The design, development and use of pipe cutting tools for remote handling in JET

The authors report on remote handling tools which have been specifically designed to meet requirements for pipe cutting at JET (Joint European Torus). The principal requirements were the quality of cut necessary for rewelding, effective swarf removal, and compactness for remote handling. The designs of tools had to be compatible with the severe access restrictions imposed by the JET machine. The processes used by the tools are sawing from the inside and outside of pipes, and orbital lathe for larger pipes. Special features were created on the pipes to facilitate tool location. The blade and toolbit designs have evolved to optimize cutting forces and tool durability. Satisfactory reliability has been achieved by performing 200 h of cutting during the two year period of development. Subsequently, over 100 `hands-on´ cutting operations have been made on the JET machine since 1988 and a further 150 cuts are planned for 1992. Using a programmable controller the feed rate can be changed throughout the cutting operation into a predetermined way, thereby optimizing the tools´ efficiency