Weil-McLain 88 Connect steam boiler piping continued, See page 18 for numbered circle references

Boiler manual: • Installation • Start-Up • Maintenance • Parts

Connect steam boiler piping (continued)

Figure 26 Multiple Steam Boiler Piping Gravity Condensate Return

See page 18 for numbered circle references.

APipe 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.

BFor 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.

CInstall boiler piping as shown in the preceding pages of this manual.

Part No. 550-100-068/0308

DInstall 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.

EConstruct common supply drop header with pipe size at least same size as largest boiler header size.

FUse:

•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.

GInstall 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.

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