Weil-McLain 550-141-829/1201 Connect Steam Piping, General piping information, Install piping

Connect Steam Piping

General piping information:

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

•Maintain 24-inch minimum from waterline to bottom of header (minimum 507/8" from floor or top of foundation).

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

•Use swing joints in steam piping.

•If installation is to comply with ASME or Canadian requirements, an additional pressure limit control is needed. Install control between existing pressure control and pressure gauge. Control must be installed with siphon (supplied with boiler) between control and boiler. Set control to minimum of 5 psi above setpoint of existing control and maximum setting of 15 psi. Wire as shown on boiler wiring diagram.

Install piping:

1.See Tables at right and FIGURE 9 on page 15 or FIGURE 10 on page 16.

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 minimum pipe sizes shown. Consult your Weil-McLain distributor or sales office before installing alternate piping.

2.Install relief valve vertically in “R” tapping on back of boiler. See FIGURE 9 or 10 and also refer to tag attached to relief valve for manufacturer’s instructions.

Pipe relief valve discharge line near floor close to floor drain to

eliminate potential of severe burns. Do not pipe to any area where freezing could occur. Do not plug, valve or place any obstruction in discharge line.

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3.Float-type low water cutoff only — install blowdown line in bottom of cutoff. See FIGURE 9 or 10 and also refer to low water cutoff manufacturer’s instructions for details.

Pipe blowdown line near floor close to floor drain to eliminate

potential of severe burns. Do not pipe to any area where freezing could occur. Do not plug, valve or place any obstruction in discharge line.

STEAM PIPING SIZE TABLE

FOR ONE AND TWO-PIPE SYSTEMS

		RISER		HEADER
BOILER				PIPE		EQUALIZER
MODEL		PIPE SIZE *		SIZE		PIPE SIZE
NUMBER		A	B	“H” * *		“J”
SGO-3	2½"		—	2½"	1½"
SGO-4	2½"		—	2½"	1½"
SGO-5	2½"		—	3"	1½"
SGO-6	2½"		2½"	3"	1½"
SGO-7	2½"		2½"	3"	1½"
SGO-8	2½"		2½"	3"	1½"
SGO-9	2½"		2½"	3"	1½"

STEAM PIPING SIZE TABLE

FOR ONE-PIPE COUNTERFLOW SYSTEMS

				HEADER
		RISER
BOILER				PIPE		EQUALIZER
MODEL		PIPE SIZE *		SIZE		PIPE SIZE
NUMBER		A	B	“H” * *		“J”
SGO-3	2½"		—	2½"	1½"
SGO-4	2½"		—	2½"	1½"
SGO-5	2½"		—	3"	1½"
SGO-6	2½"		2½"	4"	1½"
SGO-7	2½"		2½"	4"	1½"
SGO-8	2½"		2½"	4"	1½"
SGO-9	2½"		2½"	4"	1½"

*Based on ASHRAE Fundamentals Handbook recommendations, allowing ½ oz. pressure drop at 0 psig.

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

Can be reduced to 2".