What Are Check Valves?

Check valves belong to the vast family of industrial valves- the ubiquitous devices found in almost every single industrial facility. The check valve is also known as a one way valve and as its name indicates, the valve allows the media to flow only in one direction. Here are some interesting facts about check valves:

They operate on differential pressure, which means that the valve will open up only if the pressure upstream is greater than the pressure downstream.
Check valves are mostly installed close to the outlet of the pump to avoid the backflow of media.
Most check valves work automatically without any human intervention.
The main purpose of installing check valves is to avoid the reverse flow in many industrial applications.
Check valve manufacturers supply check valves in various industrial sizes, dimensions, and materials.

Check valve installed in the outdoor of our clients industrial unit to control the flow of direction by Oilway

The components that comprise the check valve are quite similar to that of the other industrial valves. The disc is the main component that differs in how it is assembled. The main components include:

Hinge
Bonnet joint.
Hinge pin
Valve body
Disc
End connection

Check valve models made by check valve suppliers

The valve market is flooded with at least a dozen different types of check valves that differ with how the disc moves. Let's take a closer look at the most common check valve models.

Swing check valve or tilting disc check valve

One of the most common types of check valves is the swing check valve, characterized by the disc that swings on a hinge or shaft. It allows the full, unobstructed flow in the open position and automatically closes when the pressure decreases.

Also Read : A Simple Guide To Sizing Check Valves

Wafer check valve

An industrial Wafer check valve is compact, lightweight, affordable and very ideal for applications with low-pressure loss. The valve has a thin disc held in position by a hinge on the top. As a result, the bottom of the disc is free to swing back and forth when the valve is operated or closed.

Ball check valve

Ball check valves come in two models- the free-floating ball check valve and the spring-loaded ball check valve. They are used in simple applications like small motor pumps and low head systems. In a free-floating ball check valve, the sealing seat is conically tapered to bring the ball back into the seat and create a leak-proof seal.

Duckbill check valve

This valve type has a one-piece elastomeric component that enables the flow through a soft tube. When the backpressure collapses inside the tube, the flow is stopped.

Stop check valve

A stop check valve is a two-in-one valve. It acts as a globe valve and as a check valve. Thus, it fulfils dual purposes of isolation and backflow prevention. In addition, this valve has an additional external control mechanism in a perpendicular or angular direction. Because of its dual operating capacity, the stop check valve is widely used in steam generators, turbine cooling systems, and power plants.

Lift check valve

The lift check valve's disc lifts off the valve seat to create space for the flow of media. The valve automatically closes when the pressure in the inlet decreases below the back pressure.

Check valves and their functioning mode

Check valves depend on minimum upstream pressure called cracking pressure to operate without a hitch. The cracking pressure varies with the valve design and size. Here's a step-by-step explanation of a check valve's working mode:

When the upstream pressure aligns with the cracking pressure, the valve opens to allow the flow.
When the upstream pressure falls below the cracking pressure, it creates a back pressure, forcing the flow to come back from the inlet to the outlet.
This forces the valve to close and stop the flow automatically.
The closing mechanism also differs with each model and size.
The direction of the flow is indicated with an arrow on the valve body.

Oilway: Indonesia's leading check valve suppliers

Oilway is one of the country's leading industrial valve suppliers, dealing with high-quality check valves of all models, sizes, and dimensions. Call us @+86-21-69891289 to know more about our products.