SYR Grivory Pressure Regulating Valve 15mm CX 400Kpa & 600Kpa

This is a high-quality pressure-regulating valve with a pressure relief valve.

Typically, a valve like this would be placed on the water feed of a whole house, or at least before the Geyser. The important part is that the pressure rating needs to be matched to the pressure rating of the Geyser.

The 400Kpa valve regulates pressure to 300Kpa (3Bar).

While the 600Kpa valve regulates pressure to 460Kpa (4.6Bar).

There are many products that regulate pressure, but not all of them have a pressure relief valve. The relief valve allows it to release water to reduce the pressure after the valve. This will typically be used to release pressure from water hammer when a tap is closed quickly or when pressure builds up due to the geyser heating up. 

It is very important to limit the pressure before filter systems and vessel systems to under 6 Bar, and to have them protected by a pressure relief valve or a pressurised buffer tank. 

Have a look at the video for a demonstration of how it works.