Ten Wrong Ways to Damage the Water Pump


As a water source conveying and pressurizing device, the water pump plays an important role in the water supply system. There are often some failures in the use of the water pump.


1. Overload

Whether it is flow, pressure or speed, long-term work that deviates from the rated design point may lead to aggravation of the pump load. For example, the full-open power of the centrifugal pump will shorten its life, or even "sudden death".


2. Difficulty inhaling the medium

  1. If the inlet liquid level is too low, it is easy to generate eddy current, suck in air, cause cavitation and reduce the flow head;
  2. The water inlet pipe or water inlet is blocked by foreign objects, resulting in a decrease in the flow head;
  3. The temperature of the medium increases, the vaporization pressure of the medium increases, and the cavitation allowance decreases, resulting in a decrease in the suction lift;
  4. The water inlet pipeline is unreasonable (for example, the water inlet pipe has too many elbow joints, the pipe diameter is smaller than the pump inlet), the pipeline loss increases, and the cavitation allowance is reduced, which is easy to cause cavitation;
  5. The elevation of the pump installation increases, the atmospheric pressure decreases, and the cavitation allowance decreases, resulting in a decrease in the suction lift.


3. Only close the valve, the water pump will not be powered off

Except for automatic pumps and intelligent pumps, ordinary water pumps run under closed valve conditions for a long time without any bypass. The energy consumption of all systems is wasted in "heating" the water, causing pump cavitation and causing unstable pump operation and even accidents.


4. Corrosion

The conveyed medium corrodes the overcurrent components, mechanical seals, etc. For example, hydrochloric acid corrodes stainless steel, hydrofluoric acid corrodes silicon carbide, etc.

Note: There will be dense pinholes of different sizes on the corroded surface, like the surface of the moon.


5. Abrasive

The liquid containing solid particles is conveyed, and the over-current components such as the pump cavity and the impeller are continuously flushed, which reduces the flow rate, head and life of the pump.

Note: When the abrasion is severe, fish scales will appear on the abraded surface.


6. Pump body burst

Because the outlet is blocked or the inlet pressure is too high, or the low temperature causes the liquid in the pump chamber to freeze, the actual pressure of the pump chamber is much higher than its bearing pressure, and finally the pump body cracks.


7. Vibration

The pump is installed on a rigid foundation that lacks vibration damping measures, or the foundation is too weak to provide sufficient strength. The lack of support in the water inlet and outlet pipelines will eventually cause the unit to be unevenly stressed and restrict the running vibration of the pump, and the pump will "jump" like it is on a trampoline.


8. Get wet

The onshore pump is in a humid environment for a long time or the mechanical seal fails, and the leaking liquid splashes on the unsealed part of the motor.

The submersible pump mechanical seal and seal fail, the cable has no seal, the pump enters the moisture in a humid environment or the cable falls into the pool, causing the liquid to penetrate into the motor cavity.

Note: There are water stains and condensation beads in the motor, and the insulation resistance is less than 50 megohms, which is regarded as damp.


9. Irregular inspection

The water pump has never been given enough "care", the inspection and regular maintenance are not required by the instructions, the mechanical seal is not replaced regularly, the iron pump and aluminum pump are not repainted, and the vibration is not checked, so that the pump is not cured from "minor illness". to the "incurable disease".


10. Poor heat dissipation

The motor of the submersible pump is dehydrated when it is exposed to the water surface, or it is trapped in the mud, which makes the motor heat dissipation slowly, which is easy to cause burnout, especially the oil-filled motor with poor heat dissipation has the possibility of explosion.

The onshore pump is installed in a corner or in a closed box, and the fan cannot circulate the surrounding air, resulting in poor heat dissipation of the motor.