I need a vent hole, but I don't know the formular for the size.

[DrDarrell]

Hello:

I have a air system pressure of 235 psig. I need to install a vent into the piping and the flow rate through the vent hole has to be 5-scfm. I don't think the size of the plumbing makes a difference, but it is 4 inch class # 300 piping.

Thank you for your assistance,
Darrell

 

Dr Darrell,
You could try looking up "Flow of air in pipes" pages 401 and 402 of Machinerys' Hand book. These appear to be the formula s you are looking for.
Regards David

 

[DrDarrell]

Thank you david,

I did look in my Machinery's Handbook. Unfortunately, I have the 19th edition. I guess it's time to upgrade. I will crunch some numbers with those formulars.

 

[sbc]

If you can measure the flow, why not go large and
install a valve for adjustment?