Complaint
Check valve is a valve referred to the opening and closing parts for the circular disc and by its own weight and medium pressure to block the media flow back.
It belongs to automatic valve class, also known as check valve, check valve, return valve or isolation valve. Disc movement is divided into lifting type and swing type. Lift check valves are similar in construction to globe valves except for the lack of a stem to drive the disc. The medium flows from the inlet end (the lower side) and flows from the outlet end (the upper side). The valve is opened when the inlet pressure is greater than the sum of the weight of the disc and its flow resistance. On the contrary, the valve is closed when the medium flows backwards. Swing check valves have a tilt and can rotate around the axis of the disc, the working principle is similar to the lift type check valve.
Check valves are often used as bottom valves in pumping devices to prevent water from returning. Check valve and globe valve combined use, can play the role of safe isolation. The disadvantage is that the resistance is large, and the sealing is poor when it is closed.
