You Do Need power plug adapter while traveling from Belgium to American Samoa.

Here is Why You Need An Adapter

The outlet and plug type used in American Samoa are A, B, F and I and in Belgium are C and E. This is how they look like.

Belgium

In Belgium, outlets of type C and E are in use.

Type C

Type E

American Samoa

In American Samoa, outlets of type A, B, F and I are in use.

Type A

Type B

Type F

Type I