A major Canadian refinery was experiencing a gas compressor flow shortfall in a critical VRU task. They turned to the Rotary Test Center (RTC) for some objective detective work.
The Mystery Thickens
The compression package had seen over a decade of use, changes in location, ownership and task – leaving an uncertain history. The mystery was compounded by the fact that rebuilds did not solve the low flow performance problem.
Probing the Issue
The refinery shipped the compressor to the RTC and it was set up on the test stand with a full array of sensors, transmitters and probes. Thus providing data for the detective work.
Customizing the Test Procedure
A full test procedure was developed and structured to analyze every aspect of the compressors mechanical operation and performance. The full procedure wasn’t executed as the flow shortfall of 20-27% became immediately apparent.
The flow shortfall was analyzed in several ways, utilizing different equipment and processes, to be absolutely certain of the findings. It was confirmed, the shortfall the refinery was measuring on site was also seen in a controlled, laboratory like setting.
The investigation continued with a thorough inspection of the compressors internals, assuming there must be some sort of geometrical or mechanical deficiency.
Upon disassembly of the compressor by the Ro-Flo Compressor mechanics, it was instantly noticed that the bearing spacing rings were not the OEM components. The correct, OEM, bearing spacing rings were installed and the testing was resumed. This time the full procedure was run. Multiple speed and pressures were run as the ASME Power Test Codes and ISO standards mandated.
The test results showed that flow was within 3% of expectation across all compressor settings. The non-OEM component was the culprit and the change out with a Ro-Flo OEM part was completely successful.
It is noteworthy that the initial testing, transportation to and from the Ro-Flo rebuild shop, and the retesting were all done on a tight timeline driven by the refinery’s shutdown schedule. Urgency applied due to the need to meet emissions or face an extended shutdown. The entire process was complete with a performing compressor on the road to the refinery in less than five days.
Solve Your Mysteries with RTC
Whether it’s related to field performance, designers needing prototype confirmation, or a warranty dispute, equipment performance can present a wide variety of questions in the Oil and Gas Industry. The RTC offers solutions to even the long-standing “mysteries” you may be facing.