Water Piping Pressure Test; Temperature Pressure Relief Valve - A.O. Smith 185874-001 Instruction Manual

The water within the water heater tank expands as it is heated and
increases the pressure of the water system. If the relieving point of the
water heater's temperature-pressure relief valve is reached, the valve
will relieve the excess pressure. the temperature-pressure relief
valve is not intended for the constant relief of thermal expansion.
This is an unacceptable condition and must be corrected.
It is recommended that any devices installed which could create a
closed system have a by-pass and/or the system have an expansion
tank to relieve the pressure built by thermal expansion in the water
system. Expansion tanks are available for ordering through a local
plumbing contractor. Contact the local water supplier and/or a service
agency for assistance in controlling these situations.
note: to protect against untimely corrosion of hot and cold
water fittings, it is strongly recommended that di-electric unions
or couplings be installed on this water heater when connected
to copper pipe.
fIGure 5.
Figure 5 shows the typical attachment of the water piping to the
water heater. The water heater is equipped with 3/4 inch NPT water
connections.
note: If using copper tubing, solder tubing to an adapter before
attaching the adapter to the cold water inlet connection. do not
solder the cold water supply line directly to the cold water inlet.
It will harm the dip tube and damage the tank.

water pIpInG pressure test

This section is only for the manufacturer installing the water heater
when the installation is to comply with H.U.D. Standards.
When testing the water ways, H.U.D. Standards state:
"Water distribution system. All water piping in the water distribution
system shall be subjected to a pressure test. The test shall be made by
subjecting the system to air or water at 100 psi for 15 minutes without
loss of pressure. when air pressure is used, the water heater shall
not be connected during the test".
note: If water piping system is to be air pressure tested, the water
heater must be disconnected from the water piping system. Failure
to disconnect the water heater during air pressure testing of water
piping system could result In death, serIous BodIlY InjurY,
or propertY daMaGe.
teMperature-pressure relIef valve
10
fIGure 6.