Ultrasound Testing for bearings
Ultrasound Testing is one of the most effective ways to monitor bearings: it catches developing faults — inadequate or contaminated lubrication, spalling and pitting of races and rolling elements, fatigue cracking — early, so repairs are planned rather than forced by a breakdown.
Why ultrasound testing suits bearings
Bearings fail in a predictable sequence, and that sequence is visible in data long before the bearing seizes. Because a failed bearing usually takes the machine — and sometimes the shaft — with it, catching the early stages is one of the clearest wins in all of predictive 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 bearings
- Inadequate or contaminated lubrication
- Spalling and pitting of races and rolling elements
- Fatigue cracking
- Electrical fluting (from VFD-driven motors)
- Overload and misalignment 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 bearings: 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 bearings specifically. Ultrasound and high-frequency envelope vibration rise first, while the bearing is still serviceable; defect frequencies then appear and grow; temperature rises late. The earlier you act, the cheaper and more planned the repair.
Where it is blind. Ultrasound Testing does not cover every failure mode on bearings. The equipment profile also lists Vibration analysis (envelope/demodulation for early defects), Bearing temperature monitoring, Oil/grease 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 steam traps · Ultrasound Testing for control valves · Ultrasound Testing for compressors
Other techniques on bearings
Vibration Analysis for bearings · Thermography (Infrared Inspection) for bearings · Oil Analysis for bearings
Related
Predictive maintenance for bearings · Ultrasound Testing overview · Ultrasound Testing