The leakage of the mechanical seal of the pump is one of the most prone faults in the failure of the pump. Therefore, the mechanical seal of the pump is also one of the more critical wearing parts in the pump components. For liquid medium, usually the pumps are shipped with fluororubber mechanical seals, and some manufacturers use nitrile rubber mechanical seals. If the corrosiveness is serious, PTFE mechanical seals should be used.
Step / Method
1. The first possibility of water leakage at the mechanical seal is the wear of the dynamic and static rings of the mechanical seal. There are six reasons for the wear of the dynamic and static ring planes of the mechanical seal:
2. The installation is too tight. Observe the plane of the dynamic and static rings of the mechanical seal. If there is severe scorching, the plane becomes black and deep marks, the seal rubber becomes hard and loses its elasticity. This phenomenon is caused by too tight installation. Solution: Adjust the installation height. After the impeller is installed, pull the spring with a screwdriver. The spring has a strong tension. It will reset after loosening, and the moving distance can be 2-4MM.
3. The installation is too loose. Observe the sealing and static ring plane of the machine. There is a thin layer of scale on the surface that can be wiped off. The surface is basically free of wear. This is caused by the loss of spring elasticity and poor assembly, or the axial movement of the motor.
4. Poor water quality contains particles. Due to poor water quality, containing small particles and high content of hydrochloride in the medium, grooves and ring grooves are formed on the plane of the abrasive wear mechanical seal or on the scratched surface. Treatment: improve water pressure or medium, and replace mechanical seal.
5. Dry grinding damage caused by lack of water. This phenomenon is more common in the negative pressure at the inlet of the bottom valve installation, there is air in the inlet pipe, and there is air in the pump cavity. After the pump is turned on, the friction of the mechanical seal generates high temperature during high-speed operation and cannot be cooled. Check the mechanical seal and the spring tension is normal , The friction surface is scorched and blackened, and the rubber is hardened and cracked. Treatment method: exhaust the air in the channel and the pump cavity, and replace the mechanical seal.
6. Cavitation. Cavitation mainly occurs in hot water pumps. Because the medium is hot water, the water temperature is too high to generate steam, and the steam in the pipeline enters the high place in the pump cavity. This part of the steam cannot be excluded, resulting in water shortage operation, the mechanical seal dry grinding fails, and the cavitation equipment automatically discharges Air valve, replace mechanical seal.