If you need to make sure that your custom post type doesn’t have the ‘visual’ tab, you can easily diable it. Suppose you have a custom post type named ‘movie’:
add_filter( 'user_can_richedit', 'disable_for_cpt' );
function disable_for_cpt( $default ) {
global $post;
if ( 'movie' == get_post_type( $post ) )
return false;
return $default;
}