in compliance with the manufacturer’s recommendations. This typically requires the use of a primer to clean the pipe or tubing and a solvent-weld glue. All joints must comply with code requirements. Plastic joints must be designed and installed so that the longitudinal pull-out resistance of the joint will be at least equal to the tensile strength of the plastic piping material. Heat-fusion joints must be at least as strong as the pipe or tubing being joined. All heat-fusion fittings are to be labeled ASTM D 2513. The joints must be gastight when made. Compression-type mechanical joints can be used to join plastic pipe and tubing. Gasket material in the fitting must be compatible with the pipe or tubing being used and the gas being carried. Due to the nature of plastic pipe, a stiffener must be flush with the end of the pipe or tubing and extend at least to the outside end of the compression fitting when it is installed. The stiffener must be free of rough or sharp edges and shall not be a force fit. You cannot use split tubular stiffeners. When plastic pipe or tubing is used with LP-gas systems, it must meet the requirements of NFPA 58.

FLANGES AND FLANGE GASKETS Flanges used with gas piping must meet the requirements of ASME B 16.1, ASME B 16.20, or MSS SP-6. Pressure and temperature ratings must equal or exceed the requirements for the intended application. Standard facings are permitted


4.67

for use under the code. Where 150-pound pressure-rated steel flanges are bolted to Class 125 cast-iron flanges, the raised face on the steel flange shall be removed. Can lapped flanges be used underground? No. They must only be used above ground or in exposed locations, and they must be accessible for inspection. Gasket material must be capable of withstanding the design temperature and pressure of the piping system and the chemical constituents of the gas being conducted without change to its chemical and physical properties. The material must be chosen with regard to fire exposure. Such materials can include the following: • Metal • Metal-jacketed asbestos (plain or corrugated) • Asbestos • Aluminum “O” rings • Spiral-wound metal gaskets If a flanged joint is opened, the gasket shall be replaced. Full-face gaskets shall be used with all bronze and cast-iron flanges.

PIPING-SYSTEM INSTALLATION How much do you know about piping system installations? Whatever your answer, you are about to learn more. We will start with prohibited locations. See the list below for places not to install piping systems: • Piping shall not be installed in or through a circulating-air duct. • Piping shall not be installed in a laundry chute. • Piping shall not be installed in a dumbwaiter. • Piping shall not be installed in an elevator. • Piping installed downstream of the point of delivery shall not extend through any townhouse unit other than the unit served by such piping. • Concealed piping is not allowed to be located in solid partitions or solid walls unless installed in a chase or casing. • Generally speaking, concealed piping is not allowed to be fitted with unions. • Concealed piping is not allowed to be equipped with tubing fittings, right and left couplings, bushings, compression couplings, or swing joints made by combinations of fittings. There are two exceptions: tubing joined by brazing and fittings listed for use in concealed locations. Pipe Protection Given the high risk for personal injury and property damage with a damaged gas

4.68


Tradetip Gas outlets that are not connected to appliances are required to be capped in a gas-tight seal. As you might expect, there is an exception: Listed and labeled flush-mounted-type quick-disconnect devices and listed and labeled gas convenience outlets shall be installed in accordance with the manufacturer’s instructions.

pipe, it should not come as any surprise that gas piping must be protected. When underground piping is installed below grade and enters an outer foundation or basement wall, the gas pipe must enter through a suitable sleeve. This sleeve is to protect the pipe and is usually required to be two pipe diameters larger than the pipe conveying the gas. All annular space between gas pipe and a sleeve must be sealed. Gas pipe that is concealed must be protected. Black or galvanized-steel pipe is an exception that does not require special protection. Other types of pipe that are installed in wood studs, joists, rafters, or similar wood members that are less than 1 1/2 inches from the nearest edge of the wood member must be protected. This is typically done with stud guards or nail plates. The plates are required to have a minimum thickness of 1/16 inch and be made of steel. This type of pipe shield is required to cover the area of the pipe where the member is notched or bored and must extend a minimum of 4 inches above sole plates, below top plates, and to each side of a stud, joist, or rafter. Solid Floors Pipe installed in solid floors must be laid in channels in the floor and covered in a way that allows access to the piping with a minimum amount of damage to the structure. Pipe protection must be provided to prevent damage from exposure, excessive moisture, and corrosive substances. If it is not practical to install the pipe in channels, the pipe can be installed in a conduit of Schedule 40 steel, wrought iron, PVC, or ABS pipe with tightly sealed ends and joints. When conduit is used, both ends must extend no less than 2 inches beyond the point where the pipe emerges from the floor. Venting of the conduit is required. The vent must extend above grade to the outdoors and must be installed so as to prevent the entry of water and insects. Above-ground Outdoor Piping When installing above-ground outdoor gas piping, the pipe must be installed at an elevation of not less than 3 1/2 inches above the ground. Gas pipe installed on


4.69

! Codealert Uncoated, threaded, or socket-welded joints shall not be used in piping in contact with soil or where internal or external crevices are known to occur.

roof surfaces is also required to be elevated at least 3 1/2 inches above the surface. All outdoor piping must be installed so that it is supported and located where it will be protected from physical damage. Any gas pipe that passes through an outside wall must be protected against corrosion by coating or wrapping with an inert material. When pipe sleeves are used for protection, the annular space must be sealed. Corrosion Corrosion protection is required for metallic pipe or tubing. This is required when soil conditions or moisture is present and may cause a corrosive action. Zinc coatings, such as galvanizing, are not approved as a suitable protection when gas pipe is installed below ground. Any ferrous metal that is exposed to exterior conditions must be protected from corrosion. The mode of protection must be approved by the code official. In events when dissimilar metals are joined below grade, an insulating coupling or fitting must be used. No gas piping is allowed to be laid in contact with cinders. Outside Appliances When outside appliances are serviced, the individual gas lines must be installed at a minimum of 8 inches below finished grade, provided that the installation is ap-

Tradetip Pipe protective coatings and wrappings must be approved for the application and must be factory-installed. There is an exception: As long as the protective coating is installed in accordance with the manufacturer’s instructions, field application of coatings and wrappings is allowed. This applies to pipe nipples, fittings, and locations where the factory coating or wrapping has been damaged or necessarily removed at joints.

4.70


?

Did you know

A minimum depth of 12 inches is required for underground piping installations unless there is a provision in Section 404.9.1 of the code that overrules the regulation.

proved and installed in locations that are not susceptible to physical damage. Remember that normal cover for an underground pipe is 12 inches. Beneath Buildings Underground piping is generally not allowed beneath buildings. If the pipe is encased in a conduit of wrought iron, plastic pipe, or steel pipe designed to withstand superimposed loads, then installation can be done beneath buildings. When this is done, the conduit must extend into the occupiable portion of the building. When the conduit ends, the space between the conduit and the gas piping must be sealed to prevent the possible entrance of any gas leakage. The end sealing of a conduit must be capable of withstanding the full pressure of gas pipe. This conduit must not extend less than 4 inches outside of a building and it must be vented above grade to the outdoors. The entrance of water or insects must be prevented at the termination of the conduit. Corrosion resistance is required for conduits, and they must be in accordance in 404.8. Outlet Locations Unthreaded portions of piping outlets must extend at least 1 inch through finished ceilings and walls; where it extends through floors or outdoor patios and slabs, the extensions must not be less than 2 inches above the penetration surface. All outlets must be supported adequately. Typically, outlets are to be installed in the room or space that contains the appliance or equipment being served.

! Codealert Trenches for gas piping must be graded so that the pipe has a firm, substantially continuous bearing on the bottom of the trench.


4.71

Plastic-pipe Limitations The only place where plastic pipe can be used for gas is outside underground. It cannot be used in or under buildings or slabs. Maximum operating pressure for plastic gas piping must not exceed 100 psig for natural gas or 30 psig for LP gas. Here are the exceptions: Plastic gas pipe is allowed to terminate above ground outside of buildings where it is installed in premanufactured anodeless risers that are in compliance with the manufacturer’s instructions. Plastic pipe is permitted to terminate with a wall head adapter within buildings where the pipe is inserted in a piping material for fuel-gas use in buildings. Tracers What are tracers? The most common type of tracer is a yellow insulated-copper wire. It can be some other type of approved conductor. The tracer is installed alongside nonmetallic gas piping. This allows the pipe to be found and traced electronically. Ideally, tracer wires should terminate above ground at each end of a pipe run. When this is not the case, the tracer must be installed so that it is accessible. A minimum conductor size of 18 AWG is required. And, the tracer must be covered in insulation that is approved for direct burial. Changes in Direction Changes of direction in gas piping are allowed when they are accomplished with the use of fittings, factory bends, or field bends. Elbow fittings have to be factorymade welding elbows or transverse segments cut therefrom. The fitting requires an arc length measured along the crotch at least 1 inch in pipe sizes 2 inches and larger. Metallic-pipe bends must meet the following requirements: • All bends must be made with bending tools and procedures that are intended for the purpose. • All bends must be smooth and free from buckling, cracks, or other evidence of mechanical damage. • Longitudinal welds of pipe must be near the neutral axis of the bend. • The maximum arc for a bend must not exceed 90 degrees.

?

Did you know

Listed and labeled flush-mounted-type quick-disconnect devices and listed and labeled gas convenience outlets shall be installed in accordance with the manufacturer’s instructions.

4.72


Tradetip Outside and underground connections between metallic and plastic pipe must be made only with Category I transition fittings in accordance with ASTM 2513.

• The inside radius of a bend shall be not less than six times the outside diameter of the pipe. Plastic-pipe bends must comply with code requirements, which are noted below: • At no time may the pipe be damaged during bending. • The internal diameter of a pipe must not be effectively reduced. • Joints are not allowed to be located in pipe bends. • The radius of the inner curve of bends must not be less than 25 times the inside diameter of a pipe. • If a manufacturer specifies the use of special bending tools or procedures, the tools and procedures must be used.

TESTING Testing of a gas installation is required before the system is concealed or put into use. There are different types of inspections that may be conducted. Examples of these inspections are noted below: • Visual examination during manufacture • Visual examination after manufacture • Visual examination during fabrication • Visual examination after fabrication

! Codealert It is not allowable to insert a device inside a pipe or fitting that will reduce the cross-sectional area or obstruct the free flow of gas. The only exception to this rule is that approved gas filters are allowed.


4.73

• Visual examination during assembly • Visual examination after assembly • Pressure tests • Supplementary types of nondestructive inspection techniques, such as magneticparticle, radiographic, or ultrasonic are not required unless specifically listed in the adopted code or in an engineering design. • Repairs and additions to gas systems must be inspected. However, minor repairs and additions can be tested with a noncorrosive leak-detecting fluid instead of a pressure test. A pressure test is required on new branches that are installed to new appliances. Connections to existing piping can be tested with a noncorrosive leak-detecting fluid instead of a pressure test. Piping systems can be tested as sections or as a whole. It is not permitted to use a valve in a line as a bulkhead between gas in one section of a piping system and the test medium in an adjacent section unless two valves are installed in series with a valved “telltale” located between the valves. Only valves that are rated for test pressure are allowed to be tested with pressure. Regulators and valve assemblies fabricated independently of the piping system in which they are to be installed can be tested with inert gas or air at the time of fabrication. Oxygen cannot be used to test a gas system. Suitable testing mediums include: • Air • Nitrogen • Carbon dioxide • Inert gas There are times when appliances are not intended to be tested with a gas system. If the appliances cannot be disconnected from the system during the testing procedure, they can be isolated from the test. Blanks, blind flanges, or caps can be used for this purpose. Flanged joints at which blinds are inserted to blank off other equipment during a test are not required to undergo additional testing. An appliance that is not rated for system test pressure must be isolated prior to a system test. This requires complete disconnection from the system. In cases where the appliance has a valve that is rated for test pressure, the appliance can be isolated by closing the valve prior to testing the gas system. Test Pressure and Duration Test pressure is measured with a manometer or a pressure-measuring device that is designed and calibrated to read, record, or indicate a pressure loss caused by leakage during a test. The source of pressure shall be isolated before the pressure tests are made. Mechanical gauges used to measure test pressures must have a range whose highest end is not greater than five times the test pressure.

4.74


Test pressure must not be less than 3 psig. The pressure used must be no less than 1 1/2 times the proposed maximum working pressure. Test pressure exceeding 125 psig is not allowed. The test pressure must not exceed a value that produces a hoop stress in the piping greater than 50 percent of the specified minimum yield strength of the pipe. A pressure test is required to be maintained for a minimum of 30 minutes for each 500 cubic feet of pipe volume or fraction thereof. Testing of a system with a volume less than 10 cubic feet or a system in a single-family dwelling shall be not less than 10 minutes. At no time shall the duration of a test be required to exceed 24 hours. If a leak is suspected, it must be found. The use of an approved gas meter or a noncorrosive leak-detection fluid is normally used. Never use a source of ignition to seek leaks. In other words, don’t use a lit torch or match to find a gas leak. Once a leak is found, it must be fixed and retested.

SERVICING A SYSTEM When servicing a system that requires the gas piping to be opened, certain procedures must be followed. The first step is turning off the gas, but that is not all that is required. Gas in the piping system must be vented to the outdoors or a ventilated area that is sufficient in size to prevent accumulation of flammable mixtures. Any remaining gas must be displaced with inert gas. See Table 4.39 for details. Once servicing is complete and a system is ready to be put back into operation, the system must be purged of air and inert gases. Some situations require the purging of a system with inert gas. This is not required when air can be purged quickly with fuel gas. The air must be purged to a point of discharge in free air. At no point may the site of purging be left unattended during the purging process. Once the purging is complete, the vent must be closed securely. See Table 4.40 for piping that requires purging with inert gas.

PIPE SUPPORT Pipe support is an essential part of a piping system. Components used for pipe support must be of adequate strength and quality to support pipe properly. Acceptable forms of hangers may include the following: • Pipe hooks • Metal pipe straps • Bands

4.75


TABLE 4.39 Length of piping requiring purging with inert gas for servicing or modification, courtesy of 2006 International Fuel Gas Code. NOMINAL PIPE SIZE (inches)

LENGTH OF PIPING REQUIRING PURGING

21/2

> 50 feet

3

> 30 feet

4

> 15 feet

6

> 10 feet

8 or larger

Any length

For SI: 1 inch ⫽ 25.4 mm, 1 foot = 304.8 mm

TABLE 4.40 Length of piping requiring purging with inert gas before placing in operation, courtesy of 2006 International Fuel Gas Code. NOMINAL PIPE SIZE (inches)

LENGTH OF PIPING REQUIRING PURGING

3

> 30 feet

4

> 15 feet

6

> 10 feet

8 or larger

Any length

For SI: 1 inch ⫽ 25.4 mm, 1 foot = 304.8 mm

• Brackets • Hangers suitable for the size of the piping Pipe support must be installed in such a way as to prevent excessive vibration. The intervals between supports must comply with local requirements. Section 415 of the code deals with interval spacing, and we will talk about that later in this chapter. It must be determined that the pipe supports will not become disengaged by movement of the supported piping.

WET GAS Wet gas is a type of gas that can allow liquid to accumulate in a piping system. Piping for a wet-gas system must be installed with a grade, or pitch, on it. The pip-

4.76


Tradetip When a gas system has been shut down and turned back on, it must be checked for leaks.

ing must slope downward at a rate of not less than 1/4 inch in 15 feet to prevent the need for trap installation. Gas drips, usually called drip legs, are required at low points in a piping system. If condensation may accumulate, a drip is required. Outlets at gas meters require gas drips. The drip must be installed to constitute a trap to collect any accumulation of condensation. The condensation shall then shut off the flow of gas before the condensate can run back into the gas meter. Drips must be installed to be readily accessible and to be protected from freezing. Sediment traps must be installed downstream of equipment shutoff valves as close to the inlet of equipment as practical when a sediment trap is not incorporated as part of the gas utilization equipment. Tee fittings can be used to make a sediment trap. This usually means a tee fitting, a 8-inch nipple, and a cap. Illuminating appliances, ranges, clothes dryers, and outdoor grills do not require sediment traps.

SHUTOFF VALVES Shutoff valves are required on gas piping systems. Valves used must be of an approved type. They may not be installed in concealed locations or furnace plenums. Access must be provided for valves. All gas meters require valves. The valves must be located on the supply side of the meters. When a single meter is used to supply gas to multiple locations, each supply must be equipped with its own shutoff valve. A common piping system that supplies multiple buildings with gas must have shutoff valves installed outdoors at each building. Shutoff valves used to isolate multiple supply lines must be plainly marked with an identification tag attached by the installer so that the valve can be readily identified for which supply line it controls. When an MP regulator is used, a shutoff valve must be installed immediately ahead of the regulator. Shutoff valves are to be provided for each appliance supplied with gas. This valve must be in the same room as the appliance being served and not more than 6 feet from the appliance. The valve cannot be installed upstream from a union, connector, or quick disconnect device that it is serving.


4.77

?

Did you know

The discharging of purged gases must be done into spaces that are not confined and that do not contain sources of ignition, unless precautions are taken to perform the purging in a safe manner by ventilating the space, controlling the purging rate, and eliminating any hazardous conditions.

Valves for decorative appliances in vented fireplaces are not prohibited from being installed in an area remote from the appliance if such valves are provided with ready access. The valves must be permanently identified, and they are not allowed to serve additional equipment. Piping from the shutoff valve to within 3 feet of the appliance connection shall be sized in accordance with Section 402. Shutoff valves that are located in a firebox or a fireplace must be installed in accordance with the appliance manufacturer’s instructions.

FLOW CONTROLS Flow controls can be necessary to maintain a proper rate of gas flow. Line=pressure regulators are used to keep operating pressure lower than supply pressure. Access is required for the regulators, and they must be protected from physical damage. If regulators are installed in outdoor locations, they must be approved for the installation. There are a number of rules that apply to MP pressure regulators. They are noted below: • Must be approved and suitable for the inlet and outlet gas pressure for the application • Must maintain a reduced outlet pressure under lockup conditions • Must have a capacity that is adequate to supply the appliances served • Must be accessible • If indoors, must be vented to the outdoors or equipped with a leak-limiting device • Must be equipped with a sediment trap • Require a gas drip within 10 pipe diameters downstream of the regulator outlet Vent piping cannot be smaller than the vent connection on the pressure-regulating device. Piping that is run for relief vents and combination relief and breather vents must be run independently to the outdoors, and they must serve no more than one device vent. When vent piping is serving only breather vents, it may be connected in a manifold arrangement sized in accordance with an approved design that minimizes back pressure in the event of diaphragm rupture.

4.78


MANUFACTURED-HOME CONNECTIONS The rules for connecting appliances in manufactured home are not difficult to understand, but they are important. Under normal conditions these types of connections must be done by one of the following methods: • Rigid metallic pipe and fittings • Corrugated stainless-steel tubing in compliance with the manufacturer’s recommendations • Semirigid metallic tubing and metallic fittings not more than 6 feet long and located entirely in the same room as the appliance being served (Do not use semirigid metallic tubing in a motor-operated appliance through an unprotected knockout opening.) • Listed and labeled appliance connectors that comply with ANSI Z21.24 if located entirely in the same room as the appliance being served • Listed and labeled convenience outlets in conjunction with listed and labeled appliance connectors • Listed and labeled appliance connectors complying with ANSI Z21.69 and listed for use with food-service equipment having casters or otherwise subject to movement for cleaning, and other large, movable equipment • Listed and labeled outdoor appliance connectors in compliance with ANSI Z21.75/CSA 6.27 and installed in accordance with the manufacturer’s instructions When appliances have to be moved for cleaning, such as commercial cooking appliances, the appliances must be connected to the piping system with an appliance connector that is listed for compliance with ANSI Z21.69. Connector Length Gas connectors that are not made of rigid metallic piping are limited in length. Most appliance connectors are required to be no more than 3 feet in length. However, connectors for ranges and domestic clothes dryers can have a maximum length of 6 feet. If rigid metallic pipe is used as a connector, it can have a longer length so long as the piping is sized properly for the distance of the piping run. All measurements are to be made along the centerline of the connector.

?

Did you know

Pressure regulators that require venting must be vented to the outdoors and protected from the entrance of insects, water, and foreign objects. Regulators that do not require venting must be labeled as such.


4.79

Gas-connector Prohibitions Gas connectors must not be concealed within or extended through walls, floors, partitions, ceilings, or appliance housings. The exception to this is fireplace inserts that are factory equipped with grommets, sleeves, or other means of protection in accordance with the listing of the appliance.

MOTOR-VEHICLE FACILITIES LP-gas Fuel-dispensing Facilities The International Fire Code is used to govern the use of LP-gas motor-vehicle fuel-dispensing facilities. Components, containers, storage, and devices must be approved. Hoses, hose connections, vehicle fuel connections, dispensers, LP-gas pumps, and electrical equipment used for LP gas must be listed. Fuel-dispensing facilities are governed by the International Fire Code, but there is more to be considered. The point of transfer for dispensing operations must be 25 feet or more from buildings having combustible exterior wall surfaces; buildings having noncombustible exterior wall surfaces that are not part of a 1-hour fire-resistance-rated assembly; buildings having combustible overhangs; or property built on public streets, sidewalks, or railroads and at least 10 feet from driveways and buildings having noncombustible exterior wall surfaces that are part of a fire-resistance-rated assembly with a rating of 1 hour or more. That was a mouthful, and there is more. Here comes the exception: The point of transfer for dispensing operations is not required to be separated from canopies that provide weather protection for dispensing equipment constructed in accordance with the International Building Code. Dispensing Devices Dispensing systems are required to have a manual shutoff valve and an excess flow-control check valve. The valves are to be installed in the liquid line between the pump and the dispenser inlet where the dispensing device is installed at a remote location and is not part of a complete storage and dispensing unit mounted on a common base. An excess flow-control valve is required, or an emergency shutoff-valve must be installed in or on the dispenser at the point at which the dispenser hose is connected to the liquid piping. A differential back-pressure valve shall be considered equivalent protection. Listed shutoff valves must be located at the discharge end of the transfer hose. Hydrostatic relief valves are required for hoses and piping used to dispense LP gas. The maximum allowable length for the hose is 18 feet. The hose must be protected from mechanical damage.

4.80


! Codealert Connectors for gas appliances must have the capacity required for the total demand of the connected appliances.

Private Fueling Self-service LP-gas-dispensing systems are not to be open to the public. They are limited to the filling of permanently mounted fuel containers on LP-gas-powered vehicles. Self-service status applies to keys, codes, and card-lock dispensing systems. An emergency shutoff switch must be located within 100 feet of but not less than 20 feet from the dispenser, and the owner of the dispensing facility must ensure the safe operation of the system and the training of users. Compressed-natural-gas Fuel-dispensing Facilities Compressed natural gas (CNG) motor-vehicle fuel-dispensing facilities are governed by the International Fire Code. In general, storage vessels and equipment used for the storage, compression, or dispensing of CNG must be approved or listed in accordance with Sections 413.2.1 and 413.2.3 of the code. All containers, compressors, pressure-relief devices, pressure-relief valves, pressure regulators, and piping used for CNG must be approved. Hoses, hose connections, dispensers, gas-detection systems, and electrical equipment used for CNG must be listed. Location Exceptions There are location exceptions, but generally compression, storage, and dispensing equipment is required to be above ground and outside. The exceptions are as follows: • When buildings are made of noncombustible construction as approved by the International Building Code and are unenclosed for three-quarters or more of the perimeter, they are allowed to have compression, storage, or dispensing equipment in the building. • When installed in accordance with the International Fire Code, compression, storage, and dispensing equipment can be installed indoors or in vaults. • If an equipment manufacturer authorizes it, residential fueling appliances and equipment can be installed indoors.


4.81

Compression, storage, and dispensing equipment not located in vaults that comply with the International Fire Code, other than residential fueling appliances, shall not be installed in the following locations: • Beneath power lines • Less than 10 feet from the nearest building or property line, public street, sidewalk, or source of ignition (Remember, dispensing equipment does not need to be separated from canopies that provide weather protection for the dispensing equipment when the structure is built in accordance with the International Building Code.) • Less than 25 feet from the nearest rail of any railroad track • Less than 50 feet from the nearest rail of any railroad main track or any railroad or transit line where power for train propulsion is provided by an outside electrical source, such as a third rail or overhead catenary. • Less than 50 feet from the vertical plane below the nearest overhead wire of a trolley bus line. Residential Applications Residential fueling appliances must be connected in a way that will not cause damage to the premises. When installed outdoors, they must be located on firm, noncombustible surfaces. Interior installations require venting to the outdoors. Additionally, a gas detector must be installed in the same room or space housing the appliance. The detector must be capable of operating at one-fifth of the lower limit of flammability of natural gas. This detector must be located within 6 inches of the highest point in the room or space. In case of a system failure, the detector shall stop the operation of the appliance and activate an audible or visual alarm. Private Fueling Facilities Self-service CNG-dispensing systems, including key, code, and card-lock dispensing systems, must be limited to the filling of permanently mounted fuel containers on CNG-powered vehicles. Owners of such facilities must ensure the safe operation of the facilities. Pressure regulators have to be designed and installed to assure proper operation. This means protecting the regulators from freezing rain,

Tradetip Vehicle-impact protection for LP-gas storage containers, pumps, and dispensers must be provided in accordance with the International Fire Code.

4.82


sleet, snow, ice, mud, or debris. The protection is allowed to be integral with the regulator. Piping to equipment must be provided with a manual shutoff valve, and the valve must be accessible. Emergency Shutdown An emergency shutdown device is required to be located within 75 feet of but not less than 25 feet from dispensers and must also be provided in the compressor area. In the case of an emergency and upon activation, the shutdown device is required to shut down the system that it is monitoring. This includes shutting off the power supply to the compressor and closing valves between the main gas supply and the compressor and between storage containers and dispensers. Closed Transfer System The use of a closed transfer system must be approved by a code official. Documented procedures must be submitted to the code official for review. There must be a plan for handling a low-pressure or high-pressure natural-gas release during a discharge. Complete drawings of the piping diagram must be submitted to a code official. Cylinders used in the venting of CNG must be rigidly supported. There must be a minimum of two points of support. Horizontal and lateral movement of the vessel or cylinder is prohibited. Protection of the vessel must be provided for the highest rated pressure volume of the vessel. It should be noted that the structure or appurtenance must be constructed of noncombustible materials. This structure or appurtenance used for stabilizing cylinders must be separated from site equipment, features, and exposures as noted in your local code book. See Table 4.41 for an example. Vent Tube A vent tube that diverts gas flow to the atmosphere must be installed on cylinders prior to beginning the venting process or a purging operation. Vent-tube materials must comply with International Fire Code requirements. The minimum distance required for a vent tube to terminate above grade is 10 feet. A rain cap or other fea-

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Did you know

Fueling appliances for residential use are limited to a maximum capacity of 5 standard cubic feet of natural gas per minute and must be listed.

4.83


TABLE 4.41 Separation distance for atmospheric venting of CNG, courtesy of 2006 International Fuel Gas Code. EQUIPMENT OR FEATURE

MINIMUM SEPARATION (feet)

Buildings

25

Building openings

25

Lot lines

15

Public ways

15

Vehicles

25

CNG compressor and storage vessels

25

CNG dispensers

25

For SI: 1 foot = 304.8 mm

ture that would limit or obstruct gas flow is prohibited. A listed bidirectional detonation flame arrester must be installed at the connection fitting of a vent tube and a CNG cylinder. Air or Oxygen under Pressure Air or oxygen under pressure must not be allowed to come in contact with gas in piping. This is accomplished by the use of a back-pressure regulator and relief valve. If oxygen is used, the installation must be in accordance with NFPA 51. Interconnections A backflow preventer is required for interconnections where supplementary gas for standby use is connected downstream from a meter or a service regulator where a meter is not supplied. It is permissible to use a three-way valve to admit a standby supply and at the same time to shut off the regular supply of gas. Support Intervals As I mentioned earlier, pipe supports are required at specified intervals. Please see Table 4.42 for acceptable intervals of pipe supports.

OVERPRESSURE PROTECTION Overpressure protection is required to prevent a piping system from exceeding a pressure that would cause unsafe operation of any connected and properly ad-

4.84


Tradetip A structure or appurtenance that is used to support a cylinder must be grounded in accordance with the ICC Electrical Code. Bonding of the cylinder valve is required prior to venting operations.

TABLE 4.42 Support of piping, courtesy of 2006 International Fuel Gas Code. STEEL PIPE, NOMINAL SIZE OF PIPE (inches) 1

SPACING OF SUPPORTS (feet)

/2

6

/4 or 1

8

3 1

1 /4 or larger (horizontal)

1

5

SPACING OF SUPPORTS (feet)

/2

4

/8 or 3/4

6

7

10

/8 or 1 (horizontal)

8

Every floor level

1 or larger (vertical)

Every floor level

1

1 /4 or larger (vertical)

NOMINAL SIZE OF TUBING (SMOOTH-WALL) (inches O.D.)

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm

justed appliances. This is accomplished with the use of a line-pressure regulator and one other method. There are two options. The two devices used must be installed so that if one of the devices fails, the other device prevents overpressurization of the downstream system. The other option is to use two devices, either of which is capable of limiting pressure to the maximum working pressure of the downstream system. Maintenance requirements must be met on overpressure-protection devices. This can include periodic inspections. Pressure-relieving or pressure-limiting devices are not always required. The following list shows such circumstances: • When gas does not contain materials that could seriously interfere with the operation of a service or line-pressure regulator • When the operating pressure is 60 psi or less • When a service or pressure regulator contains acceptable features and characteristics Service or line-pressure regulators that meet the criteria for not requiring dual protection include the following:


4.85

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Did you know

An approved “No Smoking” sign must be posted within 10 feet of a cylinder support structure or appurtenance. Another required sign is one that reads: “Cylinder Shall Be Bonded.” This, too, is to be displayed on the cylinder support structure or appurtenance.

• Pipe connections to the service or line regulator do not exceed 2 inches in nominal diameter. • A regulator is self-contained with no external static or control piping. • A regulator has a single port valve with an orifice diameter not greater than that recommended by the manufacturer for the maximum gas pressure at the regulator inlet. • The valve seat is made of resilient material that is designed to withstand abrasion of the gas, impurities in the gas, and cutting by the valve and to resist permanent deformation where it is pressed against the valve port. • A regulator is capable, under normal operating conditions, of regulating the downstream pressure within the necessary limits of accuracy and of limiting the discharge pressure under no-flow conditions to not more than 150 percent of the discharge pressure maintained under flow conditions. Pressure-relieving or pressure-limiting devices must be of a certain type. Acceptable types are listed below: • A spring-loaded relief device • A pilot-loaded back-pressure regulator used as a relief valve and designed so that failure of the pilot system or external control piping will cause the regulator relief valve to open • A monitoring regulator installed in series with the service or line-pressure regulator

! Codealert The discharge of CNG from motor-vehicle fuel cylinders shall be accomplished through a closed transfer system or an approved method of atmospheric venting in accordance with Section 413.9.1 or 413.9.2.

4.86


• A series regulator installed upstream from the service or line regulator and set to continuously limit the pressure on the inlet of the service or line regulator to the maximum working pressure of the downstream piping system • An automatic shutoff device installed in series with the service or line-pressure regulator and set to shut off when the pressure on the downstream piping system reaches the maximum working pressure or some other predetermined pressure less than the maximum working pressure; the device must be designed to remain closed until manually reset • A liquid-seal relief device that can be set to open accurately and consistently at the desired pressure • The devices can be installed either as an integral part of the service or line-pressure regulator or as separate units Settings Settings for pressure-relieving or pressure-limiting devices must be set so that the pressure does not exceed a safe level beyond the maximum allowable working pressure for connected piping and appliances. Unauthorized Operation Unauthorized operation of shutoff valves must be prevented. Shutoff valves may not be cut off while rendering pressure-relieving or pressure-limiting devices inoperative. So how do you accomplish this? One way is to have the valve locked in an open position. Authorized personnel must be told to leave the shutoff valve open. If there is a reason for closing the valve, an authorized person must be present to ensure that the valve is locked in an open position when feasible. Another way around the problem is to use duplicate relief valves. Each valve must have adequate capacity to protect the system being served. Isolating valves and three-way valves must be arranged so that only one safety device can be rendered inoperative at a time.

Tradetip External control piping must be protected from falling objects, excavations, and other causes of damage and designed and installed so that damage to any control piping will not render both the regulator and the overpressure-protection device inoperative.


4.87

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Did you know

Pressure-relieving and pressure-limiting devices must be made from materials that will not be impaired by corrosion of external parts by atmosphere or internal parts by the gas being conveyed. The devices must be constructed to allow someone to operate the units to determine if the valves for the devices are free. An additional requirement is that the devices must be made in such a way that allows them to be tested to determine the pressure at which they will operate and so that they can be examined for leakage when they are in a closed position.

Vents Gas from discharge stacks, vents, and outlet parts for all pressure-relieving and pressure-limiting devices must be discharged outdoors. The terminal ends of these vents must be protected from the entry of water, insects, or other foreign material that could cause a blockage. Discharge stacks and vent lines must be a minimum of the same size as the outlet of the pressure-relieving device. Size Size matters when it comes to fittings, pipe, and openings. Devices located between the system to be protected and the pressure-relieving device must be sized to prevent hammering of the valve and impairment of relief capacity. Had enough? I have. Let’s move into the next chapter on chimneys and vents. It will be a good change of pace.


CHAPTER 5

CHIMNEYS AND VENTS

Chimneys and vents are governed by three codes. This chapter describes the provisions of the 2006 International Fuel Gas Code. The other codes that come into play are the International Mechanical Code and the International Building Code. The mechanical code pertains to factory-built units. Masonry chimneys are regulated by the building code. All appliances are required to discharge products of combustion to the outdoors, except for appliances that are exempted by Section 501.8 of the gas code. We will consider those later in the chapter. All abandoned inlet openings in chimneys and vents must be closed by an approved method. They cannot be left open. Appliances that are equipped with mechanical forced-draft systems create positive pressure in the venting system. When these appliances are used, the venting system must be designed for positive pressure. Room air is not allowed to enter a flue. This is accomplished with the installation of a noncombustible seal. Access must be provided to flues for inspection and cleaning. Appliances are not allowed to be connected to a flue serving a factory-built fireplace unless the appliance is listed specifically for this use. Any connection of this type must be in strict compliance with the manufacturer’s recommendations. When an appliance is connected to a flue that serves a masonry fireplace, the flue gases from the appliance must enter the flue directly. The connector and flue used for this type of application must be accessible or removable for inspection and cleaning. All connectors are required to be installed according to their listing. Not all appliances are required to be vented. The following list details appliances that do not require venting: • Ranges • Built-in domestic cooking units that are listed and marked for optional venting • Hot plates


5.2


• Laundry stoves • Type 1 clothes dryers • Refrigerators • Counter appliances • Room heaters that are listed for unvented use • Direct-fired make-up air heaters • Other equipment listed for unvented use and not provided with flue collars • Specialized equipment of limited input such as laboratory burners and gas lights • Single booster-type automatic instantaneous water heaters under certain conditions

SINGLE BOOSTER-TYPE AUTOMATIC INSTANTANEOUS WATER HEATERS Single booster-type automatic instantaneous water heaters that are designed and used solely for the sanitizing-rinse requirements of a dishwashing machine in a commercial kitchen with a mechanical exhaust system do not have to be vented. Draft hoods may be required for this type of installation. When they are required, the draft-hood outlet must not be less than 36 inches vertically and 6 inches horizontally from any surface other than the heater.

REQUIREMENTS OF NONVENTED APPLIANCES Appliances in the list above do have installation requirements. If the aggregate input rating exceeds 20 Btu per hour per cubic foot of volume of a room or space in which the appliances are installed, one or more must be provided with a venting system or other approved means for conveying the vent gases to the outdoor atmosphere so that the aggregate input rating of the remaining unvented appliances and equipment does not exceed the input maximum.

! Codealert Connectors connected to a masonry chimney flue must be connected not less than 12 inches above the lowest portion of the interior of flue.

CHIMNEYS AND VENTS

5.3

! Codealert Masonry chimneys utilized to vent appliances shall be located, constructed, and sized as specified in the manufacturer's installation instructions for the appliances being vented and Section 503 of the code.

If the room where the appliances are located is connected to another space with an opening of comparable size that cannot be closed, the volume of that space can be used in calculating the requirements for ventilation. When power exhausters are used, appliances connected to them must be connected on the inlet side of the exhauster. All joints on the positive pressure side of the exhauster must be sealed to prevent flue-gas leakage as required by the manufacturer’s installation instructions.

RESIDENTIAL AND LOW-HEAT APPLIANCES There are only three types of flue lining systems that are approved for use with residential-type and low-heat appliances. They are as follows: • Clay flue lining the meets or exceeds the requirements of ASTM C 315 or equivalent standard • Listed chimney lining systems that comply with UL 1777 • Approved materials that will resist without cracking, softening, or corrosion flue gases and condensate at temperatures up to 1,800 degrees F

Tradetip Appliances that fall into the classification of Category II, III, or IV systems must be installed in accordance with the appliance manufacturer’s instructions.

5.4


Category I Appliances Flue lining systems for use with Category I appliances are limited to two choices. They must comply with Section 501.12 of the code, or the chimney lining systems must be listed and labeled for use with gas appliances with draft hoods and other Category I gas appliances listed and labeled for use with Type B vents.

EXISTING CHIMNEYS AND VENTS Whether you are disconnecting an existing chimney or vent or attaching to it, the work must be in compliance with the code requirements. These requirements include such elements as: • Size • Flue passageways • Cleanout • Clearances Chimney or vent sizes must be resized as needed to control flue-gas condensation in the interior of the chimney or vent. They must also be sized to provide appliances with their required draft. Resizing requirements for Category I appliances are given in Section 502. Flue-gas passageways must be kept free of obstructions and combustible deposits. Cleaning is required of any existing chimney or vent that was used previously for venting a solid or liquid fuel-burning appliance or fireplace. Flue liners, chimney inner walls, and vent inner walls must be continuous and free of cracks, gaps, perforations, or other damage or deterioration that would allow the escape of combustion products, including gases, moisture, or creosote. Clearance requirements for chimneys and vents are controlled by the International Building Code. The manufacturer’s installation instructions must also be followed. Noncombustible firestopping or fireblocking has to be demonstrated in accordance with the International Building Code. Some masonry chimneys are not required to have clearance between combustible materials and exte-

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Did you know

Masonry chimney flues are required to be equipped with a cleanout opening that has a minimum height of 6 inches. The upper edge of the opening must be located not less than 6 inches below the lowest chimney-inlet opening. A tightfitting, noncombustible cover must be provided for the cleanout opening.

CHIMNEYS AND VENTS

5.5

rior surfaces. In order for this to be the case, the chimney must be equipped with a lining system that is tested and listed for installation in chimneys in contact with combustible materials in accordance with UL 1777 and installed in accordance with the manufacturer’s instructions.

VENTS Vents are required to be listed and labeled, except for special provisions in Section 503.7 of the code. Type B and BW vents must be tested and be in compliance with UL 441. Vents of the Type L type are required to meet the regulations for UL 641. Category II and III appliances must meet the requirements of UL 1738. Plastic vents, which are approved for Category IV appliances, are not required to be listed or labeled when the vents are specified by the appliance manufacturer and installed in accordance with the manufacturer’s recommendations. Insulation Shields Insulation shields are required for vents that pass through insulated areas. The shields are required to be not less than 26-gauge sheet metal. When installed, the shield must provide clear space between the vent and the insulation materials. The amount of clearance required is determined by the manufacturer’s requirements for the vent material. Vents that go through attics require a shield that terminates not less than 2 inches above insulation materials. Protection Protection must be provided for vents that are in concealed locations and are subject to physical damage. If a vent penetrates wood members closer than 1 1/2 inches to the edge of the wood member, shield plates must be installed to prevent the vent from being harmed. Shield plates are required to be made of steel with a minimum thickness of 1/16 inch. The plates must cover the risk area and extend a minimum of 4 inches above sole plates, below top plates, and to each side of a stud, joist, or rafter.

Tradetip When appliances are not connected directly to a chimney or a vent, a connector must be installed. The specifications of the connectors must comply with Section 503 of the code.

5.6


?

Did you know

Venting systems must satisfy the draft requirements of appliances being served and must be in compliance with the manufacturer’s requirements.

VENTING Venting for appliances is normally required. This can be accomplished in various ways. For example, exhaust systems and ventilating hoods can be used in commercial applications to vent industrial appliances, such as those in which the process itself requires fume disposal. Industrial appliances that are in large, well-ventilated spaces may be allowed to discharge directly into the space. Listed direct-vent appliances are to be installed in compliance with the manufacturer’s recommendations. Mechanical Draft Systems Mechanical draft systems are available in various configurations. Acceptable systems include the following: • Systems that are listed and installed in accordance with the manufacturer’s instructions for both the draft system and the appliance being served • With the exception of incinerators, appliances vented by means of a mechanical draft system or either forced or induced draft design • Systems designed to prevent leakage of vent or flue gases into buildings • Vent connectors that serve appliances vented by natural draft and not connected to any portion of mechanical draft systems operating under positive pressure • Exit terminals of mechanical draft systems not less than 7 feet above grade where located adjacent to public walkways

! Codealert No portion of a venting system shall extend into or pass through any circulating air duct or furnace plenum.

CHIMNEYS AND VENTS

5.7

Tradetip Plastic piping that is used for venting appliances must be listed for the intended use and be approved. Special gas vents must be listed and installed in accordance with the manufacturer’s instructions.

When automatically operated appliances are connected to ventilation hoods or exhaust hoods, the system is required to have a damper or a power means of exhaust. Provisions must be made to allow the flow of gas to the main burners only when the damper is open to a position to properly vent the appliance being served and when the power means of exhaust is in operation. Above-ceiling Systems Venting systems that pass through an above-ceiling air-handling space or other nonducted portion of an air-handling system must comply with one of three rules: • The system must be listed as a special gas vent, a system that serves Category III and IV appliances, or some positive-pressure type. All joints must be sealed in compliance with the appliance manufacturer’s instructions. • The system can be installed so that it has no fittings or joints between sections in the above-ceiling space. • The system can be installed in a conduit or enclosure with sealed joints separating the interior of the conduit or enclosure from the ceiling space.

MASONRY CHIMNEYS Masonry chimneys are generally required to be lined with approved clay flue lining, a listed chimney-lining system, or other approved material that will resist corrosion, erosion, softening, or cracking from vent gases at temperatures up to 1,800 degrees F. These chimneys are to be installed in accordance with NFPA 211. There are exceptions: • Masonry chimney flues serving listed gas appliances with draft hoods • Masonry chimney flues serving Category I appliances • Appliances that are listed for use with Type B vents • Chimneys that have a lining that is specifically listed for use with an appliance that is being served

5.8


• Liners installed in accordance with the manufacturer’s recommendations • A permanent identifying label attached at the point where the connection is to be made to the chimney liner: “This chimney liner is for appliances that burn gas only. Do not connect to solid or liquid-fuel-burning appliances or incinerators.” Chimney Termination Chimneys for residential-type, low-heat appliances must extend a minimum of 3 feet above the highest point where they pass through a roof of a building. They must be at least 2 feet higher than any portion of a building within a horizontal distance of 10 feet. See Figure 5.1 for an example of chimney terminations. Chimneys that serve medium-heat appliances must extend a minimum of 10 feet higher than any portion of any building within 25 feet. Chimneys must extend at least 5 feet above the highest connected appliance draft-hood outlet or flue collar. Chimney Sizing Limitations We will talk about sizing chimneys later in the chapter, but first you need to know about limitations that will be applied when sizing chimneys. You can use any approved engineering method to size a chimney. Section 504 of the code pertains to sizing requirements. Venting systems that use mechanical draft must be sized in accordance with approved engineering methods. There are two other considerations. When sizing a chimney for a single appliance with a draft hood, the effective areas of the vent connector and chimney flue shall be not less than the area of the appliance flue collar or draft hood outlet but not greater than seven times the drafthood-outlet area. If two appliances with draft hoods are to be connected to a chimney, the effective area of the chimney flue must not be less than the area of the larger draft-hood outlet plus 50 percent of the area of the smaller draft-hood outlet, but not greater than seven times the smallest draft-hood-outlet area.

?

Did you know

Decorative shrouds cannot be installed at the termination of factory-built chimneys unless the shrouds are listed and labeled for use with the specific chimney system.

CHIMNEYS AND VENTS

5.9

FIGURE 5.1 Chimney terminations, courtesy of the 2006 International Fuel Gas Code.

5.10


! Codealert Can an incinerator be vented by a chimney that serves other appliances? Yes, but there are conditions. The gas input to the incinerator shall not be included in calculating chimney size, provided that the chimney flue diameter is not less than 1 inch larger in equivalent diameter than the diameter of the incinerator flue outlet.

Chimney Inspections A chimney must be inspected before replacing an existing appliance or connecting a vent connector to it. The chimney must be free from obstructions. If the chimney has been used previously for venting solid or liquid fuel-burning appliances or fireplaces, it must be cleaned before appliance replacement or vent connection. The chimney lining must comply with NFPA 211. An exception is that when the appliance being replaced is approximately the same type of appliance with the same basic input rating and efficiency, the existing chimney can be used in its existing condition so long as it is safe. If a chimney is found to be unsafe, it must be repaired, rebuilt, lined, relined, or replaced to conform with NFPA 211, and it must be suitable for the appliances to be vented. It is not permissible to combine connections for appliances of different fuel types. By this I mean that you cannot connect a gas appliance to a vent or chimney that also serves a device that burns solid fuel. Liquid-fuel-burning Appliances Flues that serve liquid-fuel-burning appliances and gas appliances must be connected through separate openings or through a single opening where joined by a suitable fitting located as close as practical to the chimney. If two or more openings are provided into a single chimney, the connection points must be at different levels. When appliances are automatically controlled, they must be equipped with safety shutoff devices. Combination Appliances Can you connect a combination gas- and solid-fuel-burning appliance to a single chimney? If it is equipped with a manual reset device to shut off gas to the main burner in the event of sustained backdraft or flue gas spillage, it can be connected

CHIMNEYS AND VENTS

5.11

Tradetip Chimneys need to be supported properly. To do so, you must take into account the design and weight of the materials used. Factory-built chimneys must be supported and spaced in accordance with the manufacturer’s installation instructions.

on a single chimney. Additionally, the flue must be sized to properly vent the appliance. This ruling also applies to gas- and oil-burning appliances.

CLEANOUTS Cleanouts are required for chimneys that formerly carried flue products from liquid or solid fuel-burning appliances in order to be used with fuel-gas appliances. The cleanouts are to have tight-fitting covers and installed so that their upper edge is at least 6 inches below the lower edge of the lowest chimney inlet opening.

COMBUSTION AIR The remaining space surrounding a chimney liner, gas vent, special gas vent, or plastic piping installed within a masonry, metal, or factory-built chimney must not be used to supply combustion air. However, the space can be used to supply combustion air to direct-vent appliances that are designed for installation in a solidfuel-burning fireplace and installed in accordance with the manufacturer’s requirements.

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Did you know

The space surrounding a chimney liner, gas vent, special gas vent, or plastic piping installed within a masonry chimney flue cannot be used to vent another appliance. However, the insertion of another liner or vent within the chimney, as provided for in the code, is not prohibited.

5.12


Tradetip Gas vents are to be installed in accordance with the manufacturer’s installation instructions.

GAS VENTS Gas vents can be installed in masonry chimneys. They must be installed in accordance with the manufacturer’s recommendations. The vent must be identified with a permanent label installed at the point where the vent enters a chimney. This label is required to read: “This gas vent is for appliances that burn gas. Do not connect to solid or liquid fuel-burning appliances or incinerators.” Terminating Gas Vents There are a number of requirements for terminating gas vents. A vent that is 12 inches or less in size and located not less than 8 feet from a vertical wall or similar obstruction shall terminate above the roof in accordance with Figure 5.2. Gas vents that are over 12 inches in size or are located less than 8 feet from a vertical wall or similar obstruction shall terminate not less than 2 feet above the highest point where they pass through the roof and not less than 2 feet above any portion of a building within 10 feet horizontally. A Type B or L gas vent must terminate at least 5 feet in vertical height above the highest connected appliance draft hood or flue collar. A Type B-W gas vent must terminate at least 12 feet in vertical height above the bottom of a wall furnace. When going through a roof, vents must extend through the roof flashing, roof jack, or roof thimble and terminate with a listed cap or listed roof assembly. Gas vents are required to terminate at least 3 feet above any forced-air inlet located within 10 feet of the vent.

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Did you know

Gas vents that extend through an exterior wall are not allowed to terminate adjacent to the wall or below eaves or parapets, except as provided in Sections 503.2.3 and 503.3.3 of the code.

CHIMNEYS AND VENTS

5.13

FIGURE 5.2 Locations for terminating gas vents, courtesy of the 2006 International Fuel Gas Code.

Vents for Category I Appliances Natural draft venting systems serving one or more listed appliances equipped with a draft hood or appliances listed for use with Type B gas vents installed in a single story of a building must comply with one of three conditions. The first option is to work within the code requirements of Section 504. Another option is to obtain an approved engineering design. The third option is to size the vent as described below. When sizing an individual gas vent for a single, draft-hood-equipped appliance, the effective area of the vent connector and the gas vent shall not be less than the area of the appliance draft hood outlet or greater than seven times the draft hood outlet area. Gas vents connected to two appliances with draft hoods must be sized so that the effective area of the vent is not less than the area of the larger draft-hood outlet plus 50 percent of the area of the smaller draft-hood outlet but not greater than seven times the smaller draft-hood-outlet areas. Offsets Type B and L vents that are sized in accordance with Item 2 or 3 of Section 503.6.9.1 of the code must extend in a generally vertical direction with offsets not exceeding 45 degrees, except that a vent system with not more than one 60-degree offset is permitted. Angles of more than 45 degrees from vertical are considered horizontal. When calculating horizontal runs, the total horizontal distance of a vent plus the horizontal vent connector serving draft-hood-equipped appliances must not be greater than 75 percent of the vertical height of the vent.

5.14


Multistory Buildings Category I appliances can have a common gas vent in multistory installations if the system is of an approved engineering design. With this in mind, crawl spaces, basements, and attics are to be considered as floor levels. When appliances connected to a common vent must be located in rooms separated from occupiable space, the rooms are required to have provisions for adequate combustion, ventilation, and dilution air that is not supplied from an occupiable space. See Figure 5.3 for an illustration of .

SIZING CONNECTORS The sizing of connectors and common segments of multistory venting systems listed for use with Type B double-wall gas vents is done with a table in your code book. We will discuss that table later in the chapter; now, we are going to talk about provisions that must be met in order for the table to be effective. The available total height (H) for each segment of a multistory venting system is the vertical distance between the level of the highest draft-hood outlet or flue collar on that floor and the centerline of the next highest interconnection tee. The appliance input rating and available connector rise are used to determine sizing. The size must not be smaller than the draft-hood outlet or flue-collar size. The input rating is also used to determine the size of common vertical segments and of the interconnection tee at the base of that segment.

FIGURE 5.3 Plan view of practical separation method for multistory gas venting, courtesy of the 2006 International Fuel Gas Code.

CHIMNEYS AND VENTS

5.15

Tradetip Gas vents shall be supported and spaced in accordance with the manufacturer’s installation instructions.

LABELING A label is required where solid and liquid fuels are used extensively. The label must be applied permanently to identify gas vents. The signage can be mounted on a wall, ceiling, or at the point where a vent connector enters a gas vent. Exact placement of the label is to be determined by a code official. Each label is required to read as follows: “This gas vent is for appliances that burn gas. Do not connect to solid or liquid fuel-burning appliances or incinerators.”

SINGLE-WALL PIPE Single-wall pipe is required to be made of galvanized sheet steel that is not less than 0.0304 inches thick or other approved, noncombustible, corrosion-resistant material. Uninsulated single-wall pipe can be installed outside when the climate is warm enough. Exterior installation is not allowed in regions where the 99-percent winter design temperature is below freezing (32 degrees F). The requirements for terminating a single-wall pipe are as follows: • At least 5 feet in vertical height above the highest connected appliance drafthood outlet or flue collar • At least 2 feet above the highest point where it passes through a roof of a building • At least 2 feet higher than any portion of a building within a horizontal distance of 10 feet • Termination point equipped with an approved cap or roof assembly Roof Penetration When single-wall pipe penetrates a roof, it must extend without interruption through the roof flashing, roof jack, or roof thimble. If the roof is made of combustible material, a noncombustible, nonventilating thimble must be provided at the point of passage through the roof. This thimble must extend at least 18 inches above and 6 inches below the roof with the annular space open at the bottom and closed on the top.

5.16


! Codealert Vent caps and roof assemblies must have a venting capacity that is not less than that of the pipe to which they are attached.

Installation Rules There are some installation rules to be followed when working with single-wall pipe: • The pipe must not originate in an unoccupied attic or concealed space. • The pipe is not allowed to pass through an attic. • The pipe is not allowed to pass through an inside wall. • The pipe is not allowed to pass through a concealed space. • The pipe is not allowed to pass through a floor. • Penetrations of exterior combustible walls must comply with Section 503.10.15 of the code. • Single-wall pipe used to vent an incinerator must be exposed and readily examinable for its full length and shall have suitable clearances maintained. • Clearances for single-wall pipe can be determined by Table 5.1. Single-wall Pipe Size Venting systems made from single-wall metal pipe can be sized in one of three manners. As usual, an approved engineering design is acceptable. When this is not available, you can use Section 504 of the code for appliances equipped with draft hoods. Then there is the easy way. When you are working with a single appliance that has a draft hood, the vent can be sized so that the areas of the connector and the pipe are each not less than the area of the appliance flue cover or draft-hood outlet, whichever is smaller. The vent area must not be greater than seven times the draft-hood-outlet area.

Tradetip Single-wall metal pipe must be supported for the design and weight of the material used and must have all portions supported.

5.17

CHIMNEYS AND VENTS

TABLE 5.1 Clearances for connectors, courtesy of 2006 International Fuel Gas

Code. MINIMUM DISTANCE FROM COMBUSTIBLE MATERIAL

APPLIANCE Listed appliances with draft hoods and appliances listed for use with Type B gas vents Residential boilers and furnaces with listed gas conversion burner and with drafthood Residential appliances listed for use with Type L vents

Listed Type B Listed Factory-built gas vent Type L vent Single-wall chimney material material sections metal pipe As listed

As listed

6 inches

As listed

6 inches

6 inches

9 inches

As listed

As listed

9 inches

As listed

As listed

As listed

As listed

6 inches

9 inches

As listed

9 inches Not permitted

18 inches

As listed

36 inches

As listed

Listed gas-fired toilets Unlisted residential appliance with draft hood Residential and low-heat appliances other than above

Not permitted Not permitted Not permitted Not permitted

Medium-heat appliances

Not permitted

VENTING TERMINATION LOCATIONS Venting termination locations must comply with a number of code requirements. For example, a mechanical draft venting system must terminate at least 3 feet above any forced-air inlet located within 10 feet. There are, as you might expect, two exceptions: The rule does not apply to the combustion air intake or to a directvent appliance. It also doesn’t apply to the separation of the integral outdoor air inlet and flue-gas discharge of listed outdoor appliances. With the exception of direct-vent appliances, a mechanical draft venting system must terminate at least 4 feet below, 4 feet horizontally from, or 1 foot above any door, operable window, or gravity air inlet into any building. The bottom of the vent terminal must be located at least 12 inches above grade. Vent terminals of direct-vent appliances with an input of 10,000 Btu per hour or less shall be located at least 6 inches from any air opening into a building; appliances with inputs over 10,000 Btu per hour but not over 50,000 Btu per hour must be installed with a 9-inch vent termination clearance; and appliances with an input over 50,000 Btu/h must have at least a 12-inch vent-termination clearance. The bottom of the vent terminal and the air intake must be located at least 12 inches above grade.

5.18


Category II and IV Appliances Category II and IV appliances that use through-the-wall vents and noncategorized condensing appliances cannot terminate over public walkways or over areas where condensate or vapor could create a nuisance or hazard or be detrimental to the operation of regulators, relief valves, or other equipment. In some cases, based on local experience, appliances in Category I and III can be forced to meet these same criteria.

UNCONDITIONED AREAS Vent connectors used for appliances with draft hoods or Category I appliances located in unconditioned areas, such as crawl spaces and attics, have to meet certain criteria. The portion of the connector in the unconditioned area must be Type B, Type L, or listed vent material having equivalent insulation properties. There is an exception: Single-wall metal pipe within exterior walls of a building located where the local 99-percent winter design temperature is 5 degrees F or higher can be used in unconditioned spaces other than attics and crawl spaces.

RESIDENTIAL-TYPE APPLIANCE CONNECTORS Residential-type appliance connectors for appliances not installed in attics or other unconditioned spaces must be designed for listed appliances that have draft hoods. Appliances with draft hoods and equipped with listed conversion burners, as well as Category I appliances, must have connectors that meet the following requirements: • Type B or L vent material • Galvanized sheet steel that is not less than 0.018 inch thick • Aluminum (1100 or 3003 alloy or equivalent) sheet that is not less than 0.027 inch thick

! Codealert The drainage of condensate systems must be designed to collect and dispose of condensate from venting systems serving Category II and IV appliances and noncategorized condensing appliances in accordance with Section 503.8, Item 4, of the code.

5.19

CHIMNEYS AND VENTS

• Stainless-steel sheet not less than 0.012 inch thick • Smooth interior-wall metal pipe having resistance to heat and corrosion equal to or greater than that of the specifications above • A listed vent connector • Vent connectors not allowed to be covered with insulation • Listed insulated vent connectors installed according to the terms of their listing

LOW-HEAT EQUIPMENT Low-heat equipment requires a factory-built chimney section or steel pipe having resistance to heat and corrosion equivalent to that of the appropriate galvanized pipe. See Table 5.2 for options. All joints on the chimneys must be made in accordance with the manufacturer’s instructions.

MEDIUM-HEAT EQUIPMENT Medium-heat appliances and incinerators require vents that are rated for the purpose. This means that a factory-built, medium-heat chimney is needed. The thickness of the chimney can be determined by using Table 5.3. Steel vent connectors for appliances with a vent-gas temperature in excess of 1000 degrees F measured at the entrance to the connector must be lined with medium-duty fire brick or an equivalent. The lining is required to be at least 2.5 inches thick for a vent connector having a diameter or greatest cross-sectional dimensions of 18 inches or less. It must be at least 4 1/2 inches thick laid on a 4 1/2inch bed for a vent connector having a diameter or greatest cross-sectional dimen-

TABLE 5.2 Minimum thickness for galvanized-steel vent connectors for low-heat appliances, courtesy of 2006 International Fuel Gas Code. DIAMETER OF CONNECTOR (inches)

MINIMUM THICKNESS (inch)

Less than 6

0.019

6 to less than 10

0.023

10 to 12 inclusive

0.029

14 to 16 inclusive

0.034

Over 16

0.056

For SI: 1 inch = 25.4 mm.

5.20


TABLE 5.3 Minimum thickness for steel vent connectors for medium-heat appliances and commercial and industrial incinerators vent-connector size, courtesy of 2006 International Fuel Gas Code. DIAMETER (inches)

AREA (square inches)


Up to 14

Up to 154

0.053

Over 14 to 16

154 to 201

0.067

Over 16 to 18

201 to 254

0.093

Over 18

Larger than 254

0.123

For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm2.

sion greater than 18 inches. Factory-built chimney sections, when used, must be joined together in accordance with the chimney manufacturer’s instructions.

MULTIPLE DRAFT HOODS Sometimes appliances are equipped with multiple draft hoods or flue collars. When this is the case, the manifold for the hoods must be constructed in accordance with the manufacturer’s instructions. In the event there are no instructions available, an approved engineering design is required. Is there a practical in-thefield solution to sizing? Yes: You can build a manifold that has an effective area equal to the combined area of the flue collars or draft-hood outlets, and the vent connector must have a minimum of 1 foot in rise. Wasn’t that easy?

Tradetip When two or more appliances are vented through a common vent connector or vent manifold, they must be located at the highest level consistent with available headroom and the required clearance to combustible materials and must be sized in accordance with Section 504 of the code or some other approved engineering method. As an alternative, when there are two drafthood-equipped appliances, the effective area of the common vent connector or vent manifold and all junction fittings must be not less than the area of the larger vent connector plus 50 percent of the area of the smaller flue-collar outlet.

CHIMNEYS AND VENTS

5.21

! Codealert Vent connectors have to be installed to avoid turns or other construction features that create excessive resistance to flow of vent gases.

MULTIPLE APPLIANCES When multiple appliances are connected to a single vent, the smaller connector must enter at the highest level consistent with the available headroom or clearance to combustible material. It is not permissible for vent connectors serving Category I appliances to be connected to any portion of a mechanical draft system operating under positive static pressure.

JOINTS Joints between sections of connector piping and connections to flue collars and draft-hood outlets must be fastened by an approved method. The methods include sheet-metal screws and listed materials that are installed in accordance with the manufacturer’s requirements.

CONNECTOR LENGTH The maximum horizontal length of a single-wall connector must be 75 percent of the height of the chimney or vent except for engineered systems. It is desirable to keep vent connectors as short as is practically possible. The maximum horizontal

?

Did you know

Did you know that vent connectors cannot be installed with dips or sags? The connectors are required to have a grade upward, toward the vent or chimney, of a minimum of 1/4 inch per foot. The only exception to this is a connector attached to a mechanical draft system installed in accordance with the manufacturer’s instructions.

5.22


! Codealert Vent connectors are required to be supported for the design and weight of the material used, to maintain clearances, and to prevent physical damage and separation of joints. The entire length of a vent connector must be provided with ready access for inspection, cleaning, and replacement.

length of a Type B double-wall connector must be 100 percent of the height of the chimney or vent except for engineered systems. In cases where multiple appliances are being vented by a single vent, the maximum length of an individual connector from the appliance outlet to the junction with the common vent or another connector must be 100 percent of the height of the chimney or vent.

CHIMNEY CONNECTIONS Vent connectors are not allowed to make chimney connections at the extreme bottom of the chimney in order to avoid stoppages. When an installation is made to facilitate removal of a connector, the connector must be attached firmly. Connectors must not extend into chimneys to a point where they will restrict the space between the connector’s end and the opposite end of the chimney flue.

WALL PENETRATION Single-wall connectors passing through combustible walls must meet code criteria. This normally involves the installation of a thimble in the wall. If a thimble is not used, all combustible material must be removed from around the pipe that passes through the wall. The clearance must meet code requirements, and materi-

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Did you know

Vent connectors must not be connected to a chimney flue serving a fireplace unless the fireplace flue opening is permanently sealed.

CHIMNEYS AND VENTS

5.23

! Codealert Vent connectors for medium-heat appliances are not allowed to pass through walls or partitions that are made of combustible material.

als used to fill the space around the pipe must be noncombustible. Since a thimble is often the most practical answer, it is most common to install approved thimbles in the walls where single-wall pipes will pass through combustible walls. Note that the thimble must be ventilated. Other rules to follow are listed below: • Listed appliances with draft hoods and Type B gas vents require thimbles to be at least 4 inches larger in diameter than the vent connector. However, when the vent connector has a run of more than 6 feet visible between the draft hood outlet and the thimble, it is permissible for the thimble to be at least 2 inches larger in diameter than the vent connector. • Unlisted appliances with draft hoods require a thimble that is not less than 6 inches larger in diameter than the vent connector. • Thimbles for residential and low-heat appliances are required to be at least 12 inches larger in diameter than the vent connector.

VENTED APPLIANCES Vented appliances are required to be installed with draft hoods. Exceptions to this rule do exist. Vented appliances that do not require draft hoods are listed below: • Dual oven-type combination ranges • Incinerators • Direct-vent appliances • Fan-assisted combustion-system appliances • Appliances requiring chimney draft for operation • Single firebox boilers equipped with conversion burners with inputs greater than 400,000 Btu per hour • Appliances equipped with blast, power, or pressure burners that are not listed for use with draft hoods • Appliances designed for forced venting

5.24


DRAFT HOODS Draft hoods must be installed without alteration, exactly as furnished and specified by the appliance manufacturer. If a required draft hood is not supplied by an appliance manufacturer , the hood installed must be listed or approved. If no instructions are available, the hood must be the same size as the flue collar for the appliance. Draft hoods for conversion burners must be listed or approved. All draft-control devices supplied by appliance manufacturers are to be installed in accordance with the manufacturer’s recommendations. If instructions are not provided, the device is to be attached to the flue collar of the appliance or as near to the appliance as is practical. Draft hoods and barometric draft regulators have to be installed in the same room or enclosure as the appliance in such a manner as to prevent any difference in pressure between the hood or regulator and the combustion-air supply. Draft hoods and draft regulators must be installed in the position for which they are designed with reference to the horizontal and vertical planes. They must be located so that the relief opening is not obstructed by any part of the appliance or adjacent construction. Relief openings must be accessible for checking vent operation. Draft hoods must be located so that the relief openings are at least 6 inches from any surface except that of the appliances served and the venting system to which the hoods are connected. Check the label on the appliance for any specific instructions for clearance and comply with it. Never reduce required clearances. Devices that obstruct or retard the flow of vent gases must not be installed in a vent connector, chimney, or vent. The following list outlines conditions that are not considered to be obstructions: • Draft regulators and safety controls that are listed and installed in accordance with the manufacturer’s instructions • Draft regulators and safety controls that are installed in accordance with an approved engineering design • Listed reclaimers and automatically operated vent dampers that are installed according to the requirements of the manufacturer

Tradetip Manually operated dampers are not allowed to be installed in vent connectors for appliances. Fixed baffles are not considered manually operated dampers.

CHIMNEYS AND VENTS

5.25

• Approved economizers, heat reclaimers, and recuperators installed in venting systems of appliances not required to be equipped with draft hoods, provided that the appliance manufacturer’s instructions cover the installation of such a device in the venting system and performance is in compliance with the code • Vent dampers serving listed appliances installed in accordance with the code or approved engineering methods

TABLE DEFINITIONS You will need to know certain definitions used in tables within the code. The tables are required to obtain essential data when working with gas systems. To prepare you for working with gas tables, a listing of commonly used words, terms, and abbreviations is provided below. Appliance categorized vent diameter/area: The minimum vent area/diameter permissible for Category I appliances to maintain a nonpositive vent static pressure when tested in accordance with nationally recognized standards Fan-assisted combustion system: An appliance equipped with an integral mechanical means to either draw or force products of combustion through the combustion chamber or heat exchanger Fan minimum: The minimum input rating of a Category I fan-assisted appliance attached to a vent or connector Fan maximum: The maximum input rating of a Category I fan-assisted appliance attached to a vent or connector. Nat maximum: The maximum input rating of a Category I draft-hoodequipped appliance attached to a vent or connector Fan + fan: The maximum combined appliance input rating of two or more Category I fan-assisted appliances attached to the common vent Fan + nat: The maximum combined appliance input rating of one or more Category I fan-assisted appliances and one or more Category I draft-hoodequipped appliances attached to the common vent Na: Vent configuration is not allowed due to potential for condensate formation or pressurization of the venting system or is not applicable due to physical or geometric restraints Nat + nat: The maximum combined appliance input rating of two or more Category I draft-hood-equipped appliances attached to the common vent We are getting closer to the tables that will be used for much of your planning for gas systems. At first glance, the tables can be intimidating. They are not to be feared. Once you understand the tables, they will make your work with gas systems easier.

5.26


VENTING TABLES Venting tables are not allowed to be used when obstructions are present. Vents serving listed appliances with vent dampers must be installed in accordance with the manufacturer’s instructions or in compliance with code requirements. The code requirements that I am referring to illustrate that the maximum capacity of a vent system is to be determined using the Nat Max column in the venting table. Minimum capacity is determined as if the appliance were a fan-assisted appliance, using the Fan Min column to determine the minimum capacity of a vent system. Where the corresponding Fan Min is Na, the vent configuration is not permitted and an alternative venting configuration must be utilized. Minimum Size There may be times when the size you arrive at using a table is smaller than the appliance hood outlet or flue collar. If this happens, can you use the smaller size? It would be logical to think that the vent must be at least as large as the appliance hood outlet or flue collar, but this is not always the case. When certain conditions are met, the vent can be smaller than the hood outlet or flue color. When is this allowed? See the list below: • The total vent height (H) is at least 10 feet • Vents for appliance draft-hood outlets or flue collars 12 inches in diameter or smaller not reduced more than one table size • Vents for appliance draft-hood outlets or flue collars larger than 12 inches in diameter not reduced more than two table sizes • The maximum capacity listed in the tables for a fan-assisted appliance reduced by 10 percent • The draft-hood outlet is greater than 4 inches in diameter (It is not acceptable to connect a 3-inch-diameter vent to a 4-inch draft hood outlet. This provision does not apply to fan-assisted appliances.) Vent Offsets Single-appliance venting configurations with zero lateral lengths are not allowed to have elbows in the venting system. Single-appliance venting configurations

Tradetip Connections between chimney liners and listed double-wall connectors are to be made with adapters that are listed for the job at hand.

CHIMNEYS AND VENTS

5.27

with lateral lengths include two 90-degree elbows. For each additional elbow up to and including 45 degrees, the maximum capacity listed in the venting tables must be reduced by 5 percent. Additional elbows that are greater than 45 degrees up to and including 90 degrees present the maximum capacity listed in the venting tables and need to be reduced by 10 percent. High Altitudes Systems designed for high altitudes should be sized using sea-level input ratings for maximum capacity. However, actual input that is based on derated input for the altitude is to be used when determining the minimum capacity. Multiple Inputs When you are sizing a system with multiple inputs, you should use an input rate based on the lowest appliance input rating to establish minimum capacity. Maximum capacity is determined based on the highest appliance-rating input. Liner Sizing Corrugated metallic chimney-liner systems that are listed can be sized with the tables in your code book. To do this, use the tables for Type B vents and reduce the maximum capacity by 20 percent. This reduction allows for one 90-degree bend at the bottom of the chimney. If the chimney has additional bends or offsets, extra reduction is needed. This reduction was discussed above in the section on vent offsets.

VENT AREA AND DIAMETER Vertical vents that have larger diameters than the vent connectors must be sized using the connector diameter for maximum vent capacity. Flow area for a vent cannot exceed seven times the flow area of the listed appliance’s categorized vent area, flue-collar area, or draft-hood outlet. One exception is a system with an approved engineering design.

CHIMNEY AND VENT LOCATIONS Tables cannot be used for chimneys and vents that are exposed to the outdoors below the roof line. Is a Type B vent or listed chimney-lining system passing through an unused masonry chimney flue considered to be exposed to the outdoors? No, it is not. Neither is one that passes through an unventilated enclosure or chase insulated to a value of at least R8.

5.28


Clay-tile-lined exterior masonry chimneys that are sized with the tables must meet certain criteria, which are outlined below: • The vent connector is a Type B double-wall device. • The vent-connector length is limited to 18 inches for each inch of vent-connector diameter. • The appliance is equipped with a draft hood. • The input rating is less than the maximum capacity listed in the table. • For a space-heating appliance with an input rating greater than the minimum capacity given in the table • If the above cannot be met, an alternative venting design must be used. • One exception is that of vents installed for listed appliances when the installation is done according to the manufacturer’s instructions.

COMPONENT COMMINGLING A single run of vents or vent connectors with different diameters and types of vent and connector components is permitted. All of the sizes and types used must be permitted by the tables in your code book.

CONVERSION ACCESSORIES Draft-hood conversion accessories for use with masonry chimneys venting listed Category I fan-assisted appliances must be listed and installed in accordance with the manufacturer’s instructions.

VENT OBSTRUCTIONS Venting tables cannot be used when vent obstructions exist. Vents serving listed appliances with vent dampers must be installed in accordance with the manufacturer’s instructions or certain other code requirements. Alternate options include using vent tables and keeping the maximum capacity of the vent connector must be determined using the Nat Max column. The maximum capacity of the vertical vent or chimney is to be determined using the Fan + Nat column when the second appliance is a fan-assisted appliance or the Nat + Nat column when the second appliance is equipped with a draft hood. When calculating minimum capacity, the appliance is to be treated as if it is a fan-assisted appliance. Use the Fan Min column to determine the minimum capac-

CHIMNEYS AND VENTS

5.29

ity of the vent connector. The Fan + Fan column is used when the second appliance is a fan-assisted appliance, and the Fan + Nat column is used when the second appliance is equipped with a draft hood in order to determine whether the vertical vent or chimney configuration is not permitted (Na). If the vent is not permitted, an alternative method of venting will be required.

CONNECTOR LENGTH The vent-connector length is to be kept as short as possible. A maximum length can be determined by allowing 18 inches of connector length for each inch of diameter of the connector. If a longer length is essential, there are ways to accommodate the need. See Table 5.4 for examples of maximum vent-connector length.

MANIFOLDS When sizing vent manifolds, you must apply a 10-percent reduction to the common vent capacity element of the common vent tables. The length of the common vent-connector manifold must not exceed 18 inches for each inch of common vent-connector-manifold diameter.

FITTINGS Tee and wye fittings connecting to a common vent must be sized so that the fitting is equal to the size of the vent. It is acceptable for fittings to be reduced in size where they connect to appliance vent connectors.

VENT HEIGHT When there are multiple appliances all located on one floor, the available total height is to be measured from the highest draft-hood outlet or flue collar up to the level of the outlet of the common vent.

?

Did you know

The cross-sectional area of a common vent must be equal to or greater than the cross-sectional area of the largest connector.

5.30


TABLE 5.4 Maximum vent connector length, courtesy of 2006 International Fuel Gas Code. DIAMETER OF CONNECTOR (inches)


3

4 1/2

4

6

5

71/2

6

9

7

101/2

8

12

9

131/2

10

15

12

18

14

21

16

24

18

27

20

30

22

33

24

36

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.

Multistory installations require that the available total height be figured for each segment of the system based on the vertical distance between the highest draft-hood outlet or flue collar entering that segment and the centerline of the next higher interconnection tee. Multistory sizing for the lowest portion of a system is to be calculated with sizing tables.

MULTISTORY OFFSETS Multistory offsets in common vents are limited to a single offset in each system. A system that has an offset must comply with code requirements. The offset must not exceed 45 degrees. Vents must not be reduced in size above the offset. Horizontal length of a vent must not exceed 18 inches per inch of the common vent diameter. The section of venting that contains the offset must be sized with a reduction factor of 20 percent.

CHIMNEYS AND VENTS

5.31

VERTICAL VENT MAXIMUM SIZE There are times when two or more appliances are connected to a common vent or chimney. The vent or chimney must not be more than seven times the smallest listed appliance categorized vent area, flue-collar area, or draft-hood-outlet area unless there is an approved engineering design.

LINER SIZING AND CONNECTIONS Liner sizing is done with code tables. Connections between chimney liners and listed double-wall fittings must be made with listed adapter fittings designed for the purpose. If double-wall connectors are required, tee and wye fittings used for the connection to the common vent chimney liner must be made with double-wall fittings. See the list below for tips on sizing requirements: • Type B vents have to be calculated with a reduction factor of 20 percent when determining maximum capacity. • When using the 20-percent reduction factor, the use of one 90-degree elbow is allowed.

CONNECTOR MAXIMUM AND MINIMUM SIZES Vent connectors must not be increased at a rate of more than two sizes greater than the listed-appliance categorized vent diameter, flue-collar diameter, or drafthood-outlet diameter. When used with draft hoods, vent connectors must not be reduced to a size smaller than the diameter of the draft-hood outlet. Fan-assisted appliances are allowed, under certain conditions, to have a vent that is smaller than the flue-collar diameter. What are the conditions? The vent connector must have a smooth interior surface. The appliance must be equipped with a draft hood. There is also a condition that limits size reductions. Vent connectors for fan-assisted appliances that have flue collars with diameters of 12 inches or less cannot be reduced more than one table size. Flue collars that are larger than 12 inches can be reduced by up to two table sizes.

?

Did you know

Vertical common vents used in multistory systems must be Type B double wall and installed with a listed vent cap.

5.32


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Did you know

When appliances have more than one input rate, the minimum vent-connector capacity has to be determined from code tables. The sizing must be less than the lowest appliance input rating. Maximum vent-connector capacity is determined from code tables and must be greater than the highest appliance input rating.

COMMERCIAL COOKING APPLIANCES A fan-powered exhaust system is required when commercial cooking appliances are vented by means of Type I or II kitchen exhaust hoods. The exhaust system has to be interlocked with the appliances to prevent appliance operation when the exhaust-hood system is not operating. If a solenoid valve is installed in the gas piping as part of an interlock system, the gas piping must not be installed to bypass the valve. It is not allowable for dampers to be installed in the exhaust system. What is the exception? The interlock is not required if heat sensors or other approved methods automatically activate the exhaust-hood system when cooking operations occur.

FACTORY-BUILT CHIMNEYS Factory-built chimneys for heating appliances that produce flue gases having a temperature not greater than 1,000 degrees F, measured at the entrance to the chimney, must be listed and labeled in accordance with UL 103. The chimneys must be installed and terminated in accordance with the manufacturer’s instructions. Structural members that support factory-built chimneys have to be designed to support the additional weight of the chimney. This applies to joists, rafters, and similar building components. When factory-built chimneys are used for medium-heat appliances that produce flue gases having a temperature above 1,000 degrees F, measured at the entrance to the chimney, they must be listed and labeled in compliance with UL 959. Installation and termination must be done in accordance with the manufacturer’s recommendations.

CHAPTER 6

SPECIFIC APPLIANCES

What are specific appliances? The technical answer is that they are those that that the code identifies as specific appliances. They can include appliance types from log lighters to incinerators. Furnaces and clothes dryers can also be included as specific appliances. So what does this category mean to you? It means that there are special provisions for specific appliances. Much of what you will learn about specific appliances is that they have to be installed in accordance with manufacturer’s requirements. There are references to code sections and approval agencies. Much of the material does not require great explanation. However, there are some sections that have meat on the bones, and those are the ones that we are going to work with here.

DECORATIVE APPLIANCES Decorative appliances that are designed to be installed in approved solid-fuelburning fireplaces must be tested in accordance with ANSI21.60. Natural-gas decorative appliances that are lighted manually must be tested in accordance with ANSI Z21.84. As you will find with most appliances in this category, they must be installed in accordance with the manufacturer’s instructions. With the exception of the appliances tested in accordance with ANSI Z21.84, decorative appliances approved for installation in approved solid-fuel-burning fireplaces must utilize a direct ignition device—an ignitor or a pilot flame to ignite the fuel at the main burner—and must be equipped with a flame-safeguard device. This device must automatically shut off the fuel supply to a main burner or group of burners when the means of ignition of such burners becomes inoperative. Decorative appliances for installation in fireplaces cannot be installed where prohibited by Section 303.3 of the code.


6.2


! Codealert Log lighters must be tested in accordance with CSA 8 and installed in accordance with the manufacturer’s instructions.

FIREPLACES Vented Gas Fireplaces Vented gas fireplaces are to be tested in accordance with ANSI Z21.50. These appliances fall under code provisions found in Section 602.2 of the code. And, of course, they must be installed in accordance with the manufacturer’s installation instructions. Access must be provided to these appliances. When panels, grilles, or access doors are required to be removed for normal servicing, they must not be attached to the building. Vented Wall Furnaces Vented wall furnaces are required to be tested in accordance with ANSI Z21.86/CSA 2.32. They must be installed in compliance with the instructions of the manufacturer. Venting for these units must comply with Section 503 of the code. It is not permissible to install a vented wall furnace in a place where the unit will become a fire hazard. If the furnace is installed between a bathroom and an adjoining room, the unit must not circulate air from the bathroom to other parts of a building. Clearance between an air inlet or outlet on a furnace and a door must be a minimum of 12 inches. Doorstops and door closers may not be installed to obtain the required clearance. Wall furnaces are not to be fitted with ducts. If a casing extension boot is used, it must be listed as a part of the appliance.

Tradetip Incinerators and crematories must be installed in compliance with the manufacturer’s instructions.

SPECIFIC APPLIANCES

6.3

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Did you know

Incinerators for commercial-industrial uses must be built in accordance with NFPA 82.

Access must be provided for cleaning heating surfaces and removing burners. It is also required that access be present for the replacement, repair, or servicing of sections, motors, controls, filters, and other working parts.

FURNACES Floor Furnaces Floor furnaces are required to be tested with ANSI Z.86/CSA 2.32. As usual, the units have to be installed in accordance with the manufacturer’s instructions. There are placement requirements that must also be followed for floor furnaces. A furnace installed in a floor is prohibited from certain locations, which are noted below: • Doorways • Stairway landings • Aisles • Passageways of any enclosure • Exits from any room or space Walls When the register of a floor furnace with a horizontal warm-air outlet is installed, it must not be closer than 6 inches to the nearest wall. Occupants of a building must not be required to walk over the warm-air registers of floor furnaces. To accomplish this, the code requires registers to be at least 18 inches from two adjoining sides of the floor-furnace register to the walls. Remaining sides are permitted to be placed not closer than 6 inches to a wall. When wall-register models are used, the registers must not be placed closer than 6 inches to a corner. Thermostats Controlling thermostats for floor furnaces must be located within the same room or space as the furnace that they serve. As an option, the thermostat can be located in a room or space that is adjacent to the one where the floor furnace is located so long as the thermostat space is permanently open to the furnace location.

6.4


! Codealert Floor furnaces are not allowed to be installed in concrete floor construction that is built on grade.

Clearance Clearance is an important factor in the installation of floor furnaces. The lowest portion of a floor furnace must not have less than 6 inches of clearance from grade level except where the lower 6-inch portion of the floor furnace is sealed by the manufacturer to prevent entrance of water, in which case the minimum clearance shall not be less than 2 inches. There may be times when this clearance cannot be obtained. In such cases, the ground below and the sides of the furnace must be excavated to form a pit under the furnace. This will allow the required clearance to be obtained. There must be 12 inches of clearance around the sides of a furnace, except that there is a minimum requirement of 18 inches of clearance on the side of the furnace where the control center is located. Duct Furnaces Duct furnaces must be installed on the positive pressure side of circulating air blowers. Removable access panels on both the upstream and downstream sides of furnaces are required. Controls, combustion-air inlets, and draft hoods must be located outside of ducts. When a draft hood is used, it must be located in the same enclosure from which combustion air is taken. All duct furnaces must be tested in accordance with ANSI Z83.8 or UL 795. As usual, they must be installed in accordance with the manufacturer’s requirements.

AIR HEATERS Nonrecirculating Direct-fired Industrial Air Heaters Nonrecirculating direct-fired industrial air heaters must be listed to ANSI Z83.4/CSA 3.7. As you might imagine, they must be installed in accordance with the manufacturer’s instructions. These units cannot be used to supply any area containing sleeping quarters. They can only be installed in industrial or commercial occupancies. The units are, however, permitted to supply ventilation air. For clearance, consult the rating plate and the manufacturer’s instructions.

SPECIFIC APPLIANCES

6.5

! Codealert Floor furnaces that are installed in basements that are used as habitable space must be enclosed in compliance with Section 609.6 of the code and must project into a nonhabitable space.

Atmospheric Vents Valve train components that are equipped with atmospheric vents, gas reliefs, or bleeds must have their discharge lead to the outdoors. The devices must be protected from blockage of insects and foreign matter. In the event that a listed vent limiter is installed on a valve train component, an atmospheric vent is not required. Relief Openings Nonrecirculating direct-fired industrial air heaters are required to operate at rated capacity without overpressurizing the space served by the heater. They accomplish this by taking into account the structure’s designed infiltration proving, properly designed relief openings, an interlocked power exhaust system, or a combination of these methods. Louvers and counterbalanced gravity dampers are allowed to be treated as relief openings. Motorized dampers and closable louvers are permitted when they are verified to be in their full open position prior to mainburner operation. Recirculating Direct-fired Industrial Air Heaters Recirculating direct-fired industrial air heaters must be listed to ANSI Z83.18, and, they must be installed in accordance with the manufacturer’s instructions.

Tradetip Floor furnaces installed in upper stories of buildings must project into nonhabitable space and must be separated from such space by an enclosure that is made of noncombustible material. The furnace must be given access and clearance on all sides and the bottom of not less than 6 inches. Combustion air must be in accordance with Section 304 of the code.

6.6


! Codealert When duct furnaces are installed so that supply ducts convey air to areas outside the space containing the furnace, the return air shall also be conveyed by a duct sealed to the furnace casing and terminating outside the space containing the furnace.

These units can only be installed in industrial and commercial occupancies. They are not allowed to serve any area containing sleeping quarters or in hazardous locations that contain flammable solids, liquids, or gases; explosive materials; or substances that can become toxic when exposed to heat or flame. Air Supply The air supply for direct-fired industrial air heaters must be taken from the building, ducted directly from the outdoors, or a combination of both. These systems must incorporate a means to supply outside ventilation air to the space at a rate of not less than 4 cubic feet per minute per 1,000 Btu per hour of rated input of the heater. When separate air induction is used, it must provide an interlock to lock out the main-burner operation until the mechanical means is verified. Any outside air dampers or closing louvers must be verified to be in the open position prior to main-burner operation.

CLOTHES DRYERS Exhaust Systems Clothes-dryer exhaust systems must not be comingled with other types of exhaust systems. These units must be exhausted in accordance with the manufacturer’s recommendations. All moisture and products of combustion must be conveyed to the outside of the building that houses the appliance.

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Did you know

All air handled by a nonrecirculating direct-fired industrial air heater, including combustion air, shall be ducted directly from the outdoors.

SPECIFIC APPLIANCES

6.7

Tradetip Nonrecirculating direct-fired industrial air heaters must be provided with access for the removal of burners, the replacement of motors, the replacement of controls, the replacement of filters, and the replacement of other working parts. Access is also required for lubrication of parts that require maintenance.

Duct Penetrations Duct penetrations through fireblocking, draft stopping, walls, floors, ceilings, or other assemblies required to be fire-resistant-rated are determined by the nature of the duct. Galvanized steel and aluminum ducts are allowed for such penetrations when their thickness meets the minimum requirements of the local code-enforcement office. Exhaust Installation Exhaust installations for clothes dryers must terminate on the outside of the building housing the appliance. Backdraft dampers are not allowed in these exhaust systems. Screens must not be installed where ducts terminate. You cannot use screws to install or connect the piping system if they will interfere with the air flow. It is against the code to connect these systems to a vent connector, a vent, or a chimney. Exhaust ducts are not allowed to extend into or through ducts or plenums. Makeup Air When working with systems that exhaust more than 200 cubic feet per minute (CFM), makeup air must be provided. Closets used to house clothes dryers must have an opening that contains 100 square inches for makeup air, or makeup air must be provided from some other approved source.

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Did you know

Direct-fired industrial air heaters are allowed to provide fresh air ventilation.

6.8


Tradetip Don’t install direct-fired industrial air heaters with a clearance that is less than what is listed on the label of the product and the manufacturer’s recommendations.

Domestic Ducts Exhaust ducts for domestic clothes dryers are to be made of metal with a smooth interior finish. The minimal nominal size of these ducts is 4 inches in diameter. All of the ductwork is to be supported and secured in place. Male ends of ducts at overlapped joints must extend in the direction of the air flow. Transition ducts for clothes dryers used to connect the appliance to the exhaust duct system must be metal, are limited to a single length not to exceed 8 feet, and must be listed and labeled for the application. Transition ducts must never be concealed in construction. Exhaust ducts for clothes dryers cannot exceed 25 feet from the dryer location to the outlet terminal. The maximum length of the duct must be reduced 30 inches for each 45-degree bend and 5 feet for each 90-degree bend. The maximum length of the exhaust duct does not include the transition duct. As you might expect, there is an exception: When the clothes dryer make and model number are known and the manufacturer’s installation instructions can be provided to a code official, the exhaust duct, including any transition duct, may be installed in accordance with the manufacturer’s requirements. Commercial Clothes Dryers Commercial clothes dryers with exhaust ducts serving Type 2 dryers must be installed in compliance with the manufacturer’s recommendations. When exhaust-

! Codealert Clothes dryers must be tested in accordance with ANSI Z21.5.1 or ANSI Z21.5.2. They must be installed in accordance with the manufacturer’s recommendations.

SPECIFIC APPLIANCES

6.9

Tradetip All vertical duct risers for dryers listed to ANSI Z21.5.2 must be provided with a cleanout or other means for cleaning the interior of the duct.

fan motors are installed, they must be installed outside of the airstream. If multiple installations are involved, the fan shall either operate continuously or be interlocked to operate when any individual unit is operating. A minimum clearance of 6 inches is required between ducts and combustible materials.

SAUNA HEATERS Sauna heaters must be installed in accordance with the manufacturer’s instructions. They must be installed in locations that will minimize any possibility of accidental contact by a person in the room. Guards can be used to prevent contact with the heaters. They must have a low coefficient of thermal conductivity. Guards are not allowed to substantially affect the transfer of heat from the heater to the room. Air Intakes Not all sauna heaters are of a direct-vent type, and those that are not have to be fitted for air intake. This can be a draft hood and combustion-air intake located outside of a sauna room. Sometimes these devices are placed in dressing rooms that are adjacent to a sauna. When this is the case, provisions must be made not to physically block the combustion-air and draft-hood inlets and to prevent physical contact with the draft hood and vent assembly. Warning notices may be required. If so, they must be posted in conspicuous places to prevent blockage of the air systems. Letters used on the warning notices are required to be a minimum of 1/4 inch high and must contrast with the background of the warning notice.

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Did you know

Fire dampers cannot be installed in clothes-dryer exhaust duct systems.

6.10


Controls Heat and time controls are required for saunas. For example, sauna heaters require a thermostat that will limit room temperature to 194 degrees F. When such a thermostat is not an integral part of a sauna heater, the heat-sensing element must be located within 6 inches of the ceiling. Heat-sensing elements of the capillary tube and bulb type must be attached to a wall or other support and must be protected from physical damage. Ventilation Ventilation of sauna rooms must be provided for. The opening must not be less than 4 inches by 8 inches. This opening is required to be located near the top of the door into the sauna room. With the exception of saunas in one- and two-family dwellings, a warning notice must be posted. The posting must be permanent and of an approved material. It is to be mechanically attached to the outside of the sauna room and to read as follows: “WARNING: DO NOT EXCEED 30 MINUTES IN SAUNA. EXCESSIVE EXPOSURE CAN BE HARMFUL TO HEALTH. ANY PERSON WITH POOR HEALTH SHOULD CONSULT A PHYSICIAN BEFORE USING SAUNA.” The letters must be not less than 1/4 inch high and must contrast with the background of the warning notice. Forced-air Warm-air Furnaces Forced-air warm-air furnaces must be tested in accordance with ANSI Z21.47 or UL 795 and installed in accordance with the manufacturer’s instructions. The minimum unobstructed total area of the outside and return-air ducts or openings to a forced-air warm-air furnace shall not be less than 2 square inches for each 1,000 Btu/h output rating capacity of the furnace and not less than that specified in the furnace manufacturer’s installation instructions. Minimum unobstructed total area of supply ducts from a forced-air warm-air furnace shall not be less than 2 square inches for each 1,000 Btu/h output rating capacity of the furnace and not less than that specified in the furnace manufacturer’s installation instructions. The exception to this rule is that the total area of the supply-air, outside, and return-air ducts shall not be required to be larger than the minimum size required by the furnace manufacturer’s installation instructions. Prohibited Sources There are many locations that are prohibited sources for outside or return air for forced-air heating systems: • Locations that are 10 feet from an appliance vent outlet • Locations that are 10 feet from the vent opening from a plumbing drainage system

SPECIFIC APPLIANCES

6.11

! Codealert The panels, grilles, and access doors required to be removed for normal servicing operations must not be attached to the building in which the heater is installed.

• Locations that are 10 feet from the discharge outlet of an exhaust fan, unless the outlet is 3 feet above the outside air inlet • Locations where there is a presence of objectionable odors, fumes, or flammable vapors • Locations that are less than 10 feet above the surface of any abutting public way or driveway • Locations at grade level by a sidewalk, street, alley, or driveway • Locations that are considered to be hazardous or unsanitary • Locations designated as refrigeration machinery rooms • Locations whose volume is less than 25 percent of the entire volume served by such systems, except where the amount of return air taken from a room or space is less than or equal to the amount of supply air delivered to such rooms or spaces • Locations where an appliance serves as the sole source of return air, with exceptions as noted below Exceptions to locations where appliances serve as the sole source of return air are numerous. Let’s work our way through this. If the appliance is a direct-vent appliance or an appliance not requiring a vent in accordance with Section 501.8, it is excepted. If the room or space complies with one of the following requirements, it is excluded: • The return air must be taken from a room or space having a volume exceeding 1 cubic foot for each 10 Btu/h of combined input rating of all fuel-burning appliances therein.

Tradetip Combustion air must not be taken from inside a sauna room. A heater that is not of a direct-vent type must be provided with combustion-air inlets and draft.

6.12


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Did you know

Equipment that is powered by internal-combustion engines and turbines and fixed permanently must be installed in accordance with the manufacturer’s installation instructions and NFPA 37.

• The volume of supply air discharged back into the same space shall be approximately equal to the volume of return air taken from the space. • Return-air inlets must not be located within 10 feet of any appliance firebox or draft hood in the same room or space. • Rooms or spaces containing solid-fuel-burning appliances provided that returnair inlets are located not less than 10 feet from the firebox of such appliances. • Closets, bathrooms, toilet rooms, kitchens, garages, mechanic rooms, boiler rooms, and furnace rooms are excluded.

UNIT HEATERS Unit heaters must be tested in accordance with ANSI Z83.8. They are also required to be installed in accordance with the manufacturer’s instructions. Support provided for the heaters must be adequate to support the weight and dynamic loads associated with the equipment. All hangers and brackets are to be made of noncombustible material. Ducts must not be connected to a unit heater unless the heater is listed for such installation. Suspended-type unit heaters require a minimum of 18 inches of clearance from combustible materials when measured at the sides. A clearance of 12 inches at the bottom and 6 inches above the top if the unit heater has an internal draft hood or 1 inch above the top of the sloping side if the heater has a vertical draft hood are required. The clearance requirements for floor-mounted-type unit heaters are a little different. Combustible materials must be kept at least 6 inches from the sides and

Tradetip Pool and spa heaters have to be tested in accordance with ANSI Z21.56 and must be installed in accordance with the manufacturer’s instructions.

SPECIFIC APPLIANCES

6.13

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Did you know

Volume dampers must not be placed in the air inlet to a furnace in a manner that will reduce the required amount of air to reach the furnace.

back of these heaters. If the unit is vented vertically, the measurement for clearance is to be made from the draft hood or vent instead of the rear wall of the heater. These heaters are not allowed to be installed on combustible flooring. Servicing of equipment requires a minimum clearance that is in compliance with the manufacturer’s installation instructions. A unit that is listed may be allowed to have reduced clearance if the manufacturer allows it in the installation instructions. Unvented Heaters Unvented heaters have to be tested in accordance with ANSI Z21.11.2. They must be installed in accordance with the manufacturer’s recommendations. If the heaters are not using fuel gas, they fall under the regulations of the International Mechanical Code. Such heaters are not allowed to be used as the sole source of comfort heating in a dwelling unit. Places where they cannot be installed include Groups A, E, and I. The aggregate input rating of all unvented appliances installed in a room or space cannot exceed 20 Btu/h per cubic foot of volume of such room or space. When the appliance is installed in a room or a space that is adjacent to another area that has a permanent opening between the two spaces, the volume of the adjacent room can be used for sizing purposes. When unvented heaters are used, they must be equipped with an oxygen-depletion-sensitive safety shutoff. If oxygen depletion is detected, the system must shut down the heater. The depletion level is based on the manufacturer’s recom-

! Codealert Circulating air for fuel-burning, forced-air-type, warm-air furnaces shall be conducted into the blower housing from outside the furnace enclosure by continuous airtight ducts.

6.14


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Did you know

Unvented room heaters are not allowed to have an input rating in excess of 40,000 Btu/h.

mendations, but it cannot fall lower than 18 percent. The safety shutoff cannot be adjustable in the field.

COOKING APPLIANCES Most cooking appliances intended for permanent installation have to be tested in accordance with ANSI Z21.1, ANSI Z21.58, or ANSI Z83.11 and installed in compliance with the manufacturer’s requirements. The types of cooking appliances that fall into this category are: • Ranges • Ovens • Stoves • Broilers • Grills • Fryers • Griddles • Hot plates • Barbecues Domestic ranges cannot be installed on combustible flooring unless they are positioned on their own bases or legs. All domestic appliances are required to be

! Codealert Outdoor-air inlets that are required for residential portions of a building must be covered with a screen having 1/4-inch openings. Inlets serving nonresidential portions of a building must be covered with screens having openings larger than 1/4 inch and not more than 1 inch.

SPECIFIC APPLIANCES

6.15

listed and labeled for domestic use. Unless listed for an exception, all domestic open-top boilers are to be equipped with a ventilating hood. A minimum clearance of 24 inches is required between the cooking top and the combustible material above the ventilating hood. The hood must be at least as wide as the open-top broiler unit and centered over the unit.

WATER HEATERS Water heaters are required to be tested in accordance with ANSI Z21.10.1 and ANSI Z21.10.3. As usual, they must be installed in accordance with the manufacturer’s guidelines. If the water heater is not fueled by gas, the installation is regulated by the International Mechanical Code. If a water heater is used in a combination mode as both a potable hot-water source and a space heater, the appliance must be listed and labeled for the dual use. This type of unit falls under the regulations of the International Plumbing Code.

REFRIGERATORS Refrigerators have to be tested in accordance with ANSI Z21.19 and must be installed in accordance with the manufacturer’s instructions. Clearance is required at the top and back of refrigerators. Use the manufacturer’s recommendations for clearance when they are available. If you are on your own, leave at least 2 inches of clearance behind and at least 12 inches above the appliance.

AIR CONDITIONING Air-conditioning units that are gas-fired have to be tested in compliance with ANSI Z21.40.1 or ANSI Z21.40.2 and installed according to the manufacturer’s instructions. Gas engines are not allowed to be connected rigidly to gas-supply

! Codealert Ventless firebox enclosures used with unvented decorative room heaters must be listed in compliance with ANSI Z21.91.

6.16


Tradetip Unvented decorative room heaters are not allowed to be placed in factorybuilt fireplaces unless the fireplace system is specifically tested, listed, and labeled for such use under the code.

piping. This requirement is meant to protect against the effects of normal vibration. The clearances required for cooling equipment are outlined in Sections 308.3 of the code. When this type of equipment is installed in alcoves and closets, the clearances must comply with Table 308.2 of the code. All air-conditioning equipment is required to be installed in compliance with the manufacturer’s recommendations. Unless the equipment is listed otherwise, it is to be installed on a noncombustible surface. All ducts, both return and supply, must be placed to ensure proper circulation of air. Where air-conditioning equipment is installed within a space separate from the spaces served by the equipment, the air circulated by the equipment shall be conveyed by ducts that are sealed to the casing of the equipment and that separate the circulating air from the combustion and ventilation air. Refrigeration Coils Under normal conditions, a refrigeration coil is not to be installed in conjunction with a forced-air furnace when circulation of cooled air is provided by the furnace blower. Furnaces must not be located upstream from cooling units unless the cooling unit is designed or equipped so as not to develop excessive temperature or pressure.

! Codealert Vented room heaters are to be tested in accordance with ANSI Z21.86/CSA 1.32 and must be designed and equipped as specified in Section 602.2 of the code. All installations must be done in compliance with the manufacturer’s instructions.

SPECIFIC APPLIANCES

6.17

The coils must be installed in parallel with or on the downstream side of central furnaces to avoid condensation in the heating element. An exception to this is a furnace that is listed for installation downstream. Means of control flow must be sufficient to prevent any circulation of cooled air through a furnace. Boilers Can you imagine boilers and air conditioning working together? It can happen. When refrigeration systems are combined with boilers, they must be installed to allow the chilled medium to be piped parallel with the heating boiler. Valves have to be installed to prevent commingling of the two systems. Flow-control valves or other automatic means are required to prevent gravity circulation of the boiler water during the cooling cycle.

ILLUMINATING APPLIANCES Illuminating appliances have to be tested in accordance with ANSI Z21.42 and installed in accordance with the manufacturer’s instructions. When these devices are designed for walls or ceilings, they must be securely attached to substantial structures so that they are not subject to dependence on gas piping for support. Devices that are meant for mounting on posts have to be securely and rigidly attached, and the post itself must be rigidly attached. Posts that are greater than 3 feet in height shall be at least equivalent to that of a 2 1/2-foot-diameter post constructed of 0.064-inch-thick steel or a 1-inch Schedule 40 steel pipe. Posts 3 feet or less in height shall not be smaller than a 3/4inch Schedule 40 pipe. When water may collect at the bottom of posts, a drain opening is required.

! Codealert Commercial cooking appliances, except those exempted by Section 501.8 of the code, must be vented by connecting the appliance to a vent or chimney. The connection must meet the requirements of the code and the manufacturer’s instructions. As an alternative, the appliance can be vented in accordance with Section 505.1.1 of the code.

6.18


! Codealert Gas-fired toilets—and, yes, they do exist—have to be tested in accordance with ANSI Z21.61. Installation is to be done in compliance with the recommendations of the manufacturer. Clearance is required for ready access for use, cleanout, and any needed servicing.

INFRARED RADIANT HEATERS All infrared radiant heaters are to be tested in accordance with ANSI Z83.6 and installed within the guidelines of the manufacturer. These units are to be in a fixed position independent of gas and electric supply lines. All hangers and brackets for this equipment must be made of noncombustible products.

BOILER STANDARDS Boiler standards are established by ANSI Z21.13 or UL 795. Other codes and requirements can come into play. For example, some boilers are required to meet the standards of ASME CSD-1 or the ASME Boiler and Pressure Vessel Code. NFPA 85 can also be a standard. Check boiler installations carefully. The International Mechanical Code usually controls the installation of boilers. Operating instructions must be attached to a boiler by a permanent means. Controls are to be set, adjusted, and tested by installers. It is the job of an installer to provide a control diagram and boiler operating instructions. In all cases, boilers require the manufacturer’s rating data and a nameplate to be attached to the unit.

Tradetip Means must be provided for disposal of condensate and to prevent its dripping onto heating elements.

SPECIFIC APPLIANCES

6.19

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Did you know

Did you know that gas pipe that serves a heating system can also serve cooling equipment? However, the two systems are not allowed to be operated simultaneously.

CHIMNEY DAMPERS If an unlisted decorative appliance for a vented fireplace is installed, the fireplace damper must have a permanent free opening equal to or greater than those identified in Table 6.1. We are about to move into the next chapter ont gaseous hydrogen systems. Take a break and when you are ready, let’s move on. We are almost done.

Tradetip Pressure regulators are not always provided for appliances. When this is the case, you must provide one. Multiple installations require one regulator of adequate capacity to serve the appliances.

6.20


TABLE 6.1 Free opening area of chimney damper for venting flue gases From unlisted decorative appliances for installation in vented fireplaces, courtesy of 2006 International Fuel Gas Code. MINIMUM PERMANENT FREE OPENING (square inches)a CHIMNEY HEIGHT (feet)

8

6

7,800

14,000

23,200

34,000

8

8,400

15,200

25,200

10

9,000

16,800

15

9,800

20 30

13

20

29

39

51

64

46,400

62,400

80,000

37,000

50,400

68,000

86,000

27,600

40,400

55,800

74,400

96,400

18,200

30,200

44,600

62,400

84,000

108,800

10,600

20,200

32,600

50,400

68,400

94,000

122,200

11,200

21,600

36,600

55,200

76,800

105,800

138,600

Appliance input rating (Btu per hour)

For SI: 1 inch ⫽ 25.4 mm, 1 foot = 304.8, 1 square inch = 645.16m2, 1 British thermal unit per hour = 0.2931 W. a. The first six minimum permanent free openings (8 to 51 square inches) correspond approximately to the crosssectional areas of chimneys having diameters of 3 through 8 inches, respectively. The 64-square-inch opening corresponds to the cross-sectional area of standard 8-inch by 8-inch chimney tile.

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Did you know

Stationary fuel-cell power systems that have a power output of more than 10MW must be tested in accordance with ANSI CSA America FC1. They are required to be installed in accordance with the manufacturer's recommendations and NFPA 853.

CHAPTER 7

GASEOUS HYDROGEN SYSTEMS

When working with gaseous-hydrogen systems, you must pay attention to the International Fire Code. Chapters 30 and 35 of that code apply to these systems. Compressed gases are covered in Chapter 27 of the 2006 International Fire Code. When permits are required, they are regulated by Section 106 and as required by the International Fire Code. What is a gaseous-hydrogen system? It is an assembly of piping, devices, and apparatus designed to generate, store, contain, distribute, or transport a nontoxic, gaseous-hydrogen mixture that contains at least 95 percent hydrogen gas by volume and not more than 1 percent oxygen by volume. These systems can include the following: • Compressed-gas containers • Reactors • Appurtenances • Pressure regulators • Interconnecting piping • Tubing • Controls

GENERATING AND REFUELING OPERATIONS Ventilation is required for hydrogen-generating and -refueling operations. Places where these operations may occur include the following: • Public garages • Private garages


7.2


Tradetip A room or space that is intended exclusively to house a gaseous-hydrogen system is known as a hydrogen cutoff room.

• Repair garages • Automotive-motor-fuel-dispensing facilities • Parking garages that contain hydrogen-generating appliances • Refueling systems Rooms and spaces that are not part of the living space of a dwelling unit and that communicate directly with a private garage through openings must be considered to be part of the private garage.

VENTILATION TYPES Natural Ventilation Natural ventilation is regulated by the code. An indoor location that is intended for hydrogen-generating or -refueling operations is limited to a maximum floor area of 850 square feet, and it must communicate with the outdoors in order to be in compliance with the code. A hydrogen-generating appliance is limited to a maximum output capacity of 4 standard cubic feet per minute of hydrogen for each 250 square feet of floor area in such spaces. A minimum cross-sectional dimension for air openings is 3 inches. Ducts that are used must have the same cross-sectional area as the free area of the opening to which they connect. Appliances with sources of ignition are required to be located within 12 inches of a ceiling.

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Did you know

A self-contained or factory-matched package of integrated systems for generating gaseous hydrogen is a hydrogen-generating appliance. It utilizes electrolysis, reformation, chemical, or other processes to generate hydrogen.


7.3

! Codealert The necessary supply of air for ventilation and dilution of flammable gases must be provided by an approved engineered system if the design is not done within code guidelines.

Garage Openings A garage is required to have two permanent openings. The higher opening is required to be located entirely within 12 inches of the ceiling of the garage. A lower opening must be located entirely within 12 inches of the floor of the same garage. The code requires both openings to be in the same exterior wall. They must communicate directly with the outdoors and have a minimum free area of 1/2 square foot per 1,000 cubic feet of garage volume. Louvers and Grilles The size of louvers and grilles must be calculated. The size is based on the net free area of each opening. When the free area is known, it is required to be used in calculating the size of opening required to provide the free area specified. When the free area is not known, wood louvers must have 25 percent free area, and metal louvers and grilles must have 75 percent free area. They must be installed in a fixed-open position. Mechanical Ventilation Mechanical ventilation is to be installed in accordance with the International Mechanical Code. When it is used, equipment and appliances with an ignition source have to be placed in such a way that the source of ignition is below the mechanical-ventilation outlet.

Tradetip Compressed-gas containers, cylinders, and tanks must comply with Chapters 30 and 35 of the International Fire Code.

7.4


?

Did you know

Flammable-gas cylinders in occupancies regulated by the International Residential Code are not allowed to exceed 250 cubic feet at normal temperature and pressure (NTP).

DESIGN Compressed-gas containers, cylinders, and tanks are to be designed, constructed, and tested in accordance with Chapter 27 of the 2006 International Fire Code, the ASME Boiler and Pressure Vessel Code (Section VIII) or DOTn49 CFR, Parts 100-180.

PRESSURE RELIEF DEVICES

Valves Valves, including shutoffs, check valves, and other mechanical restrictions must not be installed between the pressure-relief device and the container being protected. A locked-open shutoff valve is required on containers equipped with multiple pressure-relief-device installations; the arrangement of the valves must provide the full required flow through the minimum number of required relief devices at all times. Installation Valves and other mechanical restrictions are not allowed to be located between pressure-relief devices and the point of release to the atmosphere.

Tradetip Pressure-relief devices must meet code requirements and be sized and selected in accordance with CGA S-1.1, CGA S-1.2, and CGA S-1.3.


7.5

! Codealert Containers must be provided with pressure-relief devices in accordance with the ASME Boiler and Pressure Vessel Code (Section VIII), DOTn 49 CFR, Parts 100-190, and Section 703.3.7 of the code.

?

Did you know

Vessels other than containers shall be protected with pressure-relief devices in accordance with the ASME Boiler and Pressure Vessel Code (Section VIII) or DOTn 49 CFR, parts 100-180.

Sizing Sizing of pressure-relief devices is required to be done in accordance with the specifications used to build the container. Its purpose is to prevent the maximum design pressure of the container from being exceeded. In other words, if the pressure rises to an unsafe level, the relief device relieves the pressure to maintain safety. Protection Pressure-relief devices and all associated bent piping must be designed, installed, and located so that their operation will not be affected by water or other debris accumulating inside or obstructing the vent.

! Codealert Compressed-gas containers, cylinders, tanks, and systems have to be protected from accidental movement in accordance with Chapter 30 of the 2006 International Fire Code. All electrical wiring is to be done to the standards of the ICC Electrical Code.

7.6


Tradetip Pressure-relief devices have to be located so that there is ready access for inspection and repair.

CONFIGURATION Pressure-relief devices must be situated to discharge in an unobstructed manner to the outdoors. The International Fire Code regulates the installation. Discharge locations must be arranged to avoid the following: • Impingement of escaping gas on personnel • Containers • Equipment • Adjacent structures The introduction of escaping gas into enclosed spaces is not allowed. Discharges are not allowed to terminate under eaves or canopies. The requirements do not apply to DOT-specified containers with an internal volume of 2 cubic feet or less.

PIPING Piping, tubing, fittings, and valves that convey gaseous hydrogen must be installed in accordance with code requirements, Chapter 27 of the 2006 International Fire Code, and ASME B31.3. Cast-iron pipe, valves, and fittings are not allowed for this use. Sizing must be done in accordance with approved engineering methods. Compressed-gas-system controls have to be designed to prevent materials from entering or leaving process or reaction systems at other than the intended

?

Did you know

Relief-device vents must terminate in an approved location that is in compliance with Section 2209 of the International Fire Code.


7.7

! Codealert Piping must not be installed in or through a circulating air duct. It also must not be installed in or through a clothes chute, chimney, or gas vent. Dumbwaiters and elevator shafts must not have piping installed in or through them. Walls, floors, and ceilings must not conceal piping.

time, rate, or path. Automatic controls must be designed to be failsafe in accordance with accepted engineering practices. Identification Hydrogen systems must be marked in compliance with ANSI A13.1. The identification must include the direction of flow and are required at the following locations: • At every valve location • At wall penetrations • At floor penetrations • At ceiling penetrations • At changes of direction • At intervals that do not exceed 20 feet Piping and tubing materials are to be 300 series stainless steel or materials listed or approved for hydrogen service and the use intended through the full range of operating conditions to which they will be subjected. The design must allow for expansion, contraction, vibration, settlement, and fire exposure. Except for through penetrations, piping located inside of buildings must be installed in exposed locations and provided with ready access for visual inspection.

! Codealert Pipe that passes through concrete or masonry walls has to be protected against differential settlement.

7.8


?

Did you know

Brazing alloys are required to have a melting point that is greater than 1,000 degrees F.

When in an underground location, pipe, including joints and fittings, must be protected from corrosion and installed in accordance with approved engineering methods. Underground piping is not allowed to penetrate the outer foundation or basement wall of a building. Protection Protection is not required for stainless-steel piping, stainless-steel tubing, or black steel. Other types of piping or tubing must be protected when it is installed less than 1 1/2 inches from the edge of wood members, through holes or notches in wood studs, joists, rafters, and similar wood members. When protection is required, it must be provided in the form of shield plates that have a minimum thickness of 1/16 inch. These plates must be made of steel and cover the area of the pipe where the member is compromised. A shield plate is to extend a minimum of 4 inches above sole plates, below top plates, and to each side of a stud, joist, or rafter. Outdoor Piping Outdoor piping that is installed above ground has to be supported securely and protected from physical damage. Any piping that passes through an exterior wall requires a protective sleeve. All annular space between the piping and the sleeve must be sealed from inside so that the sleeve is ventilated to the outdoors. Piping must be protected from corrosion when it is underground. Exterior-wall penetrations of pipe require protection from corrosion by either a coating or wrapping made of an inert material.

! Codealert Mechanical joints are required to maintain electrical continuity through the joint, or a bonding jumper must be installed around the joint.


7.9

Tradetip Brazing alloys must have a melting point greater than 1,000 degrees F.

?

Did you know

Mechanical joints are required to maintain electrical continuity through the joint, or a bonding jumper must be installed around the joint.

Joints ASME B31.3 is the standard that joints must adhere to. These joints include fittings of the following types: • Welded • Brazed • Flared • Socket • Slip • Compression Gaskets and sealants used in hydrogen service must be listed in compliance with ASME B31.3. Threaded and flanged connections are not allowed for use in areas other than hydrogen-cutoff rooms and outdoors.

! Codealert The handling of compressed-gas containers, cylinders, and tanks must comply with Chapter 27 of the 2006 International Fire Code.

7.10


Tradetip Hydrogen compressed gas, used inside or outdoors, must comply with the material-specific provisions of Chapters 30 and 35 of the 2006 International Fire Code.

Components Piping components, valves, and regulators are required to be listed or approved for hydrogen service. These devices must be accessible. All such devices have to be designed and made to withstand the maximum pressure that they may encounter.

SHUTOFFS Connections to storage containers and tanks require accessible shutoff valves. The only exception is the connection of a relief valve.

CONTAINERS Compressed-gas containers, cylinders, and tanks, with the exception of those with a water volume of less than 1.3 gallons and those designed for use in a horizontal position, must be installed in an upright position. To be considered in a vertical position, the container, cylinder, or tank axis can be inclined as much as 45 degrees from the vertical.

! Codealert Deionized water must be utilized to perform hydrostatic pressure testing and must be acquired from a potable source. When a pneumatic test is done, the test medium must be air, nitrogen, carbon dioxide, or an inert gas. Oxygen is not allowed for use in pneumatic testing.


7.11

INSPECTIONS Inspections and approval are required prior to putting a system into operation. A pressure test is required. Visual inspection of the entire piping system while it is under a pressure test is the normal requirement. A verified code official is needed for the inspection of a system. However, if a code official approves the inspection methods outlined in ASME B31.1, an engineered system can be used. Pneumatic test pressure must not be less than one-and-one-half times the maximum working pressure for systems less than 125 psig and not less than 5 psig, whichever is greater. A pneumatic test pressure must not be less than 110 percent of the maximum working pressure. Testing Time A test is required to be maintained for a minimum of 30 minutes for a pipe volume or fraction thereof of 500 cubic feet. For piping systems having a volume of more than 24,000 cubic feet, the maximum test duration is 24 hours. Test gauges must be in compliance with code requirements. For example, tests that require a pressure of 10 psig or less need a gauge that has increments of 0.10 psi or less. Hydrostatic test pressure must not be less than one-and-one-half times the maximum working pressure. The pressure must not be less than 100 psig. When this is the case, the gauge must have increments of 1 psi or less. Tests that require a pressure of more than 100 psig need a gauge that has increments of 2 psi or less. Measuring devices that have an equivalent level of accuracy and resolution are permitted where specified by a design engineer and approved by a code official. Pressure Test Hydrostatic or pneumatic leak tests are required. The test procedures are outlined in ASME B31.3; other methods are permitted, provided that the testing is done in accordance with the minimum provisions called for in Sections 705.3.1 and 705.4.1 of the code.

?

Did you know

If test pressure is to exceed 125 psig, the pressure must not exceed a value that produces hoop stress in piping greater than 50 percent of the specified minimum yield strength of the pipe.

7.12


! Codealert Pipe joints, which include welded joints, must be left exposed for inspection during a test for leaks.

Disconnection Disconnection of appliances may be required prior to a test. If the appliances are not rated to withstand maximum test pressures, they must be isolated during a test. This can mean disconnecting the appliance and capping the supply pipe. If the appliances are designed to handle the test pressure, they can be left connected and have their shutoff valves closed. Leaks Leaks are not acceptable during test conditions. When they are identified from a reduction in the pressure gauge, they must be found and corrected. Once they are fixed, a new test is required. Purging of gaseous-hydrogen piping systems must comply with Section 705.5.1 through 705.5.4.

SERVICE There are times when systems require service. When this is the case, the system must be isolated from the gas supply at the nearest convenient point. Line pressure must be vented outdoors. Remaining gas is required to be displaced with inert gas.

OPERATION Putting a hydrogen system into operation requires the cleaning of the system. This is done by running inert gas through the system. The inert gas must be used until air is removed. At this point hydrogen can be allowed into the system. All inert gas must be expelled. The point of discharge must be monitored during the cleansing process; then the vent opening is to be closed. Purging operations are not allowed to discharge into confined spaces. Neither can they discharge into areas where a source of ignition exists. However, with


7.13

Tradetip Gaseous-hydrogen systems and detection devices are governed by the International Fire Code and the manufacturer’s instructions.

proper ventilation the discharge into an ignition area may be allowed. But all risk of hazardous conditions must be removed. Vent Outlets Vent pipe outlets for purging are required to be placed so that inert and fuel gas are released outdoors not less than 8 feet above the adjacent ground level. The gas must be discharged upward or horizontally away from adjacent walls to assist in dispersion. Vents cannot be placed in such a way that leaves or other obstructions will trap gas. The vents must be at least 5 feet from any building opening or lot line of a property.

SUITABLE LOCATIONS Suitable locations for indoor gaseous-hydrogen systems are noted below: • Inside a building in a hydrogen-cutoff room designed and constructed in accordance with Section 420 of the International Building Code • Inside a building not in a hydrogen cutoff room where the system is listed and labeled for indoor installation and installed in accordance with the manufacturer’s instructions • Inside a building in a dedicated hydrogen-fuel-dispensing area having an aggregate hydrogen delivery capacity not greater than 12 SCFM and designed and constructed in accordance with Section 703.1

Tradetip Expansion joints have to be provided with temporary restraints if required for the additional thrust load under test.

7.14


?

Did you know

Gaseous-hydrogen systems are required to be located outdoors in accordance with Section 2209.3.2 of the International Fire Code.

There you have it. Now you know the gas code. We have reached the end of our journey. I hope my work helps you in your career. The code is not that difficult to follow once you understand it, and I hope that I have made this process easier for you.

INDEX

Appliance, automatically controlled, 2.2 Appliance, category I, 5.4, 5.18 Appliance, combination, 5.10 Appliance connectors, residential-type, 5.18 Appliance, cooking, 6.14 Appliance, decorative, 6.1 Appliance, equipment, 2.2 Appliance, fan-assisted combustion, 2.2 Appliance, gas fireplaces, 6.2 Appliance, illuminating, 6.17 Appliance, liquid-fuel-burning, 5.10 Appliance, low-heat, 2.2, 5.3 Appliance, multiple, 5.21 Appliance, under-floor, 3.16 Appliance, unvented, 2.2 Appliance, vented, 5.23 Appliance, vented wall furnace, 6.2 Applications, residential, 4.81, 5.3 Approved agency, 2.2 Atmospheric pressure, 2.2 Automatic ignition, 2.2 Alternative options, 1.10 Appliances, outside, 4.69 Applications, 1.8 Approval, 1.9, 1.16 Approved construction documents, 1.11 Areas, unconditioned, 5.18 Attic installations, 3.15

A Above-ceiling systems, 5.7 Above-ground outdoor piping, 4.68 Access, 2.1, 3.15 Action, corrosive, 4.64 Additions, 1.5 Air, combustion, 3.8, 5.11 Air conditioner, gas-fired, 2.1, 6.15 Air conditioning, 2.1 Air-conditioning equipment, 3.20 Air, dilution, 3.8 Air, exhaust, 2.1 Air-handling unit, 2.1 Air heaters, 6.4, 6.5 Air heaters, air supply, 6.6 Air heaters, atmospheric vents, 6.5 Air heaters, industrial, non-recirculating direct fired, 6.4 Air heaters, industrial recirculating direct fired, 6.5 Air, indoor, 3.8 Air, makeup, 2.2, 3.8 Air, combination, 3.10 Air, outdoor combustion, 3.9 Air supply, mechanical combustion, 3.11 Air under pressure, 4.83 Air, ventilation, 3.8 Alteration, 2.2 Anodeless riser, 2.2, 4.63 I.1

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I.2


B Baffle, 2.3 Barometric draft regulator, 2.3 Beneath buildings, 4.79 Board organization, 1.19 Boiler, hot-water-heating, 2.3 Boiler, low-pressure, 2.3 Boiler, steam-heating, 2.3 Boiler standards, 6.18 Boilers, 3.21, 6.17, 6.18 Bored holes, 3.5 Boring, 3.4 Branch length, 4.4 Brazing, 2.3 Broiler, 2.3 BTU, 2.3 Buildings, beneath, 4.70 Buildings, multistory, 5.14 Buildings, relocated, 1.7 Burner, 2.3

C Category I appliances, 5.4 Category II and IV appliances, 5.18 Category I appliances, vents for, 5.13 Change in occupancy, 1.5 Changes in direction, 4.71 Chimney, 2.3, 5.1 Chimney connections, 5.22 Chimney dampers, 6.19 Chimney inspections, 5.10 Chimney sizing limitations, 5.8 Chimney termination, 5.8 Cleanouts, 5.11 Clearance, grade, 3.15 Clearance reduction, 3.20 Closed transfer system, 4.82 Clothes dryer, 2.4, 6.6 Clothes dryer, commercial, 6.8 Clothes dryer, domestic ducts, 6.8 Clothes dryer, duct penetrations, 6.7 Clothes dryer, exhaust installation, 6.7 Clothes dryer, exhaust systems, 6.6 Clothes dryer, makeup air, 6.7 Clothes dryer, type 1, 2.4 Code, 2.4 Code official, 2.4 Cold-formed steel framing, 3.5 Coils, refrigeration, 6.16 Combination air, 3.10 Combination appliances, 5.10 Combined spaces, 3.9 Combustible construction, 3.15

Combustion, 2.4, 3.8 Combustion air, 2.4, 3.8, 5.11 Combustion-air ducts, 3.11 Combustion chamber, 2.4 Compressed-natural-gas fuel-dispensing facilities, 4.80 Concealed location, 2.4 Concealed piping, 2.4 Condemned installations, 1.18 Condensate, 2.4 Condensate disposal, 3.1 Connections, chimney, 5.22 Connections, manufactured-home, 4.78 Connector, appliance, 2.5 Conncetor, sizing, 5.14 Connector, chimney or vent, 2.5 Connector length, 4.78, 5.21 Construction, combustible, 3.15 Construction, prefabricated, 1.15 Construction documents, 1.11, 2.5 Control, 2.5 Controls, flow, 4.77 Conversion burner, 2.5 Cooking appliances, 6.14 Corrosion, 4.69 Corrosive action, 4.64 Counter appliances, 2.5 Cubic foot, 2.5 Cutting, 3.4

D Damper, 2.5, 6.19 Decorative appliance, vented, 2.5 Definitions, table, 5.25 Design-flood elevation, 2.5 Devices, dispensing, 4.79 Dilution air, 2.5, 3.8 Direct-vent appliances, 2.5 Direction, changes in, 4.71 Disconnection, 1.18 Dispensing devices, 4.7 Disposal, condensate, 3.18 Documents, construction, 1.11, 2.5 Documents, retention of, 1.13 Draft, 2.5 Draft hood, 2.6, 5.23 Draft, mechanical or induced, 2.6 Draft regulator, 2.6 Draft systems, mechanical, 5.6 Drip, 2.6 Drop, pressure, 4.4 Dry gas, 2.6 Duct furnace, 2.6

INDEX

Ducts, 3.3 Ducts, combustion-air, 3.11 Ducts, supply, 3.21

E Elevated structures, 3.17 Elevation of ignition source, 3.13 Emergency shutdown, 4.82 Equipment, 2.6 Equipment, air-conditioning, 3.20 Equipment, low-heat, 5.19 Equipment, medium-heat, 5.19 Exceptions, location, 4.80 Existing chimneys, 5.4 Existing installations, 1.4 Existing vents, 5.4 Expiration, 1.12 Extensions, 1.12

F Facilities, LP-gas fuel-dispensing, 4.7 Facilities, motor-vehicle, 4.79 Fireplace, 2.6, 6.2 Fireplace, factory-built, 2.6 Firing valve, 2.6 Fittings, 4.65 Flame safeguard, 2.7 Flange gaskets, 4.66 Flanges, 4.66 Flood hazard area, 2.7 Flooding, 3.2 Floor, solid, 4.68 Floor furnace, 2.7 Floor furnace, gravity-type, 2.7 Flow controls, 4.77 Flue, appliance, 2.7 Flue collar, 2.7 Flue gases, 2.7 Flue liner, 2.7 Fuel-dispensing facilities, compressednatural-gas, 4.80 Fuel gas, 2.7 Fuel-gas-utilization equipment, 2.7 Fuel types, 3.2 Fueling, private, 4.80 Fueling facilities, private, 4.81 Fumes, 3.12 Furnace, 2.7, 3.21, 6.3 Furnace clearance, 6.4 Furnace, duct, 6.4 Furnace, enclosed, 2.8 Furnace, floor, 6.3 Furnace, forced-air, 2.8 Furnace, gravity-type, 2.8

Furnace, horizontal forced-air, 2.8 Furnace, multiple-position, 2.8 Furnace plenum, 2.8, 3.20 Furnace, thermostats, 6.3 Furnace, up-flow, 2.8 Furnace, wall, vented, 6.2, 6.3

G Garages, parking, 3.14 Garages, public, 3.14 Garages, private, 3.14 Gas-connector prohibitions, 4.79 Gas convenience outlet, 2.8 Gas piping, 2.8 Gas piping installations, 4.1 Gas utilization equipment, 1.2, 2.8 Gas, wet, 4.75 Gas vents, 5.12 Gas vents, terminating, 5.12 Gaseous hydrogen systems, 7.1 Gases, 3.12 Grade clearance, 3.15 Grilles, 3.11 Guards, 3.18

H Hazardous location, 2.8 Heaters, radiant infrared, 6.18 Heaters, sauna, 6.9 Heaters, unit, 6.12 Heaters, water, 6.15 Heating equipment, 1.14 Historic designation, 1.6 Hoods, draft, 5.24 Hoods, multiple draft, 5.20 House piping, 2.8 Hybrid pressure, 4.4

I Ignition pilot, 2.9 Illuminating appliances, 6.17 Incinerator, 2.9 Indoor air, 3.8 Industrial air heaters, direct-fired, nonrecirculating, 2.9 Infrared radiant heater, 2.9, 6.18 Inspections, chimney, 5.10 Inspections, final, 1.14 Installation, 3.13 Installation rules, 5.16 Installation shields, 5.5 Installations, attic, 3.15 Installations, condemned, 1.16 Installations, existing, 1.4

I.3

I.4


Installations, gas piping, 4.1 Installations, piping-system, 4.67 Interconnections, 4.83 Intervals, support, 4.83

J Joint, 2.9 Joint, plastic pipe, 4.66 Joint, welded, 2.9 Joints, 4.65, 5.21 Joists, 3.4

L Labeled, 2.9 Labeling, 3.1, 5.15 Ladders, permanent, 3.17 Length, branch, 4.4 Length, connector, 4.78, 5.21 Liability, 1.7 Limit control, 2.10 Limitations, plastic-pipe, 4.71 Liquefied-petroleum gas, 2.10 Liquid-fuel-burning appliances, 5.10 Living space, 2.10 Locations, exceptions, 4.80 Locations, outlet, 4.70 Log lighter, 2.10 Louvers, 3.11 Low-heat appliances, 5.3 Low-heat equipment, 5.19 LP-gas fuel-dispensing facilities, 4.79 LP systems, 4.5 Lubricated plug-type valve, 2.10

M Main burner, 2.10 Maintenance, 1.5 Makeup air, 3.8 Manufactured-home connections, 4.78 Masonry chimneys, 5.7 Materials, piping, 4.62 Mechanical combustion-air supply, 3.11 Mechanical draft systems, 5.6 Medium-heat equipment, 5.19 Metallic fittings, 4.65 Meter, 2.10 Minimum standards, 1.4 Modifications, 1.9 Modulating, 2.10 Motor-vehicle facilities, 4.79 Multiple appliances, 5.21 Multiple draft hoods, 5.20 Multistory buildings, 5.14

N Nonstructural steel, 3.6 Non-vented appliances, requirements of, 5.2 Notching, 3.4

O Occupancy, 2.10 Occupancy, change in, 1.5 Offset vent, 2.10 Offsets, 5.13 Operating pressure, 4.5 Operation, unauthorized, 4.86 Options, alternative, 1.10 Orifice, 2.10 Outdoor combustion air, 3.9 Outdoor locations, 3.7 Outdoor piping, above-ground, 4.68 Outlet, 2.11 Outlet locations, 4.70 Outside appliances, 4.69 Overpressure protection, 4.83 Oxygen under pressure, 4.83 Oxygen-depletion safety shutoff system, 2.11

P Parking garages, 3.14 Penetrations, 3.4 Penetrations, roof, 5.15 Penetrations, wall, 5.22 Permanent ladders, 3.17 Permits, 1.8, 1.10 Pilot, 2.11 Pipe protection, 4.67 Pipe, single-wall, 5.15 Pipe sizing, 4.2 Pipe support, 4.74 Piping, 2.11 Piping materials, 4.62 Piping systems installation, 4.67 Pit locations, 3.7 Plastic, thermoplastic, 2.11 Plastic pipe joints, 4.66 Plastic pipe limitations, 4.71 Plenums, furnace, 3.20 Plumbing, 3.2 Point of delivery, 2.11 Portable fuel-cell appliance, 2.11 Prefabricated construction, 1.15 Pressure drop, 2.11, 4.4 Pressure, hybrid, 4.4 Pressure, operating, 4.5

INDEX

Pressure test, 2.11 Private fueling, 4.80 Private fueling facilities, 4.81 Private garages, 3.14 Pressure, air under, 4.83 Pressure, oxygen under, 4.83 Prohibited appliance locations, 3.6 Prohibitions, gas-connector, 4.79 Protection, 5.5 Protection, overpressure, 4.83 Protection, pipe, 4.67 Public garages, 3.14 Punishment, 1.17 Purge, 2.11

Q Qualifications, 1.19 Quick-disconnect device, 2.11

R Ready access, 2.11 Reconnection, 1.18 Records, 1.9 Reduction, clearance, 3.20 Refrigeration coils, 6.16 Refrigerators, 6.15 Registered design professional, 2.11 Regulator, 2.12 Relief opening, 2.12 Relief valve, temperature, reseating or selfclosing type, 2.13 Relief valve, vacuum, 2.12 Relocated buildings, 1.7 Repair, 3.2 Requirements of non-vented appliances, 5.2 Residential appliances, 5.3 Residential applications, 4.81 Residential type appliance connectors, 5.18 Riser, gas, 2.13 Risers, anodeless, 4.63 Rodents, 3.3 Roof penetration, 5.15 Roofs, 3.17 Roofs, sloped, 3.18 Room heater, unvented, 2.13 Room heater, vented, 2.13 Rules, 1.8 Rules, installation, 5.16

S Safety shutoff device, 2.13 Sauna heaters, 6.9 Sauna, prohibited sources, 6.10 Sauna, ventilation, 6.10

Seismic resistance, 3.3 Service, 3.15 Servicing a system, 4.74 Settings, 4.86 Shaft, 2.13 Shields, insulation, 5.5 Shutdown, emergency, 4.82 Shutoff valves, 4.76 Single booster-type automatic instantaneous water heaters, 5.2 Single-wall pipe, 5.15, 5.16 Size, 4.87 Sizing connectors, 5.14 Sizing limitations, chimney, 5.8 Sizing, pipe, 4.2 Sizing tables, 4.5 Sleeping unit, 2.13 Sloped roofs, 3.18 Solid floors, 4.68 Spaces, combined, 3.9 Specific gravity, 2.13 Standards, minimum, 1.4 Stationary fuel-cell power plant, 2.13 Steel, 3.5 Stop-work order, 1.17 Structural safety, 3.4 Structural-steel framing, 3.5 Structures, elevated, 3.17 Studs, 3.4 Supply ducts, 3.21 Support intervals, 4.83 Support, pipe, 4.74 Systems, LP, 4.5 Systems, piping, 1.2 Systems, servicing, 4.74

T Table, definitions, 5.25 Tables, sizing, 4.5 Tables, venting, 5.26 Termination, chimney, 5.8 Termination, gas vents, 5.12 Termination locations, venting, 5.17 Test pressure and duration, 4.73 Testing, 4.72 Thermostat, electric-switch type, 2.14 Thermostat, graduating, 2.14 Thermostat, snap-acting, 2.14 Threads, 4.64 Tracers, 4.71 Transfer system, closed, 4.82 Transition fittings, plastic to steel, 2.14 Trusses, 3.5 Tube, vent, 4.82

I.5

I.6


U Unauthorized operation, 4.86 Unconditioned areas, 5.18 Under-floor appliances, 3.16 Unit heaters, 6.12 Unit heaters, high-static pressure type, 2.14 Unit heaters, low static pressure, 2.14 Unit heaters, unvented, 6.13 Unlisted boiler, 2.14 Unsafe conditions, 1.17 Unvented room heater, 2.14

V Validity, 1.12 Valve, 2.14 Valve, automatic or semiautomatic, 2.14 Valve, equipment shutoff, 2.15 Valve, individual main burner, 2.15 Valve, manual main gas-control, 2.15 Valve, manual reset, 2.15 Valve, service shutoff, 2.15 Valve, shutoff, 4.76 Vent, 2.15, 4.87, 5.1, 5.4 Vent area, 5.27 Vent, category 1 appliances, 5.13 Vent, cooking appliances, 5.31 Vent, component commingling, 5.28 Vent, connector, 2.15, 5.29, 5.31 Vent, conversion accessories, 5.28 Vent, diameter, 5.27 Vent, existing, 5.4 Vent, factory built chimneys, 5.31 Vent, fittings, 5.29 Vent, gas, 5.12 Vent gases, 2.16 Vent height, 5.29 Vent liner sizing and connections, 5.31 Vent locations, 5.27 Vent manifolds, 5.29 Vent multistory offsets, 5.30 Vent obstructions, 5.28 Vent, offsets, 5.26 Vent piping, breather, 2.16 Vent piping, relief, 2.16 Vent size, 5.31 Vent, special gas, 2.16

Vent, terminating gas, 5.12 Vent tube, 4.82 Vent, type B, 2.16 Vent, type BW, 2.16 Vent, type L, 2.16 Vent, vertical maximum size, 5.31 Vented appliance categories, 2.15 Vented appliance category I, 2.15 Vented appliance category II, 2.15 Vented appliance category III, 2.15 Vented appliance category IV, 2.15 Vented appliances, 5.23 Vented gas fireplace, 6.2 Vented room heater, 2.15 Vented wall furnace, 2.15, 6.2 Ventilation, air, 3.8 Venting, 5.6 Venting, high altitudes, 5.27 Venting, liner sizing, 5.27 Venting, minimum size, 5.26 Venting, multiple inputs, 5.27 Venting system, 2.16 Venting system, forced-draft, 2.16 Venting system, gaseous hydrogen systems, 7.1 Venting system, induced draft, 2.16 Venting system, mechanical draft, 2.16 Venting system, natural draft, 2.16 Venting tables, 5.26 Venting termination locations, 5.17 Ventilation, 3.8 Vibration, 3.2 Violations, 1.16

W Wall heater, unvented, 2.17 Wall penetration, 5.22 Water heater, 2.17, 6.15 Water heaters, single booster-type automatic instantaneous, 5.2 Wind, 3.2 Wet gas, 4.75 Workmanship, 4.64

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