Q.How to calculate back pressure ?

Back pressure is mainly due to the resistance faced by the fluid along its path from ship's manifold to shore's shore tank. Certain factor directly propotional to back pressure are

- Bends in the Pipe line

- Height of Shore tank(1 bar is 10meter of water colum)

- Length of Pipe line

- Viscocity of the Liquid

- Density of the liquid

-Diameter of Pipe( small size pipe more resistance)

Back pressure is the summation of all the resistance.

Some oil tanker terminals will advice the ships to maintain certain Pressure at the ships manifold during dischargeing operation. Terminal will decide this value depending upon their tanks location.

All the tankers have a maximum working pressure for its manifold, So ships cannot exceed above that pressure while discharging (Cargo pipe pressure test certificate).

In those case terminals may use a booster pump to push the liquid from terminal's side to shore storage tank.