You Do Need power plug adapter while traveling from Pitcairn Islands 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 Pitcairn Islands is I. This is how they look like.

Pitcairn Islands

In Pitcairn Islands, outlets of type I are in use.

Type I

Liberia

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

Type A

Type B

Type C

Type F