The LogiCamms Asset Management team was engaged to investigate the root cause of multiple quadraflex coupling failures (thermoplastic elastomer) and provide an engineering solution to improve asset reliability. Due to unplanned maintenance events, significant production losses and unplanned downtime was incurred. The scope of works included:
- Review existing operational data relating to the quadraflex coupling assembly
- Review specification of the quadraflex coupling
- Communicate with key maintenance stakeholders to better understand historic failure events
- Develop a set of acceptable alignment figures and tolerances to ensure all future lube oil pump to auxiliary gearbox shaft alignments are conducted consistently and within the recommended alignment tolerances
- Develop a step-by-step procedure with the aim of providing technical guidance to maintenance technicians conducting shaft alignment work when replacing the quadraflex coupling assembly
- Calculate the correct torque setting for the lube oil pump holding down bolts
SOLUTION
The overall solution comprised of the following activities:
- Verified if the existing quadraflex coupling was suitable for the current type of service application and operating environment
- Conducted torque calculations to determine the horsepower rating
- Developed and approved an alignment procedure to ensure all maintenance technicians use the same procedure to achieve consistent and accurate results
- Reduced the current level of coupling misalignment and lube oil system vibration
- Updated the existing information in the maintenance management system to reflect the correct coupling specification
BENEFITS
Benefits as a result of the project activities include:
- A reduction in lube oil pressure compressor trips as a result of fewer coupling failures
- A reduction in unplanned maintenance and machine downtime
- Life extension of the quadraflex coupling from a couple of weeks to 16,000 hours
- An increase in production volume due to a reduction in offline machinery as a result of unplanned corrective coupling maintenance
