Openings made from plate per Section VIII-Div 1.
Openings made from plate per Section VIII-Div 1.
(OP)
An Authorized Inspection Agency is telling me that when welding openings manufactured from plate (in this case SA516-70 manway into an LPG storage tank) directly to the vessel shell or head per Figure UW-16.1(i) that act as a integrally reinforced opening that is calculated as an optional type flange per Appendix 2 must also meet the requirements of UW-13(f) (1) and (2) for material testing. I am arguing that the nozzle is not a Hub type flange as described in UW-13(f) and that it is not used for tubesheet applications as described in appendix 20 therefore does not require test specimen per Fig UW-13.3. Has anyone encountered this problem before??





RE: Openings made from plate per Section VIII-Div 1.
I assume in this case the SA-516-70 plate is rolled to a ring, welded the seam, then this cylinder forms the neck of the manway. Sounds like integral reinforcement as long as the weld to shell meets those rules. But where does the Appendix 2 flange issue come in?
What is attached to the end of the nozzle neck?
RE: Openings made from plate per Section VIII-Div 1.
Sorry for the confusion.
RE: Openings made from plate per Section VIII-Div 1.
Brian
Pressure Vessels and Autoclave Systems
www.mcabeeconstruction.com
The above comments/opinions are solely my own and not those of McAbee Construction.
RE: Openings made from plate per Section VIII-Div 1.
Appendix 2, para 2-2(d) addresses *hubbed* flanges, not, say, slip-on flanges and doesn't allow us just to cookie cutter them out of plate. But on the other hand, the loads acting on your flange are different from those acting on an App 2 flange (well, I guess a reverse flange is similar).
So, I can't point to a Code paragraph to support what the AI says. Sounds good though.
RE: Openings made from plate per Section VIII-Div 1.
you are likely referring to fig UW-16(p), or possibly your flange is inserted into a hole with the same diameter as the OD of the ring (can't find a figure directly applicable to this, possibly your ref.to UW-16(i) is correct, though this doesn't exactly represent your case IMO).
Now can't see where's the hub, so don't understand the position of your AIA. The wording of UW-13(f) is very clear, you must have a machined hub for it be applicable (whilst the fact that a tubesheet or flat head is referenced is less important).
The worryings behind UW-13(f)(2) are clearly two:
1) when the hub is machined from plate, the resistance of the hub to tearing may be impaired by defects in the lamination
2) point 1 is important only if the pressure load passes, at least partly, through the hub (but of course the hub is normally there only for that).
Neither of these two points is applicable to your flange, if my understanding of your geometry is correct.
prex
http://www.xcalcs.com
Online tools for structural design
RE: Openings made from plate per Section VIII-Div 1.
Many thanks.
RE: Openings made from plate per Section VIII-Div 1.
RE: Openings made from plate per Section VIII-Div 1.