Openings in blind flanges
Openings in blind flanges
(OP)
I am required to make 4 x 1/8" NPT holes in a class 150 blind flange and would like to know if the rules of UG-36 (Openings in Pressure Vessels) apply to the design.
Thank you.
Thank you.





RE: Openings in blind flanges
jt
RE: Openings in blind flanges
RE: Openings in blind flanges
Best Regards,
Michigander
RE: Openings in blind flanges
It's ASME. And you're two editions out of date. And the referenced table applies to a single, centrally located, opening. Four openings are out of the scope of ASME B16.5. Thus, the fall-back to ASME VIII-1.
Alex-
Shortest span? In what context? You have round holes, right? Although you'll technically have to run the numbers, four 1/8" NPT holes should not be terribly problematic provided they're spaced reasonably far apart.
jt
RE: Openings in blind flanges
I am also required to design an additional blind flange, which has a partial penetration located in the center of the flange, as shown in Sketch 1. I have read the code and I was unable to find anything that would help me register the design. Any suggestions?
Thank you,
Alex
RE: Openings in blind flanges
Consider the thin spot to be a through hole. Now either check the table which Michigander provided (but check the appropriate edition per Section VIII Div. 1) or run opening reinforcement calc's. If either passes, you can reasonably argue that the design is ok.
If both fail, then either add reinforcement (still treating it as a through hole), or you might get some relief from an FEA per U-2(g) and typically evaluated per VIII Div. 2 Appendix 5.
jt
RE: Openings in blind flanges
RE: Openings in blind flanges
jt
RE: Openings in blind flanges
Thank you.
RE: Openings in blind flanges
jt