Running oil on high PSI
We recently completed the overhaul of a Baudouin P15 pump engine, and when it came to the 24hr FAT (Factory acceptance test) we noted something worrying, leading us to perform an RCA.
There were no issues to start, with the engine test being carried out as usual:
- Engine installed onto testbed and all connections were made
- The engine was then primed by turning the engine over
- All rocker covers were removed, and it was checked that oil was at the rocker gear. This was noted and the rocker covers were replaced
- The engine was then run with no load for 2 hours so the engine could be checked for operation and leaks
After 2 hours the engine was running as it should and the panels were showing expected readings.
The load was increased to 100% before being brought back down to 80% after confirmation all ok at 100%.
- All engine temperatures were recorded as normal
- Oil was recorded at the top of the engine in the rocker gear
- No abnormal noises or vibrations were noted
After several hours running at 1800rpm @ 335hp, with good temperatures, the oil pressure was reported @ 98psi before settling at 90psi*.
*The manual states it should be between 50 and 60 psi.
The load was taken off and the engine was run down to idle speed and shut down. Once cooled the fluids were drained, ready for investigation work to commence.
We then carried out an RCA, covering all possible causes including:
- The engine oil circulating pump
- The cooler
- The filters
- Big end and main bearings (as a precautionary measure only to check for any damage from the oil pressure increase)
- Pressure relief valve – set to operate at 5.5bar of pressure. (This valve did not trip as the pressure was recorded at 98psi, this would point to the pressure issue being located before this point in the circuit.)
With all possible components checked and ruled out, we asked the operator to send through engine running logs from previous onsite 12-hour performance test runs, so we could compare the running data, and see if the oil lubricating pump was standard 50 – 60 psi operating pressure.
Once received, we could see that the 12-hour running logs showed the engine previously operated with 89 psi oil working pressure, and also discovered that the pump had been uprated from a 60psi unit to a 90 psi unit.
After it was confirmed that the engine oil pump had been uprated to run at 90 psi, it was evident that the oil pump had been operating correctly.
Confidence was back in the oil pump and the 24-hour test was restarted.
This RCA would have been carried out for any issues such as this on completion of an overhaul as a matter of course, but in this instance, had we been aware of the uprated pump and running history of the engine, it could have been avoided.
When we cover your engines under our long term service agreement contract, these differences are documented, enabling us to adjust and allow for deviations from the manual when carrying our servicing, overhauls and testing of your equipment.