What Is a PRV?

By Anita Wong

November 22, 2025

When you turn on a faucet in your home, you should get a gentle stream of water, not a torrential blast. That's because most homes have a valve that keeps residential water pressure at a safe level, preventing damage to pipes and appliances. Discover what a pressure-reducing valve is and how it works to ensure your home plumbing is operating smoothly.

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What Is a Pressure-Reducing Valve?

A pressure-reducing valve controls the force at which water enters your plumbing system. Ideally, residential water pressure should be between 40 and 60 pounds per square inch (psi). This is enough force for household use, ensuring you can still enjoy a satisfying shower and power your dishwasher.

Pressure above 80 psi is considered excessive and can stress your plumbing infrastructure and appliances, increasing the risk of leaks and damage.

What Is the Purpose and Function of a PRV?

A residential PRV ensures safe and steady water pressure in your home. The water pressure in city mains can be as high as 150 psi to efficiently distribute water to users, which is excessive for residential purposes.

A plumbing pressure valve kicks in when the pressure in your water line is at a high psi. This valve has an adjustable tension spring. Based on the settings, the spring controls a flap or diaphragm that regulates water flow.

When the PRV detects higher-than-desired water pressure, the valve opening narrows. Less water gets through, reducing pressure. However, if it's lower than desired, the valve opening widens. More water gets through, increasing pressure.

Where Is Your Home's Pressure-reducing Valve?

Home water pressure regulators are typically located near the main water line that connects your home to the water supply. You might find the valve outside your house in a garage or basement, near the water meter or inside a utility closet.

Look for a bell- or dome-shaped valve, often made of brass, bronze or stainless steel. It's frequently located beside the main shutoff valve, where your residential plumbing system begins. Some older homes may not have a PRV, but you can install one if needed.

Adjusting the Settings of a Water Pressure Regulator

At the top of your PRV, you'll find a bolt held in place by a locknut. You can adjust water pressure by loosening the locknut and turning the bolt.

To increase pressure, turn the bolt clockwise.
To decrease pressure, turn the bolt counterclockwise.
Check the water pressure with each adjustment by attaching a pressure gauge to an outside faucet.
When you've reached the appropriate setting, tighten the locknut.

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Benefits of a Water Pressure-Reducing Valve

Water pressure regulators do more than stop your faucet from gushing like a fire hydrant. They also offer practical benefits such as:

Extending the life of pipes and appliances. Most plumbing systems and appliances aren't made to withstand high water pressure over time. A PRV can reduce maintenance and repair costs.
Ensuring consistent pressure. Water pressure from city mains varies depending on the time of day and demand. A PRV keeps water pressure at a steady level.
Preventing water waste. The higher the water pressure, the more water that flows from your taps. Excessive pressure can result in wasted water, as much of it flows back into the drain, leading to higher utility bills.

Maintaining Home Water Pressure Safety

Ensuring your water pressure valve works properly can help keep your pipes and appliances running at their peak. Signs that your water pressure may be too high include a clanging sound in your pipes when you turn off a faucet as well as leaks, especially around the water meter.

To determine if your water pressure levels are within the recommended range, attach a pressure gauge to an outdoor faucet. Based on your findings, you may need to adjust, replace or install a pressure-reducing valve to ensure safe water pressure in your home.

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