Boiler Manual - Weil-McLain

GV90+ gas-fired water boiler — Boiler ManualGas piping (continued)Natural Gas1. Refer to Figure 65 for pipe length and diameter.Size gas supply piping for total flow to all connectedappliances. For each GV90+ boiler, provide for thefollowing gas flow (cfh = cubic feet per hour):Boiler modelCFH natural gasGV90+3 70GV90+4 140GV90+5 105GV90+6 1752. Inlet pressure required at gas valve inlet:• maximum 14” w.c.• minimum 3.5” w.c.Install 100% lockup gas pressure regulatorin supply line if inlet pressure exceeds14” water column. Adjust for 14” w.c.maximum.Propane Gas1. Contact gas supplier to size pipes, tanks and 100%lockup gas pressure regulator.2. Adjust propane supply regulator provided by gassupplier for 14” w.c. maximum pressure.3. Inlet pressure required at gas valve inlet:• maximum 14” w.c.• minimum 3.5” w.c.Figure 65 Pipe capacity for 0.60 specific gravity natural gasGas pipelength(feet)Capacity in cubic feet of gas per hourNatural gas only, with specific gravity of 0.60Based on pressure drop of 0.3” w.c.Gas pipe diameter —½” ¾” 1” 1¼” 1½”10 132 278 520 1050 160020 92 190 350 730 110030 73 152 285 590 86040 63 130 245 500 76050 56 115 215 440 67075 45 93 175 360 545100 38 79 150 305 460150 31 64 120 250 380For additional gas pipe sizing information, refer to ANSI Z223.1 (orB149.1 orB149.2 for Canadian installations).Part number 550-142-054/1211 55