Abstract: A method for mitigating the deposition of wax on production tubing walls. The method comprises positioning at least one ultrasonic frequency generating device adjacent the production tubing walls and producing at least one ultrasonic frequency thereby disintegrating the wax and inhibiting the wax from attaching to the production tubing walls. A system for mitigating the deposition of wax on production tubing walls is also provided.

Abstract: Known methods of controlling inertia welding and friction welding processes fail to control metal upset, and so require post machining of the welded components. The invention pre-determines the ideal rates of relative rotation, force applied and metal upset rates for a given material to be welded, enters those rates in a microprocessor memory and then connects the microprocessor to the apparatus on which the weld is to be effected. The microprocessor monitors the actual rates, compares them with the ideal rates and, should differences occur, generates signals from those differences with which to adjust operation of the apparatus.

Abstract: An electrode assembly for electro-chemically machining an article, such as an aerofoil shaped blade for a turbo machine. The assembly comprises a plurality of electrodes 2,3 for location adjacent a workpiece 7. Each electrode 2,3 is constrained to move in a first direction towards each other and towards the workpiece 7 and has two side members 22,23 carried by a main body 21. The side members 22,23 are constrained to move with the main body 21 and also relative to the main body in directions parallel to the first direction. The side members 22,23 advance ahead of the main body 21 and when they abut the side members 22,23 of the other electrodes 2,3 their advancement is stopped while the main bodies 21 of the electrodes 2,3, continue to approach each other for a predetermined distance. In this way edge effects during machining are eliminated enabling an accurate shape of article to be produced.