Check valve, in particular for medical applications

Check valve, especially for medical use, having a first hose connector housing and a second hose connector housing and a diaphragm disk positioned between the two hose connector housings, the diaphragm disk being made of a flexible material which, at an over-pressure in an entry channel of the first hose connector housing, can be lifted from an annular valve seat surrounding an inlet space connected with the inlet channel and which, at an over-pressure in an exit channel of the second hose connector housing, safely and in minimal time can be pressed onto the valve seat, wherein the diaphragm disk is provided with an annular bead at the outer circumferential area which is received in opposed annular grooves of the hose connector housings, wherein the diaphragm disk radially outwardly of the valve seat is provided with openings leading to an exit space and, wherein the wall of the second hose connector housing opposite to the openings is provided with recesses connected to the exit channel,

• characterized in that
• the wall of the second hose connector housing opposite to the openings is provided with a curvature directed away from the diaphragm disk in the direction of the exit channel,
• the exit channel is provided with an entry opening in the wall the diameter of which being smaller than the diameter of the exit channel,
• the exit channel is tapering conically to the entry opening in an transition section and,
• in the transition section the recesses are provided which are connected with the exit space, said recesses being dimensioned such that the difference in the flow section between the entry opening and the exit channel basically is compensated.