Open vent capacity 1

[babak528]

Hi, I have a atmospheric storage tank. I have calculated the required relieveing rates..I need to check and see if the 4" gooseneck on the roof is sufficient! How can I calculate the maximum venting through a goose neck opening?

 

[Samm17]

There is a formula in table C.2 in API 12F for a free vent that you could use.


Q = 1667 Cf A (Pt-Pa)^0.5

where
Q is the venting capacity in standard cubic feet of free air per hour (SCFH);
Cf is 0.5 (the flow coefficient);
A is the hatch area in.2 (A = 44 in.2 for 8-in. round hatch);
Pt is the absolute pressure inside the tank in inches of water;
Pa is the absolute pressure outside the tank in inches of water.

 

[IFRs]

See API 2000 has a lot of good information. Some consider this device critical enough to only use ones with tested and documented flow.

 

[babak528]

thanks