Weil-McLain GV90+ - Manual (Page 55)

Part number 550-142-054/0411
55
GV90+
gas
-
fired water boiler
— Boiler Manual
Figure 65 Pipe capacity for 0.60 specific gravity natural gas
Gas pipe
length
(feet)
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 diameter —
½” ¾” 1” 1¼” 1½”
10 132 278 520 1050 1600
20 92 190 350 730 1100
30 73 152 285 590 860
40 63 130 245 500 760
50 56 115 215 440 670
75 45 93 175 360 545
100 38 79 150 305 460
150 31 64 120 250 380
For additional gas pipe sizing information, refer to ANSI Z223.1 (or
B149.1 orB149.2 for Canadian installations).
Gas piping
(continued)
Natural Gas
1. Refer to Figure 65 for pipe length and diameter.
Size gas supply piping for total flow to all connected
appliances. For each GV90+ boiler, provide for the
following gas flow (cfh = cubic feet per hour):
Boiler model CFH natural gas
GV90+3 70
GV90+4 140
GV90+5 105
GV90+6 175
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:
• maximum 13” w.c.
• minimum 4” w.c.