The structure of the pipeline multi-stage centrifugal pump is mainly composed of: low pressure suction section (feed pipe, feed chamber); pump body (volute, guide wing, anti-wear ring); high pressure output end (pump head); balance device (balance pipe, Balance plate, balance disc); sealing device (packing seal, mechanical seal); pump shaft (shaft sleeve, impeller, positioning key, bearing).
Auxiliary devices: brackets, bases, couplings, motors, filters, etc.
Fault judgment and elimination phenomenon: After the pump is started, the pump pressure drops and the pump does not flow up.
The main reasons of pipeline multistage centrifugal pump:
Incomplete venting and air in the pump;
The filter or the oil inlet line is blocked (the oil flow is not smooth), and the inlet of the primary impeller is blocked;
Oil temperature is too low or too high;.
The liquid level (pressure) of the large tank or buffer tank is too low;
The balance device is seriously worn (the balance pipe is blocked or caused by improper operation
The low-pressure end of the centrifugal pump is not tightly sealed, and the leakage causes the air to enter the pump
Approach:
Re-vent until the liquid naturally flows out from the vent valve at the output end;
Clean the filter or check the diameter of the oil inlet line;
It is appropriate to control the oil delivery temperature between 450C and 500C;
Check the oil tank and buffer tank level and pressure;
Check the balancing device (open to check if necessary);
Check and replace the low-pressure end seal of the centrifugal pump or adjust the cap screw
Always check the bearing temperature, it should not be higher than the ambient temperature 35 ℃, rolling shaft. The higher temperature of the bearing shall not exceed 75℃; the higher temperature of the sliding bearing shall not exceed 65℃. Check the motor temperature rise frequently.
Check the leakage at the shaft seal every shift, and it is advisable to keep the packing seal at 10-20 drops per minute; for the mechanical seal, it must be in good condition.
Always observe whether the pressure of the pump and motor current are normal and stable. Pay attention to whether the pump has any abnormal conditions such as noise. Find problems and deal with them in time.