how to sync the system table with pg_dump

Hi,

I tried to use pg_dump to restore (sync) a database, but I noticed that
the system table pg_namespace was not synced.

I tried the following pg_dump command to just restore that table without
success either.

Does pg_dump support for the system tables or something I missed ?
Is there another way to sync the system tables ?

Thanks,
Gary

% pg_dump -t pg_namespace -h nppdist nppsd3 | psql -h nppsds1 -d nppsd3
SET
SET
SET
SET
SET
SET
SET
SET
ERROR: relation "pg_namespace" already exists
ALTER TABLE
ERROR: duplicate key violates unique constraint
"pg_namespace_nspname_index"
CONTEXT: COPY pg_namespace, line 1: "pg_toast 10 \N"
ERROR: permission denied: "pg_namespace" is a system catalog
ERROR: permission denied: "pg_namespace" is a system catalog
REVOKE
REVOKE
GRANT