Temperature-Pressure Relief Valve; T&P Valve Discharge Pipe Requirements - Lochinvar POWER VENTED GAS HEATERS Installation And Operating Manual

TEMPERATURE-PRESSURE RELIEF VALVE

WARNING
This water heater is provided with a properly rated/sized
and certifi ed combination Temperature-Pressure Relief
Valve (T&P valve) by the manufacturer. The valve is
certifi ed 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 new T&P valve must meet the requirements
of local codes, but not less than a combination temperature-
pressure relief valve rated/sized and certifi ed as indicated
in the above paragraph. The new valve must be marked
with a maximum set pressure not to exceed the marked
hydrostatic working pressure of the water heater (150 psi
= 1,035 kPa) and a discharge capacity not less than the
water heater Btu/hr or kW input rate as shown on the water
heater's model rating plate.
For safe operation of the water heater, the temperature-
pressure relief valve must not be removed from its
designated opening nor plugged. The T&P valve must
be installed directly into the fi tting of the water heater
designed for the relief valve. Install discharge piping so
that any discharge will exit the pipe within 6" (15cm) above
an adequate fl oor drain, or external to the building. In
cold climates it is recommended that it be terminated at
an adequate drain inside the building. 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 feet (9.14m)), or use of more than four elbows can
cause restriction and reduce the discharge capacity of
the valve.
Explosion Hazard
•
Temperature-pressure relief
valve must comply with ANSI
Z21.22-CSA4.4 and ASME
code.
•
Properly sized temperature-
pressure relief valve must be
installed in opening provided.
•
Do not plug, block, or cap the
discharge line.
•
Failure to follow this warning
can result in excessive tank
pressure, serious injury or
death.
No valve or other obstruction is to be placed between
the T&P valve and the tank. Do not connect discharge
piping directly to the drain unless a maximum of 6"
(15cm) air gap is provided. To prevent bodily injury,
hazard to life, or property damage, the relief valve must
be allowed to discharge water in adequate quantities
should circumstances demand. If the discharge pipe is not
connected to a drain or other suitable means, the water
fl ow may cause property damage.
Temperature-pressure relief valve discharge pipe
•
must terminate at an adequate drain.
T&P valve discharge pipe requirements:
•
Shall not be smaller in size than the outlet pipe size
of the valve, or have any reducing couplings or other
restrictions.
•
Shall not be plugged or blocked.
•
Shall not be exposed to freezing temperatures.
•
Shall be of material listed for hot water distribution.
•
Shall 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 fl oor
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
•
Shall not have any valve or other obstruction between
the relief valve and the drain.
DANGER
The T&P valve must be manually operated at least once
a year. Caution should be taken to ensure (1) no one is
in front of or around the outlet of the 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 in this manual, and replace
the temperature-pressure relief valve with a properly
rated/sized new one.
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CAUTION
Water Damage Hazard
• Burn hazard.
• Hot water discharge.
• Keep clear of
HOT
HOT
temperature-pressure
relief valve discharge.
BURN
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