Metal seal for a flap valve

A metal seal for a flap valve, comprising:

• a valve housing with a flow channel, in the flow cross-section;
• a valve disk is disposed such that it can be swiveled around a swivel axis between an open position and a shutoff position,
• a plurality of sealing elements, which can be pressed against one another, and are disposed on the outer circumference of the valve disk and on the inner circumference of the valve housing, and they have at least one annular metal sealing lip, which in the shutoff position bears with elastic preload on an oppositely situated, likewise annular metal mating sealing face, wherein
• either the metal sealing lip is disposed on the outer circumference of the valve disk and the mating sealing face is disposed on the inner circumference of the valve housing or the mating sealing face is disposed on the outer circumference of the valve disk and the metal sealing lip is disposed on the inner circumference of the valve housing, wherein
• the metal sealing lip is produced in an additive method from metal materials having shape, cross-sectional geometry and/or alloy adapted to the different circumferential regions of the metal sealing lip and wherein the metal sealing lip has circumferential portions wherein the flexural strength is different as a function of the distance of these circumferential portions relative to the swivel axis of the valve disk;
• wherein the circumferential portions of the metal sealing lip with largest distance to the swivel axis of the valve disk comprise a first metal alloy having stiffness greater than the stiffness of a second metal alloy of which the circumferential portions of the metal sealing lip have the smallest distance to the swivel axis of the valve disk.