Permits a variety of positioning devices which respond to a linear motion to be mounted on the actuator of a control valve, either directly or by employing an intermediate mounting bracket. The standardized mounting applies to positioners which are mounted on the side of the actuator, to those actuators which have a travel of 100 mm or less, and is designed to cover three basic types of actuator design: a)those with some form of cast or fabricated yoke to connect the actuator power unit to the valve; b)those which use some form of central tube yoke to connect the actuator power unit to the valve; c)those in which the yoke incorporates two or more columns or pillars to connect the actuator power unit to the valve.