Questions regarding non-destructive testing of pressure vessels
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I would like to ask the experts: for pressure vessels (towers) in ethylene plants, can TOFD inspection be used as a substitute for radiographic inspection? Or can a combination of TOFD and PT inspections be used as a replacement for radiographic inspection? Thank you!
It should be replaceable; the standards require RT or UT (which explicitly includes TOFD) as well as recordable pulse-reflectometry testing. RT has film archives for easy tracking, and TOFD also has data collected for analysis and evaluation, which needs to be archived; therefore, it complies with the regulations. It’s just important to pay attention to the storage of the data obtained from TOFD testing.
As long as the data is well preserved, it can be replaced
Replacing RT with TOFD is no problem, but design approval is required. TOFD testing has blind spots regarding surfaces or near-surface areas; therefore, the standards specify additional MT procedures as a complement.
The tolerance specifications describe it this way, which should be sufficient, but it’s best to consult with the design team.
It is completely fine to use TOFD in place of RT. If the original design was for RT testing, then design change procedures need to be carried out.
It is possible to use TOFD in place of RT. But it needs sufficient practical experience and performance to back it up.
It is possible to use TOFD in place of RT. However, it is necessary to design an agreement and concurrent change order. Additionally, care must be taken to keep the test record documents.
TOFD can replace RT, and it is mainly used for carbon steel and low-alloy steel with a thickness of at least 12 mm.
It is possible to use TOFD in place of RT.
TOFD testing has blind spots regarding surfaces or near-surface areas; therefore, the standards specify additional MT procedures as a complement. Which standard is used for supplementation?