Abstract: A valve with ball of controlled deformation for fluid shut-off comprising an external containment body (11), inside which is arranged a shutter element (13), movable between a closure position and an opening position of the valve, the shutter element cooperating with one or more seats (12) and providing for seal elements with respect to the containment body and to the shutter element, in which the shutter element provides for yielding zones (15a) in its spherical portions (15) disposed downstream of the seats with respect to a pressure zone. Preferably the yielding zones are provided by notches (19) produced on surface zones of the shutter elements in correspondence with the spherical portions.

Abstract: A supply unit including a direct voltage energy source formed of a number of rechargeable batteries; an electric motor for driving the vehicle; and an electric circuit interposed between the direct voltage energy source and the electric motor. The electric circuit is reconfigurable, and provides for a first operating mode to control the alternating supply voltage of the motor, and a second operating mode, alternative to the first operating mode, and wherein the reconfigurable circuit provides for rectifying an alternating voltage to recharge the batteries.

Abstract: An improved device for shifting the seats of a top entry ball valve, consisting of two identical portions, one for each valve seat, which are permanently interposed between the valve body and the relative seats; each portion comprises a stop ring made rigid with the valve body by first locking means, and a seat shifting second ring cooperating with a valve seat and movable axially by operating means into a withdrawn position to enable said valving element to be extracted or into an active position in which it is locked in position by second locking means. Preferred embodiments of said means are also described.