Trane IntelliPak 2 Series, Инструкция по установке, эксплуатации и обслуживанию

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RT-SVX24Q-EN 67
Table 23. Sizing natural gas pipe mains and branches (continued)
Gas SupplyPipe Run
(ft)
Gas Input (Cubic Feet/Hour)
1¼" Pipe 1½" Pipe 2" Pipe 2½" Pipe 3" Pipe 4" Pipe
200 209 313 602 960
1,700 3,460
Notes:
1 . Table is based upon specific gravity of 0.60. Refer to the latest edition of the National Fuel Gas Code, Z223.1, unless superseded by local gas codes.
2 . If more than one unit is served by the same main gas supply, consider the total gas input (cubic feet/hr.) and the total length when determining
the appropriate gas pipe size.
3 . Obtain the Specific Gravity and BTU/Cu.Ft. from the gas company.
4 . The following example demonstrates the considerations necessary when determining the actual pipe size:
Example: A 40' pipe run is needed to connect a unit with a 850 MBH furnace to a natural gas supply having a rating of 1,000 BTU/Cu.Ft. and a
specific gravity of 0.60
Cu.Ft/Hour = Furnace MBH Input
Gas BTU/Cu.Ft. X Multiplier
Table 24, p. 67
Cu.Ft/Hour = 850
The above table indicates that a 2" pipe is required.
Table 24. Specific gravity multipliers
Specific
Gravity Multiplier
0.50 1.10
0.55 1.04
0.60 1.00
0.65 0.96
Table 25. Gas heating capacity altitude correction factors
Altitude (Ft.)
Sea Level To
2000
2001 to
2500
2501 to
3500
3501 to
4500
4501 to
5500
5501 to
6500
6501 to
7500
Capacity Multiplier
1.00 .92 .88 .84 .80 .76 .72
Note: Correction factors are per AGA Std. 221.30 - 1964, Part VI, 6.12. Local codes may supersede.
Figure 49. Two-stage natural gas train for 850, 1100
Mbh heaters
Pilot Line
Gas Orifice
2-Stage
Regulating
Valve
Pilot Gas Valve
Safety Valve
Pilot Regulation
Figure 50. Modulating (850-2500 Mbh heaters) and
two-stage (1800-2500 Mbh heaters) natural gas train
Ignition control board
Ignition transformer
Safety valve
Single stage
regulating valve
Combustion blower
Combustion blower
pressure switch
Butterfly gas
control valve
Actuator
Table 26. Gas heat inlet sizes
Standard Gas Heat Input
(MBh) Gas Heat Inlet Sizes (in.)
850 1
1100
1 1/4
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