Leak valve for use in a patient ventilation system, with a valve housing composed of a first housing part and of a second housing part and preferably made of plastic, wherein both housing parts form a fluid channel, which is preferably circular in cross section, and the valve housing comprises: a first connector stub on the first housing part, a second connector stub on the second housing part, and a common, radially outwardly protruding housing area between the two connector stubs (4, 5), an inner annular surface provided in the first housing part, which annular surface, in the connected state of the two housing parts (2, 3), lies opposite an inner annular surface provided on the second housing part, at least one through-opening, preferably a plurality of through-openings, arranged along the circumference, which through-openings are arranged approximately at the height of the outwardly protruding housing area and permit a discharge of the fluid from the fluid channel in the form of a leakage stream, an annular leakage channel for the leakage stream, which leakage channel is likewise arranged approximately at the height of the outwardly protruding housing area, extends along at least part of the circumference of the housing, preferably along the entire circumference of the housing, and is formed by both housing parts (2, 3), a locking mechanism, by means of which the two housing parts (2, 3) can be connected to each other, at least one latching tab, preferably a plurality of latching tabs, curved according to the inner radius of the connector stub and provided as latching mechanism, which latching tabs have a lug at the front and, in the locked state, extend along and bear on the inside of the connector stub and engage with their lug on the outer front face of the connector stub (4 or 5) and ensure axial locking, and wall areas, which are curved according to the inner radius of the connector stub, are provided between the latching tabs and bear on the inner surface of the connector stub (4 or 5), wherein, in the locked state of the two housing parts (2, 3), a clamping connection is formed in addition to the locking connection, characterized in that a plurality of bearing projections are provided along the circumference of the annular surface (6 or 7). a first connector stub on the first housing part, a second connector stub on the second housing part, and a common, radially outwardly protruding housing area between the two connector stubs (4, 5), an inner annular surface provided in the first housing part, which annular surface, in the connected state of the two housing parts (2, 3), lies opposite an inner annular surface provided on the second housing part, at least one through-opening, preferably a plurality of through-openings, arranged along the circumference, which through-openings are arranged approximately at the height of the outwardly protruding housing area and permit a discharge of the fluid from the fluid channel in the form of a leakage stream, an annular leakage channel for the leakage stream, which leakage channel is likewise arranged approximately at the height of the outwardly protruding housing area, extends along at least part of the circumference of the housing, preferably along the entire circumference of the housing, and is formed by both housing parts (2, 3), a locking mechanism, by means of which the two housing parts (2, 3) can be connected to each other, at least one latching tab, preferably a plurality of latching tabs, curved according to the inner radius of the connector stub and provided as latching mechanism, which latching tabs have a lug at the front and, in the locked state, extend along and bear on the inside of the connector stub and engage with their lug on the outer front face of the connector stub (4 or 5) and ensure axial locking, and wall areas, which are curved according to the inner radius of the connector stub, are provided between the latching tabs and bear on the inner surface of the connector stub (4 or 5), wherein, in the locked state of the two housing parts (2, 3), a clamping connection is formed in addition to the locking connection, characterized in that a plurality of bearing projections are provided along the circumference of the annular surface (6 or 7).