Mechanical Seal , also known as seal, mainly for pumps, compressors, hydraulic transmission, and other similar equipment, rotary shaft seals. Mechanical seal by a pair of several pairs of fixed ring and static ring composed of flat friction pairs formed seal. Classification of mechanical seals: Rotating or stationary by spring elements can be divided into: Built-in rotating flow of non-equilibrium single-seal, referred to as rotary; Static exterior flow balanced single seal, referred to as Static. By static face seal ring is located inside or outside can be divided into: Built-in and external-mounted. Leakage by sealing the direction of media can be divided into: internal loss and the outflow type. By media in the face caused by unloading the situation can be divided into: balanced and non-balanced. According to the logarithm of seal face can be divided into: single face and double face. According to the number of springs can be divided into: single-and multi-spring type spring type. By elastic elements Category: spring compression and the corrugated tube. By non-contact type mechanical seal structure categories: hydrostatic pressure type, the fluid dynamic pressure type, dry gas seal type. By sealed chamber temperature categories: high, medium, general, low temperature sealing. Separated by sealed cavity pressure: high, high, medium and low pressure mechanical seal.