What Is The Air Cushion Check Valve

What Is an Air Cushion Check Valve

An air cushion check valve is a specialized type of non-return valve designed to control the backflow of fluids while minimizing water hammer — a sudden pressure surge caused by the abrupt stoppage or reversal of fluid flow. What sets it apart is the air cushion (or air chamber) mechanism, which slows down the closing action of the valve disc, reducing shock to the piping system.

How Does an Air Cushion Check Valve Work

In a typical check valve, when flow reverses, the disc slams shut — often causing vibrations or pressure surges. In an air cushion check valve, the valve’s disc or piston is cushioned by compressed air in a chamber. This air absorbs the kinetic energy of the closing disc, allowing it to close more gradually and smoothly, thus preventing water hammer and prolonging system life.

Where Are Air Cushion Check Valves Used

• ①Marine systems (e.g., ballast, bilge, and cooling systems)

• ②Pump discharge lines

• ③High-pressure pipelines

• ④Industrial water systems

• ⑤HVAC and chilled water circulation systems

Key Benefits of Air Cushion Check Valves

• ①Reduces water hammer and pipeline stress

• ②Extends system component lifespan

• ③Smooth and controlled valve closing

• ④Ideal for high-flow, high-pressure applications

• ⑤Low maintenance and high reliability

Typical Features

• ①Horizontal or vertical installation

• ②Cast iron, carbon steel, or stainless steel body

• ③Rubber or metal seat

• ④Air cushion adjustment screw

• ⑤Spring-loaded disc for faster closing if needed