I've been asked to assist in ultrasonic wall thickness testing for a certain type of heat exchanger we use in our process. The exchanger is a stainless steel tube that is inserted into a cast housing. These housings are between 30 and 50 years old. The theory is that they are worn away, due to age, at various degrees. I've never done testing like this before. Would you folks give me an idea of what I should expect and perhaps, some various techniques on the subject. Thanks in advance....

Sharkey,

More info about the exchanger and test conditions is needed to provide any meaningful suggestions. Who is actually doing the testing, an ASNT certified third party or someone who read the Instrument Manual? A trained, experienced and certified inspector should already know what is needed if they know what it is they are inspecting. It almost sounds like you have been tasked with the job based on the questions you've asked. An unenviable task at best if you haven't had much previous experience and training.

Can you attach a photo or something that shows what the actual physical configuration is? [preferably with some dimensional information- tube size & thickenss-shell size and thickness, et al]. What are you planning to UT, the "housing"[I assume this is the shell] or the "tube" and did you mean this actually has a single tube? Wjat about tubesheets...any?? How thick is it supposed to be? If the housing, a material of construction is needed and...? The longer I think about it the longer the list of questions grows.

This message has been edited. Last edited by: Dana,

Thanks, Dana. Sorry it took so long to reply.
Actually, I'm just observing at this point. The company brought in an outside analyst (certified) to check the shell thickness in these particular heat exchangers. I don't have any spec sheets or pictures. This equipment was built in the 40's and 50's! They are cast steel shells in which a stainless tube is inserted. Anhydrous ammonia is circulated between the shell and the tubes. They are used to cool down an emulsion in 3 stages, from 110 deg to 45 deg. We know that the equipment is degraded. The test is to confirm, in order to request a CIR to replace it. I just wanted to familiarize myself with procedures before they brought this guy in. I do very little ultrasound, other than leak detection.

Sharkey,

I know this is old and you probably already have the testing completed by now, but we started doing Eddy Current Testing for all our tube bundles. I got the initial training and really enjoyed it, then it was given to the Mechanical Inspection group.

It's a whole different world than leak detection.