A valve for regulating the flow of a medium, with a housing, with at least three valve discs, wherein at least one valve disc is arranged in the housing so as to be non-rotatable, wherein at least two valve discs are arranged so as to be rotatable relative to the at least one valve disc arranged so as to be non-rotatable, wherein the valve discs each have at least one passage opening, wherein the passage openings are designed in such a way that in a first relative position of the valve discs the flow of the medium is blocked and in a second relative position the flow is maximally open and wherein the passage openings are formed in such a way, that in the second relative position the passage openings of the valve discs expose an opening area of more than 50%, preferably more than 60%, particularly preferably more than 65%, of the area of the flow cross-section.