Threaded tubing joint

Claim 1

A THREADED PIPE JOINT HAVING THE CHARACTERISTIC OF MAINTAINING LEAK TIGHTNESS AFTER REPEATED MAKE-UP, SAID JOINT COMPRISING A PIPE MEMBER HAVING A CYLINDRICAL OUTER SURFACE AND A TAPERED BUTTRESS THREAD AT THE END THEREOF VANISHING ALONG SAID OUTER CYLINDRICAL SURFACE PROVIDING A LENGTH OF FULLY FORMED AND A LENGTH OF VANISHING THREADS AND A COUPLING MEMBER HAVING A COMPLEMENTARY THREAD ON THE INTERNAL SURFACE THEREOF, SAID THREAD BEING FULLY FORMED THROUGHOUT THE LENGTH THEREOF AND AT LEAST AS LONG AS THE TOTAL LENGTH OF FULLY FORMED AND VANISHING THREADS ON THE PIPE, THE COMPLEMENTARY THREADS ON EACH MEMBER HAVING FOLLOWING-FLANKS IN BEARING RELATIONSHIP AND SUBSTANTIALLY NORMAL TO THE LONGITUDINAL AXIS OF THE JOINT LEADING-FLANKS IN BEARING RELATIONSHIP AND HAVING A LARGER FLANK-ANGLE THAN SAID FOLLOWING-FLANKS, AND CREST AND ROOT TRUNCATIONS PROVIDING FLAT CRESTS AND ROOTS WHICH ARE PARALLEL TO THE LONGITUDINAL AXIS OF THE JOINT, SAID CREST TRUNCATIONS OF THE FULLY FORMED THREADS EXCEEDING SAID ROOT TRUNCATIONS, BY AN AMOUNT PROVIDING VOIDS OF PREDETERMINED AMOUNT BETWEEN THE CRESTS AND ROOTS OF SAID COMPLEMENTARY THREADS THROUGHOUT THE LENGTH OF THE JOINT WHEN THE PIPE AND COUPLING ARE IN HAND-TIGHT ENGAGEMENT, THE CRESTS OF THE COUPLING THREADS ENGAGING THE ROOTS OF THE VANISHING PIPE THREADS AFTER POWER MAKEUP OF THE JOINT TO TIGHTNESS, BUT THE VOIDS BETWEEN THE CREST AND ROOTS OF FULLY FORMED THREADS REMAINING AFTER SAID POWER MAKE-UP, THE INITIAL VOIDS BETWEEN THE COUPLING THREADS AND VANISHING PIPE THREADS PREVENTING THE DEVELOPMENT OF DELETERIOUS HOOP STRESSES AT THE END OF THE COUPLING DURING POWER MAKE-UP.