Rheem 136-1826 installation instructions Cold Water Supply, Gpm Npt

b. WATER

Water piping should be installed according to the local code requirements, ASHRAE, ASPE and BOCA or other regulatory agencies.

COLD WATER SUPPLY

The cold water supply piping, to the heater must be adequate to handle the design load requirements of the hot water system. The following table illustrates the flow and minimum pipe sizes.

			Min			Min			Min
	Model	Flow	Pipe	Model	Flow	Pipe	Model	Flow	Pipe
	Size	GPM	NPT	Size	GPM	NPT	Size	GPM	NPT
136		22	1-1/4	825	85	2	1413	90	2-1/2
181		30	1-1/2	926	90	2-1/2	1467	90	2-1/2
	264	42	1-1/2	962	90	2-1/2	1570	90	2-1/2
331		53	1-1/2	1083	90	2-1/2	1630	90	2-1/2
	399	63	1-1/2	1125	90	2-1/2	1758	90	2-1/2
	512	82	2	1178	90	2-1/2	1826	90	2-1/2
	627	85	2	1287	90	2-1/2
726		85	2	1337	90	2-1/2

It is recommended that a gate valve be installed in the cold water supply line adjacent to the heater. If Local Codes require a check valve - provisions must be made for thermal expansion.

A minimum pressure of 30 PSIG must be maintained in the system to prevent damage to the heater due to lack of water circulation caused by vapor formation at suction side of the system pumps.

NOTE: Should the cold water supply be interrupted, for any reason, the gas supply must be manually shut off to prevent heater damage. When the service is restored the lines must be vented to eliminate accumulated air.

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