Backflow prevention device with reduced pressure zone

A backflow prevention device to be installed on hydraulic systems comprising:

• an internally hollow body provided with an inlet opening, an outlet opening and an exhaust opening;
• at least one check assembly, comprising a stem, an elastic element and a plate, said check assembly being housed in said body;
• a deformable mobile diaphragm having a disc-shaped form with a central opening and an elbow radial section, said mobile diaphragm being arranged in the flow direction within the body and suitable for interrupting the fluid connection between the outlet opening and the inlet opening and between said inlet opening and the exhaust opening;
• wherein said stem of said check assembly is stabilized and integral with respect to said body;
• and wherein said plate is slidably arranged along said stem and cooperatively placed in surface contact with said mobile diaphragm in such a way to interrupting the fluid connection between said inlet opening and said outlet opening of the body.