日韩免费视频-欧美在线一区二区三区-天天激情-草久在线-日本做受-男人操女人免费视频-国产精品美女在线-99色网-美女av片-色屁屁草草影院ccyycom-91精品推荐-天天插综合网-欧美第一页在线-亚洲精品污一区二区三区-大奶一区二区-h在线网站-高h喷水荡肉爽文np肉色视频-一级做a爰片-少妇被中出-久久久久人妻一区-香蕉a视频-国产又爽又猛又粗的视频a片-亚洲第一成年网-久久久精品波多野结衣-爱爱视频一区

GFD/FQ multi-function fire-retardant breathing valve produced and sold by Baigang Valve Group is a ventilation device installed on the top of a fixed storage tank.Reduce the evaporation loss of oil and other liquids, control the tank pressure, to prevent the tank from being damaged by overpressure or vacuum.GFD/FQ multi-function fire-retardant breathing valve can also prevent the external flame from entering the role.GFD/FQ multi-function fire-retardant breathing valve is suitable for oil, petrochemical materials and other media, also suitable for cold areas, breathing valve operating pressure before leaving the factory are strictly tested and tested, users are not allowed to change or change the weight of the valve disc.Type of single breath valve, single suction valve, breathing valve, all kinds of structure can be combined with the flame arrestor structure, can also prepare the required nozzles.