GB/T586-2015 Cast steel check valve 

     Check Valve refers to a valve whose opening and closing parts are circular discs, which rely on its own weight and medium pressure to block the backflow of the medium. The Marine Check Valve is an automatic valve also known as a check valve, check valve, return valve or isolation valve. The movement mode of the valve disc is divided into lifting type and swing type. The structure of the lift check valve is similar to that of the globe valve, but it lacks the valve stem that drives the valve disc. The medium flows in from the inlet side (lower side) and flows out from the outlet side (upper side). When the inlet pressure is greater than the sum of the weight of the disc and its flow resistance, the valve opens. Conversely, when the medium returns, the valve is closed. Swing check valves have a swash plate that can be rotated about an axis. Its working principle is similar to a lift check valve. Check valves are often used as foot valves in pumping units to prevent…