A tubular member includes a tube body, a tube end, an exterior surface, an interior surface, a nominal wall thickness, a longitudinal axis, a welded seam, and a patch of material. The welded seam forms an arcuate portion of the interior surface, and the patch covers a portion of the interior surface that includes a portion of the welded seam, extending from the tube end to an axially spaced first location. The resulting interior surface from the tube end to the axially spaced first location has a uniform inside diameter.

A threaded connection having a straight central axis, where the pin threads and the box threads are arranged such that when the connection is fully made up, the pin roots and box crests come into at least partial interference substantially in line with a pin root taper plane and a box crest taper plane, and wherein the angles of the pin root taper plane and box crest taper plane allow for reduction of axial compressive forces on the plurality of pin threads and plurality of box threads along the central axis.

A threaded connection having a straight central axis, where the pin threads and the box threads are arranged such that when the connection is fully made up, the pin roots and box crests come into at least partial interference substantially in line with a pin root taper plane and a box crest taper plane, and wherein the angles of the pin root taper plane and box crest taper plane allow for reduction of axial compressive forces on the plurality of pin threads and plurality of box threads along the central axis.

A threaded connection including a pin with a plurality of pin threads, the plurality of threads comprising a plurality of pin crests and pin roots; and a box with a plurality of box threads, the box threads comprising a plurality of box crests and box roots, where the plurality of box roots and the plurality of pin crests are parallel to a horizontal axis, and where the plurality of pin roots are parallel to and collinear with a pin root taper plane, the pin root taper plane being not parallel to the horizontal axis creating at least one void space upon make-up of the threaded connection between the plurality of pin crests and the plurality of box roots, and at least one void space upon make-up between the plurality of pin roots and box crests.

A threaded connection including a pin with a plurality of pin threads, the plurality of threads comprising a plurality of pin crests and pin roots; and a box with a plurality of box threads, the box threads comprising a plurality of box crests and box roots, where the plurality of box roots and the plurality of pin crests are parallel to a horizontal axis, and where the plurality of pin roots are parallel to and collinear with a pin root taper plane, the pin root taper plane being not parallel to the horizontal axis creating at least one void space upon make-up of the threaded connection between the plurality of pin crests and the plurality of box roots, and at least one void space upon make-up between the plurality of pin roots and box crests.

A threaded product is provided having an external thread form on a tubular pin member comprises load and stab flanks on either side of a crest, along with smooth transitions between the crest and flanks. An elliptical root between the flanks aids in reducing stress and forms a dope volume between a non-conforming crest of an internal thread form of a tubular box member. Flanks of the internal thread of the box member contact flanks of the external thread of the pin member to form areas of mating contact on either side of the thread.

A threaded product is provided having an external thread form on a tubular pin member comprises load and stab flanks on either side of a crest, along with smooth transitions between the crest and flanks. An elliptical root between the flanks aids in reducing stress and forms a dope volume between a non-conforming crest of an internal thread form of a tubular box member. Flanks of the internal thread of the box member contact flanks of the external thread of the pin member to form areas of mating contact on either side of the thread.

A drill pipe assembly includes a first drill pipe, a second drill pipe, and a tubular pipe link residing between and fluidically coupled to the first drill pipe and the second drill pipe. The tubular pipe link includes a first end and a second end opposite the first end. The first end is threadedly coupled to a threaded end of the first drill pipe to form a threaded connection. The second end is attached to the second drill pipe. The first end of the pipe link has less threads than the threaded end of the first drill pipe. At least some of the threads of the first end of the pipe link are collapsible to disconnect the first drill pipe from the second drill pipe responsive to torque to tighten the first drill pipe to the pipe link.

A drill pipe assembly includes a first drill pipe, a second drill pipe, and a tubular pipe link residing between and fluidically coupled to the first drill pipe and the second drill pipe. The tubular pipe link includes a first end and a second end opposite the first end. The first end is threadedly coupled to a threaded end of the first drill pipe to form a threaded connection. The second end is attached to the second drill pipe. The first end of the pipe link has less threads than the threaded end of the first drill pipe. At least some of the threads of the first end of the pipe link are collapsible to disconnect the first drill pipe from the second drill pipe responsive to torque to tighten the first drill pipe to the pipe link.

The present invention is a system and methods that facilitates the application of PVC primer (solvent) or PVC glue to the inner surfaces of PVC unions and the outer surface of PVC pipes. The invention consists of a PVC primer (solvent) or PVC glue reservoir, a method of pressurizing the reservoir, and forcing the PVC primer (solvent) or PVC glue through a series of tubes and holes in the apparatus and into a foam applicator which transfers the PVC primer (solvent) or PVC glue onto the inner surface or onto the outer surface of a PVC union or PVC pipe to a predetermined depth thus reducing waste of the PVC primer (solvent) or PVC glue. The foam application housing contains a foam applicator specifically for applying PVC primer (solvent) or PVC glue to either the inner surface of a PCV union or to the outer surface of a PVC pipe giving a uniform application of PVC primer (solvent) or PVC glue.