Device for dynamic control of a water flow

A device for the dynamic control of a flow, comprising, in one body, one inlet chamber, one outlet chamber, one piston, which is positioned between the inlet chamber and the outlet chamber and is flexible between a first position that is moved relative to the inlet chamber, wherein the piston in the first position restricts the flow between the inlet chamber and the outlet chamber, and a second position that is moved relative to the outlet chamber, wherein the piston in the second position does not restrict the flow between the inlet chamber and the outlet chamber, and a retaining spring that acts upon the piston in the first position, wherein the inlet chamber is at least partially circular and surrounds the piston, that the piston involves a cylindrical jacket section that is positioned in the area of the inlet chamber and penetrated by restricted radial passages, and a transversal section, which defines an intermediate chamber and is penetrated by an axially restricted passage, and that the restricted radial passages, the axially restricted passage, and the retaining spring are proportioned relative to each other in such a manner that the effect of the spring is essentially equal to the force that tends to move the piston from the first position to the second position when the maximum flow is diverted, which could cause an instability in a thermostatic mixer, and the intermediate chamber within the body of the device is restricted by an inlet connection, in which an inlet chamber is defined and axially circumferential passages are provided, which flow into the circular inlet chamber, which surround the piston.