Valve for fluids, preferably for gases

A valve for fluids or gases, having at least stage comprising:

• an inlet passage and an outlet passage for a fluid within which a primary volume (V) is defined;
• a shutter interposed between the inlet passage and the outlet passage and movable along a movement direction (L) between an open position, in which it allows the flow of the fluid from the inlet passage to the outlet passage, and a closed position, in which it prevents the flow of fluid;
• an actuating means movable along the movement direction (L) and operatively active on the shutter for moving the shutter itself into the open position;
• a first stabilization membrane interposed between the shutter and a fixed portion of the valve;
• said first stabilization membrane being conformed so as to expose an active wall to the fluid present between the outlet passage and the shutter;
• said active wall having an outer surface arranged at the outlet passage and facing towards a rear surface of the shutter opposite the inlet passage;
• said outer surface being conformed so that the pressure of the fluid acting on said active wall generates a force that is lower than the force generated by the pressure of the fluid acting on the rear surface of the shutter so as to prevent the fluid opening the shutter, when the shutter is in the closed position and when the valve is in a back pressure condition, in which the fluid flows from the outlet passage to the inlet passage;
• wherein the valve further comprises a secondary volume (W) arranged along the movement direction (L) and separated from the primary volume (V) by the first stabilization membrane;
• said shutter having a through hole configured to put said secondary volume (W) in fluid connection with said inlet passage when said shutter is in the closed position and when the valve has a normal pressure condition;
• said actuating means comprising an interstitial space in fluid communication with said through hole for the passage of the fluid towards said secondary volume (W), and
• a second stabilization membrane arranged snap-fitted into the secondary volume (W) for splitting it into an auxiliary volume (U) and an intermediate volume (Y);
• said intermediate volume (Y) being comprised between the first stabilization membrane and the second stabilization membrane for containing air at a pressure substantially equal to an atmospheric pressure value.