We have been working in the manufacturing and testing of a package of high pressure dual plate check valves, class 1500 and 2500, up to 12″.
Dual plate valves are a check valve design type self operated by the flow pressure. Both semi discs opens in case that upstream pressure exceeds the downstream pressure. This aperture is conditioned by the elasticity of a spring, that automatically shuts the discs when the flow velocity decreases, avoiding system surges and water hammer due to the reversal of the flow. The design f this type of valve is simple and robust, that is the reason why it is a normal choice in a wide range of industries.
The advantages of this kind of non return valves includes a lighter weight than full-body swing check valves or tilting disc check valves. A shorter face to face dimension is a relevant characteristic too, over all in some pipeline systems highly conditioned by the available space. The cost of manufacture and maintenance of a dual plate non return valve is lower than a swing check valve and slamming rates are lower, thanks to the fast reaction of the spring to the pressure drops.
Those non return valves are also called “backflow preventers”. You can find more information about this kind of valves in the “Other Check Valves” section of our webpage.