To restore a database and have the tables owned by a different user use the pg_dump command like this:
as root user run:
su postgres
pg_dump -Fc database_name > database_name.dump
exit
Now you can restore using pg_restore.
createuser -P -s -e new_user
createdb -O new_user new_database
su postgres
pg_restore -v -d new_database -O -U new_user -h localhost database_name.dump
exit
After this don’t forget to modify the new_user and drop the superuser privilege.