U.S. Boiler Company Alpine ALP500C, Installation, Operating And Service Instructions

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54
Warning
Explosion Hazard. Failure to properly pipe gas
supply to boiler may result in improper operation
and damage to the boiler or structure. always
assure gas piping is absolutely leak free and of
the proper size and type for the connected load.
an additional gas pressure regulator may be
needed. Consult gas supplier.
nOTiCE
Size corrugated stainless steel tubing (CSST)
to ensure proper capacity and minimize flow
restrictions.
A. Size gas piping. Design system to provide
adequate gas supply to boiler. Consider
these factors:
Inlet Pressure 14.0 in wc (3.4 kPa)or less; 0.3 in wc (0.07 kPa) Pressure Drop
Nominal Pipe
Size, In.
Inside
Diameter, In.
Length of Pipe, Ft.
10 20 30 40 50 60 70 80 90 100
½ 0.622 131 90 72 62 55 50 46 42 40 38
¾ 0.824 273 188 151 129 114 104 95 89 83 79
1 1.049 514 353 284 243 215 195 179 167 157 148
1¼ 1.380 1060 726 583 499 442 400 368 343 322 304
1½ 1.610 1580 1090 873 747 662 600 552 514 482 455
2 2.067 3050 2090 1680 1440 1280 1160 1060 989 928 877
2½ 2.469 4860 3340 2680 2290 2030 1840 1690 1580 1480 1400
3 3.068 8580 5900 4740 4050 3590 3260 3000 2790 2610 2470
Table 29: Maximum Capacity of Schedule 40 Black Pipe in CFH* (natural gas) For gas Pressures
of 1/2 psi (3.4 kPa) or Less
* 1 CFH of Natural Gas is approximately equal to 1 MBH; contact your gas supplier for the actual heating value of your
gas.
1. Allowable pressure drop from point of
delivery to boiler.
Maximum allowable system
pressure is ½ psig (3.4 kPa). Actual point of delivery
pressure may be less; contact gas supplier for
additional information. Minimum gas valve inlet
pressure is printed on the rating label located in the
boiler’s vestibule compartment.
2. Maximum gas demand.
Refer to the boiler’s
input as printed on its rating label. Also consider
existing and expected future gas utilization
equipment (i.e. water heater, cooking equipment).
3. Length of piping and number of fittings.
Refer to Tables 29 (natural gas) or 30 (LP gas) for
maximum capacity of Schedule 40 pipe. Table 31
lists equivalent pipe length for standard fittings.
4. Specific gravity of gas.
Gas piping systems for
gas with a specific gravity of 0.60 can be sized
directly from Table 29 and gas with a specific
gravity of 1.5 can be sized from Table 30, unless
authority having jurisdiction specifies a gravity
factor be applied. For other specific gravity, apply
gravity factor from Table 32. If exact specific
gravity is not shown choose next higher value.
Vii. gas Piping
Inlet Pressure 14.0 in wc (3.4 kPa) or less; 0.5 in wc (0.12 kPa) Pressure Drop
Nominal Pipe
Size, In.
Inside
Diameter, In.
Length of Pipe, Ft.
10 20 30 40 50 60 70 80 90 100
½ 0.622 172 118 95 81 72 65 60 56 52 50
¾ 0.824 360 247 199 170 151 137 126 117 110 104
1 1.049 678 466 374 320 284 257 237 220 207 195
1¼ 1.380 1390 957 768 657 583 528 486 452 424 400
1½ 1.610 2090 1430 1150 985 873 791 728 677 635 600
2 2.067 4020 2760 2220 1900 1680 1520 1400 1300 1220 1160
2½ 2.469 6400 4400 3530 3020 2680 2430 2230 2080 1950 1840
3 3.068 11300 7780 6250 5350 4740 4290 3950 3674 3450 3260