What is a Pressure Limiting Valve?

Have you ever heard of a Pressure Limiting Valve?

If you own your home or are currently building a new home, you may have heard the term Pressure Limiting Valve or PLV for short. But do you know what a PLV is, what it does, or whether you even need one?

Tomson Pressure Limiting Valve

Put simply, a Pressure Limiting Valve is a valve which reduces the pressure of the water flowing through it.

Throughout your home, there is a series of water pipework, both hot and cold, in the walls, ceiling space and often underground. The pipes carry water to all the various taps and outlets throughout your home, including taps and toilets in kitchens, bathrooms, ensuite and laundry.

When all the taps are turned off in the home, the pressure inside the pipework increases to the static pressure of the incoming water supply. This incoming water pressure can fluctuate from very high to low for a multitude of reasons depending on the time of day.

A home without a Pressure Limiting Valve is subject to fluctuating water pressure as set by SA Water, who set the pressure at a level to ensure all households can maintain a water supply.


Why is a Pressure Limiting Valve important?

This water pressure fluctuation is the reason why a Pressure Limiting Valve is so critical. Without a Pressure Limiting Valve, the water pressure in your home can reach extremely high pressures, which may be outside manufacturer specifications for appliances in your home. Manufacturers of appliances like hot water heaters and washing machines set a maximum inlet water pressure, which means to maintain your warranty the water pressure to these appliances cannot exceed 500kPa.

The installation of a Pressure Limiting Valve is an excellent way for you to protect your assets in your home, whether it’s extending the life of appliances or merely ensuring your washing machine is covered by warranty.

The risks of fluctuating pressures extend to your home insurance too. Without a Pressure Limiting Valve, if an appliance or fixture fails because of excess water pressure, you may not be covered. A typical example is a Flexi hose that connects to your toilet cistern. These Flexi hoses have a maximum inlet pressure of 500kPa, and manufacturers recommend you replace these every ten years. If a Flexi hose bursts, it can cause flooding in the home, significant issues and inconvenience.

When building a new home, your builder must meet the relevant Australian Standards (AS3500.1), which states that the water pressure on your property must not exceed 500kPa. The Australian Standards warn that:

“Pressures above 500kPa can cause damage from water hammer, reduced life of appliances, taps and fittings, and cause excessive noise in the system.”

The Installation of a Pressure Limiting Valve is vital on any property, whether it’s a home or commercial property. It is cheap insurance to ensure that you get the best life out of appliances, meet Australian Standards and protects the integrity of your plumbing system.


More Information

Do you need a Pressure Limiting Valve? Contact RD Plumbing Solutions today for more information, or to arrange an inspection by one of our licensed Plumbing Technicians.

Call 0422 902 890 or contact us online.