Views: 2453 Author: Site Editor Publish Time: 2020-05-29 Origin: Site
All kinds of seals used in industry, such as non contacting mechanical seal, pump seal, spring seal, gland packing and elastomer bellows seal, need to be maintained, otherwise, the seal will fail and affect the normal operation of the equipment. The following describes how to maintain the mechanical seal of centrifugal pump.
Before starting the centrifugal pump, check the impeller of the centrifugal pump to ensure that the impeller can rotate flexibly. If the impeller has large resistance or abnormal noise when rotating, it is necessary to dismantle the centrifugal pump to check whether various matching dimensions meet the design requirements. When the turning resistance of the turning gear is large, it is necessary to check whether the spring compression is too large.
Check the cooling water of the centrifugal pump. In order to prevent the excessive pressure in the cavity of the mechanical seal device from causing the water block to accelerate the wear, the size of the cooling water inlet is required to be smaller than the water outlet. Before starting the centrifugal pump, clean cooling water should be introduced to ensure good heat dissipation effect in the process of starting.
Before starting the centrifugal pump, start the conveying system. Fill the cavity of the centrifugal pump with the conveyed fluid to prevent the mechanical seal or motor from burning.
Leakage may occur after the centrifugal pump is started. If the amount of leakage is small and has no effect on production, pay attention to observe the leakage part rather than dismantle the mechanical seal immediately. Frequent disassembly of mechanical seal will affect the service life of mechanical seal and pump.
The fluid supply of the conveying system shall be sufficient and stable to avoid cavitation during the operation of the pump. The lack of liquid supply in the system will cause dry friction between the dynamic ring and the static ring of the mechanical seal, and even cause the motor to burn.
If the mechanical seal is used for more than 3 months, it may leak due to impurities in cooling water, wear of dynamic ring and static ring, etc. The mechanical seal with leakage shall be judged reasonably to determine whether it needs to be replaced. If there is a large amount of scale in the cooling water pipe, it needs to be cleaned with detergent. If the wear of the dynamic ring and the static ring is serious, the compression of the dynamic ring spring can be increased by adjusting the pump shaft so as to increase the pretightening force to improve the sealing effect.
To improve the sealing effect and service life of mechanical seal of centrifugal pump, it is necessary to take the dimensional error and installation accuracy of key parts such as shaft and bearing of centrifugal pump as the basis to ensure the installation accuracy and reasonable pretightening force of mechanical seal. Attention should be paid to the quality of cooling water and the stability of the liquid flow of the conveying system to ensure the stability of the centrifugal pump.