Spherical Tank

[Abeerj]

Hi,

Testing the welding during construction should it be RT or UT ?

Thanks

 

[kingnero]

Yes.

 

[Tmoose]

I think in the US at least there are Codes that will make the answer clear.

What types of welds, and what material?

The description as a "spherical tank" makes me think having two sided access could be either very easy, or darned near impossible.

http://www.esabna.com/us/en/education/blog/radiographic-and-ultrasonic-testing-of-welds.cfm

 

[Abeerj]

Hi

Thanks for your answer....actually the spherical tank is shown in the attached file

 

[fegenbush]

A vessel similar to the one you have shown would commonly be constructed to ASME Section VIII Division 2. This standard is detailed as to the radiographic and ultrasonic inspection required. These projects are quite involved and cannot be answered by individuals who do not have a thorough understanding of the requirements.

 

[Abeerj]

Dear Mr.fegenbush

Yes it is constructed to ASME Section VIII Division 2

The contractor is insisting on having UT instead of RT , I went through the standard and I was confused of categories ..so I asked for help.

By the way ...I didn't understand what you've written: These projects are quite involved and cannot be answered by individuals who do not have a thorough understanding of the requirements"".

 

[IRstuff]

What fegenbush means is that detailed questions about a project that no one else has the requirements for cannot be accurately answered.

TTFN
I can do absolutely anything. I'm an expert!
homework forum: //

http://www.engineering.com/AskForum/aff/32.aspx

faq731-376 forum1529

 

[vhengr]

Based on the requirements (i.e. acceptance criteria, pros and cons of weld flaws/imperfections, type of weld, thickness of plates, recordkeeping of test results, cost and time schedule etc ) one has to take a call for appropriate NDT method.
UT and RT have their distinct advantages and the method which is best suited should be used. Both tests are good enough to detect volumetric discontinuities.

Though State-of-art scenario today is still in favor of RT; Ultrasound Test is commonly used for testing thicker sections accessible from one side only, and can often detect finer lines or planar defects which may not be as readily detected by radiographic testing.
(RT cannot detect discontinuities that are located perpendicular to the rays & UT cannot detect discontinuities that are parallel to the ultrasonic beam)

Cheers! -VH

 

[Abeerj]

vhengr Thanks a lot

 

[boo1]

Go back to the Kobelco contracting document and review the requiremnts