The sealing leakage condition of the hydraulic system is a complex issue that requires meticulous attention. Leakage in hydraulic systems is mainly divided into leakage at fixed seals and leakage at moving seals. Leakage at fixed sealing points mainly occurs at the bottom of the cylinder, the connection points of various pipe joints, etc. The leakage at the moving seal is mainly concentrated in the piston rod area of the cylinder, the valve stem of the multi-way valve and other parts.　

Mechanical seals are one of the precise and structurally complex mechanical basic components, and they are key parts of various pumps, reaction synthesis kettles, turbine compressors, submersible motors and other equipment. Its sealing performance and service life depend on many factors, such as model selection, machine accuracy, correct installation and use, etc.