PLATE FOR FLANGE 1

[marsich]

Heat exchanger ASME CODE (no U stamp)
Can I use a plate (SA516Gr60) to machine a shell/channel flange?
For a welding neck type? And for a loose type?
Where is forbidden? ASME VIIIdiv1?

Thank you all.

 

[deanc]

You need to read Appendix 2

 

[jte]

With no U stamp, you can do pretty much anything you want. Be sure to put the apprentice welders on this job. They need the practice before they will be qualified to work the U stamped jobs!

jt

 

[moltenmetal]

"ASME code (no U stamp)" I would interpret to mean "to be designed and fabricated in accordance with ASME, but neither stamped nor registered".

I'm with deanc: read Appendix 2.

Just in case jte has convinced you that you can do what you like, and in case you don't have a copy of the code, I'll hazard a simple answer:

Code gurus: PLEASE read and correct this statement if it is incorrect- but my understanding is as follows:

For a hubless flange (i.e. a loose flange or slip-on with two welds), approved plate is OK. For a hubbed flange, you can only use plate (or forged bar!) if the correct NDE is done FIRST, before machining, to demonstrate that there are no flaws such as laminations etc. in the material. Presume this also applies to a tubesheet, since it too is in tension across potential laminations in the material at the shell to tubesheet joint.

 

[marsich]

I agree (my client, too): "ASME code (no U stamp)" means "to be designed and fabricated in accordance with ASME, but neither stamped nor registered"

I have a copy of Appendix 2 (addenda 06) but my interpretation is different (maybe ‘cause of my bad English).
About hubbed flange: if I want to use a plate I’ve to respect the following step:
(a) UT on the plate
(b) Roll the plate (calander) in order to obtain a ring with the axis parallel to the original flat plate
(c) Joints the bevel
(d) MT or PT
So, the thickness of the starting plate is the upper limit of difference from the ext. and the int. diameter of the flange.
About hubless flange there’s no restriction.
Please correct me.
Now is rising the same question about the tubesheet…

 

[SnTMan]

marsich, your understanding of Apx 2 is correct if (c) means full penetration weld of the ring.

About the tubesheet, if it is gasketed both sides (non-welded) there is no restriction, although NDE of the OD is not a bad idea.

If it is welded to a cylinder forming a corner joint NDE is normally required for the bevel before welding and the OD after, see UG-93(d)(3)

If a hubbed tubesheet, I wouldn't but it can be done, see UW-13(f)(2)

Regards,

Mike

 

[marsich]

Thank you all.
Ivan