Check Valves 101: A Simple Guide

It’s estimated that there will be 140,000 new engineering jobs created by 2026.

Even with so many job opportunities, it’s essential to continue learning as much as possible so you can be a valuable employee wherever you end up.

If you don’t already know how check valves work, this post is for you. We created this guide to teach you what a check valve is, how they’re used, and how to pick the best one for a project.

Keep reading to learn more about this essential component of many systems.

What Are Check Valves?

A check valve is a two-port valve through which air or fluids flow in one direction. They can be open or shut depending on the pressure and direction of flow within the pipes.

There are several different types of check valves, each of which has a different application. One of the biggest benefits of this valve is they work automatically so no operation is required once they’re put in place.

How to Use Check Valves

Each type of check valve falls into two basic categories which we’ll focus on here.

Normally Open

A check valve that is normally open allows a medium to flow through it freely from one direction to another. However, when there is backflow, the valve will shut due to the pressure on that end of the valve.

A great example of how this type of valve is used would be in a water treatment plant. In this case, it’s essential for the water to only flow in one direction to avoid contaminating clean water.

Normally Closed

Normally closed check valves prevent the flow of air or fluid until there’s a certain amount of pressure built up. This is known as cracking pressure. Check valves can be made to meet any cracking pressure needed.

An example of where this type of value would be used is in a run-off pipe to prevent system overload. Once a system started building too much pressure, the valve would open to release air or fluid to avoid disaster.

Choosing the Right Valve

When choosing a check valve for a project or system, there are a few things you have to consider.

Media and Materials

The first thing you have to think about is what will be flowing through your system. This is particularly true when working with highly viscous liquids which require special valves.

Cracking or Sealing Pressure

You should already know if a valve needs to be normally open or closed. From there, you need to determine how much pressure will be required to open or close the valve.

Speed of Closing

If it’s essential for a valve to close completely within milliseconds of pressure being reached, this is something else to consider. Some valves allow minimal leakage while others have tight seals that don’t allow anything to get through.

In Need of Check Valves?

Now you know the basics of what check valves are and how to use them within various systems.

If you’re in need of check valves for a specific project and need to find the best one for it, contact us today. We would be more than happy to ensure you get the right valve for your application.