This standard specifies the nominal working conditions, technical requirements, test methods, inspection rules and signs, packaging, transportation, storage, etc. of piston single-stage refrigeration compressors. This standard applies to organic refrigerants (R12, R22, R404A, R134a, R407C, R410A, etc.) and inorganic refrigerants (R717), and single-stage piston type fully enclosed, semi-hermetic, and open refrigeration compressors with cylinder diameters not greater than 250mm . This standard does not apply to compressors in the following products: a) Household refrigerators and freezers; b) Transportation and special-purpose refrigeration and air-conditioning equipment.