1) Installation is too tight
Observing the plane of the dynamic and static ring of mechanical seal, if there are serious burning, deep black marks on the plane, hardening or losing elasticity of the sealing rubber, all of these are caused by the over-tightening of the installation.
Solution: Adjust the installation height, after the impeller is installed, pull the spring with a screwdriver, the spring has strong tension, and reset immediately after loosening, with a moving distance of 2-4 mm.
2) Installation is too loose
There is a thin layer of scale (which can be erased) on the surface of the sealing and static ring plane of the observer, and the surface is basically free of wear and tear. This is caused by the loss of spring elasticity and poor assembly, or by the axial movement of the motor.