Lennox International Inc Gas Piping, Every 8 to 10 feet 2.44 to 3.01 m with suitable hang

Gas Piping									4 −	The piping should be sloped 1/4 inch (6.4 mm) per 15
										feet (4.57 m) upward toward the meter from the fur-
										nace. The piping must be supported at proper intervals
		CAUTION								[every 8 to 10 feet (2.44 to 3.01 m)] with suitable hang-
										ers or straps. Install a drip leg in vertical pipe runs to the
If a flexible gas connector is required or allowed by										unit.
the authority that has jurisdiction, black iron pipe									5 −	A 1/8" N.P.T. plugged tap or pressure post						is located
shall be installed at the gas valve and extend outside
										on the gas valve to facilitate test gauge connection.
the furnace cabinet. The flexible connector can then
										See figures 35 and 36.
be added between the black iron pipe and the gas
									6 − In some localities, codes may require the installation of
supply line.
										a manual main shut-off valve and union (furnished by
Gas Supply
										the installer) external to the unit. The union must be of
1 − This unit is shipped standard for left or right side instal-										the ground joint type.
	lation of gas piping (or top entry in horizontal applica-
												IMPORTANT
	tions). Connect the gas supply to the piping assembly.
2 −	When connecting the gas supply piping, consider fac-
									Compounds used on threaded joints of gas piping
	tors such as length of run, number of fittings, and fur-
									must be resistant to the actions of liquified petro-
	nace rating to avoid excessive pressure drop. Table 9
									leum gases.
	lists recommended pipe sizes for typical applications.
								NOTE − If emergency shutoff is necessary, shut off the main
3 −	The gas piping must not run in or through air ducts,
	clothes chutes, gas vents or chimneys, dumb waiters,							manual gas valve and disconnect main power to the fur-
	or elevator shafts.							nace. The installer should properly label these devices.
						TABLE 9
					Gas Pipe Capacity − ft3/hr (m3/hr)
Nominal		Internal					Length of Pipe − feet (m)
Iron Pipe
		Diameter
	Size
		inches	10	20	30	40		50			60		70	80	90	100
inches
		(mm)	(3.048)	(6.096)	(9.144)	(12.192)		(15.240)			(18.288)		(21.336)	(24.384)	(27.432)	(30.480)
	(mm)
	1/2	.622	175	120	97	82		73			66		61	57	53	50
	(12.7)	(17.799)	(4.96)	(3.40)	(2.75)	(2.32)		(2.07)			(1.87)		(1.73)	(1.61)	(1.50)	(1.42)
	3/4	.824	360	250	200	170		151			138		125	118	110	103
(19.05)		(20.930)	(10.19)	(7.08)	(5.66)	(4.81)		(4.28)			(3.91)		(3.54)	(3.34)	(3.11)	(2.92)
	1	1.049	680	465	375	320		285			260		240	220	205	195
	(25.4)	(26.645)	(919.25)	(13.17)	(10.62)	(9.06)		(8.07)			(7.36)		(6.80)	(6.23)	(5.80)	(5.52)
	1−1/4	1.380	1400	950	770	660		580			530		490	460	430	400
(31.75)		(35.052)	(39.64)	(26.90)	(21.80)	(18.69)		(16.42)			(15.01)		(13.87)	(13.03)	(12.18)	(11.33)
	1−1/2	1.610	2100	460	1180	990		900			810		750	690	650	620
	(38.1)	(40.894)	(59.46)	(41.34)	(33.41)	(28.03)		(25.48)			(22.94)		(21.24)	(19.54)	(18.41)	(17.56)
	2	2.067	3950	2750	2200	1900		1680			1520		1400	1300	1220	1150
	(50.8)	(52.502)	(111.85)	(77.87)	(62.30)	(53.80)		(47.57)			(43.04)		(39.64)	(36.81)	(34.55)	(32.56)
	2−1/2	2.469	6300	4350	3520	3000		2650			2400		2250	2050	1950	1850
	(63.5)	(67.713)	(178.39)	(123.17)	(99.67)	(84.95		(75.04)			(67.96)		(63.71)	(58.05)	(55.22)	(52.38)
	3	3.068	11000	7700	6250	5300		4750			4300		3900	3700	3450	3250
	(76.2)	(77.927)	(311.48)	(218.03)	(176.98)	(150.07)		(134.50)			(121.76)		(110.43)	(104.77)	(97.69)	(92.03)

NOTE − Capacity given in cubic feet (m3 ) of gas per hour and based on 0.60 specific gravity gas.

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