Mechanical seals are one of the basic mechanical components with precision and complex structure. They are the key components of various pumps, reaction synthesis kettles, turbo compressors, submersible motors and other equipment. Its sealing performance and service life depend on many factors, such as type selection, machine accuracy, correct installation and use, etc.

　　Type selection method Mechanical seals are based on different working conditions and media properties, including high temperature and low temperature resistant mechanical seals, high pressure resistant and corrosion resistant mechanical seals, particle-resistant media mechanical seals and light weight suitable for easy vaporization For mechanical seals of hydrocarbon media, mechanical seals of different structural types and materials should be selected according to different uses.

The main parameters of 　　 type selection are: sealed cavity pressure (MPA), fluid temperature (℃), working speed (M/S), fluid characteristics, and effective space for installation and sealing. The basic principle of the selection is: according to the pressure of the sealed cavity, determine whether the sealing structure adopts balanced or unbalanced, single end face or double end face, etc. According to the working speed, it is determined to adopt the rotary or static, fluid dynamic pressure or non-contact type.

　　 According to the temperature and fluid properties, determine the friction pair and auxiliary sealing materials, and correctly select the mechanical seal circulation protection system such as lubrication, flushing, heat preservation, and cooling. According to the effective space for installing the seal, it is determined to adopt multiple springs, single springs or wave springs, built-in or exterior-mounted.