氣壓符號與實體識別

＃２Ｐ／２Ｗ

＃３Ｐ／２Ｗ

＃５Ｐ／２Ｗ

＃５Ｐ／３Ｗ／ＣＣ

closed centres

＃５Ｐ／３Ｗ／ＯＣ

open centres

＃５Ｐ／３Ｗ／ＰＣ

pressure centres

特殊封口應用

＃２Ｐ／２Ｗ與５Ｐ／２Ｗ互換性

＃３Ｐ／２Ｗ與５Ｐ／２Ｗ互換性