The technique:

Either for safety or performance improvement, it is extremely important to have good predictive maintenance strategies towards control valves. With Valve Analysis it is possible to monitor each aspect of its performance, and then provide a diagnostic.

The data acquisition occurs mainly in the field, with a portable system, which is prepared to dynamically drive the valve. The test can take from 10 to 20 minutes per valve, a little more or less depending on the case. More complex testing may demand more time. The valve must be in bypass mode during testing, either manually or automatically.

Mainly primary faults that can be detect are faulty diaphragm; leakage; wear (on many parts); looseness; bending shaft etc.

Dynamic parameters that can be evaluated:

  • Travel;
  • Spring travel;
  • Spring compression;
  • Seat conditions;
  • Friction;
  • I/P calibration;
  • Positioner calibration;
  • Linearity;
  • Dynamic Error;
  • Hysteresis;
  • Overall performance;
  • Repeatability;