The piston performs upwards and downwards motion inside the cylinder, which is also called as the reciprocating motion. During its motion the piston enables suction and compression of the refrigerant. During its motion inside the cylinder the refrigerant should not leak through the gap between the cylinder walls and the piston to the crankcase, hence piston is covered with the piston rings. The gap between the piston and the cylinder is also filled with the lubricating oil, which also prevents the leakage of the compressed refrigerant to the crankcase. Pressure die casted, gravity die casted, shell moulded pistons are made out of aluminium alloys, graded closed grained cast iron.
The piston rings are circled around the piston. When the piston performs reciprocating motion inside the cylinder, it is the piston rings that come in contact with the walls of the cylinder. There is lots of friction between the cylinder walls and the piston rings, thus they have to be replaced from time-to-time for proper functioning of the compressor. This helps increasing the life of the piston and prevents replacement of the complete piston. Piston rings are individually centrifugally casted out of high grade cast iron materials.
K9 branded pistons and piston rings are the best choice for your compressor.