Weil-McLain 78 manual 6a Connect Steam Boiler Piping, General steam piping information

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6a Connect Steam Boiler Piping

General steam piping information:

•Hartford Loop piping arrangement and wet return are required for steam boilers.

•Maintain 24-inch minimum from waterline to bottom of header (56-1/4" from bottom of section).

•When using condensate receiver, feed pump must be energized by boiler-mounted pump controller.

Cold	Check
water fill		Water meter
	valve

Manual isolation

valve

Pressure

reducing valve

(when used)		To condensate
		return piping or
	Manual
		condensate
	isolation
		receiver
	valve
		(see fig. 18,
		page 17)
Figure 14 Cold Water Fill Piping

Install piping:

Install piping as shown on page 16 for single boilers, page 18 for multiple boilers.

Improperly piped systems or undersized piping can contribute

to erratic boiler operation and possible boiler or system damage. Piping system must be installed as shown, using pipe sizes shown. Consult local Weil- McLain distributor or sales office before installing alternate piping.

1.Connect supply and return piping:

a.See table below and:

1)Size forced condensate return piping by pump.

2)Size gravity condensate return same as equalizer “J” pipe size.

b.Install system drain valve in lowest part of return piping close to boiler. ASME size requirements are shown in Table, page 13.

c.Connect cold water fill piping as shown in Figure 14. Also shown are recommended valves and water meter, if used. Water meter will detect added makeup water, indicating leaks in system.

Steam Boiler Pipe Size Table

Based on 2-Pipe Steam System

				*Riser		* *
			Pipe Size - In.			H	J
Fig.	Boiler					Header	Equalizer
No.	Model	A		B	C	In.	In.
15	378	3				3	2
15	478	4				4	2
15	578	4				4	2-1/2
16	678	3		3		4	2-1/2
16	778	4		4		4	2-1/2
16	878	4		4		4	3
16	978	4		4		6	3
17	1078-1278	4		4	4	6	3

* Based on ASHRAE Handbook recommendations, allowing 1/2 oz. pressure drop per 100 feet of pipe for dry return.

**Based on ASHRAE Handbook recommendations, allowing 2 oz. pressure drop per 100 feet of pipe at 3.5 PSIG. Maintain minimum 24" height from waterline to header.

Part No. 550-141-705 15