A valve system (5) connectable to a fluid channel (3), wherein the valve system (5) includes an actuating element (33) and a closing element (17) for selectively closing and opening of the channel (3), wherein the valve system (5) includes a chamber (15) and a movable coupling member (37), wherein at least one section (48) of the coupling member (37) is located within the chamber (15) and the coupling member (37) is capable of moving under its gravitational force into a transfer position in which the coupling member (37) may transfer to the closing element (17) an external force acting on the actuating element (33) towards the closing element (17).
