Abstract: A system is provided for easily replacing a single tube in shell and tube heat exchangers without removing the bundle. The system comprises: (1) a rod which is inserted into the tube to be replaced and left in place when the tube is removed and (2) a special tool which is adapted to fit into the end of a replacement tube and over the rod.

Abstract: Apparatus for temporary positioning about a cylindrical object such as an underwater pipeline or the like for mounting and indexing a tool across the surface of the pipeline for treating same.

Abstract: A pipe cutting device comprises a split frame which may be clamped around the circumference of a pipe (either inside or outside of the pipe). Floatingly or freely mounted on the rollers carried by the frame, to rotate about the pipe, is a ring gear having at least one arcuate arm mounted thereon to rotate with the gear as it turns around the pipe. At one end, the arm is pivotally mounted on the ring gear. At the other end, the arm is selectively biased toward the pipe by a compression spring or other suitable force. This way, a blade mounted on the arm may be driven into the pipe by a controlled amount. A gear train selectively raises or lowers the blade with respect to the surface of the pipe depending upon the position of a clutch arrangement. A special feature of the cutter is that it is easily adapted to cut from either the outside or the inside surface of a pipe.