Ultrasonic testing of welds with a thickness of 2 to 8mm
The need for non-destructive testing of welds of small thickness, unfortunately, has been confirmed in
many accidents, sometimes especially in Power Engineering, whitch were disasters. The requirements
of the supervisory bodies, investors, and economy create a need for such studies, often with
a range of many thousands of pieces (pipe) or meters (structures).
However, in this respect the existing
state of standardization in the two basic methods ie UT and RT is not perfect.
UT research standards do
not provide welds testing in less than 8 mm, while standard on the RT provide for such testings
but their credibility is particularly low.
This low reliability, due to geometric mismatch of the
incident beam to glues in the weld defects that are particularly dangerous in this range of
In the test tube weld, it is difficult to detect glue on the end or the initiation of the peripheral joints
of the pipe. It is a defect with a small size that occurs in these joints the most, and also (because of
its rapid development) the most dangerous because it causes frequent breakdowns.
Such UT detection method
is difficult, because it is a "small defect" is located radially next "big" peripheral face of
inequality and the ridge.
Such tests are necessary, however, and it allows the specific selection of
parameters of probes the construction and calibration of tests IBUS-TD method. Using methods that are insufficiently
provide this type of detection of defects is a serious technical error.
In particular, radiographic tests should not be used, because the probability of detecting most dangerous defect is negligible.
in ultrasonic testing when using special probes and conditions Instructions IBUS-TD better than
satisfactory results have been achieved.
This is confirmed in the qualification of the method carried out by the Office of Technical Inspection and
recognition methods for testing equipment under supervision of OTI.
Certificates awarded by the Office of Technical Inspection (in polish)
Examination of thin welds according to IBUS-TD method. To order it in foreign language