Causes of Fire Pump Vibration and How to Maintain Multistage Pumps

There are many reasons for the vibration of the unit and the building of the pump room, and some factors are related and interacted with each other. In summary, there are mainly the following four reasons.

1. Electrical aspects The motor is the main equipment of the unit. The unbalanced magnetic force inside the motor and the imbalance of other electrical systems often cause vibration and noise. For example, during the operation of an asynchronous motor, the radial alternating magnetic pull between the stator and rotor is generated by the interaction of the harmonic flux of the stator and rotor teeth, or during the operation of a large synchronous motor, the magnetic center of the stator and rotor is inconsistent or the air gap in each direction is different Exceeding the allowable deviation value, etc., may cause periodic vibration and noise of the motor.

2. In terms of machinery, the quality of the rotating parts of the motor and water pump is unbalanced, shoddy, poor installation quality, the axis of the unit is asymmetrical, the swing exceeds the allowable value, the mechanical strength and rigidity of the parts are poor, the bearings and sealing parts are worn and damaged, and the water pump is critical. The resonance caused by the rotating speed and the natural frequency of the unit will produce strong vibration and noise.

3. In terms of hydraulics, the flow rate and pressure distribution of the pump inlet is not uniform, the pressure pulsation of the working liquid at the pump inlet and outlet, liquid circumvention, bias flow and shedding, non-rated working conditions and pump cavitation caused by various reasons are common. Causes of pump unit vibration. Rapid changes in pressure in the water pipeline and water hammer caused by dynamic transition processes such as pump start and stop, valve opening and closing, working condition changes, and accident emergency shutdown often cause vibrations in the pump room and unit.

4. In terms of hydraulics and other aspects, unreasonable design of the water inlet channel of the unit or not matching the unit, improper submersion depth of the water pump, and unreasonable start-up and shutdown sequence of the unit, etc., will deteriorate the water inlet condition, generate vortex, induce cavitation or aggravate Vibration of unit and pump room. When the unit using destructive siphon vacuum cut-off is started, if it is difficult to entrain the air in the hump section, the siphon time will be too long; the flap door design of the unit with flap valve cut-off is unreasonable, and it opens and closes constantly, constantly hitting the flap seat; support The uneven subsidence of the foundation of the water pump and the motor or the poor rigidity of the foundation will also cause the unit to vibrate

      The daily maintenance of the fire pump is very important. It is necessary to take care of it frequently. It will shorten the service life of the pump. So, if you are interested, you can take a look at

10 aspects that need to be paid attention to in water pump maintenance:

1. Regularly check whether there is no shortage of oil at the refueling point of the motor and the pump body, and whether the sound of the bearing running during the operation of the pump is normal

2. Is the concentricity of the electricity coupler and the pump coupler consistent?

3. Whether there is water leakage or air leakage in the suction pipe of the water pump

4. Whether the balance pipe is blocked. 5. Whether the outlet pressure of the water pump is normal

6. Whether the water pump vibrates too much during operation

7. Is the bearing seat of the water pump overheated?

8. Is the manual cranking flexible?

9. Is the installation foundation of the water pump firm?

10. The water pump uses packing seals, which need to be fastened or replaced frequently