Pressure Limiting Valves FAQ’s

We understand that all of the plumbing jargon can be a little bit overwhelming. That is why we have decided to talk about a few of the most common plumbing terms and requirements in order to help you understand and feel comfortable with what may be happening or may need to be happening at your house. Today we are talking about a pressure limiting valve.

What is a Pressure Limiting Valve?

A pressure limiting valve (PLV) is a valve that reduces the pressure of the water which flows through it. Water mains pressure can reach extreme pressures and without a pressure limiting valve the pipes in your house could reach this pressure too.

Do I Need a Pressure Limiting Valve?

Short answer is yes. A pressure limiting valve is vital for a number of reasons.

Firstly, The Plumbing Code of Australia and the Australian Standards (AS/NZS 3500) require that water pressure on your property must not exceed 500kPa. Water mains pressure may be considerably greater than this.

The Australian Standards also state that any new buildings or extension work done to your plumbing requires the installation of a pressure limiting value. Failure to do this means that your building does not comply. The standards go on to say that ‘pressures above 500kPa can cause damage from water hammer, reduced life of appliances, taps and fittings, and cause excessive noise in the system.’

While the Plumbing Code of Australia and the Australian Standards require pressure limiting valves, so do many manufactures of appliances and fixtures. Many manufactures of taps, showers, hot water systems and washing machines, just to name a few, set a maximum inlet water pressure. Water pressure which exceeds their maximum voids their warranty.

If appliance warranty was not enough, without a pressure limiting valve you may not be covered by your insurance company. If an appliance or fixture fails as a result of high water pressure you may not be covered by insurance.

Will A Pressure Limiting Valve Reduce My Shower Pressure?

We hear you. Who doesn’t like a shower massage. You do not need to worry. A pressure limiting valve set at the correct kPa will still enable you to have great shower pressure.

Demonstration Of Pressure Limiting Valves

Below is an example of water pressure before and after a pressure limiting valve was installed. This particular series is by one of our Plumbers Kurt.