The minimum distance from the end of blind thread hole to the inner surface of the flange (inner surface of the container)

[mechengineer]

Hi experts,
Could you please advise me on the minimum required distance from the end of a blind threaded hole to the inner surface of a flange (i.e., the pressure-retaining surface of the vessel)? Also, could you provide the relevant design codes and engineering standards that apply?

Thanks

 

[LittleInch]

I know of no code or standard that allows for part wall drilling of holes when connected to the fluid retaining part.

B16.5 section 6.11.2 allows for through wall holes and has recommended min thread lengths as tapped holes into flanges, especially blind flanges, is common. Part wall holes are not common.

Hence this action is not permitted and sounds positively hazardous.

What exactly are you trying to do?

 

[David3399]

I know of no code or standard that allows for part wall drilling of holes when connected to the fluid retaining part.

Tell tale holes...Sec. VIII Div. 1 - UG-25.

 

[r6155]

ASME VIII -1
UG-43
d) Studded Connections. Connections may be made bymeans of studs. The vessel shall have a flat surface machined on the shell, or on a built‐up pad, or on a properly attached plate or fitting.
The distance from the inside surface of the vessel to the bottom of a drilled hole to be tapped shall not be less than the corrosion allowance plusone‐fourth of the minimum required wall thickness............