NDT's Mandatory/Required by ASME Code 5

[rogervm]

I need help to understand what is mandatory by the ASME Code about Non Destructive Testing (NDT) during the fabrication of pressure vessels. When a technical specification for a Pressure Vessel is prepared, How to know exactly what NDT’s have to be included in that specification as mandatory?, What part of the ASME Code describe the NDT’s requirement?

Thanks in advance.

 

[metengr]

Do you have access to a copy of the ASME Boiler and Pressure Vessel Code? Specifically, Section VIII, Div 1 Part UG and Part UW?

 

[rogervm]

Yes I have.

 

[metengr]

The information is all there in Part UW.

 

[rogervm]

Well Thanks.

 

[lostsailor]

rogervm
To expand on metengr's reply,in addition to UW, you are also going to need to review the applicable sections in
Subsection C and the Appendices applicable to the NDE methods in question.
Regards,
RLS

 

[rhg]

Basically a technical specification is used to supplementary NDT ( acoustic emission, leak testing. ultrasonic testing for plates/forgings/pipes etc.)
When no supplementary NDT is necessary only put " NDT according to ASME VIII Div. 1".
Please see ASME V when you design a pressure vessel

rhg

 

[weldtek]

In conjunction with the applicable Code sections you have to know what is required in the calcs. It is possible to design and stamp a vessel to the ASME Code with NO NDT performed.

 

[rhg]

weldtek

It is impossible to design and stamp a pressure vessel to the ASME code with NO NDT performed: Visual examination, hydrostatic test are NDT and mandatory

rhg

 

[weldtek]

Well rhg, I have to agree with you. Shame on me for overlooking the obvious. I'm so use to those two methods I completely overlooked them.

 

[JR97]

rhg,

Sorry to nitpick, but I don't consider hydrotest to be a NDT. Hydrotest is a proof test. I view NDT as being limited to those methods referenced in Section V. Visual is, hydrotest is not.

Jr97

 

[JoeTank]

JR97
I think it's reasonable to consider the hydro as NDE. The test does not render the part unuseable. In fact the hydro pressure specified is limited to that which would typically cause damage. The ASME Code defines a proof test and it is completely different than a hydro.

Joe Tank

 

[rhg]

Joe Tank: you are 100% OK

JR97: please see ASME V article 30 standard terminology for NDE SE-1316
"NDT: the development and application of technical methods to examine materials or components in way that do not impair future usefulness and seviceability in order to detec, locate, measure, and evaluate flaws; to assest integrity, properties, and composition, and to measure geometrical characters"

regards

rhg

 

[JR97]

Joetank & rhg,

I am afraid I am sticking to my position. (Please humor me one more time.) Section V, Article 1 paragraph T-110 lists the NDE methods recognized by the Code ... Hydrotest is not listed. Also, Referring to Section III, NDE requirements are detailed in Article NB-5000 (Examination), hydrotest requirements are detaile in Article NB-6000 (Testing).

I believe classifying hydrotest as an NDE method confuses the issue. Would you extend the Section NB-5500 (Qualification and Certification of Nondestructive Examination Personnel) to hydrotest personnel?

I concede I misused the term 'proof test' in my earlier post. The Code classifies hydrotesting as a 'pressure test' (ref. NB-6111).

Pressurizing the inside of a vessel can be a form of leak test, which is an NDE method - "pressure change test" per Section V, Article 10, Appendix VI. However, the test time cannot be a blanket 10 minutes as required by the Pressure test of NB-6000. To be effective as a leak test the test pressure, volume, and minimum detectable pressure drop (after consideration of temperature variations) must be correlated to the required leak rate to determine the test time.

Thanks for humoring my nitpick and I am sorry for allowing this thread to drift off topic.

JR97

 

[EmilGies]

Not that my opinion really matters, but I agree with JR97. Hydro when successfully passed is non-destructive. Section V NDE does not affect the vessel regardless of the test results.

 

[JoeTank]

JR97,
You're right. It's a test, not an examination.


Joe Tank

 

[GenB]

Gentlemen:
It is my belief that hydro is part of an NDE or NDT.
that's how is listed in my dwgs
and ASME team leaders are happy with that
genb

 

[gr2vessels]

Typical team leaders.. Preaching water, drinking wine. Also, I tend now to change my old views and agree with JR97...
Cheers,
gr2vessels

 

[metengr]

Hydrotesting is not a nondestructive test method, never was and never will be. Hydrotesting is used to assure adequacy of design, no gross material or weld defects and one salient feature is local strengthening (ie yielding) of the component material.

 

[metengr]

.....forgot to finish my very last sentence by mentioning that local yielding would only ocurr locally at regions of stress concentration or at geometric discontinuities. This is a benefit because local strain hardening increases the stregnth.