Plug valve comprising at least: - a valve body comprising an internal volume associated with at least two communication orifices (121, 122) in communication with respective conduits, - a cylindrical plug of circular section, the plug comprising at least one circuit passing between at least two orifices (211, 212) in the peripheral surface of the plug, at least two orifices (211, 212) of the plug being arranged on the peripheral surface to enable said orifices to be positioned simultaneously opposite respective communication orifices (121, 122) of the valve body, - an intermediate element comprising at least two through-orifices (311, 321) between two opposing surfaces, specifically an inner surface and an outer surface, the through-orifices (311, 321) being arranged opposite respective communication orifices (121, 122) of the valve body, the outer surface of the intermediate element being designed to be positioned opposite the internal volume of the valve body, the inner surface bearing at least one relief surrounding a through-orifice being designed so that the top of the relief forms about the orifice at least one continuous contact surface bearing against the peripheral surface of the plug, - a gasket positioned in compression on an orifice between the intermediate element and the valve body, the valve characterized in that the top of the relief of the inner surface of at least a part of the intermediate element defines a contact surface corresponding to at least all of the points of the virtual intersection between, on one hand, a cylinder parallel to the axis of the through-orifice (311, 321) surrounded by the relief and, on the other hand, a circular cylinder of which the axis coincides with the axis of the plug and of which the radius is less than or equal to the radius of the plug. - a valve body comprising an internal volume associated with at least two communication orifices (121, 122) in communication with respective conduits, - a cylindrical plug of circular section, the plug comprising at least one circuit passing between at least two orifices (211, 212) in the peripheral surface of the plug, at least two orifices (211, 212) of the plug being arranged on the peripheral surface to enable said orifices to be positioned simultaneously opposite respective communication orifices (121, 122) of the valve body, - an intermediate element comprising at least two through-orifices (311, 321) between two opposing surfaces, specifically an inner surface and an outer surface, the through-orifices (311, 321) being arranged opposite respective communication orifices (121, 122) of the valve body, the outer surface of the intermediate element being designed to be positioned opposite the internal volume of the valve body, the inner surface bearing at least one relief surrounding a through-orifice being designed so that the top of the relief forms about the orifice at least one continuous contact surface bearing against the peripheral surface of the plug, - a gasket positioned in compression on an orifice between the intermediate element and the valve body, the valve characterized in that the top of the relief of the inner surface of at least a part of the intermediate element defines a contact surface corresponding to at least all of the points of the virtual intersection between, on one hand, a cylinder parallel to the axis of the through-orifice (311, 321) surrounded by the relief and, on the other hand, a circular cylinder of which the axis coincides with the axis of the plug and of which the radius is less than or equal to the radius of the plug.