How do you plan preventive maintenance for control valves?

Control valve PM planning: categorize valves by criticality and service severity, establish inspection intervals (annual to 5 years based on history), define PM tasks (external inspection, positioner calibration, packing adjustment, diagnostic review), plan turnaround activities (internal inspection, trim replacement, actuator rebuild), maintain spare parts (common wear parts, critical valve spares), and use diagnostics for condition-based maintenance. Key metrics: unplanned failures, PM compliance, mean time between failures. Document findings for trending. Integrate with CMMS for scheduling and history. Adjust intervals based on actual performance data.