Abstract: A check valve is described using the venturi effect to enhance the force supplied by forward motion of fluid to fully open the valve, and a variable spring rate spring assembly to enable the valve to close the valve more quickly at the cessation of the forward motion of the fluid, while still allowing forward flow to fully open the valve.

Abstract: The fluid flow check valve uses a flexure plate or plates to accommodate the valve disk's axial motion required to open and close the valve. The flexure plate also limits the disk's motion in any lateral direction, so the valve disk will align properly with the valve seat and seal when it closes. The flexure plate is a flat, axial spring, made by cutting or otherwise manufacturing spiral cuts in a round, sheet metal disk. Valve qualities such as closing force, size and rigidity to lateral disk motion can be modified by varying the number and configuration of the plates, and by modifying plate characteristics. The compactness of the flexural plate design allows for a shorter valve length and cost as well as increased opportunity for flow optimisation.

Abstract: The fluid flow check valve uses a flexure plate or plates to accommodate the valve disk's axial motion required to open and close the valve. The flexure plate also limits the disk's motion in any lateral direction, so the valve disk will align properly with the valve seat and seal when it closes. The flexure plate is a flat, axial spring, made by cutting or otherwise manufacturing spiral cuts in a round, sheet metal disk. Valve qualities such as closing force, size and rigidity to lateral disk motion can be modified by varying the number and configuration of the plates, and by modifying plate characteristics. The compactness of the flexural plate design allows for a shorter valve length and cost as well as increased opportunity for flow optimization.