Page 83 - 2018_IFGC

GAS PIPING INSTALLATIONS

403.9 Metallic pipe threads. Metallic pipe and fitting in excess of 1,000°F (578°C), or assembled with press-
threads shall be taper pipe threads and shall comply with connect fittings listed in accordance with ANSI LC4/CSA
ASME B1.20.1. 6.32.
403.9.1 Damaged threads. Pipe with threads that are 403.10.4 Flared joints. Flared joints shall be used only in
stripped, chipped, corroded or otherwise damaged shall systems constructed from nonferrous pipe and tubing
not be used. Where a weld opens during the operation of where experience or tests have demonstrated that the joint
cutting or threading, that portion of the pipe shall not be is suitable for the conditions and where provisions are
used. made in the design to prevent separation of the joints.
403.9.2 Number of threads. Field threading of metallic 403.10.5 Metallic fittings. Metallic fittings shall comply
pipe shall be in accordance with Table 403.9.2. with the following:
TABLE 403.9.2 1. Threaded fittings in sizes larger than 4 inches (102
SPECIFICATIONS FOR THREADING METALLIC PIPE mm) shall not be used.
APPROXIMATE LENGTH OF APPROXIMATE
IRON PIPE SIZE THREADED PORTION NUMBER OF THREADS 2. Fittings used with steel, stainless steel or wrought-
(inches) iron pipe shall be steel, stainless steel, copper alloy,
(inches) TO BE CUT
malleable iron or cast iron.
1 / 3 / 10
2 4
3. Fittings used with copper or copper alloy pipe shall
3 3
/ / 10
4 4
be copper or copper alloy.
1 7 / 10
8
4. Fittings used with aluminum-alloy pipe shall be of
1
1 / 1 11
4 aluminum alloy.
1
1 / 1 11
2 5. Cast-iron fittings:
2 1 11
5.1. Flanges shall be permitted.
1
1
2 / 1 / 12
2 2
5.2. Bushings shall not be used.
1
3 1 / 12
2
5.3. Fittings shall not be used in systems contain-
5
4 1 / 13
8 ing flammable gas-air mixtures.
For SI: 1 inch = 25.4 mm. 5.4. Fittings in sizes 4 inches (102 mm) and
larger shall not be used indoors except where
403.9.3 Thread joint compounds. Thread joint com-
pounds shall be resistant to the action of liquefied petro- approved.
leum gas or to any other chemical constituents of the gases 5.5. Fittings in sizes 6 inches (152 mm) and
to be conducted through the piping. larger shall not be used except where
approved.
403.10 Metallic piping joints and fittings. The type of pip-
ing joint used shall be suitable for the pressure-temperature 6. Aluminum-alloy fittings. Threads shall not form the
conditions and shall be selected giving consideration to joint joint seal.
tightness and mechanical strength under the service condi- 7. Zinc aluminum-alloy fittings. Fittings shall not be
tions. The joint shall be able to sustain the maximum end used in systems containing flammable gas-air mix-
force caused by the internal pressure and any additional tures.
forces caused by temperature expansion or contraction, vibra-
tion, fatigue or the weight of the pipe and its contents. 8. Special fittings. Fittings such as couplings, propri-
etary-type joints, saddle tees, gland-type compres-
403.10.1 Pipe joints. Schedule 40 and heavier pipe joints sion fittings and flared, flareless and compression-
shall be threaded, flanged, brazed, welded or assembled type tubing fittings shall be: used within the fitting
with press-connect fittings listed in accordance with ANSI manufacturer’s pressure-temperature recommenda-
LC4/CSA 6.32. Pipe lighter than Schedule 40 shall be tions; used within the service conditions anticipated
connected using press-connect fittings, flanges, brazing or with respect to vibration, fatigue, thermal expansion
welding. Where nonferrous pipe is brazed, the brazing and contraction; and shall be approved.
materials shall have a melting point in excess of 1,000°F
(538°C). Brazing alloys shall not contain more than 0.05- 9. Where pipe fittings are drilled and tapped in the
percent phosphorus. field, the operation shall be in accordance with all of
the following:
403.10.2 Copper tubing joints. Copper tubing joints shall
be assembled with approved gas tubing fittings, shall be 9.1. The operation shall be performed on systems
brazed with a material having a melting point in excess of having operating pressures of 5 psi (34.5
1,000°F (538°C) or assembled with press-connect fittings kPa) or less.
listed in accordance with ANSI LC-4/CSA 6.32. Brazing 9.2. The operation shall be performed by the gas
alloys shall not contain more than 0.05-percent phospho- supplier or the gas supplier’s designated rep-
rus. resentative.
403.10.3 Stainless steel tubing joints. Stainless steel tub- 9.3. The drilling and tapping operation shall be
ing joints shall be welded, assembled with approved tub- performed in accordance with written proce-
ing fittings, brazed with a material having a melting point dures prepared by the gas supplier.
70 2018 INTERNATIONAL FUEL GAS CODE ®
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