One important argument in favor of reciprocating compressors is that they can be well controlled, for example their output or volume flow. The high imperviousness of the working spaces as opposed to rotating machinery denotes a further important feature of reciprocating compressors. This allows the economical high pressure compression of gases. Applications also exist in favor of a sealing system which is not based on contacting sealing elements. Examples of this include: Gases with abrasively effective particles Gases with a tendency to polymerize Flammable gases