Pressure Limiting Valve

Most modern houses are fitted with a Pressure Limiting Valve. As a rule of thumb, you can find these behind a 200mm square white panel in your garage.

This valve is referred to as a 4-in-1 valve, as it carries out four functions. The blue handle isolates your water supply. It would be a good idea to familiarise yourselves with the valve, if you ever have a major leak, turning this off is going to prevent further water damage. The arrow below the blue isolator shows the valve only allows water to flow in one direction. A non return valve is fitted to prevent house water supplies going back into the water main. The black cartridge is the guts of the valve, it limits the water supply pressure down to 500kPa, most tap ware are rated for 500kPa, any higher pressures can cause the tap seals to leak. There is also a fine filter in the cartridge to prevent debris entering the house supply.

A common problem is that the cartridge spring can deteriorate in harsh water situations. A sign of this is a loss of pressure to your taps and a small drip from the head of the cartridge. If this happens the cartridge will require replacing, not the whole valve. Any queries give me a call. Meeting your plumbing needs.