PLATE FOR FLANGE
PLATE FOR FLANGE
(OP)
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.
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.





RE: PLATE FOR FLANGE
RE: PLATE FOR FLANGE
jt
RE: PLATE FOR FLANGE
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.
RE: PLATE FOR FLANGE
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…
RE: PLATE FOR FLANGE
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
RE: PLATE FOR FLANGE
Ivan