Bryant 355MAV instruction manual MaximumCapacity of Pipe, TypicalGas Pipe Arrangement

Table 3—Maximum Capacity of Pipe*

NOMINAL				LENGTH OF PIPE (FT)
IRON	INTERNAL
PIPE	DIAMETER
SIZE	(IN.)	10	20		30	40	50
(IN.)
1/2	0.622	175	120		97	82	73
3/4	0.824	360	250		200	170	151
1	1.049	680	465		375	320	285
1-1/4	1.380	1400	950		770	660	580
1-1/2	1.610	2100	1460		1180	990	900

*Cubic ft of gas per hr. for gas pressures of 0.5 psig (14–in. wc) or less and a pressure drop of 0.5–in wc (based on a 0.60 specific gravity gas). Ref: NFGC.

Risers must be used to connect to furnace and to meter. Support all gas piping with appropriate straps, hangers, etc. Use a minimum of 1 hanger every 6 ft. Joint compound (pipe dope) should be applied sparingly and only to male threads of joints. Pipe dope must be resistant to propane gas.

CAUTION: Connect gas pipe to furnace using a backup wrench to avoid damaging gas controls.

WARNING: Gas valve shutoff switch MUST be facing forward or tilted upward. Failure to follow this warning could result in property damage or death.

WARNING: Never purge a gas line into a combustion chamber. Never use matches, candles, flame, or other sources of ignition for purpose of checking leakage. Use a soap-and-water solution to check for leakage. Failure to follow this warning could result in fire, explosion, personal injury, or death.

WARNING: Use proper length of pipe to avoid stress on gas control manifold. Failure to follow this warning could result in a gas leak resulting in fire, explosion, personal injury, or death.

Install a sediment trap in riser leading to furnace. Trap can be installed by connecting a tee to riser leading to furnace so straight-through section of tee is vertical. Then connect a capped nipple into lower end of tee. Capped nipple should extend below level of gas controls. Place a ground joint union between gas control manifold and manual gas shutoff valve. (See Fig. 26.)

GAS

SUPPLY

MANUAL

SHUTOFF VALVE (REQUIRED)

SEDIMENT

TRAP

UNION

A93324

Fig. 26—Typical Gas Pipe Arrangement

CAUTION: If a flexible connector is required or allowed by authority having jurisdiction, black iron pipe shall be installed at gas valve and extend a minimum of 2 in. outside furnace casing.

An accessible manual shutoff valve MUST be installed upstream of furnace gas controls and within 6 ft of furnace. A 1/8-in. NPT plugged tapping, accessible for test gage connection, MUST be installed immediately upstream of gas supply connection to furnace and downstream of manual shutoff valve.

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