A valve usable to repeatedly open and close a filling-emptying channel associated with a a beverage container includes a valve body (1). The valve body has a central ring (2) supported by arms (7). The ring includes a hole (4). The valve has a deformable valve plate (5) that includes an outer circumferential beveled edge (10). The valve plate further includes a central conical part (6) configured to engage in the hole. When in blocking relation of the channel, the conical part is engaged in the hole and the valve plate has a convex cup shape. Pulling outwardly on the valve body, changes the convexity of the valve plate and enables it to be disengaged from the valve body.