Temperature-Pressure Relief Valve - Lochinvar RESIDENTIAL GAS WATER HEATERS Instruction Manual

Figure 9 shows the typical attachment of the water piping to the water
heater. The water heater is equipped with 1" NPT threaded nipple
(75 gallon models) or 1.25" NPT threaded nipple (100 gallon models)
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.

TEMPERATURE-PRESSURE RELIEF VALVE

This heater is provided with a properly certified combination
temperature - pressure relief valve by the manufacturer.
The valve is certified by a nationally recognized testing laboratory
that maintains periodic inspection of production of listed equipment
of materials as meeting the requirements for Relief Valves for Hot
Water Supply Systems, ANSI Z21.22 • CSA 4.4, and the code
requirements of ASME.
If replaced, the valve must meet the requirements of local codes, but
not less than a combination temperature and pressure relief valve
certified as indicated in the above paragraph.
The valve must be marked with a maximum set pressure not to exceed
the marked maximum working pressure of the water heater
(150 psi = 1,035 kPa) and a discharge capacity not less than the
water heater input rate as shown on the model rating plate.
For safe operation of the water heater, the relief valve must not be
removed from its designated opening nor plugged.
The temperature-pressure relief valve must be installed directly into
the fitting of the water heater designed for the relief valve. Position
the valve downward and provide tubing so that any discharge will exit
only within 6" (153 mm) above, or at any distance below the structural
floor. Be certain that no contact is made with any live electrical part.
The discharge opening must not be blocked or reduced in size under
any circumstances. Excessive length, over 30' (9.14 m), or use of
more than four elbows can cause restriction and reduce the discharge
capacity of the valve, see Figure 10.
No valve or other obstruction is to be placed between the relief valve
and the tank. Do not connect tubing directly to discharge drain unless
a 6 inch air gap is provided. To prevent bodily injury, hazard to life, or
property damage, the relief valve must be allowed to discharge water
in quantities should circumstances demand. If the discharge pipe is
not connected to a drain or other suitable means, the water flow may
cause property damage.
The Discharge Pipe:
• Should not be smaller in size than the outlet pipe size of the valve, or
have any reducing couplings or other restrictions.
• Should not be plugged or blocked.
• Should be of material listed for hot water distribution.
• Should be installed so as to allow complete drainage of both the
temperature-pressure relief valve, and the discharge pipe.
• Must terminate a maximum of six inches above a floor drain or external
to the building. In cold climates, it is recommended that the discharge
pipe be terminated at an adequate drain inside the building.
• Should not have any valve between the relief valve and tank.
The temperature-pressure relief valve must be manually operated at
least once a year. Caution should be taken to ensure that (1) no one is in
front of or around the outlet of the temperature-pressure relief
valve discharge line, and (2) the water manually discharged will not
cause any bodily injury or property damage because the water may
be extremely hot.
If after manually operating the valve, it fails to completely reset and
continues to release water, immediately close the cold water inlet to
the water heater, follow the draining instructions, and replace the
temperature-pressure relief valve with a new one.
11
FIGURE 10.