Q. What items need to be included in regular pump maintenance, and what schedule should be followed?
A.Pumping systems can be complex, with many moving parts and subsystems that need to be regularly inspected and constantly maintained. Failure to frequently inspect pumping systems can lead to premature failure, losses in efficiency and increased operating costs. Therefore, it is recommended that a monitoring, maintenance and schedule be adopted, and it should include, at a minimum:
- When applicable, gland packings must be adjusted to maintain concentric alignment of the gland follower, and maintain specified leakage so the packing and follower do not overheat.
- Check for any leaks from gaskets and seals. The correct functioning of the shaft seal must be checked regularly.
- Check bearing lubricant level, and verify if the hours run show a lubricant change is required.
- Check and verify that the duty condition is in the allowable operating region for the pump.
- Check vibration, noise level and surface temperature at the bearings to confirm satisfactory operation.
- Check that dirt and dust are removed from areas around close clearances, bearing housings and motors.
- Check coupling alignment and realign if necessary.
Note: Additionally, installed auxiliary systems should be included in the maintenance plan so they are monitored and maintained to ensure that they function properly.
An inspection and maintenance log should be kept and problems that are identified should be reported immediately. A suggested guide for preventative maintenance for normal applications is listed in Table 1. Unusual applications with abnormal heat, moisture, dust, etc., may require more frequent inspection and service.
A maintenance plan should include required spare parts to keep on hand. A list of recommended spare parts will depend on normal supplier lead time when ordering parts, whether pumping equipment is used for normal duty or severe duty and whether or not there is backup pumping while a unit is down for maintenance. See Table 2 for a suggested list of spare parts for pumping units. Note that the items listed for severe duty are in addition to the items listed for normal duty.
For more information about how to maintain pumping systems, refer to HI standard, ANSI/HI 1.4 Rotodynamic Centrifugal Pumps for Manuals Describing Installation, Operation, and Maintenance at www.pumps.org.