A centrifugal pump overhaul is performed to restore pump performance, prevent failures, and extend equipment life. Below is a step-by-step procedure for a typical centrifugal pump overhaul.
Isolate the pump from power and process lines (lockout/tagout - LOTO).
Drain the pump casing and suction/discharge piping.
Vent any trapped pressure or hazardous fluids.
Use appropriate PPE (gloves, goggles, etc.).
Dial indicators, micrometers, feeler gauges
Hydraulic puller, bearing heater
Torque wrench, soft-faced hammer
Gaskets, seals, O-rings, lubricants
Cleaning solvents (degreaser, kerosene)
Alignment tools (laser or dial indicator)
Unbolt coupling halves and check for wear/misalignment.
Measure and record coupling gap and alignment.
Remove bearing housing bolts.
Extract bearings using a puller or press.
Inspect bearings for wear, pitting, or overheating.
For mechanical seals, carefully remove seal components (stationary & rotating faces).
For gland packing, remove packing rings and clean the stuffing box.
Unbolt casing bolts and separate casing halves (for split-case pumps).
For end-suction pumps, remove the back cover.
Use an impeller puller if necessary to remove the impeller.
Check shaft runout with a dial indicator (max allowable ~0.05mm).
Inspect for wear, scoring, or corrosion at seal and bearing locations.
Impeller: Check for erosion, cracks, or imbalance.
Wear Rings/Casing Rings: Measure clearance (typically 0.3–0.5mm, replace if worn).
Bearings: Replace if noisy, rough, or damaged.
Mechanical Seal: Replace if faces are scored or cracked.
Shaft Sleeve: Replace if worn or corroded.
Remove old gaskets and clean mating surfaces.
Degrease bearings, shafts, and casing.
Press or heat-fit new wear rings into casing/impeller.
Check clearance with feeler gauge.
Mount impeller on shaft and secure with a nut (use thread locker if needed).
Reassemble casing with new gaskets, ensuring proper torque sequence.
Lubricate and install new mechanical seal components (follow OEM instructions).
For packing, install new rings with staggered joints and adjust gland lightly.
Heat new bearings (if required) and press onto the shaft.
Pack bearings with recommended grease (typically ⅓ to ½ full).
Reinstall bearing housing and align properly.
Reattach coupling halves and perform alignment (laser or dial indicator method).
Check angular and parallel misalignment (max 0.05mm recommended).
Ensure proper lubrication (oil level or grease quantity).
Manually rotate the shaft to ensure smooth operation.
Conduct a hydro test if required (check casing for leaks).
Start the pump slowly and monitor:
Vibration levels (< 2.5 mm/s RMS).
Bearing temperature (< 70°C).
Leakage at seals.
Record replaced parts, clearances, alignment data, and test results.
Update maintenance logs for future reference.
A well-executed centrifugal pump overhaul ensures reliability, efficiency, and extended service life. Follow OEM guidelines for specific pump models and always prioritize safety.
The above content is compiled and published by Zhilong Drum Pump supplier, please specify, to buy oil drum pump, electric drum pump, high viscosity electric drum pump, fuel drum pump, food grade drum pump and so on, please contact us.