Centrifugal Pump is Evacuated Phenomenon How to Do?

Centrifugal pump in the practical application, there will always be a variety of conditions, one of the many reasons for centrifugal pump failure when the phenomenon of evacuation, always make you feel very headache. What if the centrifugal pump is evacuated?

After the pump is pumped, or during the process of pumping
1) The vibration of the pump body is large, and the dynamic and static rings of the mechanical seal will continue to intermittently collide, resulting in leakage, and the failure of the mechanical seal structure in serious cases;
2) The compression of the dynamic and static ring of the mechanical seal is the sum of the medium pressure and the pretension force of the spring, when evacuated, the medium pressure will not be there, the contact pressure of the dynamic and static ring will become smaller, and the seal will fail;
3) After the pump is evacuated, the mechanical seal dynamic and static ring end face of the self-washing scheme (that is, the use of pumping medium to wash) loses cooling and lubrication, dry friction occurs, and the mechanical seal fails.

First, Incidental conditions

1. Motor current drops.
2. The pressure fluctuates greatly.
3. Abnormal flow fluctuation.
4. Make a noise.
5. The pump body vibration.
6. Pump cylinder temperature rise.

Second, the cause of evacuation

1. Air leakage occurs at the entrance of the centrifugal pump.
2. Blockage occurs at the entrance of the centrifugal pump.
3. Centrifugal pump inlet pressure is not enough.
4. Centrifugal pump inlet medium temperature is too high saturated steam is too large.
5. Centrifugal pump inlet valve is not open or spool off.
6. Centrifugal pump outlet opening is too large (small).
7. Centrifugal pump seal oil with water.
8. Centrifugal pump tower or container liquid level is low or no liquid level.
9. Centrifugal pump impeller or inner grinding ring wear seriously.
10. Centrifugal pump motor reversal

Third, evacuate the corresponding treatment method

1. If the inlet is blocked, the pump should be stopped to check the leakage inlet pipeline and impeller of the centrifugal pump, and maintenance should be carried out after purging.
2. If the inlet pressure is not enough, the liquid surface back pressure should be increased.
3. If the temperature of the inlet medium is too high, the temperature of the medium should be reduced, and the steam in the centrifugal pump should be drained.
4. If the inlet valve is not opened or the spool is off, the valve should be opened or the pump should be repaired.
5. If the outlet opening is too large (small), the opening of each valve should be adjusted appropriately.
6. If the oil is sealed with water, the oil tank should be dehydrated.
7. If the liquid level in the tower or container is low, the outlet valve of the centrifugal pump should be temporarily turned off or the pump should be stopped, and the liquid level should be restored after rising.
8. If the impeller or inner grinding ring wear, it should be replaced in time.
9. If the motor is reversed, the steering should be adjusted in time.

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