Saturated steam feeds from a large pressurised tank to a condenser with a

fixed mass flow rate of $0\mathrm{.}07$ kg$/$s$.$ The length of the inlet pipe is $20$ m$,$ its diameter

is $25$ mm$,$ and it is made from forged steel. The density of the steam is $864$ kg$/$m$3$

and its dynamic viscosity is $1\mathrm{.}57\backslash$times $105$ kg$/$m s$.$

From the outlet of the condenser, saturated water passes through another

pipe. The length of the outlet pipe is $50$ m$,$ its diameter is $50$ mm$,$ and it is made

from forged steel. The density of the water is $1000$ kg$/$m$3$

and its dynamic viscosity

is $1\mathrm{.}14\backslash$times $103$ kg$/$m s$.$

a$.$ Calculate the total pressure drop through both pipes $($ignore the condenser$).$

b$.$ After some time, it is expected that the pipes will rust. Calculate the pressure drop once this takes place. Assume that the diameter of the pipes

does not change significantly.

c$.$ Suggest at least two alternative designs that might avoid corrosion and minimise the pressure drop, and what may be their advantages and disadvantages.