Cold Water Supply - Rheem 136-1826 Operating And Installation Manual

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.
Model
Flow
Size GPM
136 22
181 30
264 42
331
53
399 63
512
82
627 85
726 85
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.
Min
Pipe Model Flow
NPT
Size GPM
1-1/4 825 85
1-1/2 90
926
1-1/2 962 90
1-1/2 1083 90
1-1/2
1125 90
2 1178 90
2
1287 90
2 1337 90
Min
Pipe Model
Size
NPT
2 1413
2-1/2 1467
2-1/2 1570
2-1/2 1630
1758
2-1/2
2-1/2 1826
2-1/2
2-1/2
20
Min
Flow Pipe
GPM NPT
90 2-1/2
90 2-1/2
90 2-1/2
90 2-1/2
90 2-1/2
90 2-1/2