Abstract: A pipe connector for offshore risers has conical thread forms. The connector has a pin with a nose, an external shoulder, and conical first and second pin threaded sections. The first and second pin threaded sections are axially separated by a pin intermediate section that is free of threads. The first and second pin threaded sections are formed on a single continuous taper and on a continuous helix. The intermediate section is also conical and at the same taper as the pin first and second threaded sections. The connecter has a box with a rim, an internal base, and a conical receptacle between the rim and the base. The conical receptacle has first and second box threaded sections that make up with the pin threaded sections. The box also has an intermediate section between its first and second threaded connections that is free of threads. The intermediate sections make up with radial interference. Upper and lower metal-to-metal sealing surfaces are located at the nose and at the base of the pin.

Abstract: An apparatus and method for the cryogenic purification of gaseous mixtures is provided. The apparatus comprises a heat-insulated hermetically sealed vessel which contains liquid hydrogen. Immersed within the liquid hydrogen are a number of serially connected cartridges which contain chips of a thermally conductive mixture. A mixture of neon and helium is input into the apparatus. The neon freezes, while the helium passes through the apparatus in a gaseous state. The resulting neon is allowed to thaw into a liquid or gaseous form and is highly pure.

Abstract: An underreamer which may be mounted on a core drill to allow single phase underreaming or creation of a bore hole of larger diameter beneath a pilot hole. A plurality of levers are powered by a plurality of corresponding jacks which are adapted to exert pressure on the levers in order to cause them to extend beyond the periphery of the expander body. Each lever contains at least one roller-cutter rotatably mounted to the lever so that when the levers are forced outward, the roller-cutters crush rock beyond the periphery of the expander body and thus underream the bore hole.