Abstract
Control valves play a pivotal role in the reliable operation and safety of petrochemical plants by regulating fluid level, flow, pressure, and temperature in complex process control systems. Control valve failures, however, have numerous negative impacts on process plants, such as safety incidents, unplanned downtimes, higher maintenance costs, environmental damage, and hence the need to improve the reliability. Maintenance strategies employed for maintenance management of the control valves installed in a petrochemical plant and the reliability, availability and maintainability(RAM) improvement are explored in this research under guidance of these research questions: (a) What maintenance strategies can be implemented to improve RAM of control valves in refineries?, (b) What are the key factors contributing to the reduced reliability of control valves?.
The study followed a qualitative methodology, with seven participants purposively selected to share insights by answering open-ended interview questions derived from the literature review, followed by thematic data analysis. The findings revealed that the key maintenance strategies employed for control valves RAM improvement are preventive, condition-based predictive, and quality corrective maintenance. However, predictive maintenance has some drawbacks due to limited technology adoption and installed smart sensors for asset health monitoring and data analytics. Mechanical, process, and operational issues are common key problems experienced with control valves. These include calibration errors, packing issues, foreign particles, inadequate training, quality control procedures, cavitation, seat and air leakage, erosion, and stiction. Future research could explore the integration of technology-enabled maintenance tools for real-time health monitoring of control valves within the process control system. Furthermore, future research could consider a comparative study on control valves failures and their respective maintenance practices across multiple petrochemical plants and inclusion of control valves original equipment manufacturers (OEM’s) to broaden the generalisability and validity of the results.