Natural Gas; Propane Gas - Williamson-Thermoflo GWC-070 Manual

GWC -
gas fired water boiler
Gas piping

Natural Gas

1. Refer to Figure 61 for pipe length and diameter.
Size gas supply piping for total flow to all connected
appliances. For each GWC boiler, provide for the
following gas flow (cfh = cubic feet per hour):
Boiler model
GWC-070
GWC-105
GWC-140
GWC-175
2. Inlet pressure required at gas valve inlet:
• maximum 13" w.c.
• minimum 4" w.c.
Install 100% lockup gas pressure regula-
tor in supply line if inlet pressure exceeds
13" water column. Adjust for 13" w.c.
maximum.

Propane Gas

1. Contact gas supplier to size pipes, tanks and 100%
lockup gas pressure regulator.
2. Adjust propane supply regulator provided by gas
supplier for 13" w.c. maximum pressure.
3. Inlet pressure required at gas valve inlet:
• m aximum 13" w.c.
• minimum 4" w.c.
Part number 550-142-056/0411
— Boiler Manual
(continued)
CFH natural gas
70
105
140
175
Pipe capacity for 0.60 specific gravity natural gas
Figure 61
Capacity in cubic feet of gas per hour
Natural gas only, with specific gravity of 0.60
Based on pressure drop of 0.3" w.c.
Gas pipe
length
(feet)
½"
10 132
20 92
30 73
40 63
50 56
75 45
100 38
150 31
For additional gas pipe sizing information, refer to ANSI Z223.1 (or
B149.1 orB149.2 for Canadian installations).
Gas pipe diameter —
¾" 1" 1¼"
278 520 1050
190 350 730
152 285 590
130 245 500
115 215 440
93 175 360
79 150 305
64 120 250
1½"
1600
1100
860
760
670
545
460
380
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