Rubber O rings are elastomer materials that are used to seal connections to prevent leaks. The initial classification for rubber O rings is static and dynamic, where static rubber O rings form a seal for two surfaces that do not move, while dynamic rubber O rings make a seal between surfaces that do move.
Packing Rings reduce leakage of gas and lubricating oil from the cylinder into the distance piece and crankcase. Activated by gas pressure, they seal actively against the rod surface and the packing case cups. Their design depends on the gas composition and the operating conditions of the compressor.