Non-destructive testing of hemispherical head seams
Thread Content
For the hemispherical head of the reactor, made of 12Cr2Mo1R with a thickness of 90 mm, can TOFD testing be used as a substitute for RT testing on the welds?
It’s not a matter of simple substitution; it should be 100% RT with an additional 20% or 100% UT.
In accordance with the relevant requirements of the code for fixed capacity, both RT and TOFD can be used for inspection, following the technical specifications outlined in the design drawings. TOFD is a type of ultrasonic testing method that allows for recording of results; however, common digital ultrasonic machines do not fall under this category of recordable ultrasonic testing methods. If it is desired to speed up the project timeline, TOFD testing can be employed, and a design change can be requested for this purpose.
For pressure vessels manufactured on-site with a wall thickness of 60 mm or more, the TOFD testing method can be used as an alternative to radiographic testing for non-destructive inspection.