Abstract: It is described a subsea electric actuator (100) operating a linear valve (200), the actuator (100) comprising a roller-screw (2) for translating a rotational movement of a motor (3) to a linear movement of a gate rod (4) operating the valve (200), the actuator (100) comprising: —an actuator housing (101); —an outer roller screw part (2?) rotationally connected to the motor (3) and comprising internal threads forming a first part of a first connection (10), —an inner roller screw part (2?) comprising external threads forming a second part of the first connection (10) and being arranged inside the outer roller screw part (2?), a surface of the inner roller screw part (2?) having a first interface forming a first part of a second connection (20?; 20?) connecting the inner roller screw part (2?) to a non-rotational part of the actuator (100), the second connection (20?, 20?) is configured to rotationally lock the inner roller screw part (2?) giving linear movement of the inner roller screw part (2?) when the out

Abstract: An electric valve including, housed within a valve body, a nut having a central shaft; a screw threadingly engaged within the nut and fixed thereto to prevent the nut from turning around the screw; and a seal mounted to the central shaft and configured to move freely with respect to the central shaft, both axially and rotatably there-about. The valve further includes sliding bearings disposed between the nut and the seal and disposed between the nut and a base of the screw; a lip correspondingly disposed with respect to the seal and reversibly engagable therewith. A projection is attached at a periphery of the nut; and a limiter is positioned in an inner side of the valve body, configured so that the projection is abuttable therewith. Due to the slide bearings, neither during opening of the valve or closing of the valve does the seal slide on the lip.

Abstract: A multiple mode valve assembly including valve actuators equipped with a combination of a shaft (4) and a spindle (5), coaxial and immobilized in an axial direction, but capable of rotating freely one with respect to the other, so that by means of the spindle (5), through a threaded nut assembly (6) and the pertinent motor (9), the longitudinal displacement of the gate (3) is produced in valve opening and shutting operations, whilst by means of direct application of a rotary movement to the shaft (4), which does not affect the spindle (5), from a second motor (23), the gate (3) turns on the valve seat (2), in the shut position, producing a friction effect and consequent self-cleaning of the seal.

Abstract: A multiple mode valve assembly including valve actuators equipped with a combination of a shaft (4) and a spindle (5), coaxial and immobilised in an axial direction, but capable of rotating freely one with respect to the other, so that by means of the spindle (5), through a threaded nut assembly (6) and the pertinent motor (9), the longitudinal displacement of the gate (3) is produced in valve opening and shutting operations, whilst by means of direct application of a rotary movement to the shaft (4), which does not affect the spindle (5), from a second motor (23), the gate (3) turns on the valve seat (2), in the shut position, producing a friction effect and consequent self-cleaning of the seal.

Abstract: This valve is applicable in conduction of bauxite in pipes and is meant to allow the self-cleaning of the valve with the aid of a locking cap which connects the drive crown and the valve shaft, causing the rotation of said crown to be transmitted to the valve shaft, which as it rotates rubs on the valve seats, thus removing the depositions.