Connect Water Boiler Piping - Weil-McLain 78 Manual

Connect Water Boiler Piping

General water piping information:
Install piping:
unknown flow rates,
Cold
water fill
Check
valve
Manual
isolation
valve
Pressure
reducing
valve
(when used)
System return
(front or rear)
Figure 12 Water Boiler Piping
System
supply
(front only)
Expansion
tank
Water
meter
Manual
isolation
valve
Recommended Minimum Pipe Sizes
for Unknown Flow Rates*
Supply
Boiler Pipe Size
Model A
378 2"
478 2-1/2"
578-678 3"
778-1278 4"
known flow rates or higher flow
rate
Recommended Minimum Pipe Sizes
for Known Flow Rates
Water Supply
Flow Rate Pipe Size
GPM A
Up to 35 2"
36 to 50 2-1/2"
51 to 77 3"
78 to 142 4"
ASME Drain Valve Size
Boiler Model Valve Size (in.)
378-478
578-1178
1278
Return
Pipe Size
B
2"
2-1/2"
3"
4"
Return
Pipe Size
B
2"
2-1/2"
3"
4"
3/4
1
1-1/4