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You must know 27 basic knowledge of centrifugal pump(Part 2)

May. 20, 2020

16. What are the reasons for the abnormal heating of the centrifugal pump in operation?

Heating is the performance of mechanical energy converted into heat energy. The common causes of abnormal heating of the mechanical pump are as follows:

Heat with noise is usually caused by damage to the bearing ball isolation frame.

The bearing retaining sleeve in the bearing box is loose, and the front and rear gland are loose, causing heat due to friction.

The bearing hole is too large, causing the bearing outer ring to loosen.

There is a foreign body in the pump.

Rotor vibration, so that seal ring wear.

The pump or pump load is too large.

Rotor imbalance.

Too much or too little lubricating oil and unqualified oil.

17. What are the causes of centrifugal pump vibration?

Rotor imbalance.

The pump shaft is out of alignment with the motor, and the rubber ring on the wheel is aging.

Bearing or seal ring wear too much, the formation of the eccentric rotor.

Pump or pump gas.

Suction pressure is too low, so that liquid vaporization or close to vaporization.

The axial thrust increases, causing a series of shafts.

Improper lubrication of bearings and packing, excessive wear.

Bearing worn or damaged.

Partial blockage of impeller or vibration of the external accessory pipeline.

Too much or too little lubricating oil (grease).

The foundation stiffness of the pump is not enough, and the bolts are loose.

18. What is the standard for vibration and bearing temperature of Centrifugal pump China?

The vibration standard of a centrifugal pump is:

The rotation speed is less than 1500vpm, and the vibration is less than 0.09mm.

The rotation speed is 1500~3000vpm, and the vibration is less than 0.06mm.

The bearing temperature standard is: the sliding bearing is less than 65℃, the rolling bearing is less than 70℃.

19. When the pump is in normal operation, how large is the cooling water?

When the pump is working normally, it is most suitable to open the cooling water at the drainage temperature of about 40℃.At this point with hand contact water a little temperature, the best cooling effect. In particular, the cooling water of the end seal should not be opened too wide in winter to prevent the sealing ring of the dynamic and static ring from hardening due to low water temperature and loss of elasticity to seal failure.

20. What happens when the centrifugal pump is evacuated?

When the running pump begins to pump, it will suddenly give out noise, vibration, and is accompanied by a decrease in pressure, flow, and current. Serious pumping, the pump will occur strong vibration, pressure back to zero, no liquid out of the pump.

21. What are the reasons for the heating of the bearing box?

The pump shaft is different from the motor shaft.

Too much or too little lubricating oil (grease), oil (grease) deterioration.

The oil ring breaks or jumps out of the fixed position.

The axial thrust increases.

Insufficient or interrupted cooling water.

Bearing wear.

The flow rate is too small to make the pump close to the pump.

The foundation is not firm, the rotor is not balanced, the bolt is loose and so on the reason causes the machine pump vibration.

22, pump in the winter why to prevent freezing?

Water volume expansion occurs below zero. If the water inside the pump is not cleaned out, the force generated by volume expansion at low temperatures will cause the pump body to expand and crack, causing unnecessary damage. Anti-freezing methods mainly include the following:

Drain the water from the idle pump.

Keep cooling water flowing.

Keep the pump warm or heat it with steam or hot water.

Reserve pump to maintain inlet and outlet circulation.

23. How to deal with the frozen pump?

After the pump is frozen, never blow directly with steam, in case of the pump body due to uneven thermal expansion and rupture.

After the pump is frozen, first with cold water pouring and then to the motor car, you can use steam or hot water pouring.

24. Why should the pump be cooled?

In the operation of the pump in the flow of liquid and the pump body produce friction, rotational part and fixed part such as bearing ball and the inner and outer ring, shaft sleeve and packing parts will produce friction, due to the friction generates heat, at the same time due to the high medium temperature conduction to pump, the pump body heat, cooling the purpose is to reduce the pump body, pump seat, bearing housing and shaft sealing temperature, to prevent these parts deformation, aging and damage due to temperature rise.

25. Under what circumstances should the motor be stopped urgently?

When personal safety is endangered.

Motor smoke or smell, fire.

When a large vibration or axial series occurs.

The fuselage or bearing heats to the limit.

Motor speed is slow with abnormal sound.

26, explain homebred, the make and model of the centrifugal oil pump 100 y Ⅱ - 100 x 2 a is said what?

- the pump inlet diameter Y - 100 single-stage centrifugal pump Ⅱ - pump with material code, the second carbon steel is not corrosion-resistant temperature 200 ~ 400 ℃ A - first turning impeller diameter

27, how to distinguish the cavitation phenomenon?

1, there is a sharp sound in the pump.

2, the export pressure is not stable, serious can not hit the volume.

3. The vibration of the pump body.

4. Increase of medium temperature

We are the centrifugal pump manufacturer. If you have any questions about the operation of the Centrifugal pump, please feel free to contact us at any time.

Centrifugal Pump

Centrifugal Pump

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