Weil-McLain 80 - Manual (Page 19)

• Installation • Start-Up • Maintenance • Parts
19 Part No. 550-141-935/0602
Figure 19 Multiple Steam Boiler Piping Gravity Condensate Return
Connect steam boiler piping
(continued)
8
A Pipe as shown for gravity return systems, connecting
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 30 on page 30. 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 page 29). 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 this manual (pages 16
through 19).
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 System (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.