Valve Inspection Intervals and Condition-Based Maintenance

Fixed-interval valve maintenance is giving way to condition-based approaches that use performance data to schedule servicing only when needed. Combining periodic inspection with real-time diagnostics reduces unnecessary interventions and unplanned failures.

Establishing Baseline Performance

At installation and after each overhaul, record full-open torque, full-close torque, leak-off test result, and actuator stroke time. These baselines serve as the reference for detecting deterioration over time.

Key Inspection Parameters

Stem torque trend: rising torque indicates packing wear or seat foulingLeakage rate: rising external leakage triggers packing replacementStroke time: longer time may indicate actuator or positioner degradationSignature curve shape (control valves): deviation from baseline flags mechanical issues

Risk-Based Inspection (RBI)

RBI ranks valves by consequence of failure and probability of failure to prioritize inspection resources. Isolation valves on high-consequence process streams (toxic, flammable, high-energy) receive shorter inspection intervals and more thorough examination than utility valves.

Extending Maintenance Intervals

Valves with stable performance trends, redundant isolation capability, or low consequence ratings may qualify for extended intervals. Document the engineering justification and review annually with operations and integrity teams.

Archive all inspection records in the plant CMMSSet condition-based alerts in the SCADA or DCS where possibleReview failure mode history when setting inspection frequenciesTrain field technicians on data collection methods and equipment