What is a Swing Check Valve Used For?

Swing check valves have many uses, from sewage systems and wastewater treatment to firefighting, power plants, and various household items. One of the most commonly known examples of this valve type is the swing check valve that allows water to enter a toilet’s tank while blocking the reverse flow.

A swing check valve is a simple device designed for the one-way flow of a liquid or gas. It has a disc that swings on a hinge, opening to allow fluid to flow in, then closing to prevent backflow. Swing check valves are designed in a variety of sizes with different features to suit specific application types. There are also some slight variations on the swing design that better suit particular situations.

How Does a Swing Check Valve Work?

Swing check valves are among the most common types of check valves and are frequently used to manage a high horizontal flow. The fluid’s pressure opens the disc to allow the water or gas through. After the flow stops, the disc swings back into its closed position, resting against the valve’s seat and preventing backflow. The pressure of any backflow also serves to close the disc.

Applications of Swing Check Valves

Made of metal or PVC, swing check valves best suit pipes that receive a steady flow of fluid. Repeated instances of sudden pressure changes may damage swing check valves and result in leaking (referred to as passing) because the valve cannot seal correctly against the seat.

Swing check valves serve as a simple solution in numerous industries. Some examples include:

• Power plants. A variant of the standard swing check valve, silent check valves — also called spring check valves — use a   spring to help the valve close with more control. Silent check valves see frequent use in fluid control applications in the power generation sector, such as cooling towers. Of note, it also takes more pressure to open the valve against the spring, so spring check valves are best suited to high-pressure applications.
• Natural gas transmission. Swing check valves help prevent the improper flow of gas that could result in dangerous leaks or fires. These valves see broad usage in gas pipelines, commercial and residential gas meters, gas compressors, and more. 
• Oil and gas refineries. Refineries often use specially designed non-slam check valves to mitigate water hammer — the pressure wave created in the system by a slamming valve.
• Horizontal water lines. Swing check valves are ideal for high-volume, consistent-pressure fluid situations. They’re the most common valve used in wastewater treatment and water pumping.
• Custom solutions. Each system is different, and sometimes specific applications require a unique modification or entirely original design to solve a challenging flow issue. It may be as simple as changing the angle of the valve or decreasing the disc’s weight, but your valve manufacturer can help you determine if a customized solution is right for you.

Learn more about the industries that TVI Valves serves.

Swing check valves are affordable and easy to maintain. Since they require no external power source, they are a go-to valve for countless horizontal piping applications. At TVI, we offer swing check valves ranging in size from 3/4-inch to 8 inches, along with various other metal and plastic valves. Please contact us today so we can help you determine the best valve solution for your situation.