The function of rider rings, used mainly in oil free or mini-lube compressors, is to support or guide the piston and rod assembly and prevent contact between the piston and the cylinder (risk of seizure).
High-performance rider rings:
Different designs and types of cuts are also used.
The materials used have the same wear resistance as the piston rings, in order to meet the requirements of the most stringent conditions of service.
All of these parts are generally designed with decompression grooves to avoid their operating as piston rings which could cause premature wear.