GDC-5 electro high vacuum flapper valve is mounted in vacuum pipeline to put through or cut off the airflow in vacuum system, or used as a charging vale.是什么意思_GDC-5 electro high vacuum flapper valve is mounted in vacuum pipeline to put through or cut off the airflow in vacuum system, or used as a charging vale.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句