Single lead wedgethread connection

A thread form having a crest (35);

• a stab flank (32);
• a stab flank guide surface (44) positioned at guide angle (39) with respect to the connection centerline (43);
• further comprising:
• The guide angle being larger than the angle of friction that acts between the mating threads, but less than 40 degrees.

A pipe connection pin (2) having pin threads (10), pin thread OD at face (60), pin root diameter (9), crest diameter at face (60), the connection also having box (3) formed with tapered threads (10) to mate with the pin threads, box OD (3), box swaged ID (26), comprising:

• The pin being swaged down to the smallest OD within pipe OD tolerance and the pin ID being formed substantially equal to the average of the pipe drift diameter and the nominal pipe ID;
• the pin thread root diameter substantially running out at the pin OD;
• The box ID being swage out to substantially the pin crest diameter at face;
• the box thread root running out in the swaged box ID;
• the engaged thread length extending from the pin OD to the box ID.

A threaded pipe connection having a box (3) with tapered box threads (28) and a box face (22);

• the connection also having a pin (2) with tapered pin threads (10) dimensioned to mate with the box threads, radial interference existing between the mating threads, the box wall being thicker at the pin face that at the box face, comprising:
• More radial thread interference existing between the mating threads at the pin face than at box face;
• Interference at the pin face being sufficient to seal rated Internal fluid pressure but less than flank yield pressure;
• Interference at box face not being great enough to over stress the box wall when at rated pressures.

A screw thread form having a radial thread depth;

• an axial thread pitch;
• a crest;
• a stab flank;
• a stab flank guide surface;
• positioned at a guide angle with respect to the connection centerline;
• a pipe connection pin having pin threads;
• a pin thread O.D., a pin root diameter and a pin crest diameter at the pin face;
• a box formed with tapered threads to mate with the pin threads;
• a box O.D.;
• a box swage I.D.;
• radial interference existing between the mating threads;
• the box wall being thicker at the pin face than at the box face;
• the connection being in a family of pipe connections having a maximum angle of misalignment between the box and pin during assembly, further comprising:
• The thread depth being more than 30 percent but less than 50 percent of the axial thread pitch. The guide angle being larger than the angle of friction that acts between the mating threads, but less than 40 degrees. The pin being swaged down to the smallest OD within pipe OD tolerance and the pin ID being formed substantially equal to the average of the pipe drift diameter and the nominal pipe ID;
• the pin thread root diameter substantially running out at the pin OD;
• The box ID being swage out to substantially the pin crest diameter at face;
• the box thread root running out in the swaged box ID;
• the engaged thread length extending from the pin OD to the box ID. More radial thread interference existing between the mating threads at the pin face than at box face;
• Interference at the pin face being sufficient to seal rated internal fluid pressure but less than flank yield pressure;
• Interference at box face not being great enough to over stress the box wall when at rated pressures. All threads within that family having an optimum thread form for that range. The thread lead being not less than, the thread diameter multiplied by the tangent of the specified maximum allowable angle of misalignment.