The piston rings of reciprocating compressors need to be constantly pressed against the cylinder wall. This guarantees optimum sealing efficiency.  However, in non-lubricated applications, such as PET or oxygen compression, wear of the piston rings is unavoidable. In order to compensate this wear, the piston rings are designed with gaps. When the rings are new, the gaps are designed in such a way that the rings are almost closed when the operating temperature is reached. With increasing wear, the gaps get wider. This leads to an internal backflow of already compressed gas over the piston rings.

Here Stasskol offers the use of gas-tight piston rings whose gaps are covered by an overlapping ring design. Due to the special geometry and the high manufacturing quality, internal gas leakage is effectively avoided. This results in a higher capacity of the machine and an improved energetic efficiency of the compression.