Diaphragm Compressors

Diaphragm Compressors are ideal for compressing all types of gases where ultra high purity gas is required. These compressors isolate the gas from the hydraulic system and mechanical components, preventing contamination of the compressed gas. This makes them ideal for applications such as semiconductor manufacturing, pharmaceutical production and scientific research where even trace impurities are unacceptable.

A metal diaphragm completely separates the two systems; the hydraulic oil system and the gas compression system. During the suction stroke, the gas enters the working chamber through the inlet valve and is compressed by the change in the chamber volume. The gas is then discharged through the exhaust valve in the delivery stroke.

Diaphragm Compressors: Advantages in High-Purity Gas Compression

This theoretical process is illustrated in Figure 4. At the beginning of the suction stroke (state A), the oil piston is at the top dead centre and the diaphragm is in contact with the gas plate. The gas pressure is equal to the oil pressure.

During the delivery stroke, the gas pushes the diaphragm towards the process head. The compression cycle continues until the gas is at a lower pressure than the hydraulic oil pressure. Then the hydraulic oil pressure rises and lifts the diaphragm to the top of the process head. The system can then discharge the gas to the process or tank.