Weil-McLain 88 - Manual (Page 19)

"OILER
19 Part No. 550-100-068/1009
Connect steam boiler piping
(continued)
Pipe as shown for gravity return systems, connect- A
ing point A to the wet gravity return.
For pumped-return systems, install boiler water s
level control on each boiler with body mark at
level indicated in Figure 42, page 28. Provide at
point A either:
Separate feed pumps and check valves for each
s
boiler, or . . .
Single feed pump, with separate solenoid valve
s
for each boiler.
For pumped-return systems, install a combination B
float and thermostatic trap on each boiler to prevent
flooding of one boiler while other boiler is firing.
Install trap in skim tapping (see Figure 39, page 27).
Connect traps to condensate receiver.
Gravity-return systems are self-levelling if the wet
returns are piped to the common system wet return.
Install boiler piping as shown in the preceding pages C
of this manual.
Install stop valves per ASME code requirements. D
For pump-return systems, if using automatic s
steam valves, use only slow-opening automatic
valves. Use a Weil-McLain Boiler Control Sys-
tem (such as a BCP panel) to open each steam
valve automatically before firing burner.
Construct common supply drop header with pipe E
size at least same size as largest boiler header size.
Use: F
A Weil-McLain Boiler Control System (such as s
a BCP panel) with header-mounted pressure
control(s) to sequence boilers, or . . .
A steam pressure controller.
s
Install drip line in common supply drop header. G
Gravity-return: Pipe drip line to wet return. s
Pumped-return: Use combination float and s
thermostatic trap and drain to condensate
receiver.