Multiple instrument penetrations in a blind flange
Multiple instrument penetrations in a blind flange
(OP)
I am currently reviewing a Section VIII pressure vessel design and am stumped as how to verifiy the possible need for reinforcement in a 6" 300# blind flange that is drilled through the center with multiple penetrations. The blind flange has twenty 7/16" diameter penetrations that are spaced center-to-center 1.25" and are contained in 5 rows spaced 1.25" apart. All of the rows of penetrations are encompassed within a radius of 3-3/8" from the center of the flange. The flange (before drilling penetrations) was a standard 6" 300# RF blind flange per B16.5. Since the flange does not appear to be part of the pressure vessel proper per Section VIII paragraph U-1(e)(1)(c), I have not found an applicable code section that deals with multiple openings in a blind flange. I have looked in B31.1, B31.3 and B16.5. Have I overlooked an applicable code section? Does anyone have Code insights as to the correct way to determine the minimum thickness and whether reinforcement is required? I would certainly appreciate guidance from anyone who has dealt with instrument penetration flanges.





RE: Multiple instrument penetrations in a blind flange
RE: Multiple instrument penetrations in a blind flange
RE: Multiple instrument penetrations in a blind flange
What is the TEMA document? Would you happen to have a spreadsheet version of this calculation? Again, thank you for the input!!!
RE: Multiple instrument penetrations in a blind flange
RE: Multiple instrument penetrations in a blind flange
For reinforcement I will apply the requirements of UG-39. Is my opinion that you can use the same criteria even if you have multiple openings, providing the area of reinforcement do not overlap.
Sorry I can not justify the use of a standard B16.5 flange.
RE: Multiple instrument penetrations in a blind flange
RE: Multiple instrument penetrations in a blind flange
You also cannot use a "blind" flange as a tube sheet. There have been interpretations issued to that effect.
RE: Multiple instrument penetrations in a blind flange
I have used UG-34 and UG-39(a to e) for the same purpose.
Good Luck