What Are Pressure Reducing Valves and How Do They Work?

A pressure reducing valve (PRV) is a plumbing device used to regulate and reduce the pressure of water that enters a building’s plumbing system. It is typically installed near the main water supply line and works by automatically adjusting the water pressure to a safe and consistent level, regardless of the incoming pressure from the municipal water supply.

The valve has a spring-loaded diaphragm that reacts to changes in water pressure. When the pressure exceeds a pre-set limit, the valve reduces the flow of water to maintain the desired pressure level. This not only ensures a steady flow of water but also prevents damage to pipes and appliances caused by excessive water pressure.

Why Do You Need a Pressure Reducing Valve?

High water pressure is a common problem in many homes and buildings. While it may seem like a good thing to have strong water pressure, it can actually cause a lot of damage to plumbing fixtures and appliances. Excessive water pressure can cause pipes to burst, faucets to leak, and even damage water heaters and other appliances that rely on water pressure to function properly.

A pressure reducing valve is essential in preventing such damage and prolonging the life of your plumbing system. It ensures that the water pressure remains within safe limits, preventing leaks and reducing the risk of costly repairs and replacements.

How to Install a Pressure Reducing Valve

Installing a pressure reducing valve is a relatively straightforward process. However, it is important to note that it should only be done by a licensed plumber. Here are the basic steps involved:

  • Locate the main water supply line and turn off the water supply to the building.
  • Cut the main water supply line and install the pressure reducing valve.
  • Connect the inlet and outlet pipes to the valve and tighten the fittings.
  • Turn on the water supply and test the pressure using a pressure gauge.

It is important to ensure that the valve is installed in the correct orientation and that the pressure is adjusted to the appropriate level for your plumbing system.

Choosing the Right Pressure Reducing Valve

When choosing a pressure reducing valve, there are several factors to consider, such as the size of the valve, the material it is made of, and the pressure range it can handle. It is important to choose a valve that is compatible with your plumbing system and can handle the maximum water pressure that may occur.

Additionally, some valves may come with additional features such as a strainer to filter out debris and a bypass to allow for easy maintenance. These features may be beneficial in certain situations and should be considered when selecting a valve.


Pressure reducing valves are an essential component of any effective plumbing system. They help regulate water pressure, prevent damage to plumbing fixtures and appliances, and prolong the life of your plumbing system. If you are experiencing high water pressure, it is important to consult a licensed plumber to determine if a pressure reducing valve is necessary and to ensure that it is installed correctly. Choosing the right valve can make a big difference in the effectiveness and longevity of your plumbing system.