Chemical Pump Maintenance

Related Vendors

Lutz Pumpen GmbH

EagleBurgmann Germany GmbH & Co. KG

EDL Anlagenbau Gesellschaft mbH

Griswold Pump Company

What to Do and When

Routine preventive and protective maintenance should include the monitoring of [4]:

Bearings and lubricant: Check bearing temperatures, lubricant level and vibration. The lubricant should be clear with no signs of frothing. An increase in bearing temperature may indicate imminent failure. Shaft seal: Mechanical seals should show no visible signs of leakage. Packings should leak at a rate of no more than 40–60 drops per minute.

Vibration: Imminent bearing failure can be preceded by a change in bearing vibration. Unwanted vibration can also occur due to a change in pump alignment, the presence of cavitation or resonances between the pump, its foundation or valves in the suction or discharge lines.

Differential pressure: The difference between the pressure readings at the discharge and the suction of the pump will provide the total pressure developed by the pump. A gradual decrease in this total pressure can indicate that the impeller clearance has widened. In this case, adjusting the impeller clearance (for pumps with semi-open impellers) or replacing the wear rings (for pumps with closed impellers) will restore the pump’s design performance.

Every three months:

Check the pump’s foundation and hold-down bolts for tightness.

Change the oil after the first 200 hours of operation for a new pump and then every three months or 2,000 operating hours, whichever comes first.

Re-grease the bearings every three months or 2,000 operating hours, whichever comes first.

Check the shaft alignment.

Annually: The pump’s performance should be checked and recorded in detail at least once a year. Performance benchmarks should be established during the early stages of a pump’s operation when the parts are new and the installation adjustments are correct. This benchmarking data should include:

At three to five different flow conditions, including zero flow where this is practical:

‒the total pressure developed by the pump (the difference between the suction and discharge pressures);

‒flowrate; and

‒motor amps and voltage

Vibration signature

Bearing housing temperature.

Any change in these figures from those of the year before should be used to re-assess the level of maintenance required to get the pump back to its best performance and keep it there.

All maintenance and monitoring intervals should be shortened if the pump is used in severe-service conditions, such as with highly corrosive liquids or abrasive slurries.

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