Abstract: Concentric, tubular sections are assembled by first securing annular centralizers and insulation about the external surface of the smaller diameter tube while the tube is horizontally disposed. The larger tube is then vertically aligned and lowered into a recessed area formed below the assembly area work level. A lifting cable, secured at one end to a lifting device, is extended through the smaller diameter tube and attached to a hoisting arrangement that vertically orients the tube concentrically over the larger diameter tube. Spring-loaded legs on the lifting device are manually retracted radially to permit the smaller tube to be lowered concentrically through the larger tube. The inner tube is lowered until the legs spring radially outwardly to engage the base of the larger tube. The entire assembly may then be lifted as a unit by the hoist with the lifting device, establishing the axial positions of the two tubes relative to each other.

Abstract: Concentric, tubular sections are assembled by first securing annular centralizers and insulation about the external surface of the smaller diameter tube while the tube is horizontally disposed. The larger tube is then vertically aligned and lowered into a recessed area formed below the assembly area work level. A lifting cable, secured at one end to a lifting device, is extended through the smaller diameter tube and attached to a hoisting arrangement that vertically orients the tube concentrically over the larger diameter tube. Spring-loaded legs on the lifting device are manually retracted radially to permit the smaller tube to be lowered concentrically through the larger tube. The inner tube is lowered until the legs spring radially outwardly to engage the base of the larger tube. The entire assembly may then be lifted as a unit by the hoist with the lifting device, establishing the axial positions of the two tubes relative to each other.

Abstract: Concentric, tubular sections are assembled by first securing annular centralizers and insulation about the external surface of the smaller diameter tube while the tube is horizontally disposed. The larger tube is then vertically aligned and lowered into a recessed area formed below the assembly area work level. A lifting cable, secured at one end to a lifting device, is extended through the smaller diameter tube and attached to a hoisting arrangement that vertically orients the tube concentrically over the larger diameter tube. Spring-loaded legs on the lifting device are manually retracted radially to permit the smaller tube to be lowered concentrically through the larger tube. The inner tube is lowered until the legs spring radially outwardly to engage the base of the larger tube. The entire assembly may then be lifted as a unit by the hoist with the lifting device, establishing the axial positions of the two tubes relative to each other.

Abstract: Concentric, tubular sections are assembled by first securing annular centralizers and insulation about the external surface of the smaller diameter tube while the tube is horizontally disposed. The larger tube is then vertically aligned and lowered into a recessed area formed below the assembly area work level. A lifting cable, secured at one end to a lifting device, is extended through the smaller diameter tube and attached to a hoisting arrangement that vertically orients the tube concentrically over the larger diameter tube. Spring-loaded legs on the lifting device are manually retracted radially to permit the smaller tube to be lowered concentrically through the larger tube. The inner tube is lowered until the legs spring radially outwardly to engage the base of the larger tube. The entire assembly may then be lifted as a unit by the hoist with the lifting device, establishing the axial positions of the two tubes relative to each other.