Problems

         Causes

          Solutions

Too much shaft power

1.Friction between blades and pump shell/blades and bush/sub-blades

2.Pump is working with a lift lower than designed

3.Stuffing gland taps too tightly.

4.Belts slide.

1.To remove friction by adjusting the gap between propeller and pump shell/propeller and bush/sub-propellers

2.Make sure pump is working with designed lift by examining if motor is standard and turning down relief valve.

3.Adjust stuffing gland

4.Tension belts(see if the two belts are installed right in place).

Reduced lift and flow

1.Suction pipe and propeller flow passage are blocked by large particles

2.Pump rotary speed reduces

3.Propeller is worn

4.Leakage is increased by too much gap between propeller and pump shell end

5.Inlet valve is opened large enough

1.Remove the blocking particles

2.Make sure pump is working with designed rotary speed.

3.Replace the propeller

4Adjust the gap between propeller and pump shell end

5.Open the inlet valve large enough

Overheat bearings

1.Lubricating oil is put too much or too little

2.There are impurities in lubricating oil

3.Bearings are worn

1.Keep oil surface at the regulated level on dipstick

2.Change lubricating oil

3.Replace bearings

Working  pump generates vibration and unusual noise

1.Propeller is worn unevenly

2.Bearings are worn

3.Connection loosens

4.Cavitation in pump

1.Replace propeller

2.Replace bearings

3.Tighten loose components

4.Prevent air from pump by improvement on pumping condition

Severe shutdown sealing and leakage

1.Polyurethane oil seal is over worn

2.Axle sleeve is seriously torn

3.Stuffing seal is over worn

4.Packing ring inclines

5.There are impurities and foreign matters in packing ring

6.Packing ring bevel is consistent.

1.Replace polyurethane oil seal

2.Replace axle sleeve

3.Change with new packing ring

4.Reassemble the packing ring

5.Remove impurities and foreign matters and clean packing ring

6.Dislocate and reassemble packing ring based on requirements.