4.9 The Alaskan pipeline runs 798 miles from Prudhoe Bay to Valdez. Both cities are at sea level. The design specifications for the pipeline require a capacity of 2.4 million barrels per day (1 barrel = 42 gallons). The crude oil is maintained at 140°F in the pipeline. At this temperature, the oil has a density of 53.7 lbm/

ft3 and a viscosity of 0.00257 lbm/ft·s. The pipe is made of commercial steel.

Along the pipeline are pumping stations capable of boosting the oil pressure.

Each pumping station can provide a pressure increase of 1100 psi.

a. Determine the number of pumping stations required along the pipeline as a function of pipeline diameter (i.e., generate a plot of the number of stations vs. pipeline inside diameter).

b. From the results of (a), specify a pipe size (nominal size and schedule) for the pipeline and defend your selection. Note: The pipe tables in Appendix C may not go high enough in pipe diameter. You may need to do some research to find another source for large-pipe dimensions.