PM checklist
Centrifugal pump: a preventive maintenance checklist
A centrifugal pump tells you it is getting worse. The seal weeps, the bearing housing warms up, vibration climbs, or the flow falls at the same speed. This checklist is a starting point for those signs. Set the limits from the pump manual and from a baseline taken when the pump was healthy. The method is in the preventive maintenance guide.
Key takeaways
- Watch the seal, the bearing temperature and vibration. Those three catch most pump failures early.
- A number against last month's number is the record. "Normal" is not.
- Do not ignore a small seal leak on a pump that feeds a critical line. It is the job, not a housekeeping note.
- Alignment, coupling and base bolts belong on a planned stop, not on a running round.
- If you already take vibration or temperature on a round, put a warning limit on it so someone acts before the bearing fails.
Weekly round
Walk the pump while it is running, from a safe place. Do not reach past guards.
| Check | What to record | Act when |
|---|---|---|
| Seal or packing | Dry, damp, or a visible stream | Any stream, or a damp trend that is getting worse |
| Bearing housing temperature | The number, same spot each week | Climbing toward the limit you set, or too hot to hold a hand near |
| Vibration at the bearing | A reading, or a note if you only have a hand feel | Above the warning limit, or a new knock |
| Suction and discharge pressure | Both gauges | Discharge falling at the same speed, or suction unstable |
| Noise: cavitation rattle, or a grinding bearing | What you heard | A rattle that was not there last week |
| Base, guards and obvious coupling throw | Secure, or loose | A loose bolt, a missing guard, or oil under the coupling |
If the pump is on a condition round already, this checklist should match those parameters. Do not keep a second set of limits in a notebook.
Planned stop
Isolate the pump, including the electrical supply, and close and lock the valves your procedure names before you open the coupling guard.
| Job | Usual trigger | What "done" looks like |
|---|---|---|
| Check coupling condition and alignment | Quarterly, or after a pipe strain job | Alignment readings, and whether it was corrected |
| Grease bearings only if the manual says to, and only the amount it says | OEM interval | Shots or grams added. Over-greasing fails bearings |
| Inspect the mechanical seal flush, if fitted | Quarterly | Flush flow present, strainer clean |
| Check impeller clearance if performance has fallen | When the weekly pressures say so | Clearance found, against the manual |
| Replace packing or plan a seal change | When the weekly leak crosses your limit | What was fitted, and the leak rate after start-up |
A worked example from a typical plant
Worked example (illustrative)
A cooling-water pump, P-07, feeds a line of machines. For three weeks the bearing temperature is written as "OK". In week four the pump stops on a hot bearing and the line waits for a seal and a bearing.
The planner changes the round. Temperature is a number task with a warning limit. Vibration is a number if they have a meter, or a three-way choice (steady, higher, rough) if they do not. Seal condition is dry, damp or streaming. A streaming seal or a temperature at the warning limit opens a job while the pump is still running. The story is illustrative.
The failure was visible in the temperature the team refused to write down. The checklist's job is to make that climb impossible to miss.
Common mistakes
- Greasing on a calendar when the bearing is sealed and the manual says not to.
- Calling a seal leak "normal" because this pump has always wept. Set a limit and replace it on purpose.
- Checking vibration once, with no baseline, and then having nothing to compare.
- Opening the coupling guard while the motor can still start. Isolate and lock it.
- Using one checklist for a slurry pump and a clean-water pump. The seal and the wear parts are different.
How to put this list to work
Choose the pumps whose failure stops production, not every pump in the yard. Take a baseline temperature and vibration when the pump is healthy, and write those numbers on the checklist as the comparison. Review the round after a month. If temperatures are still being written as OK, the task is wrong and you will not see the climb.
The U.S. Department of Energy pumping sourcebook makes the same point in system language: many pump losses are operating and maintenance practice, not a need for a new pump. A seal leak, a hot bearing and a falling discharge pressure are maintenance signals. Treat them as jobs. If the pump has a standby, test that the standby actually starts. A spare pump that has seized on its shaft is not a spare. Log that start test on the standby pump's own record, with the date and whether it came up to pressure.
Sources
- Improving Pumping System Performance: A Sourcebook for Industry (opens in a new tab), U.S. Department of Energy, Hydraulic Institute
- Maintenance of work equipment (opens in a new tab), Health and Safety Executive (HSE), UK
Frequently asked questions
What causes most centrifugal pump failures?
Seals and bearings, often after a leak, a lubrication mistake, misalignment or cavitation was ignored. The weekly round is there to see those before the pump stops.
How often should pump vibration be checked?
Weekly on a critical pump is a practical start. Always measure at the same place and write the number, so a climb shows up.
Should a small seal leak be fixed immediately?
A damp seal can be watched against a limit. A stream should become a planned job now, before it damages the bearing and the product, or makes the floor unsafe.
Does this cover positive displacement pumps?
No. Gear, diaphragm and dosing pumps have different checks. Use this list only for centrifugal pumps, and follow that pump's manual.