Abstract: Provided herein are drainage valves for removing water accumulated in the lower part of fuel tanks of an aircraft. The valves can be affixed in correspondence with a lower skin forming part of the tanks. The lower skin includes recesses for the complementary housing of the heads of the valves that, in combination with some axial fastening nuts, immobilize the valves to that skin. The recesses can comprise a conical structure obtained by deformation of the lower skin, and with the deformation an inner elevated seat is further obtained, on which seat the axial fastening nuts press, maintaining the thickness of the skin in the area where the valves are located, thus preventing the area from weakening as it happens conventionally.

Abstract: The drainage valves have the purpose of removing the water accumulated in the lower part of fuel tanks of an aircraft, said valves being affix in correspondence with a lower skin forming part of said tanks. The lower skin includes recesses for the complementary housing of the heads of the valves that, in combination with some axial fastening nuts, immobilize the said valves to that skin. It is characterized in that the recesses comprise a conical structure obtained by deformation of the lower skin, and with said deformation an inner elevated seat is further obtained, on which seat the axial fastening nuts press, maintaining the thickness of the skin in the area where the valves are located, thus preventing the said area from weakening as it happens conventionally.