The single-end seal has a simple structure, easy to manufacture and install. Generally, it is a commonly used seal type when the medium itself has good lubricity and allows a small amount of leakage. When the medium is toxic, flammable, explosive, and has strict requirements on leakage, it is not suitable use.
Double end face seal has axial double end face seal and radial double end face seal. The radially arranged double end face seal structure is more compact than the axial double end face seal. The double end face seal is suitable for the medium itself with poor lubricity, toxic, flammable, explosive, volatile, containing abrasive particles and gas, etc.
The axial double end face seal has a face-to-face or back-to-back arrangement. It is necessary to introduce a sealing liquid higher than the medium pressure of 0.05 to 0.15 MPa between the two pairs of end faces to improve the lubrication and cooling conditions between the end faces and isolate the medium from the outside world. It is possible to achieve "zero leakage" of the medium.
