Water Pressure Limiting Valve

Jan 17, 2024

What Is A Water Pressure Limiting Valve?

A water pressure limiting valve (or PLV) is a vital component that limits the flow and amount of water pressure travelling though your pipes and plumbing. The valve stays open to allow pressure through and if the pressure rises above the preset maximum, the valve shuts off the water.


While most of us appreciate a nice strong shower water pressure or being able to fill the sink up quickly, if water is running through your pipes at too high of a pressure, your plumbing will begin to suffer by putting strain on your plumbing system, fittings, and appliances.


The damage that could occur due to high water pressure could include water hammer, burst pipes, water leaks, leaking taps and a wide range of issues that create strains on your plumbing. It can also reduce the lifespan of appliances such as dishwashers.

water pressure testing

How To Reduce Water Pressure In House?


If you're wondering how to reduct water pressure in house, here's how to do it:


  1. You first need to locate the regulator which has a screw or bolt along with a locking nut.
  2. Then while by utilizing a wrench, you need to loosen the locking nut, and then adjust the screw with a screwdriver in quarter-turn increments.
  3. Often to reduce water pressure, you would need to rotate the screw to the left (counter-clockwise).
  4. To increase water pressure, you need to turn the screw to the right (clockwise).

Causes of Pressure Limiting Valve Leaking


If you have tried to adjust your water pressure limiting valve and have a leaking PLV, it could be for due to improper seating of the valve or when the seal is broken. Leaks may occur if the valve operates at a pressure too near to its designated set point.


This is one plumbing job that should not be on the DIY project list! Only an experienced tradie should test, install or replace a pressure limiting valve.


Pressure limiting valves do not last forever, so, even if you don't have any signs that your PLV maybe be on its way out, the next time you have a plumber at your home, ask them to test your PLV for you. It's better to be safe than sorry!

Benefits of Installing a Pressure Limiting Valve

  • Protection - Pressure limiting valves will not only help to protect your plumbed pipes and system but also all your plumbing appliances found within your home. Extending the life of your appliances in your home is only one benefit.


  • Hot water heaters - Hot water systems are also plumbing appliances and need to be protected. You can install a pressure limiting directly at the hot water heater but our experts recommend installing the valve at the mains. Mainly because safeguarding all your plumbing systems is better than just safeguarding only your hot water heater.


  • Water-wise - Australia is a water-wise nation. Installing a pressure limiting valve will help to reduce the flow of water, ensuring you're doing your part in saving our water supply from unnecessary wastage.



  • Water bills - Installing a pressure limiting valve will cap the flow of water to your home. This reduces excessive amounts of water, in turn reducing your water bill if in the past you've been receiving high levels of water.


How Do You Know If You Need A Water Pressure Limiting Valve?

There are some key signs to look out for that may be a warning that you are in need of a water pressure limiting valve or a replacement when your pressure limiting valve is leaking. These include (but are not limited to):


  • Water Hammer Noise
  • Leaking Taps & Fittings
  • Constantly Running Inlet On Your Toilet
  • An Increase Water Bill
  • Leaking Hot Water Heaters
  • Increased Pressure In Your Water Supply


If you notice any of the above on your property or any other signs of high-pressure water supply issues, it's always best to contact a professional licensed Sydney plumber to have a look at your plumbing and to make a diagnosis as well as provide a solution for you.

Why Do We Need Water Pressure Limiting Valves In Australia?


There are Australian Standards in place to protect you and your property from potential damage that might occur. Extra precautions are taken by making every new build (or extension work at a home) install a pressure limiting valve. With a PLV, the water pressure is capped at 500kpa thus reducing the strain put on your plumbing system.


Older homes are exempt from this rule, however, taking extra precautions is recommended. Make sure you have your water pressure checked by a professional licensed plumber and have a pressure limiting valve installed.

Water Hammer and Water Pressure Limiting Valves

tap replacement

Have you ever noticed an annoying banging or excessive noise at times when you turn your plumbing on and off? Water flow may have something to do with this! Hammering is the shock wave that occurs when the water service is shut off and the high amounts of water pressure has nowhere to go. This force continues resulting in the noise, the banging in the walls after the inlet has been closed. 


Installation of a pressure limiting valve that has a maximum threshold of 500kpa may take the strain off your pipework, reducing the shock wave and possibly ending the hammering. The search to stop the hammering may be to install a pressure limiting valve. 


If you have a current hammering issue, contact our customer care phone number 9023 3232 to discuss your plumbing concern. Please note, this shock wave is not limited to only a water supply pipe, it can occur in a gas line service as well which means you'll need the services of an experienced Sydney gas fitter.


Do Hot Water Systems Need Pressure Limiting Valves?


Hot water systems are not made with a PLV but they do certainly benefit from the installation of one to the plumbing at your water meter assemblies. As you can imagine, too much pressure on your hot water system could cause damage to it (as well as many other appliances for that matter). As the high volume and strength of the water is on the search for somewhere to go, if it finds other appliances that are not cut out for a water supply above 500kpa, it may find a weakness and cause unnecessary damage. This is why the installation of PLVs are so important.


We also know what you're thinking, will a pressure limiting valve affect the pressure of your shower? Everyone loves a nice strong hot water shower, especially in winter, and your hot water system will still get great pressure even when capped at the 500kpa mark. So, don't stress! That hot water will still come through nice and strong for you.

Contact A Sydney Plumber For Water Pressure Limiting Valve Installation


If you are ever in need, then Network Plumbing is here to help with emergency plumbers available 24 hours, 7 days a week, however, our best advice is to read on further to learn and understand the importance of pressure limiting valves and how reducing your pressure is beneficial in more ways then you know. There is an Australian standard for a reason!


If after reading this blog, you are wondering whether you have a pressure limiting valve or are in need of getting our water pressure tested, then please don't delay - contact us here at Network Plumbing on 9023 3232 and we will send our technician who will be able to assess your plumbing and give you an upfront and on the spot price for the works needed to be carried out to ensure the safety of you and your family as well as extend the life of your range of appliances that use the supply of water. 

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