Sealing pair and piston unit

The utility model relates to the technical field of mechanical sealing, and provides a sealing pair and a piston unit, and the sealing pair comprises a flexible sealing ring provided with a first groove; a part of the metal sealing ring is erected in the first groove, and the metal sealing ring is provided with a second groove with the opening facing the same direction as that of the first groove. The sealing device has the characteristics of simple structure, good sealing performance, wide application range, convenience in maintenance and the like. 本实用新型涉及机械密封技术领域，提供了一种密封副及活塞单元，密封副包括：柔性密封圈，设有第一凹槽；金属密封圈，所述金属密封圈的部分架设于所述第一凹槽内，且所述金属密封圈设有与所述第一凹槽开口朝向相同的第二凹槽。本实用新型具有结构简单、密封性能好、适用范围广、便于维护等特点。