Development of a first wall clamp for remote handling

RFX is equipped with a graphite first wall made up of 2016 tiles individually supported from the vacuum vessel. Due to the small dimensions of the ports, human access inside the vacuum vessel is prevented and a robot manipulator has been designed to perform remote operations on the graphite tiles. The clamping system that withstands the applied loads must accomplish the remote handling requirements. A bayonet clamp has been chosen because it is simple, safe and can be built with clearances and chamfers that, with a proper compliance of the manipulator wrist, allow the compensation of the positioning errors between the parts that have to be matched. To avoid the vacuum welding of the clamp, the surfaces in contact under vacuum are coated with an anti-welding coating. The paper first describes the main design choices, then deals with the load capability of the clamping system and reports the results of experimental and FE analyses; the last section gives the results of the tests that were performed on anti-welding coatings.