A.O. Smith Kuwait, Instruction Manual

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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 valve must meet the requirements of Local/National
codes, but not less than a combination temperature and 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 and pressure
relief valve must not be removed from its designated opening nor
plugged. The temperature-pressure relief 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 only within 6 inches (15.2
cm) above, or at any distance below the structural fl oor. 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 (9.14 m), or use of more than four elbows
can cause restriction and reduce the discharge capacity of the valve.
No valve or other obstruction is to be placed between the relief valve and
the tank. Do not connect discharge piping directly to the drain unless a
6” (15.2 cm) 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.
The Discharge Pipe:
• 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 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 6" (15.2 cm) 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.
• The discharge pipe connected to the pressure relief device is to be
installed in a continuously downward direction and in a frost- free
environment (IEC7.12.1
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
can cause 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.
If you do not understand these instructions or have any questions
regarding the temperature-pressure relief valve call the toll free
number listed on the back cover of this manual for technical
assistance.
CLOSED WATER SYSTEMS
Water supply systems may, because of code requirements or such
conditions as high line pressure, among others, have installed
devices such as pressure reducing valves, check valves, and back
fl ow preventers. Devices such as these cause the water system to
be a closed system.
THERMAL EXPANSION
As water is heated, it expands (thermal expansion). In a closed system
the volume of water will grow when it is heated. As the volume of
water grows there will be a corresponding increase in water pressure
due to thermal expansion. Thermal expansion can cause premature
tank failure (leakage). This type of failure is not covered under the
limited warranty. Thermal expansion can also cause intermittent
temperature-pressure relief valve operation: water discharged from
the valve due to excessive pressure build up. This condition is not
covered under the limited warranty. The temperature-pressure relief
valve is not intended for the constant relief of thermal expansion.
A properly sized thermal expansion tank should be installed on all
closed systems to control the harmful eff ects of thermal expansion.
Contact a local plumbing service agency to have a thermal expansion
tank installed.
IPX1 JUNCTION BOX COVER
To have the IPX1 rating, the cover must be properly installed. This
unit is provided with an IPX1 rated junction box cover kit, follow
the installation instructions in the kit for proper installation. Figure
1 shows the expanded view of the kit for reference.
Figure 1