Abstract: A valve unit for a dosing device of a fluid has a unit body having a fluid inlet passage, a fluid outlet passage, and, therebetween, an obturator seat housing a ball obturator. An obturator passage is formed in the ball obturator, which is rotatable between an open position, in which the obturator passage fluidically connects the fluid inlet passage to the fluid outlet passage, and a closed position, in which the ball obturator prevents passage of fluid from the fluid inlet passage to the fluid outlet passage. A fluid-tight intake piston, slidingly housed in a piston chamber and integral in rotation with the ball obturator, fluidically communicates with the fluid inlet and outlet passages. Cam means arranged between the unit body and the fluid-tight intake piston cause translation of the fluid-tight intake piston from an advanced position to a retracted position for intaking residual fluid present in the obturator passage.

Abstract: A valve unit for a dosing device of a fluid has a unit body having a fluid inlet passage, a fluid outlet passage, and, therebetween, an obturator seat housing a ball obturator. An obturator passage is formed in the ball obturator, which is rotatable between an open position, in which the obturator passage fluidically connects the fluid inlet passage to the fluid outlet passage, and a closed position, in which the ball obturator prevents passage of fluid from the fluid inlet passage to the fluid outlet passage. A fluid-tight intake piston, slidingly housed in a piston chamber and integral in rotation with the ball obturator, fluidically communicates with the fluid inlet and outlet passages. Cam means arranged between the unit body and the fluid-tight intake piston cause translation of the fluid-tight intake piston from an advanced position to a retracted position for intaking residual fluid present in the obturator passage.