Is this a vessel question? forum794
Is this a piping question? forum378
'Cause I'll just bet it isn't a software related question!
Are you an engineer? What is your background in evaluating and designing blind flanges? What codes or standards are involved? What jurisdiction will the blind be installed in? Are you serious about the 11" diameter? Are you serious about the 2.5" pipe? Might these be made of steel or are they fabricated from cardboard? What pressures are involved? What fluids are involved? At what temperature? Where will the holes be located?
Sheesh.
jt