Abstract: An actuator for operation of a valve, said actuator comprising tubular housing, which accommodates therein a piston, mounted with possibility for reciprocating linear stroke motion, an operating rod, which is operatively coupled with the piston and is rotatable about the longitudinal axis upon reciprocating stroke motion of the piston and a cam follower arrangement for transferring the piston reciprocating linear stroke motion into rotation of the operating rod, The actuator is provided with at least two fixing rods for preventing rotation of the piston. The fixing rods are rigidly secured at one end wall of the cylinder. The fixing rods extend parallel to the longitudinal axis and enter into respective blind passages provided at the first piston end to allow the linear stroke motion. The actuator is provided with at least two additional fixing rods, to enable the linear stroke motion.