HomeMy WebLinkAbout2021-06-30-201INSTALLATION OF CONSUMER'S
GAS PIPING AND GAS APPLIANCES
General
Under this caption appear the fundamental code requirements which shall be observed during the
installation of any consumer's gas piping and gas appliances to assure safety and consumer
satisfaction. Responsibility for observing these requirements shall rest with the installing agency.
§201.1 Qualified Installing Agency, Gas Fitters License, Gas Fitters Permits.
A. By the term "Qualified Agency" is meant any individual, firm, corporation
or company which, either in person or through a representative, is engaged
in and responsible for the installation, replacement or repair or servicing of
gas appliances and who carries on such activities through a duly licensed gas
fitter as hereinafter provided.
B. All gas fitters shall be licensed by the Waukee Gas Dept. who are duly
qualified and who receive the recommendation and approval of the Gas
Superintendent, Gas Committee Chairman, and the Mayor.
C. Before receiving the license, the person, firm, or corporation applying for
same shall execute and deposit with the Waukee Gas Department a Surety
Bond to the Town of Waukee to be approved by the Waukee Gas
Department in the sum of One Thousand Dollars ($1,000) conditioned for
the faithful performance of all work entered upon or contracted for by such
person or them and for the strict compliance by such person or them with all
the provisions and requirements of the Waukee Gas building code. And that
such person or they will indemnify the City of Waukee for any and all losses
and damages by reason of any negligence on the part of such licensee, such
person or their agents or employees while engaged in the prosecution of
such person or their business as such licensee.
D. Application for a license as a Gas Fitter shall be made to the Waukee Gas
Department.
E. Licenses as Gas Fitters shall expire on the 15th day of September of each
year and shall be subject to renewal. Ten Dollar fee payable to the Town of
Waukee.
F. The fee for an original Gas Fitter's license shall be the sum of $10.00. And
the fee for the renewal of a Gas Fitter's license shall be the sum of $10.00.
G. The Gas Superintendent of the Waukee Gas Department may at any time for
a violation of the provisions of the Waukee Municipal Natural Gas System
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suspend a Gas Fitter's license, and in case of such suspension, the chairman
of the Gas committee shall promptly set the matter of suspension and
permanent revocation of said license for hearing, give notice to the licensee
involved and at such time and place conduct a hearing as to the permanent
revocation of said license.
H. Whosoever shall violate any of the provisions of the Waukee gas Building
Code shall be punished by a fine of One Hundred Dollars ($100) or thirty
(30) days in jail or both.
I. There are two exceptions for which a Gas Fitter's license is NOT
MANDATORY.
1. No such license shall be required for the City of Waukee, its agents,
servants or employees; and
2. The property owner may perform in the installation, replacement or
repair of such person's own consumer gas piping or the connection,
installation, repair or servicing of such person's own gas appliances
on such person's own property.
[June 11, 1991]
J. Permits to install the following appliance installation are required:
1. Space heating steam and hot water boilers, and warm air furnaces,
gas conversion burners, room heaters, unit heaters, duct furnaces and
recess heaters.
2. Gas fired incinerators.
3. Gas fired water heaters.
Inspection fee for (1) $2.50 each
Inspection fee for (2) and (3) $1.00 each
Permits are issued by the Waukee Gas Department.
K. A copy of the Waukee Gas Building Code will be furnished to the holders of
Gas Fitter's Licenses. Anyone else desiring a copy of the Gas Building Code
may purchase same at the rate of $5.00 per copy.
§201.2 Scope. This text represents basic Code Requirements of the Waukee
Municipal Gas Utility Building Code Governing the installation of consumer's gas piping and gas
appliances. These requirements apply to gas piping system extending from the point of delivery to
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the inlet connections of appliances, and the installation and operation of residential and commercial
gas appliances. They are intended to cover the design fabrication, installation, tests and operation
of such systems for fuel gases such as natural gas, manufactured gas, liquefied petroleum gas. They
are also not intended to cover systems or portions of systems supplying equipment engineered,
designed and installed for specific manufacturing, production processing and power generating
applications, such as large and high pressure boilers, melting and treating furnaces, production
ovens, etc., or for public utility piping in gas distribution and transmission system, in gas
compressing stations and in gas processing plants.
No person, firm, corporation, or other entity than the Waukee Municipal Gas System of the
City of Waukee or its customers shall install, construct, or maintain any gas main, yard line,
consumer’s gas piping, or gas distribution system, or cause movement of natural gas through any
conduit within the city limits of the City of Waukee, Iowa; and no gas shall be moved through the
Waukee Municipal Gas distribution system, or any gas line within the City of Waukee, except gas
purchased from, or with consent of, Waukee Municipal Gas System of the City of Waukee.
May 6, 1996 – Ordinance No. 2219
August 7, 2000-Ordinance No. 2322
§201.3 Work on Consumer’s Gas Piping Containing Unmeasured Gas.
Repairs, alterations, relocations and/or other work on any portion on consumer's gas piping
containing unmeasured gas shall be done by a qualified installing agency authorized to do such
work. When such work is done the Gas Company shall be notified.
The moving, connecting or disconnecting of gas meters shall be done by gas utility
employees or others authorized by the gas utility to do such work.
§201.4 Qualified Installing Agency. Installing and replacement of
consumer's gas piping or gas appliances and repair of consumer's gas appliances shall be performed
only by an individual or firm with a gas fitters permit.
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§201.5 General Precautions
§201.5.1 Turn Gas Off. All gas piping or gas appliance installation shall be
performed with the gas turned off to eliminate hazards from leaking of gas.
§201.5.2 Notification of Interrupted Service. It shall be the duty of the installing
agency when the gas supply is to be turned off, to notify all affected consumers.
§201.5.3 Before Turning Gas Off. If there is more than one meter on the premises,
precaution shall be exercised to assure that the proper meter is turned off.
§201.5.4 Checking For Gas Leaks. No matches, candles, flame or other source of
ignition shall be employed to check for gas leakage from meters, piping or appliances. Checking
for gas leakage with a soap and water solution is recommended. (See provisions of 201.18 and
201.19).
§201.5.5 Use of Lights. Artificial illumination used in connection with a search for
gas leakage shall be restricted to electric hand flash lights, electric lights controlled only by switches
remote from the area of the leakage, or approved safety lamps.
§201.5.6 No Smoking. When working on piping that contains or has contained gas,
smoking shall not be permitted.
§201.5.7 Handling Flammable Liquids. Flammable liquid used by the installer
shall be handled with proper precautions and shall not be left within the premises from the end of
one working day to the beginning of the next.
§201.5.8 Work Interruptions. When interruption in work occurs, the system shall
be left in a safe and satisfactory condition.
§201.6 Manual Gas Valve. A Manual Gas Valve shall be installed ahead
of all controls including the pilot gas valve on the following appliances:
A. Ranges - Domestic and Commercial
B. Warm Air Furnaces
C. Floor Furnaces
D. Unit Heaters
E. Duct Furnaces
F. Recess Heaters
G. Gas Conversion Burners
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H. Room Heaters
I. Space Heating Steam and Hot Water Boilers
J. Water Heaters
K. Counter Appliances
L. Clothes Dryers - Domestic and Commercial
M. Gas Logs and Grates
N. Refrigerators
Minimum distance of installation of valve 2 feet from burner manifold and 6 feet maximum.
§201.7 Copper Tubing. There will be no installation of copper tubing
unless authorized by the Natural Gas Superintendent in writing.
Gas Yard Lights may be installed with copper tubing.
§201.8 Galvanized Pipe. There will be no installation of galvanized pipe or
galvanized fittings.
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GAS PIPING INSTALLATIONS
Under this caption appear the fundamental requirements for the installation of consumer's gas
piping which must be observed to assure safety, satisfactory service and consumer satisfaction.
Responsibility for observing these requirements shall rest with the installing agency.
§201.9 Piping Plan. Before proceeding with the installation of a gas piping
system, a piping sketch or plan may be required showing there proposed location of the piping as
well as the size of different branches. Adequate consideration should be given to future demands
and provisions made for added gas services.
When an additional appliance is to be served though an extension of present piping,
capacity of the existing line shall be verified.
§201.10 Piping Must Provide for Proper Meter Location. A meter location shall
be provided for the building or premises to be served and the location shall be such that the meter
connections are easily accessible in order that the meter may be read or changed. Location, space
requirements, dimensions, and type of installation shall be acceptable to the Gas Company.
Piping from multiple meter installations shall be plainly marked by the installer so that the
piping systems supplied through them can be readily identified.
§201.11 Interconnections. Where two or more meters are installed on the same
premises but supply separate consumers, the piping systems shall not be interconnected on the
outlet side of the meters.
§201.12 Required Size of Piping and Outlets. (Not-withstanding provision of this
section to the contrary, consumer's gas piping installed for other than natural gas may be converted
to use natural gas, if the administrative authority finds, upon inspection and proper tests, that such
piping will render satisfactory gas service to the consumer, and will not in any way endanger life or
property; otherwise, such piping shall be altered or replaced, in whole or in part, to conform with
the requirements of this section)
§201.12.1 Minimum Size of Certain Piping and Outlets. All consumer's gas piping
from the point of delivery to the house piping shall not be less than one (1") inch in diameter. (See
§201.12.6)
Outlets for gas ranges shall be not less than three-fourths (3/4") inch pipe.
The minimum size of outlets shall be one-half (1/2") inch pipe.
In no case shall a branch line to any gas appliance be installed having a diameter smaller
than the inlet connection of the appliance.
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In no case shall an extension to gas piping be installed from pipe of smaller size than the
extension.
§201.12.2 Required Gas Supply. The hourly volume of gas required at each outlet
shall be taken as not less than the maximum hourly rating as specified by the manufacturer of the
appliance to be connected to each such outlet.
To obtain the cubic feet per hour of gas required, divide the maximum Btu input of an
appliance by the average Btu heating value per cubic foot of gas. Always divide by 1000 unless the
actual average Btu value is lower.
Where the Btu rating of the gas appliances to be installed have not been definitely specified,
Table 1 may be used as a reference in sizing pipe to estimate the approximate requirements in Btu
per hour of typical appliances.
TABLE 1
APPROXIMATE MAXIMUM DEMAND OF TYPICAL
GAS APPLIANCES IN BTU PER HOUR
Appliance Demand Btu/hr.
Domestic Gas Range 62,500
Storage Water Heater - up to 30 gal. tank 30,000
Storage Water Heater - 40 to 50 gal. tank 45,000
Gas Refrigerator 3,000
Gas Steam Radiators per section 2,000
Steam Boilers - per horsepower 50,000
Restaurant Range-4 top burners, 2 ovens 150,000
Restaurant Range-6 burners, 2-4 ovens 240,000
§201.12.3 Required Gas House Piping Size (See '201.12.5) To determine the sizes
of consumer's gas house piping proceed as follows:
A. Measure the length of pipe from the point where the house piping begins to
the most remote outlet in the building. (See Definition of House Piping).
B. In the first horizontal line in Table 2, select the vertical column showing the
distance, or next longer distance if table does not give the exact length.
C. Use this vertical column to locate all gas demand figures for this particular system
of gas piping.
D. Starting at the most remote outlet, find in the vertical column just selected, the gas
demand for that outlet. If the exact figure of demand is not shown, choose the next
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larger figure below in the same column.
E. Opposite this demand figure in the first column at the left in Table 2 will be found
the correct size of pipe.
F. For each succeeding section of pipe, determine the total gas demand supplied by
such section and then proceed in the manner outlined above to determine the size of
each section of pipe.
§201.12.4 Required Gas Yard Line Size. To determine the size of consumer's gas
piping from the point of delivery to the house piping proceed as follows: (See definition of Point of
Delivery).
A. Measure the length of pipe from the point of delivery to the point where the house
piping begins.
B. In Table 2 select the vertical column showing that distance, or the next longer
distance if the table does not give the exact length.
C. In this vertical column, select the figure corresponding to the demand figure of the
house piping. If the exact figure is not shown, choose the next larger figure below
in the same column.
D. Opposite this demand figure on the same line will be found the minimum size of
pipe allowable.
TABLE 2
SIZE OF GAS PIPING ENCLOSED IN CODE
§201.12.5 Sizing Requirements for Special Conditions. For conditions other than
those set forth in 201.12.3 and 201.12.4 above or those covered by Table 2, such as longer runs or
larger sizes of piping, greater gas demand, application of a diversity factor when piping multiple-
family dwellings, pressures higher than 15 inches or lower than 4 inches of water column pressure,
or specific gravity other than 0.55 to 0.75, the size of piping required shall be calculated in a
manner satisfactory to both the administrative authority and the gas company.
Where pipe sizes larger than those set forth in 2.4 are specified by pipe sizing requirements
established by the administrative authority or the Gas Company, these large sizes shall be used.
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§201.13 Materials
§201.13.1 Acceptable Piping Material. Consumer's gas piping shall be black
wrought iron or black steel pipe complying with the American Standard for Wrought Iron and
Wrought Steel Pipe, A.S.A. M36-10-1939. All pipe fittings (except stop cocks or valves) shall be
malleable iron or steel when used with wrought iron or steel pipe, except that in sizes 4" or larger,
cast iron may be used. Where approved by the administrative authority, copper or brass pipe in iron
pipe sizes assembled with threaded fittings of the same materials may be used with gases not
corrosive to such materials.
Gas Piping and fittings shall be clear and free from cutting burrs and defects in structure or
threading and shall be thoroughly brushed and scale brown.
The use of welded steel fittings, either shop or field fabricated and connected of pipe and
fittings by welding is permissible.
Defects in pipe or fittings shall not be repaired. When defective pipe or fittings are located
in a system, the defective pipe or fittings shall be replaced.
§201.13.2 Pipe Coating. When in contact with material exerting a corrosive action,
piping and fittings coated with corrosion-resisting material shall be used.
§201.13.3 Use of Old Pipe. Pipe fittings, valves, etc., removed from any existing
installation shall not be used until they have been thoroughly cleaned, inspected and ascertained to
be equivalent to new material.
§201.13.4 Joint Compounds. Joint compounds (pipe dope) shall be applied sparingly
and only to the male threads of the joints. Such compounds shall be resistant to the action of LP
gas-air mixtures.
§201.13.5 Bushings. Bushings shall not be used in house piping.
§201.14 Specifications for Pipe Threads. Pipe and fitting threads shall comply
with the American Standard for Pipe Threads, A.S.A. B2.1-1945.
§201.14.1 Damaged Threads. Pipe with threads which are stripped, chipped,
corroded, or otherwise damaged shall not be used. If a weld opens during the operation of cutting
or threading, that portion of the pipe shall not be used.
§201.14.2 Number of Threads. Pipe shall be threaded in accordance with Table 3.
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TABLE 3
SPECIFICATIONS FOR THREADING PIPE
Approximate Length Approximate No.
Iron Pipe Size of Threaded Portion of Threads to
(Inches) (Inches) be Cut
1/2 3/4 10
3/4 3/4 10
1 7/8 10
1 1/4 1 11
1 1/2 1 11
2 1 11
2 1/2 1 1/2 12
3 1 1/2 12
4 1 5/8 13
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§201.15 Concealing Pipe
§201.15.1 Minimum Size. No pipe smaller than standard 1/2" iron pipe size shall be
used in any concealed location.
§201.15.2 Piping In Partitions. Concealed piping should be located in hollow rather
than in solid partitions.
§201.15.3 Piping in Concrete or Masonry Floors. House piping shall not be
installed in solid floor slabs such as concrete or masonry unless the administrative authority
determines there is no other practical manner of installing such piping. For this type of floor
construction, the house piping should be installed above the floor, in an open or furred space,
hollow wall, attic space, or pipe chase.
Where the administrative authority determines that it is not practical to avoid the installation
of piping in solid floors, then one of the following methods of installation, when approved by the
administrative authority, shall be followed:
A. House piping may be installed in a casing or iron pipe with tightly sealed
ends and joints. The casing shall extend at lease two inches beyond the
point where the pipe emerges from the floor. Where required, the casing
shall be vented to the outside atmosphere and/or coated as specified in
201.15.5.
B. House piping may be installed in a channel in the floor. Such channel is to
be suitably covered so as to permit ready access to the piping and prevent the
entrance of corrosive materials, or it may be filled with some noncorrosive
material that can be removed with a minimum of damage to the floor.
§201.15.4 Buried House Piping. House piping shall not be buried or in contact with
the ground or fill under a building unless the administrative authority determines there is no other
practical manner of installing such piping.
Where the administrative authority determines that it is not practical to avoid installation of
house piping that is buried or in contact with the ground or fill, the administrative authority shall
specify the method of protecting this house piping from corrosion as may be required by local soil
conditions
§201.15.5 Piping Passing Through Concrete or Masonry Walls. When necessary to
install house piping through concrete or masonry walls, one of the following methods of installation
shall be followed, unless otherwise specified by the administrative authority.
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A. Piping may be installed in an iron-piping conduit tightly sealed at both ends and
extending beyond the wall.
B. Piping shall enter building above ground where possible. Where this cannot be
done due to type of construction, the pipe should be sleeved or tape coated to meet
City requirements.
§201.15.6 Reconnections. When necessary to insert fittings in piping which has been
installed in a concealed location, the piping may be reconnected by the use of a ground joint union
with the nut "center punched" to prevent loosening by vibration.
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§201.16 Installation of Piping.
§201.16.1 Building Structure. The building shall not be weakened by the installation
of any gas piping.
§201.16.2 Supporting Pipe. Gas piping shall not be supported by other piping but
shall be supported with pipe hooks, metal pipe straps, bands or hangers suitable for the size of pipe,
and of proper strength and quality at proper intervals so that the piping cannot be moved
accidentally from the installed position.
Spacing of supports in piping installations shall not be greater than the following:
1/2 inch pipe 6 feet
3/4 inch or 1 inch pipe 8 feet
1 1/4 inch or larger (horizontal) 10 feet
1 1/4 inch or larger (vertical) every floor level
§201.16.3 Do Not Bend Pipe. Pipe shall not be bent. Fittings shall be used when
making turns in gas piping.
§201.16.4 Provide Drips and Grade Piping Where Necessary. Except where a dry
gas is distributed, gas piping shall be properly drained with a minimum pitch of approximately 1/4
inch in 15 feet and to as few points as practicable. Drips shall be provided at such points to act as
storage for condensate. Pipe shall be so graded as to drain towards the meter where a drip shall be
installed that constitutes a rap wherein an accumulation of condensate will shut off the flow of gas
before the condensate drains into the meter. Whenever it is necessary to drain pipe to a different
point in the system or where it is necessary to offset the pipe in order to avoid obstruction a drip
shall be installed at each low point, and it should be readily accessible for draining. Sags in piping
shall not be permitted. As few drips as practical shall be installed. The diameter of the pipe
constituting the drip shall not be less than that of the line it serves and the minimum length of the
drip pipe shall not be less than 3".
§201.16.5 Avoid Clothes Chutes, etc. Gas pipe inside any building shall not be run in
or through an air duct, clothes chute, chimney or flue, ventilating duct, dumb waiter or elevator
shaft.
§201.16.6 Cap All Outlets. Each outlet, including a valve or stop cock, shall be
securely closed gas tight with a threaded iron plug or cap immediately after installation and shall be
left closed until an appliance is connected thereto. Likewise, when an appliance is removed from
an outlet and the outlet is not to be used again immediately, it shall be securely closed gas-tight by
means of a threaded iron plug or cap. In no case shall the outlet be closed with tin caps, wooden
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plugs, cork, etc.
§201.16.7 Location of Outlets. Outlets must be located in the room or space where
the appliance is or may be installed. The unthreaded portion of piping outlets shall extend at least
one inch through finished ceilings and walls, and when extending through floors shall be not less
than 2 inches above them. The outlet fitting or the pipe shall be securely fastened. Outlets shall not
be placed behind doors. Outlets shall be far enough from floors and walls to permit the use of a
pipe wrench of suitable size without straining or bending the pipe.
§201.16.8 Prohibited Devices. No device shall be placed inside the gas pipe or
fittings that will reduce the cross sectional area or otherwise obstruct the free flow of gas. Gas
fitters approved by the administrative authority shall not be construed as prohibited devices.
§201.16.9 Branch Pipe Connections. Where a branch connection is placed on a main
supply line before it is known what size of pipe will be connected to it, the connection shall be the
same size as the line that supplies it. Where other than dry gas is distributed, all branch connections
shall be taken from the topsides of horizontal lines and not from the bottom.
§201.16.10 Separate Ditch for Gas Pipe. The laying or installing of gas piping in the
same ditch with water, sewer, or drainage pipe is prohibited except when approved by the
administrative authority.
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§201.17 Gas Shut-off Valve
§201.17.1 Accessibility of Gas Valves. Shut-off valves controlling several piping
systems shall be placed an adequate distance from each other so they will be easily accessible for
operation and shall be installed so as to be protected from injury. They shall be plainly marked by
the installer so that the piping systems supplied through them can be readily identified.
§201.17.2 Shut-Off Valves for Multiple House Lines. In multiple tenant buildings
supplied through a master meter, or where meters are not readily accessible from the appliance
location, an individual shut-off valve for each apartment or for each separate house line shall be
provided at a convenient point of general accessibility.
§201.18 Test of Piping for Tightness. Before any system of gas piping is finally put
in service, it shall be carefully tested to assure that it is gas tight. Where any part of the system is to
be enclosed or concealed. This test should precede the work of closing in. To test for tightness, the
piping shall be filled with air or inert gas, but not with any other gas or liquid. IN NO CASE
SHALL OXYGEN EVER BE USED. 15 lbs. pressure for 15 minutes, or at least as much pressure
as the gas main will carry at all times.
§201.19 Turning on Gas
§201.19.1 Close All Gas Outlets. Before turning gas into any piping, all openings
from which gas can escape shall be closed.
§201.19.2 Checking for Leakage. After the piping has been checked, all piping
receiving gas through the meter shall be fully purged. Under no circumstances shall a line be
purged into the combustion chamber of an appliance.
§201.20 Light Pilots. After the piping has been sufficiently purged, all appliances
shall be purged and the pilots lighted. The installer shall assure themselves that all piping and
appliances are fully purged before leaving the premises.
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APPLIANCE INSTALLATION
Under this caption appears the fundamental requirements which must be observed during
the installation of any gas appliance or accessory so as to assure safety and satisfactory service as
well as consumer satisfaction. In addition to the provisions outlined in this section, the provisions
of Section 201.1 - 201.8 and 201.38 - 201.62 shall be strictly observed. Responsibility for
observing these requirements shall rest with the installing agency.
§201.21 General
§201.21.1 Appliances to Comply With Standard Requirements. Each gas
appliance and accessory designed for domestic or commercial use shall be of a type complying with
applicable American Standard Approval or Listing Requirements covering safe operation,
substantial and durable construction and acceptable performance. Such compliance may be
determined by the presence on the appliance or accessory of a label of a nationally recognized
testing agency* acceptable to the Gas Utility qualified and equipped to perform the test necessary to
determine such compliance and maintaining an adequate periodic inspection of current production
models, and whose label on the appliance or accessory states that it complies with national safety
requirements. Such compliance may also be determined by the listing of the appliances or
accessory in a list published by such nationally recognized testing agency, which states that the
appliance or accessory complies with national safety requirements.
In cases where no applicable American Standard Approval or Listing Requirements have
been developed for a given class of appliance or accessory, approval of the administrative authority
shall be obtained before the appliance or accessory is installed.
§201.21.2 Type of Gas. It shall be determined that the appliance has been designated
for use with the gas to which it will be connected. No attempt shall be made to convert the
appliance from the gas specified on the rating plate for use with a different gas without consulting
the local gas utility or the manufacturer for complete instructions.
§201.21.3 Permissible Temperatures on Combustion Materials. All gas appliances
and their flue or vent connectors shall be installed so that continued or intermittent operation will
not create a hazard to persons or property.
Minimum clearances between combustible walls and the back and sides of various
conventional types of appliances and their flue or vent connectors are specified in Sections 201.24
through 201.45.
§201.21.4 Air For Combustion. Appliances shall be installed in a location in which
the facilities for ventilation permit satisfactory combustion of gas and proper venting, under normal
conditions of use. While all forms of building construction cannot be covered in detail, this
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requirement may usually be met by application of one of the following methods in ordinary
building construction:
*The American Gas Association, Inc., Laboratories are such a nationally recognized testing
agency.
A. In buildings of conventional frame, brick, or stone construction without
enclosed appliance rooms, basement storm windows, or tight stair doors,
infiltration is normally adequate to provide air for combustion and draft
hood dilution.
B. Where appliances are installed in a confined space within a building,
provision may be made for supplying this space with air for combustion and
ventilation by eliminating the ceiling of the confined space; provided,
however, that the area above this confined space freely communicates with
the outdoors.
C. Where appliances are installed in a confined space within a building having
adequate air infiltrations, provisions shall be made for supplying this space
with air for combustion and ventilation. This may be accomplished through
use of two permanent openings freely communicating with interior areas of
adequate infiltration or by compliance with provisions of item B. or D.
These two permanent openings shall each have an area of not less than 1 sq.
in. per 1000 Btu per hour of input rating. One opening shall be near the
bottom. If necessary, continuous ducts having cross-sectional areas equal to
the opening shall be utilized to communicate with the source of air supply.
The minimum dimensions of rectangular air ducts shall be not less than 3
inches.
D. Where appliances are installed in a confined space within a building, the
building being of unusually tight construction, air for combustion and
ventilation must be obtained directly from outdoors or from spaces (crawl or
attic) freely communicating with the outdoors. Under these conditions, the
openings called for in C. shall be replaced either by the provision B. above
or by two openings having a combined area of not less than one square inch
per 1000 Btu per hour of input rating. One opening shall be near the top of
the enclosure and one near the bottom.
These openings shall be of approximately equal area and shall communicate
with the selected source or sources of adequate air supply by continuous
ducts of the same cross sectional area as the openings to which they connect.
The minimum dimensions of rectangular air ducts shall be not less than 3
inches. Any duct from the top opening must be horizontal or pitched
upward.
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E. Where appliances are installed in unconfined spaces, such as a full
basement, within a building of usually tight construction, air for combustion
and ventilation must be obtained from outdoors or from spaces freely
communicating with the outdoors. Under these conditions, a permanent
opening or openings having a total free area of not less than 1 sq. in. per
1000 Btu per hour of input rating shall be provided. Where ducts are
required, they shall be of the same cross-sectional area as the openings to
which they connect. The minimum dimension of rectangular air ducts shall
be not less than 3 inches.
F. The size of combustion air openings specified in 201.21.4 shall not
necessarily govern in installation having a combination input in excess of
400,000 Btu/Hr.
G. Operation of exhaust fans, kitchen ventilation systems or fireplaces may
create conditions requiring special attention to avoid unsatisfactory
appliance operation.
§201.21.5 Venting. Appliances shall be vented in accordance with the provisions of
Section 201.38, Venting of Appliances.
§201.21.6 Flammable Vapors. Gas appliances shall not be installed in any location
where flammable vapors are likely to be present, unless the design, operation and installation are
such as to eliminate the possible ignition of the flammable vapors.
§201.21.7 Accessibility. Every appliance shall be located so that it will be readily
accessible for operation and servicing.
§201.21.8 Avoid Strain On Pipe. Gas appliances shall be adequately supported and
so connected to the piping as not to exert undue strain on the connections.
§201.21.9 Extra Device or Attachment. No device or attachment shall be installed on
any appliance that may in any way impair the combustion of gas.
§201.21.10 Combination of Appliances. Any combination or appliances, attachments
or devices used together in any manner shall comply with the standards that apply to the individual
appliances.
§201.21.11 Use of Air or Oxygen Under Pressure. Where air or oxygen under
pressure is used in connection with the gas supply, effective means shall be provided to prevent air
or oxygen from passing back into the gas piping. The local Gas Company shall be consulted for
details.
19
§201.21.12 Venting of Pressure Regulators. Gas appliance pressure regulators
requiring access to the atmosphere for successful operation shall be equipped with a vent pipe
leading to the outer air or into the combustion chamber adjacent to a constantly burning pilot,
unless constructed or equipped to limit the escape of gas from the vent opening in the event of
diaphragm failure to not more than 1.0 cu. ft. per hour of a 0.6 sp. gr. gas at 7 inches water column
pressure. In case of vents leading to the outer air, means shall be employed to prevent water from
entering this pipe and also to prevent stoppage of it by insects and foreign matter. In case of vents
entering the combustion chamber, the vent shall be located so that the escaping gas will be readily
ignited from the pilot flame and the heat liberated will not adversely affect the operation of the
terminal element. The terminus of the vent shall be securely held in a fixed position relative to the
pilot flame. For manufactured gas a flame arrestor in the vent line may also be necessary.
§201.21.13 Listed Automatic Pilot Required With Automatic Controls. The
installation of automatic off and on controls on any appliance is prohibited, unless the appliance is
listed for such use and is equipped with a listed automatic pilot.
For information governing the installation of the use of automatic controls on Conversion
Burners, see 201.31, and on unlisted boilers see Sections 201.51 - 201.62.
20
§201.22 Appliance Connections to Building Piping.
§201.22.1 Connecting Non-Portable Appliances. Permanently connected and /or
non-portable appliances such as central heating, water heating and similar equipment that becomes
a part of the building fixtures, shall be connected to the house piping with rigid pipe and pipe
fittings. Such a semi-rigid connection shall not be more than two (2) feet in length and shall be
protected from mechanical injury.
§201.22.2 Connecting Domestic Ranges, Refrigerators, etc. Domestic gas ranges,
hot plates, refrigerators, room heaters and similar equipment shall be connected to the gas piping
with rigid pipe or listed appliance connectors of flexible metal tubing and fittings. When a semi
rigid tubing connector or a connector of flexible metal tubing and fittings is used, it shall connect to
an outlet in the same room as the appliance. The length of the connector shall not exceed 6 feet.
The connector shall be installed so as to be protected against mechanical injury.
§201.22.3 Use of Gas Hose. The connection of an appliance with any type of gas hose
is prohibited, except when used with laboratory, shop or ironing equipment that requires mobility
during operation. Such connections shall have the shut-off or stop cock installed at the connection
to the house piping. Where gas hose is used, it shall be of the minimum practical length, but not to
exceed 6 feet, and shall not extend from one room to another nor pass through any walls, partitions,
ceilings or floors. Under no circumstances shall gas hose be concealed from view or used in a
concealed location.
21
§201.23 Electrical Connections.
§201.23.1 Electrical Connections Standard. All electrical connections between gas
appliances and the building wiring shall conform to the National Electrical Code, NFPA, 2952.
§201.23.2 Electric Ignition and Control Devices. No devices employing or
depending upon an electrical current shall be used to control or ignite a gas supply if of such a
character that failure of the electrical current could result in the escape of unburned gas in failure to
reduce the supply of gas under conditions which would normally result in its reduction unless other
means are provided to prevent the development of dangerous temperatures, pressures or the escape
of gas.
§201.23.3 Electrical Circuit. The electrical ground nor shall electric circuits utilize
gas piping, casing of controls, panels or other metal parts in lieu of wiring. This provision shall not
apply to low voltage control and ignition circuits, and to electronic flame detection device circuits
incorporated as part of the appliance.
§201.23.4 Electrical Circuit and Other Electric Devices. The electrical circuit
employed for operating the automatic main gas control valve, automatic pilot, room temperature
thermostat, limit control or other electrical devices used with the gas appliance shall be in
accordance with the wiring diagrams supplied with the appliance.
§201.23.5 Continuous Power. All gas appliances using electrical controls shall have
the controls connected into a permanently live electrical circuit, i.e., one that is not controlled by a
light switch.
22
INSTALLATION REQUIREMENTS FOR SPECIFIC APPLIANCES
Under this caption appear the fundamental requirements covering installation practices for
specific types of appliances, which must be observed to assure safety and satisfactory performances
as well as consumer satisfaction. All provisions outlined in Sections 201.24 - 201.37 and 201.46 -
201.62 shall be fully observed. Responsibility for observing these requirements shall rest with the
installing agency.
§201.24 Domestic Ranges (See Sections 201.21 - 210.45)
§201.24.1 Clearance from Combustible Construction. Listed domestic gas ranges
when installed on combustible floors shall be set on their own bases or legs and shall be installed
with clearances not less than shown in Table 4. In no case shall the clearances be such as to
interfere with the requirements for combustion air and accessibility. (See 201.21.4 and 21.7).
§201.25 Water Heaters (See Sections 201.21 - 201.45)
§201.25.1 Prohibited Installations. Water heaters shall not be installed in bathrooms
and bedrooms However, water heaters of the automatic storage type may be installed as a
replacement in a bathroom, when specifically authorized by the administrative authority, providing
they are properly vented and are supplied with adequate combustion air.
§201.25.2 Location. Water heaters shall be located as close as practicable to the flue
or vent. They should be so located as to provide short runs of water piping to fixtures.
§201.25.3 Clearance. Gas-fired water heaters shall be positioned in relation to
combustible construction with a minimum clearance in accordance with Table 5. In no case shall
the clearance be such as to interfere with the requirements for combustion air and accessibility.
(See 201.21.4 and 201.21.7).
§201.25.4 Connections. Water heaters shall be connected in a manner to permit
observation, maintenance and servicing.
§201.25.5 Rigid Piping. Water heaters to be installed with rigid piping.
§201.25.6 Temperatures, Pressure and Vacuum Relief Valves. The installation and
adjustment of temperature pressure and vacuum relief valves or combustions thereof, and automatic
gas shut-off valves shall be in accordance with the requirements of the administrative authority or,
with the manufacturer's instructions accompanying such devices.
23
§201.25.7 Connection to Boiler or Tank. The method of connecting a circulating
water heater to the tank shall assure proper circulation of water through the heater, and permit a safe
and useful temperature of water to be drawn from the tank.
§201.25.8 Size of Water Circulating Pipe. The size of the water circulating piping, in
general, shall conform with the size of the water connections of the heater.
§201.25.9 Sediment Drain. A suitable water valve or cock, through which sediment
may be drawn off or the tank emptied, shall be installed at the bottom of the tank.
§201.25.10 Anti-Siphoning Devices. Means acceptable to the administrative authority
shall be provided to prevent siphoning in any boiler or tank to which any water heater is attached.
A cold water tube with a hole near the top is commonly accepted for this purpose.
§201.26 Room or Space Heaters (See Sections 201.21 - 201.45)
§201.26.1 Clearance. A room or space heater shall be placed so as not to cause a
hazard to walls, floors, curtains, furniture, doors when open, etc., and to the free movements of
persons within the room. Appliances designed and marked "For use in incombustible fire resistive
fireplace only", shall not be installed elsewhere. Listed room or space heaters shall be installed in
accordance with their listing. In no case shall the clearances be such as to interfere with the
requirements or combustion air and accessibility. (See 201.21.4 and 201.21.7).
§201.26.2 Wall Type Room Heaters. Wall type room or space heaters shall not be
installed in walls or combustible construction unless listed for such installation.
§201.26.3 Installation in Sleeping Quarters. Only room heaters listed for vented use
shall be installed in sleeping quarters for use of transients, as in hotels, motels and auto courts, in
institutions such as Homes for the Aged, Sanatoriums, Convalescent Homes, Orphanages, etc.
Such heaters shall be connected to an effective flue or vent and equipped with an automatic pilot.
§201.27 Central Heating Boilers and Furnaces (See Sections 201.21 - 201.45)
§201.27.1 Clearances. Listed central heating boilers and furnaces shall be installed
with clearances not less than specified in Table 7, except that appliances listed for installation at
lesser clearances may be installed in accordance with their listings. In no case shall the clearance be
such as to interfere with the requirements for combustion air and accessibility. (See 201.21.4 and
201.27.3).
24
Table 7
MINIMUM CLEARANCES FOR LISTED
CENTRAL HEATING BOILERS AND FURNACES
Distance from Combustible
construction -- inches
Jacket Projecting
Above Sides Front Flue Box
& Rear or Draft Hood
Boilers 6 6 18 6
Furnaces 18* 6 18 6
*A vertical clearance of 6 inches may be used with warm air furnaces equipped with
mechanical means to circulate the air and with a temperature limit control, approved by the
administrative authority, which cannot be set higher than 250 degrees F.
§201.27.2 Erection and Mounting. A central heating boiler or furnace shall be
erected in accordance with the manufacturer's instructions and shall be installed on a firm level,
fireproof foundation unless listed for installation on a combustible floor, or the floor is protected in
a manner acceptable to the administrative authority.
§201.27.3 Accessibility. The installation of central heating boilers and furnaces shall
be such as to make them accessible for cleaning of heating surfaces, removal of burners,
replacement of sections, motors, controls, filters, draft hoods and other working parts, and for
adjustment and lubrication of parts requiring such attention.
§201.27.4 Connection of Flow and Return Pipes to Boilers. The method of
connecting the flow and return pipes on steam and hot water boilers shall facilitate a rapid
circulation of steam or water. For common piping systems references may be made up to the
American Society of Heating and Ventilating Engineers - Heating, Ventilating Air Conditioning
Guide and to the Institute of Boiler and Radiator Manufacturer's (IBR) Guides.
§201.27.5 Feed Water and Drain Connections to Boilers. A steam or hot water
boiler shall be provided with a direct connection to a water supply through an individual control
valve. A drain valve, by means of which the boiler may be flushed or drained, also shall be
provided.
§201.27.6 Temperature of Pressure Relief Devices on Boilers. Steam and hot water
boilers shall be provided with automatic devices, approved by the administrative authority, to shut
down the burners in the event of undue pressure or low water in a steam boiler or overheating in a
hot water boiler.
25
§201.27.7 Plenum Chambers and Air Ducts. A plenum chamber when not a part of
a furnace shall be constructed in accordance with the manufacturer's instructions. The method of
connecting supply and return ducts shall facilitate proper circulation of air. Reference may be made
to the Standards of the National Board of Fire Underwriters for the Installation of Air Conditioning,
Warm Air Heating, Air Cooling and Ventilating Systems, NBFU Pamphlet No. 90 - August, 1952,
and to the Design and Installation Manuals of the National Warm Air Heating and Air Conditioning
Association.
§201.27.8 Return Air Connections. Return air connections in the furnace room or
directly below the furnace room shall be so made as to preclude any possibility of air being drawn
from the furnace room into the return air duct by action of the furnace fan.
§201.27.9 Furnaces Used With Refrigeration Systems and Blowers. A furnace
when used in conjunction with a refrigeration system shall be installed on the discharge side of the
blower. The furnace shall be installed in parallel with or ahead of the refrigeration coil. If the
refrigeration coil is installed in the air discharge duct from the furnace, this coil shall be installed in
the air discharge duct from the furnace, this coil shall be installed in or provided with a bypass duct
unless the furnace is listed for operation with at least 05" static pressure at the outlet air connection.
§201.27.10 Installation and Insulation. All flexible duct connections shall be made of
fire resistant materials. All supply duct work exposed in unheated attic spaces shall be insulated.
§201.28 Recessed Heaters. (See Sections 201.21 - 201.45).
§201.28.1 Installation. Listed recessed heaters may be installed in combustible
construction and shall be installed in accordance with the term of their listing.
§201.28.2 Location. Recessed heaters shall be located so as not to cause a hazard to
walls, floors, curtains, furniture, doors, etc. Recessed heaters installed between bathrooms and
adjoining rooms shall not circulate air from bathrooms to other parts of the building.
§201.28.3 Accessibility. The installation of recessed heaters shall be such as to make
them accessible for cleaning of heating surfaces, removal of burners, replacement of sections,
motors, controls, filters, and other working parts, and for adjustment and lubrication of parts
requiring such attention. Panels, grilles and access doors which must be removed for normal
servicing operations shall not be attached to the building construction.
§201.29 Floor Furnaces. (See Sections 201.21 - 201.47).
§201.29.1 Installation. Listed floor furnaces may be installed in combustible floors.
26
§201.29.2 Manual Shut-Off Valve. A separate manual shut-off valve shall be
provided ahead of all controls and a union connection shall be provided downstream from this
valve to permit removal of the controls or the floor furnace.
§201.29.3 Combustion Air. Fixed ventilation by means of a duct or grille arranged to
supply air from a permanently ventilated attic or under floor space, shall be provided to any
confined space which enclosed the floor furnace. The duct or grille shall be screened and have a
free area of at least one sq. in. per 1000 Btu per hour of gas input, and shall be installed in such a
manner as to insure proper combustion.
§201.29.4 Placement. The following air requirements that will serve in properly
placing the furnaces to serve one story:
A. No floor furnace shall be installed in the floor of any aisle, or passageway of any
auditorium, public hall, or place of assembly, or in any exit-way from any such
room or space.
B. Walls and Corners - With the exception of wall-register models, a floor furnace
shall not be placed closer than 6 inches to the nearest wall, and wall register models
shall not be placed closer than 6 inches to a corner.
C. The furnace shall be so placed that a drapery or similar object cannot be nearer than
12 inches to any portion of the register of the furnace. Floor furnaces shall not be
installed in concrete floor construction built on ground. No door or doors that can
be closed shall be permitted between the floor furnace location and the controlling
thermostat, nor shall any floor furnace be installed in such a manner that will permit
any door to swing over it.
§201.29.5 Bracing. The floor around the furnace shall be braced and headed with a
framework of material not lighter than the joists.
§201.29.6 Support. Means shall be provided to support the furnace when the floor
grille is removed.
§201.29.7 Clearance. The lowest portion of the floor furnace shall have at least a 6
inch clearance from the general ground level, except that where the lower 6 inch portion of the floor
furnace is sealed by the manufacturer to prevent entrance of water, the clearance may be reduced to
no less than 2 inches. When these clearances are not present, the ground below and to sides shall be
excavated to form a "basin-line" pit under the furnace so that the required clearance is provided
beneath the lowest portion of the furnace. A 12 inch clearance shall be provided on all sides except
the control side, which shall have an 18 inch clearance.
27
§201.29.8 Seepage Pan. Whenever the excavation exceeds 12 inches and/or water
seepage is likely, a watertight copper pan, concrete pit, or other suitable material shall be used. A
copper pan shall be made of not less than 16-ounce-per-square-foot sheet copper. Then pan shall be
anchored in place, so as to prevent floating, and the walls shall extend at least 4 inches above the
ground level, with 6 inch clearances on all sides except the control side, which shall have 18 inch
clearance. When the equipment is sealed by the manufacturer to meet this condition, the pan or pit
may be omitted if not required for maintaining a dry condition for service access.
§201.29.9 Access. Provision shall be made for access to the floor furnace by means of
an opening in the foundation wall of at least 18 by 24 inches, or through a trap door at least 18 by
24 inches located at some convenient point, and a clear unobstructed passageway to the floor
furnace of at least 18 inches by 24 inches wide.
§201.29.10 Wind Protection. Floor furnaces shall be protected where necessary,
against severe wind conditions.
§201.30 Duct and Attic Furnaces (See Sections 201.21 - 201.45).
§201.30.1 Clearance. Listed gas-fired duct or attic furnaces shall be installed with
clearances of at least six inches (6") between adjacent walls, ceilings and floors of combustible
construction and the appliance projecting draft hood, except that furnaces approved for installation
at lesser clearance, may be installed in accordance with their approval. In no case shall the
clearance be such as to interfere with their approval. In no case shall the clearance be such as to
interest with the requirements for combustion air and accessibility. (See 201.21.4 and 201.30.4).
Combustible floors under all duct or attic furnaces shall be protected according to the
manufacturer's specifications. Floor protection if required must extend at least 12" beyond all sides
of the furnace or to the wall of the furnace enclosure, if the furnace is less than 12" from the wall.
§201.30.2 Erection, Connection and Controls of Appliances. A duct or attic furnace
shall be erected and firmly supported in accordance with the manufacturer's instructions and shall
be installed on the discharge side of the blower. All duct or attic furnaces, which are automatically
fired and equipped with a fan or blower to circulate the air, must be equipped with a temperature
limit control that cannot be set higher than 250 degrees F. A flexible fire resistant duct connection
shall be made at outlet of heat exchanger on all duct and attic furnace installations. (See insulation
requirements 201.3.0.7).
§201.30.3 Accessibility. The installation of duct or attic furnaces shall be such as to
make them accessible for cleaning the heating surfaces, removal of filters or burners, replacement
of sections, controls, draft hoods and other working parts, and for adjustment of parts requiring
such attention.
Attic furnaces shall not be installed in any location inaccessible for inspection or repair.
28
The space in which any attic furnace is installed shall be accessible by an opening and passageway
as large as the largest part of the furnace, but not less than twenty-four inches by twenty-four inches
(24" x 24") and shall be continuous from the opening to the furnace control and valves. An electric
light shall be provided at or near the furnace location. Every passageway in an attic shall have solid
continuous flooring twenty-four (24") wide from the entrance opening to the furnace. A ladder or
stairway permanently fastened to the building should be provided leading to the attic opening.
§201.30.4 Location of Draft Hood and Controls. The controls and draft hoods for
duct furnaces shall be located outside the ducts. The draft hood shall be located in the same
enclosure from which combustion air is taken.
§201.30.5 Circulating Air. (Air heated by the furnace). Circulating air shall not be
taken from the same enclosure in which the furnace is located.
§201.30.6 Duct Furnaces Used With Refrigeration Systems and Blowers. A duct
furnace when used in conjunction with a refrigeration system shall be installed on the discharge
side of the blower. The duct furnace shall be installed parallel with or ahead of the refrigerating
coil. If the refrigerating coil is installed in the air discharge duct from the duct furnace, this coil
shall be installed in or provided with a by-pass duct unless the duct furnace is listed for operation
with at least 0.5" static pressure at the outlet air connection.
§201.30.7 Installation and Insulation. All flexible duct connections shall be made
with fire resistant material. All supply duct work exposed in unheated attic spaces shall be
insulated.
§201.31 Conversion Burners. (See Sections 201.24 - 201.37 and 201.46 - 201.62).
Installation of conversion burners shall conform to American Standard Requirements for
Installation of Domestic Gas Conversion Burners, Z21/ 8-2948.
§201.32 Gas-Fired Unit Heaters. (See Sections 201.24 - 201.37 and 201.46 -
201.62)
§201.32.1 Support. Suspended type gas-fired unit heaters shall be safely and
adequately supported with due consideration given to their weight and vibration characteristics.
§201.32.2 Clearances. Listed gas-fired heaters shall be installed with minimum
clearance of six inches between the appliance, projecting flue box or draft hood and combustible
construction.
§201.32.3 Ductwork. A unit heater shall not be attached to a warm air duct system
unless listed for such installation.
29
§201.32.4 Garage Installation. Unit heaters installed in garages for more than 3
motor vehicles or in airplane hangers shall be installed at least 8 feet above the floor.
30
§201.33 Clothes Dryers. (See Sections 201.24 and 201.46 - 201.62).
§201.33.1 Clearance and Venting. Listed clothes dryers shall be installed for
minimum clearance of six inches (6") from adjacent combustible construction except that clothes
dryers listed for installation at lesser clearances may be installed in accordance with their listing. A
minimum clearance of sixteen inches (16") shall be provided between the top of the flue and the
lower surface of any combustible material located above the dryer.
When this appliance is installed within the living area of a home, provision should be made
for exhausting the extracted moisture to the outside atmosphere and not into flue.
§201.33.2 Public Use. Gas-fired clothes dryers installed for multiple family use shall
be equipped with listed automatic pilots.
31
§201.34 Gas-Fired Incinerators. (See Sections 201.9 - 201.20 and 201.46 - 201.62).
§201.34.1 Clearances. Listed gas-fired incinerators shall be installed as close as
practicable to a chimney and with at least 12 inches clearance between sides and combustible
construction, except that appliances approved for installation at lesser clearances may be installed in
accordance with their listing. In no case shall the clearance be such as to interfere with the
requirements for combustion air and accessibility. (See 201.21.4 and 201.21.7) Incinerators of the
wall type shall be installed in a non-combustible wall communicating directly with a chimney flue.
§201.34.2 Smoke Pipe Connection. No draft hood shall be connected into the smoke
pipe of an incinerator. Where conditions permit, it is preferable to have the smoke pipe connected
to a separate chimney flue (See 201.42.8).
§201.34.3 Smoke Pipe Clearance. Smoke pipes shall have at least 18 inches
clearance from combustible construction and shall not pass through combustible construction
unless guarded at the point of passage as specified in 201.41.8.
§201.34.4 Smoke Pipe Material. The smoke pipe from an incinerator to a Type A
flue or vent shall be galvanized steel of a thickness at least No. 24 U. S. Standard Gauge or of
material having equivalent or superior heat and corrosion resistant properties, and the joints shall be
secured by sheet metal screws.
§201.34.5 Automatic Pilot Devices. Automatic pilot devices having a response time
of not more than 5 seconds shall be installed on all gas burners in unlisted commercial incinerators
installed in building.
§201.35 Gas Refrigerators. (See Sections 201.24 - 201.37 and 201.46 - 201.62)
Gas refrigerators shall be provided with adequate clearances for ventilation at the top and back.
They shall be installed in accordance with the manufacturer's instructions.
§201.36 Hot Plates and Laundry Stoves. (See Sections 201.24 - 2012.37 and
201.46 - 201.62) Listed domestic hot plates and laundry stoves when installed on combustible
surfaces shall be set on their own legs or bases. They shall be installed with minimum horizontal
clearances of 6 inches from combustible construction.
The vertical distance between tops of all domestic hot plates and laundry stoves and
combustible construction shall be at least 36 inches.
§201.37 Hotel and Restaurant Gas Cooking Equipment. (See Sections 201.14 -
201.37 and 201.46 - 201.62) These appliances shall be installed in accordance with the terms of
their listing.
32
VENTING OF APPLIANCES
Under this caption appear the fundamental requirements for venting gas appliances that
must be observed to assure safety to persons or property under ordinary circumstances. The
responsibility for observing:
REQUIREMENTS FOR VENTING
§201.38 Appliances Requiring Flues or Vents. Appliances of the following types
shall be flue or vent connected or provided with other approved means for exhausting the flue gases
to the outside atmosphere:
A. Space heating steam and hot water boilers and warm air furnaces, floor furnaces,
unit heaters, duct furnaces and recess heaters.
B. Gas-fired incinerators.
C. Water heaters with inputs over 5,000 Btu per hour.
D. Room heaters listed for vented use only.
E. Appliances equipped with gas conversion burners.
F. Appliances listed for vented use only.
§201.38.1 Appliances Not Requiring Flues or Vents. Any appliances included
below listed for vented use or having installation limitations shall be installed in accordance with its
listing or installation limitations.
A. Gas ranges.
B. Gas refrigerators.
C. Counter appliances.
D. domestic clothes dryers.
E. Room heater or heaters listed for unvented use, installed in the same room, which if
not vented, would make the total input rating of the unvented heating appliances less
than 30 Btu per hour per cu. ft. of room content. (See 201.26.3 for Prohibited
Installations.)
§201.39 Draft Hoods.
33
§201.39.1 Type of Draft Hoods. Every appliances listed for vented use, except
incinerators, dual oven type combination ranges, units designed for power burners or for forced
venting, shall have a draft hood.
§201.39.2 Installation of Draft Hood. Where the draft hood is a part of the
appliances or is supplied by the appliance manufacturer, it shall be installed without alteration in
accordance with the manufacturer's instructions. In the absence of manufacturer's instructions the
draft hood shall be attached to the flue collar of the appliance or as near to the appliance as
conditions permit. In no case shall a draft hood be installed in a false ceiling, in a different room, or
in any manner that will permit a difference in pressure between the draft hood relief opening and
the combustion air supply.
§201.39.3 Position of Draft Hood. A draft hood s hall be installed in the position for
which it was designed with reference to the horizontal and vertical planes and shall be so located
that the relief opening is not obstructed by any part of the appliance or adjacent construction.
§201.39.4 Special Draft Hoods. Where the installer must supply a draft hood of
special design, see "Listing Requirements for Draft Hoods ASA Z 21-12--1927".
§201.40 Types of Flues or Vents.
§201.40.1 Type A Flues or Vents. Type A Flues* or Vents* shall be employed for
venting the following appliances:
A. All incinerators.
B. All appliances which may be converted to the use of solid or liquid fuels.
C. All boilers and warm-air furnaces except where the administrative authority
approves the use of Type B gas flues or vents.
§201.40.2 Type B Gas Flues or Vents. Type B gas flues* or vents* shall be used only
with listed gas appliances which produce flue gas temperatures not in excess of 550 degrees F at the
outlet of the draft hood when burning gas at the manufacturer's normal input rating and not
specified by 201.40.1 to be vented to Type A Flues* or vents*.
For the purpose of this provision listed appliances with the exception of incinerators and
conversion burners may be accepted as producing flue gas temperatures not in excess of 550
degrees F at the outlet of the draft hood.
§201.40.3 Type C Gas Flues or Vents. Type C flues* or vents* shall be used only for
34
runs directly from the space in which the appliance is located through the roof or exterior wall to
the outer air. Such flues or vents shall not be installed in any attic or concealed space nor through
any floor. Installation with reference to clearance to combustible construction and passage through
wall or roof shall comply with provisions of 201.41.8 and 201.41.9.
§201.41 Flue or Vent Connectors.
§201.41.1 Materials. The material used for the flue or vent connector shall be
resistant to corrosion and be of sufficient thickness to withstand damage. Where a question arises
as to the suitability of a particular material, the administrative authority shall be consulted.
§201.41.2 Avoid Bends. The flue or vent connectors shall be installed so as to avoid
short turns or other constructural features that would create excessive resistance to the flow of
gases.
§201.41.3 Pitch. The flue or vent connectors shall maintain a pitch or rise from the
appliance to the flue or vent. A rise as great as possible, at least 1/4 inch to the foot (horizontal
length) shall be maintained. The vent connector shall be free from any dips or sags.
§201.41.4 Provide Vertical Runs. Wherever sufficient head-room is available,
appliances having a horizontal flue outlet shall be provided with a vertical run of flue or vent
connector before installing the horizontal length. To minimize frictional resistance in the vent
connector, it is recommended that 45 degree elbows be used.
§201.41.5 Length. The horizontal length of the vent connector shall be as short as
possible and the appliance shall all be located as near the flue or vent as practicable. The maximum
horizontal length of the vent connector shall not exceed 75% of the vertical height of the flue or
vent.
§201.41.6 Support. Flue or vent connectors shall be securely supported.
§201.41.7 Permanent Joints. To avoid the possibility of joints being pulled apart,
every joint of vent or flue pipe shall be either securely fastened in position by supporting hangers or
brackets and each joint of metal pipe shall be permanently secured together with metal screwers,
rivets, ratchet nails or by other means acceptable to the administrative authority.
§201.41.8 Clearance. Flue or vent connectors shall be located in such a manner that
continued operation of the appliance will not raise the temperature of the surrounding combustible
construction more than 90 degrees above normal room temperature. Minimum clearances from
combustible construction to flue or vent connectors for listed appliances are shown in Table 8.
35
Table 8
DRAFT HOOD, FLUE OR VENT CONNECTOR CLEARANCE
FOR LISTED APPLIANCES
Minimum Distance from Combustible
Construction
(Except as otherwise specified in
the listing of a nationally
recognized testing agency.)
Draft Metal Flue or Fine or
Appliance Hood VentConnectors Vent Connectors
(Type C) (Type B)
Boiler 6 inches 6 inches 1 inch
Warm Air Furnace 6 inches 6 inches 1 inch
Water Heater 6 inches 6 inches 1 inch
Room Heater 2 inches 6 inches 1 inch
Floor Furnace 9 inches 9 inches 3 inches*
Incinerator not permitted 8 inches not permitted
* 3 inches for a distance of not less than three feet from outlet of the draft hood. Beyond
three feet the minimum clearance is one inch.
The clearance for metal flue or vent connectors to combustible construction is protected in
accordance with this table.
Table 9
CLEARANCES WITH SPECIFIED FORMS OF PROTECTION
TYPE OF PROTECTION Where the required clearance with
no protection is:
(All combustible construc- 9 Inches 9 Inches 18 Inches
tion must be protected if Clearance Clearance Clearance
closer to the vent than Reduced Reduced Reduced
the required clearance to to to
with no protection).
1/4 in. asbestos millboard
spaced out 1 in. with
no-combustible spacers. 3 inches 6 inches 12 inches
28 gauge sheet metal on
1/4 in. asbestos mill-
board 2 inches 4 inches 12 inches
18 gauge sheet metal spaced
out 1 in. with non-
combustible spacers 2 inches 4 inches 9 inches
36
§201.41.9 Use of Thimbles. Flue or vent connectors other than Type B, shall not pass
through any combustible wall unless they are guarded at the point of passage by ventilated metal
thimbles not smaller than the following:
For listed appliances, except floor furnaces and incinerators, -- 4 inches larger in diameter
than the flue or vent connector unless there is a run of not less than 6 feet or flue or vent connector
in the open, between the draft hood outlet and the thimble, in which case the thimble may be 2
inches larger in diameter than the flue or vent connector.
for listed floor furnaces -- 6 inches larger in diameter than the flue or vent connector.
for incinerators -- 12 inches larger in diameter than the flue or vent connector.
§201.41.10 Size. The flue or vent connector shall not be smaller than the size of the flue
collar or the size of the outlet of the draft hood supplied by the manufacturer's specific instructions,
the flue or vent connector shall be made in accordance with the vent manufacturer's instructions or
in a manner acceptable to the proper administrative authority.
§201.41.11 No Dampers. No manually operated damper shall be placed in any flue or
vent connector except that a damper which will not close off more than 80 percent of the cross-
sectional area may be installed in the flue or vent connector or a gas-fired incinerator. Fixed baffles
ahead of draft hoods are not classified as dampers.
§201.41.12 Fireplace. A flue or vent connector shall not be connected to a chimney
flue having a fireplace opening unless the opening is permanently sealed.
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§201.42 Flues or Vents. (This section applies only to natural draft venting. Forced
draft or exhaust systems and power burners usually require special engineering and installation and
should be approved by the administrative authority.)
§201.42.1 Check Chimney. Before connecting a flue or vent connector, the flue or
vent shall be examined to ascertain that it is properly constructed, clear, and will freely conduct the
products of combustion to the outer air.
§201.42.2 Size. The flue or vent to which the flue or vent connector is connected shall
be of a size equal to the draft hood collar or as specified in Table 10. In no case shall the area be
less than the area of 3 inch diameter pipe. When more than one appliance vents into a flue or vent,
the flue or vent area shall be not less than the area of the largest flue or vent connector plus 50
percent of the areas of the additional flue or vent connectors. An elliptical or rectangular flue or
vent may be used provided its flue gas venting capacity as determined from manufacturer's capacity
tables is equal to the capacity of round pipe for which it is substituted.
§201.42.3 Height. The flue or vent should extend high enough above the building or
other neighboring obstruction so that wind from any direction will not strike the flue or vent from
an angle above horizontal. Unless the obstruction is of great magnitude, it is usual experience that a
flue or vent extended at least two feet above flat roofs or two feet above the highest part of wall
parapets and peaked roofs within 20 feet will be reasonably free from down drafts.
Table 10
ALLOWABLE BTU INPUT TO FIRE-CLAY TITLE LINED
CHIMNEYS FOR GAS APPLIANCES
WITH DRAFT DIVERTERS
Height from outlet of
Outside Inside Highest Appliance
Size Size
10' 20' 30' 40' 50'
4 1/2 x 8 1/2" 2 7/8 x 6 7/8" 42M 50M 61M 66M 71M
4 1/2 x 13" 3 x 11 70M 87M 103M 112M 117M
8 1/2 x 8 1/2" 6 1/2 x 6 1/2" 114M 40M 161M 177M 192M
8 1/2 x 13" 6 1/2 x 11" 185M 247M 288M 314M 340M
13 x 13" 11 x 11" 320M 420M 505M 580M 620M
38
ALLOWABLE BTU INPUT TO ROUND FLUE OR VENT PIPE
Height from outlet of
Size Inside Highest Appliance
Round Size
Pipe 10' 20' 30' 40' 50'
3" 24M 27M 30M 32M
4" 45M 50M 58M 60M 68M
5" 75M 81M 93M 100M 110M
6" 110M 130M 145M 160M 165M
7" 160M 175M 200M 215M 230M
8" 210M 230M 275M 300M 360M
§201.42.4 Chimney Entrance. In entering a chimney flue the connection shall be 12
inches above the extreme bottom to avoid stoppage. Means shall be employed which will prevent
the flue or vent connector from entering so far as to unduly restrict the space between its end and
the opposite wall of the chimney. A thimble or slip joint may be used to facilitate removal of the
flue or vent connector for cleaning.
§201.42.5 Cleanouts. Cleanouts shall be of such construction that they will remain
tightly closed when not in use.
§201.42.6 Venting Into Flues Used for Other Fuels. A gas appliance automatically
controlled may be connected through separate openings to a flue that also serves equipment for the
combustion of solid or liquid fuel. In no case shall a gas vent and a vent for a solid or liquid fuel be
connected together by a "y" before entering a common flue. If two or more openings are provided
into one flue they should be different levels.
§201.42.7 Flue Connecting Two or More Gas Appliances. In order to promote
better draft where more than one gas appliance flue or vent connector is connected to a flue or vent,
the connections should be made at different levels. Two or more gas appliances may be vented
through a common flue or vent connector when necessary, if jointed as close as practical to the flue
or vent, and provided the size of the common flue or vent is sufficient to accommodate the total
volume of flue gasses. All transitions shall be in accordance with manufacturer's instructions or in
a manner acceptable to the administrative authority.
§201.42.8 Unlined Chimneys. Where an existing chimney is unlined or where local
experience indicates that flue gas condensate might be a problem, consult the administrative
authority, for information about liners that are suitable for the locality.
§201.42.9 Vent Tops. A vent top acceptable to the administrative authority which does
not obstruct or reduce the effective cross-sectional area of the flue or vent outlet shall be used on all
type B and type C vents. Movable or spinner type vent caps are strictly prohibited.
39
§201.42.10 Room Exhausters and Appliance Blowers. No fan or blower shall be
discharged into any vent, flue, chimney or flue or vent connector into which a gas appliance is
vented by natural draft unless the vent connector from the natural draft gas appliance is reconnected
to the suction side of the fan or blower.
40
§201.43 Outside Flues or Vent.
§201.43.1 Material. Outside flues or vents are not recommended and they are
particularly unsuccessful in severe climates and in small sizes, but when they must be used the
material shall be resistant to the action of combustion products and shall possess adequate
insulation qualities or be adequately insulated to minimize condensation and aid draft.
§201.43.2 Support Flue or Vent Pipe. When a flue or vent must be installed on the
outside of the building, it shall be securely supported.
§201.43.3 Prohibited Installation. Natural draft vents extending through and
terminating adjacent to outside walls are prohibited. (See 201.43.3)
§201.44 Special Venting Arrangements.
§201.44.1 Appliances With Sealed Combustion Chambers. The provisions of
§201.39 to §201.43 inclusive, do not apply to listed appliances having sealed combustion chambers
and which are so constructed and installed that all air for combustion is derived from outside the
space being heated and all flue gases are discharged to the outside atmosphere. Such appliances
shall be installed in accordance with the terms of their listings.
§201.44.2 Mechanical Flue Exhausters. Mechanical flue exhausters may be used
with gas appliances in lieu of natural draft vents except on incinerators; when used provisions shall
be made to prevent the flow of gas to the burners in the event of failure of the mechanical exhaust
system. No gas appliance vented by natural draft shall be connected into a vent, flue, chimney or
flue or vent connector on the discharge side of a mechanical flue exhauster.
§201.45 Chimneys. All shelf chimneys shall be lined with an approved liner before
connecting any gas-heating appliance to the chimney.
41
PROCEDURES TO BE FOLLOWED TO PLACE AN
APPLIANCE IN OPERATION
Under this caption appear the fundamental procedures to be followed in placing an
appliance in operation and instructing the consumer in its safe and satisfactory use. Responsibility
for observing these requirements shall rest with the installing agency.
§201.46 Adjusting the Burner Input.
§201.46.1 Burner Input. Each burner shall be adjusted to its proper input in
accordance with the manufacturer's instructions. Over-rating of burners is prohibited.
§201.46.2 High Altitude. Gas appliances listed for high altitude operation shall be
adjusted to the high altitude input rating shown on the name plate when installed at elevations
between 2,000 and 5,000 ft. above sea level. When installed at elevations above 5,000 ft., the listed
high altitude rating shall be reduced at the rate of 4 percent for each additional 1,000 ft. Appliances
not listed for high altitude operation and installed at elevations above 2,000 shall have their ratings
reduced at the rate of 4 percent for each 1,000 ft. above sea level.
§201.47 Automatic Pilots. When an automatic pilot is provided it shall be checked
for proper operation and adjustment in accordance with the manufacturer's instructions. If the pilot
does not function properly to turn off the gas supply in the event of pilot outage, it shall be adjusted
or replaced.
§201.48 Protective Devices. All protective devices furnished with the appliance,
such as a limit control, fan control to blower, temperature and pressure relief valve, low water cut-
off device and manual operating features, etc., shall be checked to assure proper operation.
§201.49 Checking the Draft. On flue connected appliances, the appliance shall be
operated for a few minutes and the installation checked to see that the products of combustion are
going up the flue or vent properly by passing a lighted match or taper around the edge of the relief
opening of the draft hood. If the flue or vent is drawing properly, the match flame will be drawn
into the draft hood, the appliance shall not be left in operation until proper, adjustments or repairs
are made to assure adequate draft through the flue or vent.
§201.50 Instructions to the Consumer. When operating instructions are furnished
by the manufacturer they shall be left with the consumer or with the appliance.
42
REQUIREMENTS FOR INSTALLATION OF GAS BURNERS
AND CONTROLS IN UNLISTED BOILERS USED FOR HEATING
AND WATER HEATING
§201.51 Scope. The following requirements are designed to provide minimum safety
standards for the installation of gas equipment in unlisted boilers having an input over 40,000 Btu
per hour and which have a working pressure of not over 15 pounds and furnish steam, hot water, or
both for heating and water heating. Where conditions exist which are not specifically covered by
these minimum safety standards, the administrative authority shall be consulted for advice relative
to proper installation methods.
§201.52 Combustion’s Air. Properly designed permanent facilities for supplying
ample amount of outside air to assure combustion of the gas shall be provided. Where combustion
air is taken from the space in which the boiler is located and no manufacturer's instructions are
available, an opening to the outside air shall be provided having a net free area of 0.75 square feet
or more for each 1,000,000 Btu per hour of total burner input, or an opening equivalent to the total
area of the stack or stacks that are being used, whichever is the greater. The above provisions only
apply to boilers in which the products of combustion are undiluted in the flue or vent connector.
When draft diverters, check drafts, fixed check openings, barometric dampers and/or a boiler room
ventilating system is used, additional openings shall be provided for adequate air infiltration
without affecting the combustion in the firebox.
§201.53 Ventilation. Adequate ventilation of the boiler room shall be provided.
The ventilation system shall in no case adversely affect the combustion of gas in the boiler.
§201.54 Flues and Flue Connectors.
A. All boilers shall be properly and firmly connected to a chimney or stack of ample
size to carry away the flue gases. The flue connector shall not be smaller than the
outlet on the boiler.
B. Means for limiting draft shall be installed on each boiler. When a manually
operated damper is used in a normally stationary position to limit chimney draft,
positive means shall be provided to lock the damper in position. The manually
operated damper shall be installed between the boiler and any application of
automatic or modulating draft limiting devices.
C. When an automatically controlled or modulating damper is used with the burner
control assembly, this damper shall be interlocked with the burner input control
valve to prevent lighting the burner unless the damper is open.
D. Adjustable (modulating) dampers, where used for fuel-air ratio-control, shall be
equipped with suitable located maximum and minimum operating stops. The
43
minimum operating stops for such dampers shall be located to assure combustion of
the gas at the minimum burner input. These dampers shall be counterbalanced to
open in event of breakage or failure of their operating means.
§201.55 Burners. The burner or burners and their component parts shall be properly
installed and firmly secured in accordance with the burner manufacturer's instructions. The burner
or burners must be installed in such a manner as to permit their being withdrawn for repairs or
alterations without disturbing the furnace walls or settings. Weight of the walls must not rest on
horizontal burners.
The gas must be burned in such a manner throughout the range of turndown so there will be
no puffing, vibration, flame lifting, backfiring or injurious flame impingement on walls or heating
surfaces in a manner that will cause damage to the boiler parts.
Burners shall also maintain stable combustion at the minimum rate of firing or during any
sudden changes in the gas-firing rate between maximum and minimum rates.
§201.56 Air Intakes.
A. Air openings into the combustion chamber of firebox shall be provided with
sufficient area to supply an adequate amount of air for combustion under the
actual draft conditions existing at the maximum rate of firing. The air shall
be introduced in a manner so as to obtain thorough mixing of the gas and air
in order to assure combustion within the space provided.
B. For manually or automatically controlled boilers having forced or induced
draft fan or both, means shall be provided to continue safe combustion or to
shut off the gas in case of draft failure for any cause. Forced or induced
draft installations shall be provided with a mechanical timer to require a
five-minute purge period prior to pilot ignition after shut down. No spark or
ignition shall be allowed to occur in the firebox during the purging cycle.
§201.57 Pilots.
A. An adequate gas pilot or pilots shall be used to assure positive ignition of the
burner or burners.
B. An automatic pilot device or flame safeguard so constructed and installed
that no gas can flow to the main burner or burner group unless satisfactory
ignition is assured, shall be employed at each burner or group of burners
operating as a unit, for all automatically controlled boilers. Gas to main
burners and to intermittent or ignition pilots shall be automatically shut off
in case of flame failure at the point of supervision.
C. The response time of the flame safeguard to de-energize the gas shutoff
44
device on flame failure shall not exceed 5 seconds for unlisted boilers
having inputs in excess of 400,000 Btu per hour. Pilot supervision by such
automatic pilot device shall be only at the point where the flame will
effectively ignite the gas at the main burner of burners.
D. Electric ignition systems shall ignite, only a pilot. The input to the pilot
shall not exceed 3 percent of the maximum input to the main burner as fired.
If ignition of the pilot is not obtained within 15 seconds, the gas shall shut
off automatically.
E. All pilot burners and automatic pilot devices shall be supported in such a
manner that their position relative to each other and to the flame of the main
burner or burners will remain fixed. Means shall be provided to permit
ready observation of all three while firing. No wiring or control shall be
subjected to the heat from the burner unless it is specifically designed to
withstand such temperatures.
F. All automatic pilot burners and automatic pilot devices shall be readily
accessible and removable for servicing. Pilot burners shall be placed so that
they can be safely lighted manually, if required. Where push button controls
are used for manually opening pilot solenoid valves, they shall be installed
so one operator can light the automatic pilot and operate the push button
simultaneously.
G. On automatically controlled boilers, the gas supply pressure to the pilot or
group of pilots shall be regulated independently of the main burner supply
by a gas pressure regulator in the pilot supply line.
H. Pilot lines shall be connected to vertical main gas supply pipes or to the
sides or top of horizontal lines upstream from all gas control valves and they
shall be independently controlled by a manually operated pilot shut-off
valve, on installation requiring more than one pilot, a manually operated
shut-off valve shall be provided for each pilot.
§201.58 Manual Shut-off Valves.
A. Each boiler burner assembly shall have a lubricating plug type shut-off valve
with handle permanently attached that will shut off the gas to the burner and
control valve assembly.
B. If the firing rate of the burner is controlled manually, each burner shall have
a separate firing valve designed for the maximum operating gas pressure on
the burner.
45
§201.59 Control Valves.
A. All boiler input control valves and safety shut-off valves must be installed
downstream from the shut-off valves described in 201.58(A).
B. A by-pass may be installed around a throttling type burner input control
valve to provide for minimum flame. When such a by-pass or minimum
flow setting is used with a burner input control valve, a separate safety shut-
off valve shall be installed to shut off the gas supply when the limit or
protective controls are actuated.
C. Electrically operated safety shut-off valves shall fail-safe and not depend on
electricity to shut off of the gas supply. All vents from any control valve
actuated by gas pressure shall be piped into the firebox adjacent to a constant
burning pilot or to a safe point outside the building. Iron or steel pipe or
tubing shall be used for venting the valve.
§201.60 Gas Pressure Regulators.
A. Where the gas supply pressure to the burner is higher than that at which the
burners normally operate on a particular installation, a gas pressure
regulator shall be used.
B. Regulators shall be of the spring loaded, dead weight or pressure balance
type and they shall maintain a gas pressure within 10% of the operating
pressure from maximum to minimum firing rates. The weight and lever
type of regulator shall not be used.
C. The pressure regulators shall be vested (1) into the furnace adjacent to a
constant burning pilot, or (2) to a safe point on the outside of the building.
Iron or steel pipe or tubing shall be used for venting the regulator.
§201.61 Indicating Pressure Gauge Connections. A suitable connection shall be
provided for attaching a gauge to indicate the gas pressure on the burner.
§201.62 Limiting Devices.
A. Automatically controlled burners in boilers shall be equipped with safety
devices arranged to prevent excessive pressures or temperatures by shutting
off the gas.
B. Lower water cut-offs shall be used on all automatically controlled steam
boilers.
46
§201.63 Limiting Devices.
A. In addition to thermostats and safety pilots, boilers or furnaces shall be
equipped with safety devices arranged to limit high steam pressures or water
temperatures in boilers, or high air temperatures in warm air furnaces. In
steam or vacuum vapor boilers, means must be provided to guard against
firing a dry boiler or one in which the water is dangerously low. The
limiting device on boilers shall limit the maximum steam pressure, to 10%
below that for which the safety valve is set. The limit control on a warm air
furnace shall limit the outlet air to a temperature not in excess of 250
degrees F.
B. On forced hot water systems either a relay shall be provided to operate both
the pump and the burner or the burner may be controlled by the temperature
of the water and the pump controlled by thermostat.