Tapped Hole in B16.5 Blind Flange

[kjf1]

Is there any reference where I can determine what the change (if any) would be to the listed pressure rating of a B16.5 blind flange by tapping a hole in it (of NPS equal to or smaller than the NPS of the flange)? I'd rather not go through the entire calculation per Sec. VIII Div. 1 Appendix 2 if someone else has done the work already.

Thanks.

 

[hero123]

you have to do it urself my dear,

 

[dkoenig]

Refer to ASME B16.5, Table 7 for reducing flange requirements.

 

[SUPERJET]

Refer to ASME 16.36 Section 2.0. It states that ASME 16.5 applies to orifice flanges for pressure and temp. ratings. If you still need the Section VIII Appendix 2 calculation, I have it in MathCAD.