Patent ID: 8984673
Filing Date: 2015-03-24
Classification: E03C,F16K,Y10T

Abstract:
1. An air pressure equalizing flap valve, including a conduit with an inlet area, and an outlet area, a seat located in said conduit and a flapper that is movable between, on the one hand, a closed position in which it cooperates with said seat to prevent air flow into said conduit from the outlet area towards the inlet area and, on the other hand, an open position which allows air flow into the conduit from the inlet area towards the outlet area, the flapper being able to move from its closed position to its open position due to the effect of negative internal air pressure between the outlet area and the inlet area, said conduit being able to admit flow in which, for any path between said inlet area and said outlet area, the velocity vector at a given point forms an angle with the velocity vector in the inlet area which increases with the distance from the inlet area, the angle between the velocity vector in the outlet area and the velocity vector in the inlet section being between 80° and 150°, and in which the flapper, in the closed position, forms an angle between 0° and 70° with the normal of the outlet area, characterized in that the flapper has a thickness between 0.4 mm and 6 mm, wherein the flapper is movable and the movement is achieved by deformation, wherein the flapper has at least one notch.