Check air valve

A check valve refers to a type of valve whose opening and closing components are circular or rectangular valve discs that act by their own weight and medium pressure to block the backflow of medium. It belongs to the category of automatic valves, also known as check valves, one-way valves, return valves or isolation valves. The valve disc movement can be divided into lifting and rotating types. Lift check valves have a similar structure to globe valves, except for the lack of a valve stem that drives the valve disc. The medium flows in from the inlet end (lower side) and flows out from the outlet end (upper side). When the inlet pressure exceeds the sum of the weight of the valve disc and its flow resistance, the valve is opened. On the contrary, when the medium flows back, the valve closes. A swing check valve has a valve disc that is inclined and can rotate around an axis, and its working principle is similar to that of a lift check valve.