Composite Air Release Valve, ASTM A216 WCB, DN100, PN16, RF

Product Name: Composite Air Release Valve
Body Material: ASTM A216 WCB
Size: DN100, 4 Inch
Pressure: PN16, Class 150 LB
End Connection: RF Flanged

The composite air release valve has a barrel-shaped body and includes a float, stem, and disc. These valves are used at the highest point of the pipeline, where there is closed gas, or at the pump outlet to release gas from the pipe to ensure proper operation. Without the installation of an air release valve, gas resistance can build up in the pipeline, preventing the pipeline from achieving the required water capacity to meet design specifications. When negative pressure occurs in the pipeline, the valve quickly allows outside air to enter, preventing damage to the pipeline due to negative pressure.

Working Principle

The composite air release valve is equipped with two holes: a larger one and a smaller one. The larger hole, which has a diameter roughly equal to the size of the valve, allows a significant amount of air to be expelled when water is initially supplied to the system. Once the air is discharged, the float ball inside the valve rises as the water enters the body cavity, causing the plug disc to close and blocking the large hole to stop the excess air from being released.

When water is flowing normally through the pipe, if small amounts of air accumulate in the valve, the water level inside the valve decreases, causing the float ball to drop. This allows the accumulated air to be released through the smaller hole.

If negative pressure is generated in the pipeline, the valve allows outside air to enter quickly, preventing potential damage caused by the negative pressure.

Main Parts Material

Body: ASTM A216 WCB, A351 CF8, Ductile Iron QT450
Floating Ball: SS 304, SS 316, SS 316L
Sealing Material: Nitrile Rubber
Gasket: NBR
Inside Cover: Cast Steel
Bolt: Cast Steel
Outside Cover: Cast Steel
Nut: Cast Steel