×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

X-ray Slot Weld on Assembled Pressure Vessle?

X-ray Slot Weld on Assembled Pressure Vessle?

X-ray Slot Weld on Assembled Pressure Vessle?

(OP)
I have a pressure vessel made from 6061-T6 about the size of a small air compressor that’s undergone proof testing. I’d like to do nondestructive testing on it to verify no cracking occurred during the test. Particularly curious about some slot/plug welds that we have on internal bulkhead flanges to the skin.

Borescope results show that bulkhead flanges are not in intimate contact with the skin away from the weld. The skin is pulled into contact at the weld. My experts are telling me that this will make UTI unreliable and pretty much meaningless.

1). Is that true? Can I not get meaningful results with an experienced UTI Driver?
2). If true, can it be x-rayed? My same experts are telling me that the xray results will be inconclusive because there is no way to put a plate inside the assembly.

Is there seriously no way to do anything more than visual inspection and DPI? Any suggestions on how I should proceed?

RE: X-ray Slot Weld on Assembled Pressure Vessle?

If the cracking you're looking for is surface breaking, why would you not penetrant test?

If you can't put a plate inside the assembly, can you not put the plate outside and the source inside (it'll be gamma rays not x-rays but still RT)?

RE: X-ray Slot Weld on Assembled Pressure Vessle?

Quote (Ted7)

If you can't put a plate inside the assembly, can you not put the plate outside and the source inside (it'll be gamma rays not x-rays but still RT)?

Exactly. A gamma ray source tube (Ir 192) can be inserted into a hole that is about 1/2" or so in diameter. Film is then placed on the outside.

A Great Place For Engineers to Help Engineers

RE: X-ray Slot Weld on Assembled Pressure Vessle?

(OP)
I could be wrong, but if we had a crack that didn’t actually make it to the surface, a penetrant inspection wouldn’t show anything would it? I have evidence on another part that suggests the crack would start on the IML and progrates outward, but does not go all the way.

Assume we don’t have easy access to the interior. In my simple mind, why can’t you just take an image at a 45,90,-45 angle with the source and plate on the outside or something along those lines?

RE: X-ray Slot Weld on Assembled Pressure Vessle?

You can. Do it....as long as the source is on the inside and the film is on the outside.

A Great Place For Engineers to Help Engineers

RE: X-ray Slot Weld on Assembled Pressure Vessle?

You can attempt to shoot the whole component if it's small enough. Pipe welds are often shot at an angle (45° for example) with the source one side and the plate the opposite side. It gives an oval image of the entire weld but you might get depth of field issues with some of the image out of focus, plus you'll obviously have both sides of the vessel overlapping on the plate, you'll have to have some way of determining which surface the defect lies on.

If you've got a pressure vessel, surely you've got a nozzle or some other penetration that you can insert a source through?

If you've got legitimate reason to believe there may be a volumetric defect, DPI won't help you, it's just convenient sometimes to discover a surface breaking defect with 'spray paint' before you go through the whole process of radiography.

RE: X-ray Slot Weld on Assembled Pressure Vessle?

You can do any of the above but it is time and money.
If you have no problem with those then go for it.
If you have a specific bulkhead you are worried about shoot from outside, film outside (2 shots).
One slightly off centre to one side, one slightly off centre to the other side.
Very hard to describe what I am trying to say - hope you understand.
Rather than us trying to describe to you - why not ask a reputable NDT company to come and explain what they can and cannot do ?

RE: X-ray Slot Weld on Assembled Pressure Vessle?

DekDee...yes, both source and film can be on the outside; however the shot times will be increased a lot, which will increase the cost of testing.

A Great Place For Engineers to Help Engineers

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close