How Does a Pressure Reducing Valve Work?

It’s quite rare for people to worry about high water pressure. However, when it does happen, it could cause a lot of problems. If you fail to address the issue or protect your system using the right piece of equipment, you could end up spending thousands of dollars on repairs or replacement. It could also result in damaged appliances such as laundry machine and dishwashers. 

Several things can cause high water pressure. For example, supplying companies have to ensure that all of their customers get enough water supply. Hence, they sometimes have to use high pressure to pump the water, especially in areas dotted with high-rise buildings. Another factor that could cause your problem is thermal expansion, a common issue triggered by water heater use. 

It’s not possible for the supplying company to reduce the water pressure, so your only option is to have it adjusted using a pressure reducing valve. 

What is a pressure reducing valve?

Essentially, a plumber installs a water pressure reducing valve near your water meter to control the hydraulic pressure coming from the main line. It’s crucial to double check the type of pressure reducing valve you will install to ensure that they work well with your system.Here are the main three types you can find in the market: 

  • Direct-acting – It’s the simplest and most economical type which works well with both convoluted bellows and a flat diaphragm. This type of PRV works best for low to moderate water flow. 
  • Externally piloted – This type of PRV comes with double diaphragms, which allows for higher capacity and increased sensitivity to water flow and pressure changes. It also offers you the flexibility to make use of different pilot valve types such as soleniod, air-loaded, pressure, temperature or combinations. 
  • Internally piloted – It incorporates a main and pilot valve and uses inlet pressure to open the valves. Compared to the direct-acting type, it has a higher capacity and accuracy. It also senses pressure internally, so you don’t need to add an externally installed sensing line. 

To know which among the three would best fit your system, you should consult with a professional plumber. They can provide you with the necessary details to help you decide.

How does a PRV work?

Now that you’re acquainted with what a pressure reducing valve is plus its three main types, let’s take a closer look at how it works. 

A typical PRV is designed to work even in the harshest environment. Regardless of pressure or upstream flow fluctuations, a PRV ensures a steady downstream pressure. It does this with the help of its major components such as the valve body, pilot regulator, and control filter. Here’s how each part works: 

  • Valve body – It stabilises the returning water flow while regulating the pressure.
  • Pilot regulator – Think of it as the “brain” of the valve body. Basically, it determines the water flow coming in and out of the chamber.
  • Control filter – Located inside the valve system, this filter helps you minimise damage because of accumulated debris coming in from the main line.

The system works by opening or closing the valves depending on the available upstream flow. So, for example, if the pressure in the upstream line is high, the pilot regulator drops the plunger, triggering the valve to gradually open. Consequently, if the upstream flow is low, the pilot slightly lifts the plunger, causing the valve to slightly close.

This all happens continuously, even if you don’t use water. It’s a straightforward process that happens quite fast. With the right pressure reducing valve in place, you can ensure that your household or commercial space gets enough water and protect your system from all kinds of pressure-induced mishaps. 

Shop for a Pressure Reducing Valve Today!

You’d be surprised by the usefulness of a tiny piece of item like a pressure reducing valve. With it in place, you can avoid nightmarish situations such as burst pipes, damaged water consumer lines and defective appliances. The best part is that they don’t cost a lot of money.     

If you live in an area here in New Zealand where the water pressure is too high such as Christchurch, you will definitely need a PRV installed. If you’re not certain about the water pressure of the supply line, you may find it useful to check it yourself using a water pressure gauge. You can also stay on the look out for common signs of high water pressure such as:

  • Banging noise in the pipes
  • Low water supply in your hot water cylinder
  • Unreasonably high water bill
  • Unexplained noise coming from your dishwashers or washing machine

Looking for a water pressure reducing valve for your plumbing system? Find the perfect one here at Hotwater Cylinders. You can choose from more than hundreds of items in our product catalogue. If you need more information about a product, don’t hesitate to get in touch with us.