What is Ultrasonic Examination?
Ultrasonic Examination (UE) provides an exciting technology alternative to hydrostatic testing for cylinder recertification.
UE tests measure the thickness of cylinder walls over their sidewall full lengths. Cylinders do not pass the test if, at any point, the thickness of their walls falls below the established minimum.
In addition, UE identifies small faults, such as cracks, corrosion, pits, and gouges that are not always found during a standard hydrostatic test.
UE also eliminates the need to drain residual contents or remove valves and O-rings.
Ultrasonic examination eliminates problems inherent in hydrostatic testing for cylinders used in high-end specialty gas and electronic services. These cylinders receive special surface treatments and, after hydrostatic tests, must have those treatments re-applied, followed by a thorough drying of the cylinder interior.
Ultrasonic examination also results in fewer rejected cylinders than hydrostatic testing, since many of the testing errors, including leaking seals, operator mis-interpretations, and inaccurate burette readings, are no longer factors.
Since ultrasonic examination has been determined to be extremely accurate in detecting cylinder flaws, the US Department of Transportation has:
Waived the need for internal visual examination of cylinders used in certain services, and
Approved the extension of certain cylinder requalification periods