Temperature and pressure relief valve - THPT

T/P Valve:

1, Commodity name:

Temperature and Pressure Relief Valve

2, Use:

P/T Valve for solar water heater, electric heater and so on

3, T&P relief Valve Function:

*The T&P valve is designed to relieve the increase in pressure which

develops during the normal heating cycle.

*This is caused by the water expanding during the heating cycle.

*The T/P valve then will relieve the increase in pressure by releasing

drips of hot water to the drain line. It is recommended that an

expansion control valve be fitted to the cold water supply

line as it will relieve cold water

4, T/P relief valve for solar water heater

*Inlet pressure control:

*High pressure may cause excessive discharge and possible premature failure of the operating relief valve.The maximum water pressure usually occurs during the night, at the time of lowest water usage. In any mains pressure water heater installation,if the inlet water pressure exceeds 80%

of the nominal set pressure of the operation relief valve,a pressure limiting valve must be fitted to the cold inlet.(If a cold water expansion control valve is fitted it will have a lower set pressure than the T/P relief valve and thus be classed as the "operating"relief valve.)

5,T&P Valve Installation:

*T/P Valves should be installed by a licensed plumber.

*If the temperature probe protruding from inside the inlet thread is

damaged or bent,do not install,and obtain a replacement valve.

*Clean out all deposits from the threaded boss on

the heater before fitting a replacement valve,otherwise

the new valve risks contamination and premature failure.Apply PTFE thread tape

to the male taper thread,making sure that the tape does not hang over the outer end of the

thread,as this can lead to premature valve failure.Screw the valve into the heater socket.

Do not use a wrench on the valve body.Use teh hexagonal spanner flats provided.No valves,taps,

or other isolating devices are to be fitted between the P&T relief valve and the water heater.

*Install a drain line of the same nominal size as the valve,in accordance with AS3500.4.(The drain line must have a continuous fall.)