Ball valve

A valve for intercepting a fluid in a duct, the valve comprising:

• a valve body comprising an annular wall delimiting an internal compartment, an inlet and an outlet for the fluid being defined in the internal compartment, and a first shoulder and a second shoulder, internally radially protruding from the annular wall, a space being defined between the first and second shoulders;
• a ball shutter, accommodated with clearance in the space of the internal compartment, having an external surface and being rotatable about a rotation axis between an angular closing position and an angular opening position;
• a sealing device placed inside the space, abutting against a respective shoulder, suitable for obtaining a fluid seal with the external surface of the ball shutter;
• wherein the sealing device comprises a continuous sealing ring made of polymer material, placed in contact with the external surface of the ball shutter, and a continuous support ring made of metal material, coupled to the continuous sealing ring and placed between the continuous sealing ring and the shoulder;
• wherein the continuous support ring comprises a continuous annular coupling portion connected to the continuous sealing ring and a continuous annular influencing portion joined to and elastically bendable with respect to the annular coupling portion to provide an elastic lever between the continuous sealing ring and the shoulder;
• wherein the annular coupling portion comprises an annular contact portion formed by a frustoconical wall;
• wherein, in a normal use condition, an outer wall of the continuous sealing ring is at least partially in contact with a side surface of the annular wall and the annular contact portion is not in contact with the external surface of the ball shutter;
• and
• wherein, in an emergency condition, in which the continuous sealing ring is absent, the annular contact portion is in contact with the external surface of the ball shutter at least due to pressure of the fluid, obtaining the fluid seal.