The application relates to a valve for a line system, comprising a valve body which forms a valve seat, a line system with a supply line for supplying a fluid to the valve seat and with a discharge line for discharging the fluid from the valve seat, which fluid is under a supply pressure in the supply line and under a working pressure in the discharge line, a closing element which interacts with the valve seat for opening and closing the line system, which closing element releases a throttle cross section between the valve seat and the closing element, a restoring element which applies a restoring force on the closing element, which restoring force presses the closing element against the valve seat in order to close the line system, and a pressure chamber in which the fluid is under a closing pressure to close the line system.