Abstract: An actuation system for a clamping assembly for use in a pipe clamping apparatus, including a shaft and an actuator defining an actuator chamber having a peripheral chamber wall. The actuator is movably mounted about the shaft such that the shaft extends through the actuator chamber and the actuator is longitudinally reciprocable thereon. A piston is fixedly mounted about the shaft and positioned within the actuator chamber. The piston has first and second sides and an outer perimeter sealingly engaging the peripheral chamber wall to create first and second chambers such that the actuator reciprocates along the shaft in response to a differential force applied within the first and second chambers. The clamping assembly is associated with the actuator such that reciprocation of the actuator along the shaft causes the clamping assembly to move radially relative to a longitudinal axis of the shaft.

Abstract: An actuation system preferably for mounting between front and rear clamping mechanisms in a pipe clamping apparatus as part of an internal backup ring system. The system includes a guide, a cam plate positioned adjacent to the guide and rotatable relative thereto, a drive mechanism coupling the guide and the cam plate such that actuation of the drive mechanism causes the cam plate to rotate relative to the guide about an axis of rotation, and a power source for driving the drive mechanism. A backup ring assembly, having a plurality of backup shoe units, may be associated with the cam plate such that rotation of the cam plate relative to the guide plate causes the backup ring assembly to move radially relative to the axis of rotation of the cam plate in order to engage or disengage the inner wall of a pipe. The system may also include auxiliary means for dislodging the backup ring assembly when at least one of the backup shoe units is stuck to the inner wall of the pipe.