成人午夜日韩福利_极品少妇做受_黄色网站免费涩涩屋_欧美亚洲一区自拍_青青青免费在线视频_pc28算账机器人软件哪里买_中国免费黄网站日韩_国产精品视频网址大全_国产亚洲 欧美 在线_99日韩精品一区


Vacuum damage valve

Used in container or pipeline, when the pipeline or container is under negative pressure or the vacuum is gradually increased due to the system running or stopped, the valve can be automatically opened to destroy the vacuum effect, so as to prevent the pipeline and other equipment from being deflated, Phenomenon, to protect the safety of equipment.