Pump maintenance - why when and how!
Industrial plants and factories rely heavily on the reliability of their equipment and machinery; pumps being a core part of this. Downtime of a pump is costly both in terms of loss of output and the cost of repairs, and therefore pump maintenance is an integral operation within any plant to limit this downtime.
Maintenance is commonly split into two classifications; corrective and preventive maintenance. Corrective maintenance is essentially maintenance that is undertaken to cope with a pump failure that has already occurred. It has to be undertaken as quickly and efficiently as possible to get the installation up and running again with as little impact on operation as possible.
Relying on corrective maintenance however is an issue. It means that maintenance is only carried out once a problem has already arisen rather than preventing the problem from happening in the first place. To avoid downtime caused by unexpected problems with the pump, it is important to introduce apreventive maintenance schedule. This would involve a periodic check of the pump performance, an inspection of the wearing parts and lubrication of bearings and joints. By ensuring this is regularly undertaken, it allows maintenance to be carried our prior to a problem and downtime being incurred.
Employ a periodic pump maintenance schedule
It is good practice to carry out a visual inspection of the pump installation on a daily basis. This is one of the best methods of trouble shooting and preventing pump breakdown. Most of the things to look out for should be easily visible, these include:
- Wear/evidence of rubbing
- Unusual noise
Other checks however are required less regularly, and therefore preventive pump maintenance should to be planned into a periodic maintenance schedule. By setting out when certain tasks should be carried out, maintenance becomes a smoother more efficient process. Not only does it reduce the likelihood of unexpected pump failures and downtime, it also helps to reduce the cost of ownership as replacing wearing parts of example is a much cheaper process than replacing an entire pump. An example of a periodic pump maintenance schedule is below.
|PERIODIC MAINTENANCE SCHEDULE |
|Frequency ||Staff Needed ||Time ||Task |
|DAILY ||1 ||10-15 minutes || |
- Check for bearing temperatures
- Check for cavitation & bearing noise
- Check for motor current & voltage
|WEEKLY ||1 ||20-30 minutes || |
- Check for suction & discharge pressures
- Check for vibration & noise
- Visual check for sealing leakage
|MONTHLY ||1 ||20-30 minutes || |
- Remove safety guards & check for shaft & auxiliary devices
- Check for coupling alignment
- Fill lubrication oil (if necessary)
|ANNUALLY ||2 ||2-3 hours || |
- If spare pump, run the pump & check for maintainability
- Check for axial movement of motor shaft
- Remove & clean all auxiliary devices (valves, manometers, piping’s, sight glasses, etc)
- Remove coupling halves & check for wear at rubber part (renew if necessary)
|2 YEARS OR 10000 HOURS ||2 ||6-8 hours || |
- Dismantle the pump from the piping & disassemble
- Make inspection on parts, renew if necessary:
- Wear Rings/Wear Plates
- Apply coating on un-machined surfaces
|Table 1: Using periodic maintenance for pumps is the most common maintenance technique.www.pumpengineer.net |
Table taken from Pump Engineer (2015), Technical Paper: Pump Maintenance Scheduling.