Bryant 581B installation instructions Nominal Internal Length of PIPE, FT Iron Pipe Diameter Size

Table 2 Ð Maximum Gas Flow Capacity of Pipe in Cubic Ft of Gas Per Hour

for Gas Pressures of 0.5 Psig or Less and a Pressure Drop of 0.5 in. wg

(Based on a 0.60 Speci®c Gravity Gas)

NOMINAL	INTERNAL								LENGTH OF PIPE, FT*
IRON PIPE
	DIAMETER
SIZE	(in.)	10	20	30	40	50			60		70	80	90	100	125	150	175	200
(in.)
1¤2	.622	175	120	97	82	73			66		61	57	53	50	44	40	Ð	Ð
3¤4	.824	360	250	200	170	151			138		125	118	110	103	93	84	77	72
1	1.049	680	465	375	320	285			260		240	220	205	195	175	160	145	135
11¤4	1.380	1400	950	770	600	580			530		490	460	430	400	360	325	300	280
11¤2	1.610	2100	1460	1180	990	900			810		750	690	650	620	550	500	460	430
Refer to Table 10-2, National Fire Protection Association (NFPA), latest edition.
*This length includes an ordinary number of ®ttings.
NOTE: Typical natural gas heating value is 1000 Btuh per cubic ft.							115,000
For example: A 115,000 Btuh input unit equals 115 cubic ft per hour or										=	115 cubic ft/hr.
								1,000

When installing the gas supply line, observe local codes per- taining to gas pipe installations. Refer to the NFGC ANSI Z223.1-1992 (in Canada, CAN/CGA B149.1, [2]-M86) or NFPA 54-1992, in the absence of local building codes. Adhere to the following pertinent recommendations:

1.Avoid low spots in long runs of pipe. Grade all pipe 1¤4 inch in every 15 ft to prevent traps. Grade all hori- zontal runs downward to risers. Use risers to connect to heating section and to meter.

2.Protect all segments of piping system against physical and thermal damage. Support all piping with appropri- ate straps, hangers, etc. Use a minimum of one hanger every 6 ft. See Fig. 10. For pipe sizes larger than 1¤2 in., follow recommendations of national codes.

3.Apply joint compound (pipe dope) sparingly and only to male threads of joint when making pipe connections. Use only pipe dope that is resistant to action of lique®ed pe- troleum gases as speci®ed by local and/or national codes. Never use Te¯on-coated tape.

4.Install sediment trap in riser leading to heating sec- tion. This drip leg functions as a trap for dirt and con- densate. Install trap where condensate can not freeze. Install this sediment trap by connecting a piping tee to riser leading to heating section, so that straight- through section of tee is vertical. See Fig. 11. Then, con- nect capped nipple into lower end of tee. Extend capped nipple below level of gas controls.

5.Install an accessible, external, manual main shut-off valve in gas supply pipe within 6 ft of heating section.

6.Install ground-joint union close to heating section be- tween unit manual shutoff and external manual main shut-off valve.

7.Pressure-test all gas piping in accordance with local and national plumbing and gas codes before connecting pip- ing to unit.

NOTE: When pressure testing the gas supply system after the gas supply piping has been connected to the unit gas valve, the supply piping must be disconnected from the gas valve during any pressure testing of the piping systems at test pres- sure in excess of 0.5 psig. When pressure testing the gas sup- ply piping system at test pressures equal to or less than

0.5psig, the unit heating section must be isolated from the gas piping system by closing the external main manual shut- off valve and slightly opening the ground-joint union. After pressure test is completed, retighten ground-joint union.

Fig. 11 Ð Sediment Trap

CAUTION: Unstable operation may occur when the gas valve and manifold assembly are forced out of po- sition while connecting improperly routed rigid gas pip- ing to the gas valve. Use a backup wrench when mak- ing connection to avoid strain on, or distortion of, the gas control piping.

CAUTION: If a ¯exible conductor is required or al- lowed by the authority having jurisdiction, black iron pipe shall be installed at the gas valve and extend a minimum of 9 in. outside the unit casing.

WARNING: Never use a match or other open ¯ame when checking for gas leaks. Never purge gas line into combustion chamber. Failure to adhere to this warning could result in an explosion causing personal injury or death.

8.Check for gas leaks at all ®eld- and factory-installed gas lines after all piping connections have been completed. Use soap-and-water solution (or method speci®ed by lo- cal codes and/or regulations).

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