Whirlpool 318686-000 Temperature and Pressure Relief Valve, Closed System/Thermal Expansion

Please note the following:

DO NOT install this water heater with iron piping. The system should be installed only with piping that is suitable for potable (drinkable) water such as copper, CPVC, or polyethylene (PEX).

DO NOT use PVC water piping.

DO NOT use any pumps, valves, or fittings that are not compatible with potable water.

DO NOT use valves that may cause excessive restriction to water flow. Use full-flow ball or gate valves only.

DO NOT use tin-lead solder in potable water lines. Use 95/5 tin antimony or other equivalent material.

DO NOT tamper with the energy smart module, electronic thermostat, temperature sensors, heat- ing elements, electrical connections, or temperature and pressure relief valve. Tampering voids all war- ranties. Only qualified person should service these components.

DO NOT use with piping that has been treated with chromate’s, boiler seal, or other chemicals.

Temperature and Pressure

Relief Valve

Explosion Hazard

• Temperature-pressure relief valve must comply with ANSI Z21.22-CSA 4.4 and ASME code.

• Properly sized temperature- pressure relief valve must be installed in opening provided.

• Can result in overheating and excessive tank pressure.

• Can cause serious injury or death.

DO NOT add any chemicals to the system piping which will contaminate the potable water supply.

Closed System/Thermal Expansion

Typically, a closed system includes a pressure reducing valve (PRV) on the cold water inlet (supply line). As water is heated, it expands (thermal expansion). In a closed sys- tem, the volume of water will grow. 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. The tempera- ture-pressure relief valve is not intended for the constant relief of thermal expansion. This condition is not covered

Figure 5

Temperature and Pressure

Relief Valve Installation

Drain Pan

Drain

Optional location some models only

Temperature and

Pressure Relief Valve

Discharge Line 3/4 inch min.

Do not cap or plug.

6 inch maximum

under the limited warranty.

A properly-sized thermal expansion tank should be in- stalled on all closed systems to control the harmful effects of thermal expansion. Contact a plumbing service agency or your retail supplier regarding the installation of a ther- mal expansion tank.

Expansion Tank Sizing Chart

	Inlet		Water Heater Capacity (Gallons)
	Water
Expansion	Pressure		30	40	50	66	82
	40psi	2		2	2	5	5
Tank	50psi	2		2	2	5	5
Capacity	60psi	2		2	5	5	5
Needed	70psi	2		2	5	5	5
	80psi	2		5	5	5	5

A thermal expansion tank can help prevent damage to the water heater and other appliances (i.e.: washing machine, ice maker, dishwasher, etc.).

IMPORTANT: Do not plug or remove the temperature and pressure relief valve (T&P valve).

For protection against excessive pressures and temperatures, a temperature and pressure relief valve must be installed in the opening marked “T&P RELIEF VALVE” (See Figure 5). This valve must be design certi- fied by a nationally recognized testing laboratory that maintains periodic inspection of the production of listed equipment or materials as meeting the requirements for Relief Valves for Hot Water Supply Systems, ANSI Z21.22. The function of the temperature and pressure relief valve is to discharge water in large quantities in the event of excessive temperature or pressure develop- ing in the water heater. The valve’s relief pressure must not exceed the working pressure of the water heater as stated on the rating plate.

IMPORTANT: Only a new temperature and pressure relief valve should be used with your water heater. Do not use an old or existing valve as it may be damaged or not adequate for the working pressure of the new water heater. Do not place any valve between the relief valve and the tank.

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