Weil-McLain 88 Manual page 19

Boiler manual: • Installation
Connect steam boiler piping
Figure 26
Multiple Steam Boiler Piping Gravity Condensate Return
See page 18 for numbered
circle references.
A
Pipe as shown for gravity return systems, connect-
ing point A to the wet gravity return.
• For pumped-return systems, install boiler water
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
boiler, or . . .
• Single feed pump, with separate solenoid valve
for each boiler.
B
For pumped-return systems, install a combination
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.
C Install boiler piping as shown in the preceding pages
of this manual.
Part No. 550-100-068/1009
• Start-Up • Maintenance
D
Install stop valves per ASME code requirements.
• For pump-return systems, if using automatic
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.
E
Construct common supply drop header with pipe
size at least same size as largest boiler header size.
F Use:
• A Weil-McLain Boiler Control System (such as
a BCP panel) with header-mounted pressure
control(s) to sequence boilers, or . . .
• A steam pressure controller.
G
Install drip line in common supply drop header.
• Gravity-return: Pipe drip line to wet return.
• Pumped-return: Use combination float and
thermostatic trap and drain to condensate
receiver.
• Parts
(continued)
19