Jack bolt assembly

In a releasable flange assembly of the type having first and second flange members each adapted for attachment to make-up end portions of first and second flowlines, respectively, with said releasable flange assembly joining said first flowline in fluid communication with said second flowline when said first and second flange members are secured in a make-up union, and fluid cmmunication between said first and second flowlines being interrupted when said flange members are spread, the first and second flange members each having a corresponding number of aligned openings for receiving tightening bolts, at least one of said aligned openings in said first flange member being threaded, the improvement comprising a jack bolt assembly received in an aligned pair of said flange openings for securing, separating and aligning said flange members during make-up and spread operations, said jack bolt assembly having

• a primary threaded shaft portion for threadedly engaging the threads in said at least one of the openings formed in the first flange member,
• a tool engaging end formed with said primary threaded shaft portion for rotation of said jack bolt shaft as desired,
• a radially engaging surface formed adjacent said primary threaded shaft portion, said radial engaging surface extending radially inwardly from said primary threaded shaft portion,
• a thrust member receiving portion formed adjacent to said primary threaded shaft portion and said radial engaging surface, said thrust member receiving portion being aligned with said primary shaft portion and adapted to extend into the aligned opening formed in the second flange member;
• a secondary threaded portion formed adjacent to and in axial alignment with said thrust member receiving portion and adapted to be disposed within the opening formed in the second flange member and adapted to extend outwardly therefrom;
• a thrust member movably mounted on said thrust member receiving portion, said thrust member being disposed between the first and second flange members of the flange assembly, said thrust member abutting said radial engaging surface and the second flange member upon initial rotation of said primary threaded shaft portion, the engagement of said thrust member with the second flange member separating the first and second flange members of the flange assembly upon continued rotation of said primary threaded portion;
• and,
• a securing member threadedly engaging said secondary threaded portion of said jack bolt member, said securing member releasably abutting the second flange member of the flange assembly for releasably securing the second flange member with the first flange member of the flange assembly upon threaded, tightening action between said securing member and the second flange member.