8.2 Energy Losses 8.2.1 Crude oil is flowing vertically downward through 60 m of DN 25 Schedule 80 steel pipe at a velocity of 0.64 m/s. The oil has a specific gravity of 0.86 and is at 0C. Calculate the pressure difference between the top and bottom of the pipe. 8.2.2 A water main is an 18-in-diameter concrete pressure pipe. Calculate the pressure drop over a 1-mi length due to pipe friction if the pipe carries 15 ft/s of water at 50F