Mechanical seal is also known as face seal, which has a pair of end faces perpendicular to the axis of rotation. Under the action of fluid pressure and compensating mechanical external elastic force, the end face depends on the auxiliary seal to keep fit with the other end, and relative sliding, so as to prevent fluid leakage.
Mechanical seal leakage fault is one of the most prone to failure of the pump, so the pump mechanical seal also belongs to one of the key parts of the water pump, the selection of water pump mechanical seal material must be suitable for the user of the liquid medium, usually pump factory is fluorine rubber mechanical seal some manufacturers are butyl rubber mechanical seal, If the corrosion is more serious, the mechanical seal made of tetrafluoroidal material is selected.
What to do if the pump mechanical seal leaks?
There are six reasons for leakage at the mechanical seal
1. Wear of seal dynamic and static ring planes.
2. The installation is too tight. Observe the static and dynamic ring plane of the mechanical seal. If there is serious burning phenomenon, black and deep marks on the plane, the sealing rubber becomes hard and loses elasticity. This phenomenon is caused by too tight installation. Solution: Adjust the installation height, after the impeller is installed, use a screwdriver to pull the spring, the spring has a strong tension, release the reset, there is 2-4MM distance to move.
3. The installation is too loose. Observe the machine sealing, static ring plane, the surface has a very thin layer of scale, can erase, the surface is basically no wear, which is caused by the loss of spring elasticity and poor assembly, or the motor axial movement.
4, Poor water quality with particles. Due to poor water quality, small particles and high content of carbonate in the medium, the surface of abrasive wear machine seal or strained surface produces grooves, ring grooves and other phenomena. Treatment method: Improve the water pressure or medium, and replace the machine seal.
5. Dry mill damage caused by water shortage operation. This phenomenon is more common in the bottom valve installation form at the inlet of negative pressure, air inlet pipe, air in the pump chamber, after the pump starts, the friction of the machine seal high temperature when running at high speed, can not be cooled, check the machine seal, spring tension is normal, friction surface scorched black, rubber hardening and cracking. Treatment method: despite the passage and pump chamber air, replace the mechanical seal.
6. Cavitation. Cavitation occurs mainly in hot water pumps. Because the medium is hot water, the water temperature is too high to produce steam, the steam body in the pipeline into the pump chamber high, this part of the steam body can not be excluded, resulting in water shortage operation, machine seal dry grinding failure, cavitation installation of automatic exhaust valve, but also replace the machine seal.
