Causes and treatment methods of damage to the mechanical seal of centrifugal pump

Causes and treatment methods of damage to the mechanical seal of centrifugal pump

There are six reasons for the damage of the seal of the centrifugal pump as follows, and the specific content and treatment methods of each item are as follows:

1. The water quality of the centrifugal pump is poor and contains particles. Due to the poor water quality, small particles and high hydrochloride content in the medium, the abrasive wears the plane of the centrifugal pump seal or the surface of the strain produces grooves and grooves. Solution: Improve the water pressure or medium, replace the machine seal.

2. Cavitation. Cavitation (mainly from thermal centrifugal pumps). Because the medium is hot water, the water temperature is too high to produce steam, and the gas in the pipeline enters the high place in the pump chamber, and this part of the gas cannot be discharged, resulting in water shortage operation, machine seal dry grinding failure, and cavitation device. Solution: Replace the machine seal.

3. Lack of water causes damage to the dry mill of operation. This phenomenon is mostly seen in the negative pressure at the inlet of the installation form, there is air in the inlet pipe, there is air in the pump cavity, after the pump is started, the friction of the machine seal produces high temperature during high-speed operation, and it cannot be cooled, check the machine seal, the spring tension is normal, the friction surface is charred and blackened, and the rubber becomes hard and cracked. Solution: Drain the air in the channel and pump chamber, and replace the machine seal.

4. the installation is too tight to observe the dynamic and static ring plane of the mechanical seal, if there is serious scorching, the plane is blackened and very deep marks, the sealing rubber becomes hard and loses elasticity. This phenomenon is caused by an overly tight installation. Solution: Adjust the installation height, after the impeller is installed, use a screwdriver to dial the spring, the spring has a strong tension, and it is reset after being released, and there is a moving distance of 2-4mm.

5. Water leakage at the mechanical seal. Solution: Fill the leakage gap with high-density material, or replace the machine seal.

6. the installation is too loose. Observe the sealing and static ring plane of the machine, and there is a very thin layer of scale on its surface, which can be wiped off, and the surface is basically free of wear, which is caused by the loss of elasticity of the spring and poor assembly, or the axial movement of the motor. Solution: Replace the spring and motor shaft and reassemble it.