How portable pumps are used?

A. Potable pumps are used in parallel with the main Framo pump to discharge the tank in a short time
B. When main pump is not working, portable pumps are used to discharge the liquid cargo to the terminal
C. Potable pumps are used in series with the main Framo pump to discharge the tank with large pressure.
D. When main pump is not working, the portable pump is used to transfer the cargo from this tank to another empty tank, where the main pump is working
E. When main pump is not working, the portable pump is used to transfer the cargo from this tank to another tank, having the same cargo, where the main pump is working