Common faults and solutions of abrasion resistant and explosion proof mining multistage pumps

Common faults and solutions of abrasion resistant and explosion proof mining multistage pumps

1. No liquid coming out, violent jumping of the pressure gauge, abnormal internal sound:

• Too big of the slurry weight concentration --- dilute the slurry;
• Serious wear on the impeller and volute --- Replace them with new and unused ones;
• Feeding slurry quantity lower than required --- Increase feeding slurry or decrease slurry discharge;
• Clogging of suction pipeline or insufficient valve open --- Clean the pipeline or open the suction valve
• Not enough slurry input --- Increase feeding slurry input or add clean water temporarily;
• Air entering at the inlet --- Check the reasons why there’s air coming in

2. Motor Overloaded

• Too big of the slurry weight concentration --- Lower the slurry weight concentration;
• Too big of the flowrate --- Increase discharge pipeline friction resistance

3. Vibration and noise

• Cavitation --- Find out the reason and solve it;
• Non-concentricity of the pump shaft and the motor shaft --- Adjust the shafts to be concentric;
• Bearings damaged --- Replace with new bearings;
• Too big of the medium flowrate, or too high temperature --- Increase discharge pipeline friction resistance;
• Loosened fasteners or foundation --- Tighten the fasteners, strengthen the foundation

4. Leakage of shaft sealing water

• Too big pressure of the shaft sealing water --- Adjust the shaft sealing pressure;
• Wear of the packing rings --- Replace with new packings;
• Gland assembly not tightened or not evenly tightened --- Adjust gland bolt

5. Slurry leakage of the shaft seal

• Serious wear of the shaft sleeve --- Change the shaft sleeve;
• No shaft sealing water or shaft sealing water pressure too small --- Add shaft sealing or increase its pressure

6. Insufficient flow or head

• Impeller and Volute seriously worn out --- Replace with new ones;
• Pipeline NPSH lower than pump’s NPSHr --- Improve pipeline devices and increase its NPSH;
• Too big of the slurry weight concentration --- Lower the weight concentration or change to a bigger pump;
• Scarring inside the discharge pipe --- Remove it

7. Overheated bearings

• The pump bears the weight of the pipeline --- Adjust the stand of the pipeline, no pipeline weight bearing on the pump is allowed;
• Vibration --- Check and handle vibration;
• Non-concentricity of the pump shaft and the motor shaft --- Adjust the shafts to be concentric;
• Inappropriate use of lubrication or lubrication gone bad --- Change the lubrication grease;
• Bearings damaged --- Change with new bearings

8. Short packing life

• Bad material of the packings --- Change to better material;
• Shaft sealing water turned off --- Turn on the shaft sealing water

9. Oil leakage of the bearing assembly

• Oil level too high --- Lower the oil level;
• Failure of the rubber seals --- Replace with new ones

10. Pump not rotating

• Volute chamber clogged by hard sediments --- Clear the sediments;
• Impeller rotates out due to reverse rotation and the impeller and squeezed with the throatbush 

1. Speed regulation of the inverter must be set on its two terminals;

b. Adjust the adjusting screw of the bearing housing, and backward adjust the pump shaft, separate the impeller from the throatbush, and turn the shaft to tighten the impeller.

XI. Water leakage of the pump head

1)  Rubber Seals are not well pressed --- Re-assemble or tighten them

XII. Not rotating of Water Retainer

1) Deformation - Machine the outer circle of the water retainer off by 0.5-0.8mm