There have been many recent instances where an innovative new ANDT technique is utilised to inspect a component due to the part having difficult or no access to more conventional NDT techniques. Examples of this technology could be search techniques that can ‘point you in the right direction’ by quickly screening large areas of a component to check to see if everything is o/k. The utilisation of guided waves can be one example which can travel and inspect tens of metres of pipe which may be buried, insulated or completely inaccessible to more conventional NDT techniques, another is the application of Pulsed Eddy Currents which again can inspect in areas covered by insulation, cladding etc. The rationale for using this type of technology in most cases is correct as to inspect by gaining direct access to the component surface may be impossible or too expensive to contemplate. What sometimes is not
considered is what happens if this advanced innovative technique finds something that indicates a possible defect what happens next.
Do we have a plan B for confirming the result i.e. another inspection technique or do we accept the result and assess how to access ?
I recall in my earlier days when manual ultrasonic testing was considered an advanced technique for checking welds. Whilst carrying out UT testing on a clients site if you were to find a possible defect and using your UT skills, had then indicated its location within the weld. It was expected that you waited whilst the weld excavation was made to search for said defect and you had better have got it right or you were in big trouble. These days we don’t have this ‘search for the guilty’ but we probably don’t as we did in the past expect the NDT technique to find a problem.
What ANDT or ANDT & NDT methods would you combine ? It does become trickier for remote access but there does need to be a way of confirming findings. This should be considered ahead of time, agreed with client and written into the test procedure.
3 NDT 