Abstract: A valve is reciprocable between open and closed positions along a longitudinal axis and is rotatable about the axis by a rotator mechanism. The rotator mechanism includes first and second parts movable axially and rotatably relative to one another along and about the longitudinal axis. Circumferentially shiftable means is located between the first and second parts for imparting relative rotation between the parts during relative axial movement therebetween. A Belleville spring washer is located between the shiftable parts. The inner periphery of the spring washer bears on one of the parts and the outer periphery of the spring washer bears against the other part. The central portion of the spring washer bears against the shiftable means. The shiftable means is preferably either a ball or garter spring having a curved outer peripheral surface. The spring washer has a depression formed therein to provide a concave surface in contact with the curved outer peripheral surface of the shiftable means.