What Is a Reed Valve?

Reed valves are used in a variety of engine types.

A reed valve is a one-way valve, allowing liquid and air to pass through it one way and not the other. They are found in the intake track of a two-stroke engine, between the carburetor and the cylinder. The purpose of a reed valve is to accommodate different speed ranges within the engine and maximize the engine's output and efficiency, through constricting the flows of air and liquid.

How it Works

Once the liquid or air has passed through the valve, the flow is shut off and engine compression cannot force them back through. The engine will become very difficult to start if the reed valve ever breaks or becomes worn out.

In Air Brake Compressors

These valves are are mostly used on commercial road vehicles and trains to deal with air temperature and fast heat transfer for brakes. They are are water-cooled through channels of water within the seat plate.

Refrigeration Compressors

These valves are used to maximize gas tightness, prevent corrosion and optimize clearance volume. They are used in air conditioning units and refrigeration applications to maintain a steady temperature.

Reed valves used in air and gas compressors

These are similar to the reed valves for refrigeration compression, however,they aren't needed for cooling purposes. They are used in industrial and small workshop compressors to compress technical gases and air.

References

• Hoerbiger: Reed Valves
• Dans Motorcycle: Reed Valves
• Free Patents Online: Reed valve device for 2-cycle engine