GSW 319594-000 manual Temperature and Pressure T&P Relief Valve, Closed System/Thermal Expansion

FOLLOW THE

TEMPERING

VALVE MANU-

FACTURER'S

INSTRUCTIONS

T&P VALVE

AND DIS-

CHARGE

LINE

HOT

WATER

OUTLET

COLD

WATER

INLET

Figure 17 Tempering Valve Installation

TEMPERED

WATER TO

FIXTURE

TEMPERING VALVE (SET TO 49°C (120°F))

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.

WARNING

Explosion Hazard

•If the temperature and pressure relief valve is dripping or leaking, have a licensed plumber repair it.

•Do not plug valve.

•Do not remove valve.

•Failure to follow these instructions can result in death or an explosion.

Closed System/Thermal Expansion

Periodic discharge of the temperature and pressure relief valve may be due to thermal expansion in a closed water supply system. The water utility supply meter may contain a check valve, backflow preventer or water pressure-reducing valve. This will create a closed water system. During the heating cycle of the water heater, the water expands caus- ing pressure inside the water heater to increase. This may cause the temperature and pressure relief valve to dis- charge small quantities of hot water. To prevent this, it is recommended that a diaphragm-type expansion tank (suit- able for potable water) be installed on the cold water supply line. The expansion tank must have a minimum capacity of

5.6litres (1.5 US gallons) for every 190 litres (50 US gal- lons) of stored water and be rated at the working pressure of the water heater. Contact the local water supplier or plumbing inspector for information on other methods to con- trol this situation.

Important: Do not plug or remove the temperature and pressure relief valve.

The Temperature and Pressure Relief Valve:

•Must not be in contact with any electrical part.

•Must be connected to an adequate discharge line.

•Must not be rated higher than the working pressure shown on the data plate of the water heater.

The Discharge Line/Driptube:

•Must not be smaller than the pipe size of the relief valve or have any reducing coupling installed in the discharge line.

•Must not be capped, blocked, plugged or contain any valve between the relief valve and the end of the dis- charge line.

•Must terminate a maximum of 300mm (12 in.) (Canada) or 150mm (6 in.) (U.S.A.) above the floor.

•Must be capable of withstanding 121°C (250°F) without distortion.

•Must be installed to allow complete drainage of both the valve and discharge line.

Temperature and Pressure (T&P) Relief
Valve
For protection against excessive pressures and tempera-
					TEMPERATURE AND
tures, a temperature and pressure relief	valve must be				PRESSURE	RELIEF
installed in the opening marked "T&P RELIEF VALVE" (see					VALVE
Figure 18). This valve must be design certified by a nation-
ally recognized testing laboratory that maintains periodic
inspection of the production of listed equipment or materials
					DISCHARGE LINE 19mm (3/4 in.)
as meeting the requirements of the "Standard For Relief					MIN. DO NOT CAP OR PLUG.
Valves For Hot Water Supply Systems", ANSI
Z21.22/CSA 4.4. The function of the temperature and pres-
				DRAIN PAN. CONNECT TO
sure relief valve is to discharge water in large quantities in				PROPERLY		OPERATING
the event of excessive temperature or pressure developing				FLOOR DRAIN.
in the water heater. The valve's relief pressure must not
exceed the working pressure of the water heater as stated
on the data plate.		Figure 18 Temperature	& Pressure			Relief Valve
		Installation
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