Valve device

A valve device comprising:

• a valve body delimiting a housing compartment;
• an entry aperture and an exit aperture for a fluid;
• a chamber arranged to allow a transit of a fluid between the entry and exit apertures;
• a piston disposed in said compartment, the piston being mobile between a closing position in which the piston prevents the transit of the fluid between the entry and exit apertures and an opening position in which the piston allows the transit of the fluid through said exit aperture;
• a spring operatively associated with said piston and disposed outside said chamber,
• wherein in the closing position of said valve device and in a position of maximum release of said spring, a free space is defined between a head surface of said piston and an entry wall of said valve body, the free space directly facing said entry aperture;
• and
• further wherein a portion of a periphery of the entry wall has a reduced diameter thereby defining a shoulder, the shoulder sized and positioned to abut the head surface of the piston when the piston is in the closing position, and further wherein the shoulder delimits an extent of the reduced diameter of the portion of the periphery of the entry wall, thereby defining an outer extent of the free space.