The present invention is directed to a check valve 10, an injection assembly 60, and a beverage preparation machine 100, which is integrated in the injection assembly 60. The check valve 10 of the present invention is made of a body with a first fluid outlet 21, and a plug member 30 that is movable inside the body 20. The plug member 30 has a fluid inlet 32 and a second fluid outlet 31 into a first cavity 11, wherein the fluid can exercise a pressure on a first surface 381 of the plug member 30 opposing the first fluid outlet 21. The fluid pressure can overcome the force of an elastic element 40, which biases the plug member 30 into a closed position. If the force of the elastic member 40 is overcome, the plug member 30 is moved into an open position. In the closed position a fluid path from the cavity 11 out of the first fluid outlet 21 is closed, whereas in the open position said fluid path is open. To move the plug member 30 from its initial closed position to its open position, a fluid pressure on the first surface has to be equal to or larger than a predetermined threshold.