Patent ID: 8286702

Claim:
A pipe sub-section having an axially elongated first tube between stepped coupling bosses at opposite ends thereof, said first tube and coupling bosses having an axial flow bore therethrough, said first tube having a first outer diameter that is less than a second outer diameter of a first step on said bosses, a first of said bosses having a second step on an axially opposite side of said first step from said first tube, said first boss second step having a third outer diameter that is greater than said first diameter but less than said second diameter, a second of said bosses having a second step on an axially opposite side of said first step from said first tube having a fourth diameter that is greater than said second diameter, said first boss second step having a plurality of wrench flats formed about the outer perimeter thereof, a first abutment edge between the first and second steps of said second boss being formed to follow an undulated perimeter; and an axially elongated torque sleeve having an internal bore with an inside diameter corresponding to a slip fit over said first step on said bosses, a first end of said sleeve formed with an undulated perimeter to mesh with said first abutment edge perimeter, a second end of said sleeve having an inside collar around an aperture with internal wrench flats for meshing with said first boss second step.