HOW THIN CAN YOU GO? ASME 8 Div 1 - UG-45 Min Nozz Thkness (note 25) 1

[stanm]

The footnote to UG-45 refers to a material specification that does not use schedule weights acc. to B36.10M. In this case the specification's own 'regular' pipe weight should be used as the minimum thickness even when less than standard weight pipe.

This may be a stretch but can this be used for components such as hygenic tube & fittings that are produced to non B36.10 diameters and thicknesses. Fittings such as tri-clover and ASME BPE tube would be typical examples. In this application the nozzles are not subject to any external piping loads.

 

[CodeRef]

It depends..........define the material type, nozzle diameter, material specification, vessel service requirements, etc.... a can of worms..... and usually requires the AI to dig deep. There isn't a clearcut answer to your question in my opinion.

FYI..... Note 25 to UG-45 references Table 2 of B36.10M (2000) which is non existent. Table 2 is actually Table 1 that changed back in 2000..........anyway...

For example.... Tri Clover offers some fittings that meet ASME Section VIII requirements and some that do not. Each has to be evaluated on a case by case basis and subject to review by the AI. Tri Clover clamp closure designs do not meet the requirements of App 24 of Section VIII the last I checked, yet that may change anytime.
A vessel manufacturer may decide to end the scope of VIII at a stub end and attach the Tri-Clover fitting to remain outside the scope of the Section VIII and still meet the requirements and not have to worry about UG-45 at all. ......That is what I recommend. Keep the nozzle thickness and connection robust only because the service may change in the future and external loadings may become a factor and necessary.


just my 2 cents....

There are three kinds of people in this world. Those who can count and those who can't.
OR
The next statement is False.The previous statement is True.

 

[stanm]

Thanks for the quick response CodeJackal. The main question related to the minimum thickness required by UG-45 and in particular the reference to Note 25. If a tube is supplied to a specification that, for the sake of argument, lists 0.06" as the standard thickness for a particular diameter does 0.06" then satisfy UG-45 as the smallest of UG-45(b)(1), (2), (3) and (4)?

 

[CodeRef]

Here is my short answer..... tubing is not pipe and does not meet the pipe specification criteria as referenced in Note 25 of UG-45. We are talking nozzles in the big picture here, correct?
I am sure the intent of Note 25 is to apply to ......."the pipe weight indicated as regular when so designated in the specification" ...........and ...."if not so designated, the heaviest schedule listed shall be used even though this is less than the thickness of standard weight pipe of ANSI/ASME B36.10M"........ tubing is listed as gauge and pipe is listed by schedule.........Clearly, the lack of a pipe schedule is the intended reason for the note of clarification given in Note 25.

Without considering the whole package and to the extent UG-16(b),(d), and (e) play a role, it is difficult to answer.

It is best to get the opinion from your Authorized Inspection Agency and perhaps a Code Interpretation for your answer.

There are three kinds of people in this world. Those who can count and those who can't.
OR
The next statement is False.The previous statement is True.

 

[CodeRef]

stanm,

For the sake of argument....

If I changed your question to ask the following.........

If a PIPE is supplied to a specification that, for the sake of argument, lists 0.06" as the standard thickness for a particular diameter does 0.06" then satisfy UG-45 as the smallest of UG-45(b)(1), (2), (3) and (4)?

Then I would say you have a good argument! ......without considering pipe undertolerance, corrosion, loadings, lethal service, air, steam or water srvice...etc addressing all the items listed in UG-16



There are three kinds of people in this world. Those who can count and those who can't.

 

[stanm]

CodeJackal,

Thanks for all your your input. I believe that your suggestion to remove the debatable item from the ASME VIII scope is the best plan. The AI, after discussing the point, is as much a victim of code clarity as the rest of us and interpretations take more time than is commercially practicable.

Cheers