The valve body and all other metallic parts are made of brass. The sealing gaskets are of rubber adequate to its working conditions. All springs are of stainless steel. These  valves  can   realise  three  primary functions:

1. The safety valve "A" opens the passage "1" for the outflow of water when the pressure in the tank increase over its permissible limit.
2. The check valve "B" for filling the heater with water. It also prevents the outflow of water from the tank back into the supply line in case of pressure failure.
3. The return valve "C" opens the outflow of water from the tank into the supply line in case of an excessive pressure rise in the tank exceeding supply line pressure. It makes possible to decrease the pressure in the tank without uptake of hot water from it.

The valve shall be installed in the water supply line of the heater. The direction of flow should be in accordance with the arrow marked on the valve body. The water supply line should be stable to 90C temperature at least 5 m before heater because hot water may flow back through the check valve. The overflow outlet "1" should be directed downward. It is possible to connect the flexible pipe to overflow outlet for discharge of flowing water to funnel. Inside diameter of pipe should be 11 mm, maximum length -1 m. The pipe must be stable to 80C temperature.

Max. Length of engagement of pipe into the valve is 9 mm. It is recommended to use the PTFE (teflon) band for sealing. The supply line water pressure cannot exceed the nominal pressure to avoid the continuous overflow from the heater.

The ZB-8 safety valves are designed for protection against too high water pressure on electrical water heaters. Available are valves for 0,6 MPa and 0,7 MPa nominal pressure.

  specification ZB-8 0372 format pdf - download

  specification ZB-8 0377 format pdf - download

instruction regarding the codification of the safety valves pdf format - download