What is the Difference between Wafer Check Valve and Swing Check Valve?

The efficient functioning of pipeline equipment and the prevention of backflow are two of the most important functions of check valves in industrial pipeline systems. Two of the most popular kinds of these valves are swing check valves and wafer check valves. Even though they are essentially interchangeable, there are major structural, operational, and application-related differences between the two. To assist engineers and procurement experts in making the best decision for their unique requirements, this article will compare and contrast two types of check valves and highlight their main distinctions.

1. Differences in Structure and Design

Wafer Check Valve

• Because of its small profile, the valve body is ideal for installations in tight quarters.
• It uses either a dual-disc or single-disc structure, with a butterfly valve disc that opens during the flow of the medium and closes when the flow stops or reverses, relying on spring or gravity for closure.
• Featuring a wafer design, it can be directly sandwiched between two flanges, reducing the length requirements for the pipeline.
• Common materials include stainless steel, cast steel, and ductile iron, making it suitable for a wide range of media.

Swing Check Valve

• The swing check valve has a relatively larger structure and uses a hinge mechanism. The valve disc functions similarly to a door, being pushed open by the forward flow of the medium and closing under its own gravity when the flow reverses.
• It requires more installation space, especially in large-diameter pipelines, where the valve body is larger and heavier.
• Flanged connections are primarily used, with either flanged end connections or butt-welded connections to ensure sealing and pressure resistance.
• With a wide range of material options, the swing check valve is suitable for high-temperature and high-pressure conditions, such as steam pipelines, oil, and chemical industries.

2. Differences in Working Principles and Performance

Working Features of Wafer Check Valves

• Fast Closing: With the assistance of a spring mechanism, a wafer check valve can close quickly even when the flow rate decreases, helping to reduce water hammer effects.
• Low Opening Pressure: Ideal for low-pressure or medium-low-pressure systems, it can operate effectively with a small pressure differential.
• Dual-Disc Design to Reduce Impact: In most applications, the dual-disc design of the wafer check valve helps minimize fluid impact forces, thus extending the valve’s service life.

Working Features of Swing Check Valves

• The valve disc relies on gravity and fluid force to close, making it suitable for high-flow applications. However, it has a slower closing speed, which may result in a larger water hammer effect.
• Ideal for high-flow conditions, such as pump outlets or long-distance pipelines, it can withstand higher pressures and reduce fluid resistance.
• With excellent sealing performance, the swing check valve is commonly used in strict fluid control environments, such as oil, chemical, and energy industries.

3. Comparison of Application Scenarios

How to Choose the Right Check Valve?

When selecting a check valve, several factors such as operating conditions, installation space, and fluid characteristics must be considered:

• If pipeline space is limited and there is sensitivity to the water hammer, a wafer check valve is recommended. Its compact design and spring-assisted closing feature can help reduce the risk of water hammering.
• For high-flow, high-pressure systems, such as steam pipelines or high-temperature conditions, a swing check valve is more suitable. It provides lower fluid resistance and can better withstand high-pressure environments.
• At the inlet of critical equipment (such as pump outlets), a wafer check valve offers faster closing speeds to prevent backflow from damaging the equipment.
• For pipelines carrying solid particles or viscous fluids, the swing check valve’s valve disc structure is better suited to handle such media, reducing the risk of blockage.