Causes and Troubleshooting Methods for Stainless Steel Vertical Multistage Pumps
2025-12-23
| Symptoms of malfunction
| Possible reasons
| Elimination method |
| 1、The pump does not supply water.
| The inlet valve remains closed, there are blockages in the inlet and outlet pipes, as well as obstructions in the impeller passages; The motor rotates in the wrong direction or runs at extremely low speed due to missing phase; There is air ingress in the suction pipe; There is air in the pump chamber because the pump has not been properly filled with liquid; Insufficient water supply at the inlet, excessive suction pressure or leakage from the foot valve; Excessive pipe resistance indicating incorrect pump selection.
| Check and remove obstacles; Adjust the motor rotation direction and secure the motor wiring; Tighten all sealing surfaces and bleed air; Open the pump cap or release valve to remove all air; Stop the pump for inspection and adjustment; Minimize pipe bends and select a different pump. |
| 2、Insufficient pump flow
| First check reason 1: Partial blockage in the pipeline, pump flow path or impeller; scale deposits; Low voltage; Impeller wear;
| First press 1 to bypass; Remove obstructions and reset valve opening; Stabilize blood pressure; Replace the impeller.
|
| 3、Excessive power
| Exceeding the rated flow rate; Excessive suction pressure; Wear of pump bearings.
| Adjust the flow by partially closing the outlet valve; Reduce; Replace bearings. |
| 4、Noise and vibration
| Instability of the pipeline support; Liquid containing entrained gas; The occurrence of cavitation; Bearing damage; Engine operation under overload conditions;
| Secure the pipeline; Increase suction and exhaust pressure; Reduce vacuum level; Replace bearings; Adjust according to point 5. |
| 5、Engine overheating
| Excessive consumption, overload; Local friction; Damaged motor bearings; Insufficient voltage.
| Close the release valve; Check and clean; Replace bearings; Adjust the pressure. |
| 6、Water pump leaking
| Wear of mechanical seals; Sand holes or cracks in the pump housing; Uneven sealing surfaces; Loose mounting bolts. | Replacement Repair by welding or replacement Rework Puff |
Maintenance and repair of multi-stage vertical stainless steel pumps GDLF
Maintenance and repair
1. The inlet pipes must be carefully sealed, and no water or air leaks are allowed.
2. Long-term operation of GDL multistage pumps in cavitation conditions is prohibited.
3. It is prohibited to operate the GDL pipeline pump for a long time under high flow conditions when the motor current exceeds its rated current;
4.Regularly check the motor current value while the GDL pressure stabilizing pump is running, trying to keep the pump operating within its design parameters;
5.GDLF stainless steel multi-stage pumps must be supervised by authorized personnel during operation to prevent accidents;
6. Lubricate the bearings of GDLF stainless steel multistage pumps every 500 hours of operation;
7.After long-term operation, mechanical wear may lead to increased noise and vibration in the unit. Stop the unit for inspection and replace worn parts or bearings if necessary. The recommended interval between major overhauls is usually one year.
Maintenance and care of mechanical seals
1.Mechanical seal lubricant must be clean and free of solid particles.
2. Mechanical seals should never run dry.
3. Before starting, manually crank the pump (or motor) several times to prevent breakage or damage to the mechanical seal if it starts suddenly.
