HI,I'm working on my college project (The project is a plumbing system to drain a 1-m3 tank in the shortest time ). I use the discharge to atmosphere element at the end of the project but I'm really confused with this element's input data like [Flow (Typical) & Pressure drop (Typical)]. I don't know what is this inputs means I just have the elevation of the discharge point and pressure. I read (Modeling Reference - Discharge To Atmosphere) still got no answer. I also want to know is there a feature in WaterCad can Compute time to Drain or Empty a Tank.