Bleeder Blind Vent Calculations

[tzh0044]

How is a radial vent hole accounted for when trying to determine t_m in accordance with B31.3 304.5.3?

 

[gotothesky]

Small opening can be ignored.

Sometimes, Vent hole(1/4") is drilled on Tubesheet.
This hole doesn't give any effect to strength calculation.

 

[tzh0044]

After posting, I was talking with a co-worker and started thinking of the small hole in the blind as a pipe. If you were to do the minimum pipe thickness calculations for a 1/4" hole the required thickness at the design conditions were around 0.005".Using this thought process I was about to rationalize ignoring the small hole as you said. Thanks.

 

[KevinNZ]

There will be a limit when the hole size is close to the plate thickness. You have not said where the pressure acts. The hole could be under pressure or the hole could be a vent and the pressure is on the other side of the plate.

I can not think of the design method for this part from FEA.

 

[Cobra17]

I've seen it calculated to 304.5.3 and then they add the hole bore diameter to the thickness.