Joint and joint components for pipe sections subjected to axial compression loads

Joint for axially compressive loaded pipe sections, comprising:

• (a) a pair of pipe sections arranged end-to-end, the adjacent ends of the sections being threaded wherein the threads are formed in two groups, the threads in one group being spaced radially and axially from the threads in the other group;
• (b) a coupling member for connecting the threaded adjacent ends of the pipe sections, the coupling member including threads interengaged with the threads on the adjacent ends of the pipe sections;
• (c) each pipe section including a shoulder formed between said groups of threads and formed integral with and extending circumferentially around the section, the shoulder including an angled surface which faces the angled surface on the other pipe section and is oriented at an angle substantially the same as the surface on the other pipe section, each surface terminating at a circumferential edge which is closer to the edge on the other surface than is any other portion of its respective surface;
• (d) the coupling including angled surfaces which approach being complementary to and engaging the surfaces on the pipe section when the joint is formed and a compressive load is applied so that a gap is formed at either the inner or outer ends of the unequal angled surfaces when the surfaces are initially brought together and before a compressive load is applied;
• and
• (e) whereby the angled surfaces enhance the load bearing surface area of the pipe sections so that when they are subjected to an axial compression load, deformation of the sections is retarded so that the section can be loaded with greater stability near the upper rating of the section, and whereby providing the surfaces to have unequal angles which approach being complementary on full compressive loading of the joint enhance the pressure integrity of the joint because of the unequal load distribution across the surfaces.

Joint for axially compressive loaded tubular members, comprising:

• (a) a first tubular member having a threaded end with threads formed in two groups, the threads in one group being spaced radially and axially from the threads in the other group;
• (b) a second tubular member having a threaded end with threads formed in two groups which are interengagable with with said threads on the first tubular member;
• (c) each tubular member including a shoulder formed between said groups of threads and formed integral with and extending circumferentially around the tubular member, the shoulder of the first tubular member including an angled surface which faces an angled surface on the shoulder of the second tubular member, the angled surfaces of the shoulders of the first and second tubular members being unequal such that before makeup of said tubular members, each of said angled surfaces of the shoulders of the first and second tubular member terminate at a circumferential edge which is closer to the edge on the other surface than is any other portion of its respective surface;
• (d) whereby, when the first tubular member and second tubular member are initially brought together and before a compressive load is applied, a gap is formed at the inner or outer ends of said unequal angled surfaces, and when the joint is formed and a compressive load is applied, the angled surfaces approach being complementary to each other;
• and
• (e) whereby the angled surfaces enhance the load bearing surface area of the tubular members so that when they are subjected to an axial compression load, deformation of the tubular members is retarded so that the tubular members can be loaded with greater stability near the upper rating of the tubular members, and whereby providing the surfaces with unequal angles which approach being complementary on full compressive loading of the joint enhances the pressure integrity of the joint because of the unequal load distribution across the surfaces.