Compression rings create a tight seal against the cylinder wall, preventing gas leakage and ensuring high-pressure gas formation in the compression chamber for optimal air compressor performance.

Piston ring material selection is critical for durability. Common materials include cast iron and chromium molybdenum alloys, which provide excellent wear resistance, high temperature tolerance, and corrosion resistance to withstand the demanding conditions of internal combustion engines and air compressors.

Piston rings typically consist of multiple rings with close side connections. Common configurations include oil rings, oil control rings, and upper/lower spiral grooves, with each structure performing specific functions such as cylinder sealing, heat conduction, and lubrication.