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How to repair mechanical seals?
- Oct 19, 2018 -

Common problems in operation and maintenance of Air Compressors:

45.How to repair mechanical seals?

        After long-term operation of mechanical seals, the end faces of moving and static rings will be worn by friction, the springs and bushes will be corroded or damaged, and the seal rings will lose elasticity due to aging and deformation, all of which will cause leakage of mechanical seals. Therefore, after a long period of operation, the mechanical seal components must be replaced or overhauled to achieve the purpose of reuse.


        (1) grinding of moving ring and static ring face. 

        After the removal of the moving ring, after grinding, rough research is carried out first, and then polishing is carried out.

         In rough grinding, 80~160 size abrasive is used to remove the machining marks first. Then the abrasive can be fined with more than 160 grit so that the finish can meet the design requirements.Cemented carbide or ceramic ring can be polished and polished after polishing.The strength of the polishing machine can be selected from M28 to M5 boron carbide. Mirror after polishing. The ceramic ring can be polished with chrome oxide after grinding M5 agate powder.

        Graphite filled polytetrafluoroethylene (PTFE) stationary ring can be refined with kerosene, gasoline or water because of its soft material, without adding abrasive. It can also be self developed in the running in process, so the smoothness requirement is not too high.

         Grinding method, a grinder can be grinded on the grinder, no grinder can be used on flat glass 8-shaped manual grinding method.

         (2) shaft sleeve inspection. 

        If the corrosion or wear is slight, the axle sleeve can be polished with fine sandpaper and reused. If the corrosion or wear is serious, the axle sleeve can be replaced by electroplating after machining.

         (3) sealing ring. 

        Sealing ring after a period of time, in most cases lost elasticity or aging, in general need to replace the new ring.

         (4) spring. 

        If the corrosion of the spring is not serious, it can keep the original elasticity and can not be replaced. If the corrosion is more serious or the elasticity decreases much, new springs need to be replaced.


        For mechanical seals with assembling boxes, the boxes should be cleaned up, and the grooves should be checked for wear or deformation in order to correct repair, re-grooving or replacement.

         After repairing, the mechanical seal elements are reassembled, and the pressure test is carried out after assembling, and then put into normal operation.