Misunderstandings in maintenance of centrifugal pump mechanical seals
Centrifugal pumps work by using the rotation of an impeller to cause centrifugal movement of water. The six major misunderstandings in mechanical seal maintenance of centrifugal pumps are mainly reflected in:
1. Misunderstanding 1: The greater the spring compression, the better the sealing effect.
In fact, excessive spring compression will cause rapid wear of the friction pair, instantaneous burning, and seal failure. Therefore, during maintenance, the spring compression amount should be adjusted according to actual needs to ensure that it is within a reasonable range.
2. Misunderstanding 2: The tighter the dynamic ring seal, the better
If the dynamic ring seal is too tight, it will increase the wear between the seal ring and the shaft sleeve, leading to premature leakage. At the same time, an over-tight sealing ring will also increase the resistance to axial adjustment and movement of the moving ring, reducing the sealing performance. Therefore, the moving ring seal should be kept appropriately tight during maintenance.
3. Misunderstanding 3: The tighter the static ring seal, the better
The static ring seal is basically in a static state. An over-tight seal will cause excessive deformation and affect the sealing effect. At the same time, the material of the static ring is generally brittle, and excessive stress can easily cause it to break. Therefore, excessive tightening of the static ring seal should be avoided during maintenance.
4. Misunderstanding 4: The tighter the impeller lock nut, the better
Excessive locking of the impeller lock nut will only cause premature failure of the inter-shaft pad, but will affect the sealing performance. Moderately lock the lock nut to maintain a certain compression elasticity of the inter-shaft pad, which is beneficial to maintaining the sealing state.
5. Misunderstanding 5: New is better than old
When the quality or material of the new mechanical seal is improperly selected, large errors in fit size will affect the sealing effect. During maintenance, the appropriate mechanical seal should be selected based on actual needs instead of blindly pursuing the new or the old.
6. Misunderstanding 6: It is better to dismantle and repair than not to dismantle
Sometimes the seal is not damaged and the leakage can be eliminated by simply adjusting the operating conditions or adjusting the seal appropriately. Therefore, the cause of leakage should be accurately determined before maintenance to avoid unnecessary repairs.
