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
Implementation on control valves: Start by establishing a baseline — what ultrasound testing looks like on a healthy control valves. This typically takes 2–4 weeks of normal operation. Once baseline is established, any divergence from the norm signals a developing fault. Most plants find that a threshold alert (warn if exceeding baseline +X%) is simpler to manage than complex signal-processing algorithms.
Fault progression: The faults caught by ultrasound testing on control valves typically develop over days or weeks, not hours. This means you have a window to schedule repairs during planned downtime, avoid emergency callouts, and reduce parts inventory for emergency spares. That window is the value of the technique — it transforms random failures into managed maintenance.
Integration with maintenance: Condition monitoring data works best alongside a predictive or preventive maintenance schedule. Use ultrasound testing to trigger or validate the need for an intervention, rather than relying solely on calendar-based overhaul. This data-driven approach often reduces maintenance cost by 10–20% while improving reliability.
Related
Predictive maintenance for control valves · Ultrasound Testing overview · Ultrasound Testing