A diaphragm compressor is a specialized piece of equipment used to compress gases when little or no leakage is tolerable. The difference between an ordinary piston compressor and a diaphragm compressor is in the method of compression and the accompanying seals. A diaphragm compressor has a piston with piston rings, but the piston moves a volume of hydraulic oil. The oil bends a set of diaphragms up and down, and the diaphragms compress the gas. It usually has an electric motor as the prime mover, with flexible belts for power transmission.
Diaphragm grommets are made of poly vinyl chloride material. It can be used either as blanking plugs to conceal access holes, or as standard grommets by manually perforating the diaphragm for future wiring installations. Thin central film can be pierced to allow a range of different-sized wires to pass through. Generally, it is available in black color.