亚洲欧美日韩在线-激情av在线-av在线免费观看网址-久久久久久91-老外毛片-黄色你懂的-久久亚洲精品小早川怜子-意大利性荡欲xxxxxx-国产色一区-国产精品白虎-看一级黄色大片-无码任你躁久久久久久老妇-亚洲av无码专区在线-玖玖热在线视频-天天操天天爽天天干

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.