Water at 708F is flowing in a film down the outer surface of a 4 in. OD vertical tube at a rate of 1 gpm. What is the thickness of the film? What diameter of pipe would be required to transport a...

Water at 708F is flowing in a film down the outer surface of a 4 in. OD vertical tube at a rate of 1 gpm. What is the thickness of the film?

What diameter of pipe would be required to transport a liquid with a viscosity of 1 cP and a density of 1 g/cm3 at a rate of 1500 gpm, if the length of the pipe is 213 ft, the wall roughness is 0.006 in., and the total driving force is 100 ft lbf/ lbm?