Crown 29PT9467S Series 24 Minimum Piping Recommendations Water Boiler, Return Piping Size, Drop

Series 24 Minimum Piping Recommendations – Water Boiler

Recommendation 1 is used

when the load is constant and not varied due to mixing or multiple zones. Use when:

■system return water is not less than 135° F for prolonged periods of time

■system flow does not impact

flow through the boiler

	1
	SUPPLY
1
SUPPLY			REAR OF
	DRAIN VALVE		BOILER
REAR OF
BOILER	(SEE NOTE 4)
DRAIN VALVE			2A
(SEE NOTE 4)		1
3” x 12” NIPPLE	23		RETURN
		2	HEADER
AND BELL REDUCER
(SEE NOTE 3)
2	2B
RETURN	RETURN		2
	BRANCH
24-03 THRU 24-11 (W/20°F DROP)			RETURN
24-03 THRU 24-12 (W/40°F DROP)	24-12 (W/20°F DROP)

Recommendation 2 is a primary-secondary piping method that maintains a constant flow through the boiler by using a secondary boiler circulator. This arrangement isolates the boiler from flow variations but does not safe-guard against cold return water temperatures. Use when:

	MAX	CLOSELY
	4D
SYSTEM PUMP		SPACED
		TEES	BOILER CI
1 SUPPLY			(BY OTHERS

■ system return water is not less than 135° F	BOILER CIRCULATOR
for prolonged periods of time
	(BY OTHERS - SEE NOTE 5)
■ system flow does not impact flow through the	DRAIN VALVE	REAR OF
	(SEE NOTE 4)
boiler (i.e. zoning, mixing)		BOILER
		3” x 12” NIPPLE
		AND BELL REDUCER
		(SEE NOTE 4)
		2
PIPE SIZING AND NOTES FOR RECOMMENDATIONS 1 AND 2		RETURN

				RETURN PIPING SIZE (IN)				24-03 THRU 24-11 (W/20°F DROP)
	SUPPLY				RETURN	RETURN
								24-03 THRU 24-12 (W/40°F DROP)
	PIPING				HEADER	BRANCH
	SIZE (IN) (1)		RETURN (2)		(2A)	(QTY.) SIZE (2B)
BOILER	20°F	40°F	20°F	40°F	20°F	20°F			MAX
MODEL	DROP	DROP	DROP	DROP	DROP	DROP				CLOSELY
									4D
							SYSTEM PUMP			SPACED
24-03	2	1-1/2	2	1-1/2	–	–
										TEES
24-04	2	1-1/2	2	1-1/2	–	–	SUPPLY			D
24-05	2	1-1/2	2	1-1/2	–	–
							BOILER CIRCULATOR
24-06	2-1/2	1-1/2	2-1/2	1-1/2	–	–
							(BY OTHERS - SEE NOTE 5)
24-07	2-1/2	2	2-1/2	2	–	–	DRAIN VALVE
24-08	2-1/2	2	2-1/2	2	–	–
							(SEE NOTE 4)			REAR OF
24-09	3	2	3	2	–	–				BOILER
24-10	3	2-1/2	3	2-1/2	–	–
24-11	3	2-1/2	3	2-1/2	–	–
24-12	4	2-1/2	4	2-1/2	3	(2) 3	NIPPLE		23	1
							REDUCER
										2
Notes:							OTE 4)
										2
1. All piping is schedule 40.									2B	RETURN
2. Pipe sizes listed are based on a 20° F or 40°F differential (temperature drop).
								RETURN BRANCH
Select one to match application.										RETURN HEADER
3. When specified return piping is less than				3”, install 3” x 12” nipple and appropriate						2A
size bell reducer directly into boiler return tapping as shown.								24-12 (W/20°F DROP)

4.Drain valve—ball valve preferable, gate valve acceptable alternative (supplied by others).—Minimum valve size per ASME code is 3/4 ” NPT.

D

(