AUT, ECA and Linear Interpolation

  • AUT, ECA and Linear Interpolation

    Posted by leo on 27/11/2021 at 7:35 pm

    I would like to hear from those of you who are involved with AUT and ECA acceptance criteria or anyone with an opinion on it. Has anyone ever thought of or played with the idea of using linear interpolation when evaluating AUT indications using ECA? Does anyone currently use it in the industry?
    Let’s face it. The purpose of using ECA is to reduce the number of unnecessary repairs based on actual flaw length versus height. So why not introduce linear interpolation? This would allow even more cost savings for the pipeline industry. I have seen many indications repaired that really didn’t need to be.
    For example, let’s assume your acceptance criteria states the allowable length for indications from 2.5mm to <3.0mm in height is 123mm and indications from 3.0mm to <3.5mm is 106mm. In my opinion, if you are allowed to have an indication with a vertical height of 2.9mm with a length of 123mm, you should be able to accept an indication that is 3.0mm in height with a length of 119.6mm and not 106. This is where interpolation comes in.
    I would like to get others’ opinions on this.

    caleb-charles replied 2 years, 11 months ago 2 Members · 1 Reply
  • 1 Reply
  • Automated Pipeline Inspection (AUT)

    caleb-charles

    Member
    28/11/2021 at 4:04 pm

    How did you come up with the length for that height defect? I am not sure how this “interpolation” is determined.
    Explain how linear interpolation works. I have never heard of it. You sound like you want to re-engineer the ECA criteria on the job. If you want to change the ECA you should become an engineer and crunch numbers for a pipeline company.
    The AUT operators don’t really give a shit about it. If it passes it passes,if it doesn’t it doesn’t.

Log in to reply.