Patent ID: 7419587

Claim:
A water purification device comprising: a fluid pump; a diaphragm unit having a diaphragm, which separates a primary side from a secondary side; and a consumer having a pressure requirement; wherein the fluid pump is connected with the primary side and the consumer is connected with the secondary side, and the fluid pump supplies the pressure for the consumer through the diaphragm; wherein the primary side is connected with a pressure control device, which controls the pressure on the primary side in dependence on the pressure on the secondary side; wherein the pressure control device includes a control valve, which is connected to the diaphragm unit; wherein the control valve has a valve element, the valve element being acted upon by the pressure on the primary side in either an opening or a closing direction, and by the pressure on the secondary side in the other of the opening or the closing direction; and wherein the control valve is arranged in a connection line downstream of the fluid pump and upstream of the diaphragm unit.