Abstract: A pipe joint capable of transmitting high axial compressive loads includes a reduced wall thickness section at the ends of the pipe to be joined and a coupling sleeve supported in telescoping relation with the reduced wall thickness section. Shoulders formed at the ends of the reduced sections bear against the ends of the sleeve, and the ends of the reduced thickness sections bear against each other so that a portion of the axial compressive load is transmitted through the coupling sleeve and a portion through the reduced thickness sections and a substantially uniform unit stress is maintained. O-rings carried by the coupling sleeve provide a fluid-tight seal between the sleeve and the adjacent surface of the reduced thickness section of the pipe.

Abstract: A method of producing substantially distortion-free weld metal tubing wherein a mandrel and a thin metal layer covering the mandrel are used to provide structural support for a starter tube while a weld metal is being deposited on the exterior surface of the starter tube to a desired thickness. The material used for the thin metal layer is selected to have a lower melting temperature than that of the mandrel, starter tube and weld metal, and after the weld metal deposit process is completed, the entire assembly is heated to a temperature in excess of the melting temperature of the thin metal layer, the molten material is flowed out from between the mandrel and the starter tube, thereby facilitating extraction of the mandrel from the weld metal tubing.

Abstract: A method for introducing fluxing material (flux) into a tubular, centrifugal casting mold in the manufacture of centrifugally cast metallic tubes. The flux is injected directly into the pouring stream of the molten metal in a steady, continuous flow by the pressure from a stream of non-reactive gas such as nitrogen. The injection of the flux into the pouring stream begins only after the wetting of all the casting surfaces of the mold by the molten metal. This flux is supplied from a hopper with a variable speed control auger.