PISTON AND RIDER RINGS
Piston and rider rings also referred to as guide rings are used in horizontal, vertical and v-shaped cylinders. STASSKOL manufactures a wide range of one-piece or multipiece piston and rider rings with and without expansion springs as well as pressure-relief grooves. The axial and radial dimensions and the ring gaps are decided for long-life cycle of the piston and rider rings.
The basis for the exact calculation is mean piston temperature as well as the coefficient of expansion of used materials.
STASSKOL offers an extensive range of one-piece and multipiece piston and rider rings, with or without expansion springs, as well as pressure relief grooves.
There are single acting and double acting pressure relieved piston rings in one-piece an multi-piece designs with rectangular or angular section. Twin rings are also able to be supplied.
Rider rings of a one-piece, multi-piece or solid can be supplied. The design of the reciprocating compressor and working conditions determine the design. Beside the temperatures the unit loading is the most important design criterion for ring dimensions.
MODE OF OPERATION
The function of a piston ring is to seal the compressed gas in the compression chamber. In case of just one piston ring (with even or angular gap) gas leakage cannot be prevented. Therefore, in order to increase sealing effects, several piston rings are arranged in sequence depending on the pressure differential and gas molecular weight.
The function of a rider ring is to guide the piston rod and the piston assembly into the cylinder during the operation of compressor. The rider ring prevents metallic contact between the piston and the cylinder liner. Normally the rider ring is pressure relieved with angular gap. In case of a single acting piston the ring will positioned at the far side of pressure.
The range of piston and rider rings offered by STASSKOL is varied an individual mounting instructions need to be considered.
When using several guide rings in a piston there are for example prescribed positions for the individual rings to prevent heat accumulation.