Butterfly valve with variable configuration elastic gasket

A butterfly valve, comprising:

• a tubular valve body having a longitudinal axis an internal surface on which a sealing seat is circumferentially defined and a thickness wherein corresponding housings are defined,
• a disc shutter having a perimetral edge and being rotationally connected inside said tubular valve body,
• a toroidal gasket of elastomeric material housed in said corresponding sealing seat circumferentially defined on the internal surface of said tubular valve body,
• a plurality of pressers each having a proximal portion and a distal portion, slidingly coupled along the corresponding housings defined in the thickness of said tubular valve body,
• a clamping collar that opens and closes with the movement of a lever and that, when closed, exerts a pushing action on the proximal portions of said pressers,
• wherein said disc shutter is movable between an open position in which the plane defined by said disc shutter lies parallel to the longitudinal axis of said tubular valve body, and a closed position in which said disc shutter lies orthogonally to the same axis and its perimetral edge engages with the inner perimetral face of said toroidal gasket the latter being deformable under the action exerted on its outer perimetral face by the distal portions of said plurality of pressers slidingly coupled along the corresponding housings defined in the thickness of said tubular valve body,
• wherein further said pressers are movable towards said longitudinal axis of said tubular valve body by virtue of a thrust action exerted on their proximal portions by said clamping collar and reversibly movable in the opposite direction by at least the elastic contrast action exerted by said toroidal gasket,
• said butterfly valve being characterized in that the said tubular valve body comprises a lower tubular half-body and an upper tubular half-body, coaxial to each other and longitudinally separated by a plurality of angular spacers which form said housings along which said pressers slide.