Lennox G20R series, Руководство по установке

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Page 10
GAS PIPING
Gas Supply
1- This unit is shipped standard for left side installation of
gas piping. Simply connect gas supply to piping asĆ
sembly.
2- A piping hole is also fabricated in the right side of the
unit for alternate piping arrangements.
3- When connecting gas supply, factors such as length
of run, number of fittings and furnace rating must be
considered to avoid excessive pressure drop. Table 4
lists recommended pipe sizes for typical applications.
4- Gas piping must not run in or through air ducts,
clothes chutes, chimneys or gas vents, dumb waiters
or elevator shafts.
5- Piping should be sloped 1/4 inch per 15 feet upward toĆ
ward the meter from the furnace. The piping must be
supported at proper intervals (every 8 to 10 feet) using
suitable hangers or straps. A drip leg should be installed
in vertical pipe runs to the unit.
6- In some localities, codes may require installation of a
manual main shut-off valve and union (furnished by
installer) external to the unit. Union must be of the
ground joint type.
IMPORTANT
Compounds used on threaded joints of gas piping
must be resistant to the actions of liquified pertoĆ
leum gases.
NOTE-Installer must provide a
1/8" N.P.T. plugged tap in the
field piping upstream of the gas supply connection to the
unit. Tap must be accessible for test gauge connection.
See figure 12.
NOTE-In case emergency shutoff is required, shut off
main manual gas valve and disconnect main power to
unit. These devices should be properly labeled by the inĆ
staller.
FIGURE 12
GROUND
JOINT
UNION
AUTOMATIC GAS VALVE
(with manual shut-off valve)
FIELD
PROVIDED
AND INSTALLED
GROUND
JOINT
UNION
LEFT SIDE PIPING
(STANDARD)
RIGHT SIDE PIPING
(ALTERNATE)
AUTOMATIC
GAS VALVE
(with manual shut-off valve)
DRIP LEG
DRIP LEG
MANUAL
MAIN SHUT-OFF VALVE
(With 1/8" NPT
Plugged Tap Shown)
MANUAL
MAIN SHUT-OFF VALVE
(With 1/8" NPT
Plugged Tap
Shown)
TABLE 4
GAS PIPE CAPACITY - FT
3
/HR (kL/HR)
Nominal Internal
Length of Pipe-Feet(m)
Nominal
Iron Pipe Size
-Inches(mm)
Internal
Diameter
-Inches(mm)
10
(3.048)
20
(6.096)
30
(9.144)
40
(12.192)
50
(15.240)
60
(18.288)
70
(21.336)
80
(24.384)
90
(27.432)
100
(30.480)
1/4
(6.35)
.364
(9.246)
43
(1.13)
29
(.82)
24
(.68)
20
(.57)
18
(.51)
16
(.45)
15
(.42)
14
(.40)
13
(.37)
12
(.34)
3/8
(9.53)
.493
(12.522)
95
(2.69)
65
(1.84)
52
(1.47)
45
(1.27)
40
(1.13)
36
(1.02)
33
(.73)
31
(.88)
29
(.82)
27
(.76)
1/2
(12.7)
.622
(17.799)
175
(4.96)
120
(3.40)
97
(2.75)
82
(2.32)
73
(2.07)
66
(1.87)
61
(1.73)
57
(1.61)
53
(1.50)
50
(1.42)
3/4
(19.05)
.824
(20.930)
360
(10.19)
250
(7.08)
200
(5.66)
170
(4.81)
151
(4.28)
138
(3.91)
125
(3.54)
118
(3.34)
110
(3.11)
103
(2.92)
1
(25.4)
1.049
(26.645)
680
(19.25)
465
(13.17)
375
(10.62)
320
(9.06)
285
(8.07)
260
(7.36)
240
(6.80)
220
(6.23)
205
(5.80)
195
(5.52)
1-1/4
(31.75)
1.380
(35.052)
1400
(39.64)
950
(26.90)
770
(21.80)
660
(18.69)
580
(16.42)
530
(15.01)
490
(13.87)
460
(13.03)
430
(12.18)
400
(11.33)
1-1/2
(38.1)
1.610
(40.894)
2100
(59.46)
460
(41.34)
1180
(33.41)
990
(28.03)
900
(25.48)
810
(22.94)
750
(21.24)
690
(19.54)
650
(18.41)
620
(17.56)
2
(50.8)
2.067
(52.502)
3950
(111.85)
2750
(77.87)
2200
(62.30)
1900
(53.80)
1680
(47.57)
1520
(43.04)
1400
(39.64)
1300
(36.81)
1220
(34.55)
1150
(32.56)
2-1/2
(63.5)
2.469
(67.713)
6300
(178.39)
4350
(123.17)
3520
(99.67)
3000
(84.95
2650
(75.04)
2400
(67.96)
2250
(63.71)
2050
(58.05)
1950
(55.22)
1850
(52.38)