You Do Need power plug adapter while traveling from Sudan to Liberia.

Here is Why You Need An Adapter

The outlet and plug type used in Liberia are A, B, C and F and in Sudan are C and D. This is how they look like.

Sudan

In Sudan, outlets of type C and D are in use.

Type C

Type D

Liberia

In Liberia, outlets of type A, B, C and F are in use.

Type A

Type B

Type C

Type F