calculate vent rate for tank vent

[lkb3]

I have a tank that will hold a non-flammable liquid.
I know the flow rate out.
I have a "mushroom" vent for normal venting. I know the cross-sectional free area of said vent. I do NOT have a rated flow for the vent. How do I determine if this vent will be sufficient? This is the first time I've had to do this - everything else I've had a rated capacity for the vent...
Is there a way to figure this out, or should I simply look to a different vent with a known capacity?
Thank you.

 

[Duwe6]

If the vent is made by a reputable manufacturer, and not modified you can use "hillbilly" engineering. If your outlet is 3", you need a 3" or bigger vent. Don't use any pallet weights on the vacuum/pressure pallets [assuming it is a Conservation Vent] without calculating the max pressure and vacuum your tank will withstand. Unloaded pallets will relieve at about 0.5 ounces per square inch, which should be acceptable for about any tank.

Shand & Jurs, Groth, Protectoseal.

 

[zskmec]

Or, you can use API 2000. Granted it applies to petroleum and petroleum products but its a good guide to start with. The tables and formulas will help you get the required venting capacity.

zsk

"You are unique, just like everybody else." - T-shirt quote

 

[MJCronin]

Consider re-posting in the "Storage tank Engineering" forum....

 

[ukd]

As zskmec posted, check API 2000...In a tank,due to inflow to the tank, vapour will be vented out (Outbreathing) through the vent line and due to outflow from tank air will be sucked in (Inbreathing) and you have to figure out which is the dimensioning case for vent line sizing..then you have a requirement of allowable back pressure for vent line...suggest API 2000...