Nonventing Overflow

[SEJohn]

I have an existing 8' diameter vertical sulfuric acid tank venting to atomosphere. Client would like to add a desicant pot to the roof vent. We don't want the overflow to do the breating, so how do we close the overflow to breating, but still allow it to act as an overflow? What is the industry standard for this?
Thanks in advance.

 

[JStephen]

For water tanks, it is common to use a flap valve, but that would not normally be used for an acid tank. There, the main motivation is to keep bugs out, not to absolutely prevent vapor from passing.

You might check the Tideflex-type check valves, and see if they would be appropriate for the application:

http://www.tideflex.com/tf/index.php/content/view/231/366/

You could possibly use a liquid seal at the bottom of a riser pipe.

 

[Duwe6]

I would use a wafer-check valve on the overflow line, in either the horizontal portiin of the line, or - preferred - on the rising flow portion of the vertical line. NOT on the vert where the flow is down. If on the horiz portion, make sure that the wafer-check is springloaded.

 

[SEJohn]

Thank you for the help.