GB728005A - Improvements relating to branched pipes or pipe fittings - Google Patents

Abstract

728,005. Pipe joints. BABCOCK & WILCOX, Ltd. Oct. 27, 1953 [Oct. 27, 1952], No. 26923/52. Class 99 (1). [Also in Group XXII] A welded branched pipe or pipe fitting is provided with a reinforcement in the form of an external closed loop which affords local support to the pipe or fitting at or adjacent locations on opposite sides thereof where the pipe or fitting would in the absence of support be most strongly stresed when subject to internal fluid pressure. The loop has a degree of flexibility permitting deflection at those locations, due to internal fluid pressure and elastic deformation, sufficient to avoid stress concentrations which would arise with a rigid loop. As shown in Figs. 1 and 3, the loop 4 includes a ring 16 surrounding a branch pipe 10, and a U-shaped part 12 extending around the main pipe 8 and parallel to the axis of the pipe 10 and united by welds 14 to diametrically opposite portions of the ring 16. There is a clearance between the part 12 and the pipe 8 and between the ring 16 and the pipe 10, except at positions on opposite sides of the pipe 8 where local support is afforded through pads 6 of weld metal. In modifications, (a), Fig. 6 (not shown), the pipe 10 is smaller in diameter than the pipe 8 and the ends of the part 12 extend inwardly towards the ring 16, (b), Fig. 7 (not shown), the pipe 10 is inclined at 60 degrees to the pipe 8, the part 12 extending parallel to the pipe 10 and being welded at its ends to a ring 16 of elliptical or approximately elliptical form and surrounding the pipe 10, (c), a U-shaped loop 26, Fig. 8, extends around the crutch 28 between two branches 22, 24 connected to a pipe 20 and is welded to a ring 30 embracing the pipe 20, the pads 6 of weld metal being provided at the junction of the three pipes, (d), rings 38, 40, Fig. 9, surround opposite pipe parts 42, 44 of a four-way fitting and are united by members 46 extending parallel to the common axis of the parts 42, 44, pads 6 of weld metal serving as connections between the fitting and the members 46, (e), an elliptical or approximately elliptical ring 50, Fig. 10, comprising two members welded together at opposite ends of the major axis of the ring extends around opposite crutches 54, 56 between pairs of pipes 58, 60 and 62, 64, local support for the ring being provided by pads 6 of weld metal disposed at the minor axis of the ring and at the junction of the pipes, (f), a ring 4, Fig. 12, of elliptical or approximately elliptical form extends in a plane normal to the axis of a main pipe 66 and through the angles between the pipe 66 and branch pipes 68, 70, pads 6 of weld metal to provide local support for the ring being deposited at the junction of the pipes, and (g) an elliptical ring extends around a main pipe and through one of the angles between that pipe and a branch pipe, the ring being inclined to the axis of the branch pipe ; where the branch pipe projects at an angle other than 90 degrees from the main pipe, the ring extends through the larger of the angles.between the pipes.