Ultrasonic Testing - Test Blocks

This any help?

That is helpful. However, I am wondering procedurally if that is something provided by the NDT Company or if it was suppose to be electrical discharge machined by the manufacturer. I am unclear how to ask the question as I have little training in NDT but want a better grasp of the test blocks function in the procedure/process of UT Testing.

Think it would be perfectly reasonable to ask the company to provide evidence that they're competent - you could say your customer/boss/whoever is asking for documentary evidence.

They must either have test blocks themselves or have got a third party to examine their competency - either way there should be some evidence that they can do the job, otherwise anyone could buy the kit & declare themselves NDT experts.

The certification of nondestructive test (NDT) personnel involves practical demonstration that the person performing the test can detect all indications of the type that can be identified by the NDT method. The NDT method here; Ultrasonic (UT), is capable of identifying a broad range of discontinuities through the entire volume of the object it's used to examine. Therefore; the certifying authority will have test blocks corresponding to that broad range of indications. In most cases the certifying authority is the NDT examiner's employer and; if following certification procedure, will have the test blocks.

There may be some defects that can be identified by UT that are specific to the material and weld procedures you are using. If so; your NDT company should have blocks for them, or get them for your project. You should consult the designer and/or welding engineer as to whether there are any such conditions

I find it a little odd that you as the contractor are left to procuring NDT services. That function is usually performed by the owners Quality Assurance/Quality Control (QA/QC) department and I am sure they are auditing you. Since it is your contractual responsibility to procure NDT services it is also your responsibility to audit the NDT provider you hire. NDT companies like stamp holders must answer to the codes they work under, and you have every right to ask for any and all documentation to verify to your satisfaction they are in compliance.

Also, there are test blocks and there are test blocks. There are calibration blocks that simply have drilled holes to provide a reflector at a known depth so you can set up your instrument calibration, then there are test specimens that generally are a cut away of a weld of the sort material that is in question. In this case "flaws" might be machined into the block and the technician asked to demonstrate that he can find them. Finally, if specialized cases you might cut sections of material that has actually cracked in service. This was done with IGSCC flaws in the main recirc piping of Nuclear plants back in the 80's. To qualify as an inspector for IGSCC flaws you had to demonstrate your ability on an actual specimen with real flaws.

In my past experience, EPRI, the nuclear research agency had the qualification blocks with the real IGSCC flaws. We as an NDT company had built qualification blocks with machined flaws, and we either built or purchased calibration blocks.