Extracted text: Example problem for pressurized tank. Figure below was used to derive the equation used to determine the time it takes to empty the tank from h, to h,. The equation was derived by considering that the tank is open and hence at 0 gage pressure above the water. If the tank is sealed and pressure of 5.0 psig is above the water in the tank, compute the time required to empty the tank if the original depth is 15 ft. The tank diameter is 12 ft and the orifice diameter is 6 in. dh Note: If the tank is sealed with a pressure, p, above the fluid, the piezometric head p/y should be added to the actual liquid depth before completing the calculations called for in the equation. D, ys rom syste by D,