1. The problem statement, all variables and given/known data Theres a atmospheric tank with a goose neck vent on the top and also an inlet pipe [a diameter 2 inch schedule 40] on the top. There is a compressed air line [from a 50 psi compressor] going into the inlet. The pressure inside the tank should not be above 2 psi. Size the diameter of the goose neck vent. Inlet: P = 50 psi Dinner = 2.07 inches ρ = 4.32 lb/ft^3 Goose Neck Vent: P = 2 psi Dinner = ??? 2. Relevant equations Bernoulli's 0.5ρV2 + P = 0.5ρV2 + P Q = V*A [volumetric flow rate] V*A = V*A [in = out] 3. The attempt at a solution I assumed I could use bernoullis to find the V out from the compressed air line. [Pinside = 50, Poutside = 0 [atmsophere], Vin = 0, Vout=?] I got a Velocity of 68.31300511 ft/s From that and the cross sectional area of the 2.07in pipe I got a Q of 95.79056195 CFM. Next I moved onto the tank. I substituted VinAin/Aout = Vout into Bernoulli's and Solved for Aout. Aout = sqrt( Q2 / (Vin2 - 2*ΔP/ρ) Problem is I ended up getting the same cross sectional area as the inlet. I'm not sure where I went wrong. Perhaps incompressible flow? I appreciate any help.