After the pump is evacuated, or during the evacuation process

     1) The pump body vibrates greatly, and the dynamic and static rings of the mechanical seal will continue to collide intermittently, resulting in leakage, and in severe cases, the mechanical seal structure will fail;

     2) The compression of the dynamic and static rings of the mechanical seal is the sum of the medium pressure and the preload of the spring. When the pressure is evacuated, the medium pressure will disappear, and the contact pressure of the dynamic and static rings will decrease and the seal will fail;

     3) After the pump is evacuated, the end face of the mechanical seal dynamic and static ring that adopts the self-flushing scheme (that is, flushing with the pumped medium) loses cooling and lubrication, dry friction occurs, and the mechanical seal fails.

     1. Incidental conditions

     1. The motor current drops.

     2. The pressure fluctuates greatly.

     3. Abnormal flow fluctuations.

     4. Making noises and strange sounds.

     5. The pump body vibrates.

     6. The temperature of the pump cylinder increases.

Second, the reason for the time-out

    1. Air leakage occurs at the entrance of the centrifugal pump.

    2. The entrance of the centrifugal pump is blocked.

    3. The pressure at the inlet of the centrifugal pump is not enough.

    4. The medium temperature at the inlet of the centrifugal pump is too high and the saturated steam is too large.

    5. The inlet valve of the centrifugal pump is not opened or the valve core is off.

    6. The outlet opening of the centrifugal pump is too large (small).

    7. The centrifugal pump seals the oil with water.

    8. The liquid level in the centrifugal pump tower or container is low or no liquid level.

    9. The centrifugal pump impeller or inner grinding ring is severely worn.

    10. The centrifugal pump motor reverses.

    Three, take the time to deal with the corresponding method

    1. If the inlet is leaking, stop the pump and check the leaking inlet pipeline and flange of the centrifugal pump.

    2. If the inlet is blocked, stop the pump to check the leaking inlet pipeline and impeller of the centrifugal pump, and perform maintenance after purging.

    3. If the inlet pressure is not enough, the back pressure of the liquid surface should be increased.

    4. If the temperature of the inlet medium is too high, the temperature of the medium should be lowered, and the steam in the centrifugal pump should be vented.

    5. If the inlet valve is not opened or the spool falls off, the valve should be opened or the pump should be changed for maintenance.

    6. If the outlet opening is too large (small), the opening of each valve should be adjusted appropriately.

    7. If the oil is sealed with water, the sealed oil tank should be dehydrated.

    8. If the liquid level in the tower or container is low, the outlet valve of the centrifugal pump should be temporarily closed or the pump should be stopped, and the liquid level should be restored after the liquid level rises.

    9. If the impeller or inner grinding ring is worn, it should be replaced in due course.

    10. If the motor reverses, the direction of rotation should be adjusted in time.