Installation, Operation and Maintenance

Piping installation

  1. When pump is switched for other applications, pay attention to viscosity, specific gravity and temperature of new fluid, and then review if the horsepower is sufficient.
  2. Increase net positive suction head available (NPSHA):
    • Pump should be installed as close to the water source as possible for reducing suction piping length; that is to lower height of suction water level, and as much as possible, shorten the horizontal length.
    • Lower pump height.
  3. To prevent centerline not aligned due to unlevel ground, pump and motor should be installed on the same foundation.
    • Common equipment beding shall not lead to bent or distortion ---- most pump malfunctions are caused by poor center alignment.
    • Adjust pump base so that the horizontal deviation is within 0.05 mm / 1 m.
    • After base nuts are locked tight, perform center alignment again.
    • After piping is completed, perform center alignment again.
  1. There shall be support structure at pump suction and discharge piping. If temperature changes along the piping route, install expansion joint.
    • Suction piping shall not have air leakage. Air leakage will reduce pump performance.
    • Suction piping shall not have stagnant air, pump suction performance will be reduced. During pump start up, use vacuum pump to remove stagnant air or air shall be removed frequently during operation.
  2. Suction piping should have large elbow bending diameter (use long elbow piping). There shall be a straight piping in front of the suction. The length shall be three times of the suction piping diameter.
  3. The horizontal pump suction shall install off-center reducer (flat at the top and slope at the bottom). Vertical discharge shall install concentric reducer.
  4. Installation of pressure gauge:Discharge pressure gauge shall be installed in front the outlet valve.
  5. Nstallation of return piping:Return piping shall be away from the pump suction to prevent suction turbulence.

Operation procedure

  1. Make sure proper alignment is achieved between pump and motor.
  2. Is the quantity of lubricating oil (grease) inside the bearing box appropriate? Does it appear black?
  3. Use hand to rotate pump, and check if the rotation is smooth.
  4. Does the rotation direction of the motor is the same as the rotation direction shown on the pump-----for safety, dismantle the shaft coupling and start up the motor without load.
  5. If a valve was installed at the suction side, it shall be opened completely.
  6. Water for gland packing shall be clean. Check if the gland packing is hardened.
  7. Other than axial flow pump, close all discharge valves.
  8. Check all bolts and nuts for tightness.
  9. For vertical pump, pay attention if the water immersion level is sufficient.
  1. Is priming completed?
  2. Running without load may burn out components inside the pump. Must avoid.
  3. When discharge valve is closed, do not operate for long period of time.
  4. When motor operation reaches rated rpm, gradually open the discharge valve.
  5. Note if there were rubbing sound, noise or vibration etc. inside the pump, stop operation immediately. Locate the problem and adjust accordingly.
  1. Bearing temperature shall be maintained below 70℃.
  2. Check if the stuffing box leakage is proper. Initially, the leakage would be high. Gradually, tighten the gland cover until the amount of leakage is appropriate (around 40~60 drops per minute).
  3. Ideally, the temperature for stuffing box should not exceed 40℃.
  4. Check if there is any unusual noise or vibration.
  5. Frequently pay attention to pressure gauge and electric meter. If there was any abrupt change, it might be foreign objects settlement or air is being sucked in.
  6. Avoid operation for long period of time outside the rated point.
  7. Avoid extended operation at extremely low water flow rate.
  8. For vertical pump, pay attention on sufficient immersed water level.
  1. For volute pump, after outlet valve is closed, shut off the pump. For axial flow pump, first shut off the pump then close the outlet valve.
  2. During operation, if power shuts down, turn off power supply switch.
  3. If there was a possibility for water inside the pump casing forming ice (or crystallize), then water inside the pump casing must be removed.


  1. Gland packing replacement — twice a year. Gland packing cover adjustment — once a month.
  2. Change lubricating oil for the first 2 weeks of operation. After that, change in every 2000~3000 hours of operation. (For CPC R68 or SAE 20) When adding engine oil, fill to the level shown on the oil gauge. Do not over fill.
  3. For grease lubrication, change 1-2 time a year. (For #3 grease) When adding grease oil, fill only half the volume. Do not over fill.
  4. Pump centerline calibration — once a month.
  5. Dismantle and inspect — once a year.
  1. A worn out wear ring will increase water leakage, and reduce pump efficiency. When gap between a wear ring and impeller is three times the value shown on the following table, change the wear ring immediately.
    Impeller suction diameter mm 50~80 120~180 260-315 400~500
    Diameter gap mm 0.18~0.30 0.25~0.40 0.30~0.50 0.45~0.70
  2. A worn out steady bearing will cause pump to vibrate. When gap between a steady bearing and shaft is three times the value shown on the following table, change the steady bearing immediately.
    Shaft diameter mm 18~30 30~50 50~80 80~120 120~180 180~260
    Gapmm mm/100 6~10 8~13 11~16 13~19 16~23 19~27
  3. After the gland packing has been replaced, if the water leakage from the gland packing cover continued, then check the wear conditions of the shaft and shaft sleeve.
  4. If there was rubbing between coupling bolt rubbers, replaced them immediately.
  5. Realignment would be necessary if shrinking of base plate, building or ground distortion, or piping extension occured. A worn out bearing will lead to poor centerline alignment, too.
  6. Check all valves for wearing conditions.
  7. Check if there is any build up or air pocket inside the piping.
  8. Purchase factory certified and recommended spare parts for reliability and proper maintenance.

Inspection cycle

Inspection cycle Inspection part Inspection and maintenance
Every week Pump Check gland packing cover leakage quantity. If necessary, tighten.
Drive / motor Clean oil, dust, dirt, water or chemical deposit on the motor. Make sure that air flows smoothly through the motor.
Every month Pump Proper centerline alignment.
Drive / motor Check motor bearing temperature. If the temperature is too high check for any water accumulation, insulation resistance, corrosion, or lubrication problem. Contact motor anufacturer.
Every quarter Stuffing box Inspect gland packing. If necessary, replace.
Check lantern ring position.
Shaft Check shaft. A damaged shaft will accelerate gland packing wear. When damage is significant, repair or replace the shaft immediately.
Every 6 month Pump
  1. Check for any unusual vibration or noises. If occured, inspect the pump.
  2. Check the conditions of the oil and grease. If necessary, replace. 
  3. Check the contact surface of the bearing for significant wear. If necessary, replace.
Pump foundation Check the position of the foundation. A poor foundation may lead to poor center alignment of the pump and create suction or discharge stress. Proper foundation is a must.
Pump performance Check discharge and suction pressure readings for any changes. If performance reduction is above 10%, adjusted the impeller.
Annualy Flushing piping Check if the gland packing cover or by-pass piping on the bearing cover had any build-ups that blocked the flow of the fluid.
Pump efficiency Measure differential pressure and flow rate. Record electrical readings. Compare them with original efficiency. If efficiency is reduced by more than 5%, adjust impeller gap or replace wear ring.
Bearing box Replace grease or oil.
Steady bearing (vertical pump) Check if wear is severe. If it's greater than three times the allowed value, a replacement would be necessary.