EMS Inc. / Alberta / Canada / Case Studies / Legacy Compressor Main Bearing failure detection

Legacy Compressor Main Bearing failure detection

For a long standing client, a Reciprocating Compressor Condition Monitoring Program on their compression fleet was a no-brainer. The data captured, trended and analyzed by our experienced analysts brought peace of mind to their maintenance staff. They had good information to make decisions on the maintenance and operation of their fleet.

CB AMA-6 Compressor Analysis
CB-AMA-6 Compressor Analysis

Particular attention was paid to one of their compressors due to a couple of very key factors. The first was this legacy machine, a Cooper Bessemer AMA-6 compressor, was becoming very rare as far as sourcing very specific parts if a failure were ever to happen. Frame, cross heads, connecting rods and especially crank shafts were in short supply and may have to be manufactured from scratch. This would most likely be the fatal blow to this machine in its life cycle.

Secondly, was the extended overhaul hours. As with any company trying to survive in this economic climate, the overhauls were being stretched to the limit. Times on this unit were reaching near twice the recommended overhaul interval and close attention was needed to ensure that unnecessary risk was being taken. The unit was being analyzed with our Running Online Analysis (ROA) quarterly with monthly oil analysis being closely monitored.

Oil analysis results were steady and normal wear patterns were noted. However, in a 3 month span, our analyst detected a severe change in the vibration data collected on the compressor main frame. These levels were nothing seen before on the machine and detailed analysis alerted the maintenance staff to perform an immediate inspection of the compressor.

The quick on-machine diagnostics performed by our experienced analysts made this a monumental save of machinery and most importantly, money. The maintenance staff was quickly alerted within minutes of the data being captured and a plan was set into action for the compressor to be inspected.

Timing is everything.

The findings were disturbing as for months prior, oil analysis results did not give any indication of any issues or concerns. Also the previous vibration samples on the compressor were showing very minor changes over time, but the last sample were very indicative of a mechanical issue inside the machine.

Cooper Bessemer AMA Bearing Shells
CB AMA-6 Bearing Shells

Excessive bearing material was found in the sump of the crankcase. Bearing shells were removed for inspection on throws #5 and #6 as specified in the EMS Inc. analysts report. The crankshaft, however, was saved as the wear and impacting had not yet started to wear down on the bearing surfaces of the compressor.

A legacy compressor and its crankshaft was saved from the scrap yard. A near fatal blow that would have ended this machines life and made the gas field in the area difficult to manage.

In over our 25+ years of analyzing compressor fleets of all sizes and applications, these types of findings what the programs are designed for. A large percentage of data analyzed on machinery show good overall health and those trends are essential in early detection of these types of failures.

Data is power in a maintenance programs ability to assess the risk and plan normal activities with confidence. Don’t just use the calendar to plan your maintenance, use information and our experience to take it to the next level.