What Is a Check Valve? | Types of Check Valves | How Do Check Valves Work?

What Is a Check Valve?

The correct plumbing configuration for your project will require the proper valves. One of the most common and important valves is the check valve. They are also frequently referred to as non-return valves, retention, foot, or one-way valves. With all that being said, let's get to the golden question. What is a check valve?

How Does a Check Valve Work?

A check valve is a valve that ensures fluid only flows in one direction in a plumbing system. The check valve typically has two openings, and the water (or whatever) passes in one port and out the other. It works off a concept called "pressure differential." This mechanism closes the valve when the pressure is higher on the outlet side. The mechanism can come in many different forms.

how does a check valve work infographic

Types of Check Valves

  • Diaphragm: as the name suggests, inlet pressure opens a diaphragm. Otherwise, it's closed and prevents backflow.
  • Spring-loaded disc: the way this technology works is once the water pressure on the input side increases enough to push the spring, the valve opens. When the input water pressure lowers to a certain point, the spring is strong enough to close the valve.
  • Ball: works much like the disc above, but the stopper is ball-shaped.
  • Stop: this is a check valve with a manual override.
  • Lift: this mechanism relies on gravity to operate. The inlet water pressure lifts the stopper to open the valve.
  • Swing: also known as a tilting disc valve, it operates with a disc on a hinge that swings open with sufficient inlet pressure.
  • Duckbill: a duckbill is a soft tube that looks kind of like a duck's bill when it's open, and when it's closed, it looks like a crayon tip.
  • Butterfly: a check valve with a butterfly (or wafer) style disc on a hinge and spring configuration.
  • Foot: this is a check valve with a strainer on the inlet side.

Save on Valves at PlumbersStock

Now that you know what a check valve is and how it works, you can proceed with your project. Find any plumbing part that you can think of here with the professionals at PlumbersStock.com. If you have any trouble at all locating the right parts, don't give up. Please contact us. We have the expertise, the products, and the pricing to keep you happy and on top of your projects.

Related resources:
What Is a Ball Valve?
What Is a Gate Valve?
What Is a Globe Valve?
What Is a Butterfly Valve?
What Is a Curb Stop?

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