An in-tube fixing assembly includes a primary tube having an inner space and an inner wall; a fixing member inserted into the inner space from an opened end of the primary tube and provided with at least one through hole at an appropriate position; and at least one screw member, a diameter of the screw member gradually decreasing from the operation end to the insertion end, wherein the screw member is inserted into the through hole in a direction from the opened end to the inner space of the primary tube, the insertion end of the screw member abuts against the inner wall of the primary tube to form a small recess thereon that are complementary to a shape of the screw member.

Techniques for implementing a pipeline system that includes one or more pipe segments, in which each pipe segment of the one or more pipe segments includes tubing that defines a pipe bore and a fluid conduit implemented in an annulus of the tubing, and a re-deployable pipe fitting to be secured to the one or more pipe segments. The re-deployable pipe fitting includes a fitting body that defines a fitting bore through the re-deployable pipe fitting and a threaded fitting jacket to be deformed around the tubing of a pipe segment of the one or more pipe segments to facilitate securing the re-deployable pipe fitting to the pipe segment. The threaded fitting jacket includes jacket threading that enables the threaded fitting jacket to be coupled to the fitting body, removed from the fitting body, or both without using hot tooling.

An in-tube fixing assembly, which fixes an object inside or at an end of a tube, includes a primary tube having an inner space and an inner wall defining the inner space; a fixing member inserted partially or wholly into the inner space from an opened end of the primary tube and provided with at least one through hole at an appropriate position, the through hole provided with an accommodation part extending in a direction from the through hole toward the inner wall of the primary tube by a predetermined angle; and at least one screw member, one end of which is defined as an operation end and the other end defined as an insertion end, a diameter of the screw member configured to gradually decrease from the operation end to the insertion end, wherein the screw member is inserted into the through hole in a direction from the opened end to the inner space of the primary tube, such that when the insertion end is rotatably inserted into the accommodation part from the through hole, the insertion end of the screw member abuts against the inner wall of the primary tube to form a small recess thereon, the small recess and the accommodation part respectively form a first engaging thread and a second engaging thread, that are complementary to a shape of the screw member.