Ultrasound Testing for control valves
Ultrasound Testing is one of the most effective ways to monitor control valves: it catches developing faults — sticking, hysteresis and dead-band, seat and plug wear and leakage, packing and seal wear — early, so repairs are planned rather than forced by a breakdown.
Why ultrasound testing suits control valves
Control valves regulate the flows and pressures a plant runs on, and a degrading valve quietly worsens control quality, wastes energy and can fail to a dangerous position. Smart positioners and process data expose sticking, hysteresis and seat wear long before a valve fails, making them strong candidates for condition-based maintenance.
How ultrasound testing works
An ultrasonic detector picks up high-frequency sound and shifts it into the audible range, so a technician can hear faults that are otherwise silent. Because friction, turbulence and electrical discharge all emit ultrasound, the technique finds the very earliest stage of bearing wear, the hiss of a pressurised leak, and the flow through a passing valve or failed-open trap. It is fast, portable and needs no shutdown.
Faults it catches on control valves
- Sticking, hysteresis and dead-band
- Seat and plug wear and leakage
- Packing and seal wear
- Actuator and positioner faults
- Cavitation and flashing damage
What the data shows
A rising ultrasonic level on a bearing is often the first sign of wear, before vibration; a continuous hiss locates a compressed-air or steam leak; flow noise through a closed valve reveals internal leakage; a failed-open steam trap shows continuous flow.
Ultrasound Testing on control valves: implementation
What the signal looks like. A rising ultrasonic level on a bearing is often the first sign of wear, before vibration; a continuous hiss locates a compressed-air or steam leak; flow noise through a closed valve reveals internal leakage; a failed-open steam trap shows continuous flow.
How that reads on control valves specifically. Growing hysteresis or dead-band in the valve signature flags packing or actuator wear; acoustic signatures reveal internal leakage; degrading loop performance points to a sticking valve. Each maps to a specific, plannable service.
Where it is blind. Ultrasound Testing does not cover every failure mode on control valves. The equipment profile also lists Valve-signature / positioner diagnostics (travel vs signal), Acoustic monitoring for internal leakage, Process-loop performance analysis — they exist because they detect modes this technique cannot see.
Before you set a threshold. Baselining, alarm criteria and the route from alert to work order are the same problem for every technique. They are covered once in setting up a condition monitoring programme and in the ultrasound testing overview.
Ultrasound Testing on other equipment
Ultrasound Testing for bearings · Ultrasound Testing for steam traps · Ultrasound Testing for compressors
Related
Predictive maintenance for control valves · Ultrasound Testing overview · Ultrasound Testing