A388 and A578 inspections are not similar. While they are both based on a loss of back reflection A388 is tailored for forgings, while A578 is tailored for plate material. A A578 inspection will consist of scanning one major plate surface, usually as a sample inspection along grid lines on 9" centers. That is sufficient for plate material because the target flaw is pretty much limited to gross laminations. A A388 inspection inspects 100% of two perpendicular sufaces. Additionally, if the forging is cylindrical, based on geometry, A388 also requires an angle beam inspection.
If I needed a A578 inspection and a A388 inspection was performed, I would be alright with it. However, if I needed a A388 inspection and a A578 inspection was performed I would not accept the material.
This test A578 is requested for a clad pipe to check 100% for any cracks in between the clad material and base pipe .
So from your knowleadge I can extract that the procedure for A578 is different than A388. and also I belive that the A578 is more detailed testing than A388.
For your clad pipe situation you should require a UT test of the pipe with 100% coverage such as the one in A450. Lack of bond will show clearly in this type of test. And so will base metal defects.
If they did A578 on a grid with straight beam then I would not take it. Unless the grid was a fine as the wall thickness.
What did they use for a reference standard? acceptance limits?
