Medium fuel oil at 25°C is to be pumped at a flow rate of 200 m3 / h through a DN 125 Schedule 40 pipe over a total horizontal distance of 15 km. The maximum working pressure of the piping is to be limited to 4800 kPa gage and the pumps being used require an inlet pressure of at least 70 kPa absolute. Determine the number of pumping stations needed to traverse the total distance. Sketch your design. What would be an advantage to changing the pipe to Schedule 80 or Schedule 160?