Abstract: A preassembled combination connects a captured pipe element to a second pipe element. First and second segments are connected end to end surrounding a central space for axially receiving the second pipe element. The segments are configured to be drawn toward one another and into engagement with the pipe elements. An annular body forms the captured pipe element. An end face of the captured pipe element is retained within the central space by engagement between a bead projecting from a sealing surface of the captured pipe element and the coupling assembly.

Abstract: A preassembled combination for connecting a captured pipe element to a second pipe element includes a plurality of segments attached to one another end to end to form a loop around a central space. A ring seal is positioned in channels defined by the segments. The captured pipe element has a first end positioned in the central space. The coupling is configured such that once the end of the second pipe element is inserted into the central space the segments can be drawn toward one another to join the second pipe element with the captured pipe element. A method of manufacturing the combination includes the steps of engaging a ring seal with a pipe element, positioning the ring seal in a channel of the segments and attaching the segments to one another.

Abstract: A coupling used to connect structural tubing includes segments surrounding a central space which receives the tubing. Teeth on an inner surface of the segments project toward the central space and form zones of deformation in the tubing upon engagement with the tubes' outer surfaces. Ends of the tubing abut one or more tongues on the inner surface, and observation apertures in the segments permit visual confirmation that the tubing is seated. Relief pockets on the inner surfaces of the segments receive portions of the tubing which deform outwardly. An insert may be present in the central space. The insert defines a space between itself and the inner surfaces of the segments which receives the tubing. The insert has relief channels which receive deformed regions of the tubing corresponding to the zones of deformation.

Abstract: A pipe fitting for plain end pipe is formed of housing portions defining receptacles for receiving pipe elements. The receptacles are coaxial with respective axes oriented angularly with respect to each other. Each receptacle has a channel that faces a respective axis with floors at different radii of curvature. Retainers are received within the channels. The retainers have teeth and one or more offset tabs that cooperate with the channels to prevent improper assembly of the fitting. Ring seals are received within channels positioned adjacent to the receptacles. The ring seals cooperate with the retainers to hold the segments in spaced relation sufficient to insert pipe elements into the receptacles when the fitting is pre-assembled. Apertures are provided in the receptacles to permit visual determination of the presence of the retainers post assembly.

Abstract: A coupling has first and second segments attached to one another end to end surrounding a central space for receiving pipe elements. A spring assembly attaches the segments at one end and an adjustable attachment assembly attaches the segments at the opposite end. The spring assembly biases the segments away from one another sufficient to permit insertion of the pipe elements into the central space while the segments are attached to one another. The coupling may include a split ring toothed retainer for coupling plain end pipe elements, or it may have arcuate keys which engage grooved or shouldered pipe elements.

Abstract: A pipe coupling for plain end pipe is formed of segments joined end to end surrounding a central space. The segments are connected end to end by lugs on each segment with fasteners extending between them. Each segment has channels on opposite sides that face the central space with floors at different radii. Retainers are received within the channels. The retainers have teeth and one or more offset tabs that cooperate with the channels to prevent improper assembly. A ring seal is received within a channel positioned in each segment between the retainer channels.

Abstract: A pipe element has a circumferential groove with a surface portion oriented at an angle with respect to its longitudinal axis. A surface portion of the groove adjacent to the angled surface portion is oriented perpendicular to the longitudinal axis. A mechanical coupling has projecting keys that engage the groove. The keys have mating surfaces that contact both the perpendicular and angled surface portions of the groove. When the pipe element and coupling are used in combination to form a pipe joint, axial load on the pipe, resisted by the mechanical coupling, is shared between the perpendicular and angled surface portions which results in a pipe joint that can withstand higher internal pressure than if the axial load were borne by the perpendicular surface portion alone.

Abstract: A tube is surrounded by a ring attached to a sleeve. One end of the tube is attached to a pipe of the pipeline, one end of the sleeve is attached to another pipe of the pipe line. The tube and the ring and sleeve are movable axially relatively to one another when the pipe line expands or contracts linearly. A seal between the ring and the tube ensures fluid tightness of the joint.

Abstract: A pipe element has a circumferential shoulder at one end. The shoulder has an outer diameter greater than the outer diameter of the pipe element. A groove is positioned adjacent to the shoulder. The groove has a floor surface with an outer diameter less than the outer diameter of the pipe element. A bead is positioned contiguous with the groove. The bead has an apex with an outer diameter greater than the outer diameter of the pipe element. A combination of roller tools is used to cold work pipe elements and impart a desired shape to the sidewall in one method of manufacture. In another method, a spin forming tool is revolved in an orbit of increasing diameter within the pipe element captured within a die.

Abstract: A method for joining pipe elements end-to-end using a pair of pipe couplings attached to one another end to end surrounding a central space includes inserting the pipe elements into the central space, moving the coupling segments toward one another and engaging surface regions of the coupling segments with outer surfaces of the pipe elements, initially at a first contact point on the coupling segments and subsequently at second and third contact points on the coupling segments. The first contact point is located between opposite ends of the coupling segments and may be located on a region of infinite radius of curvature, may project radially inwardly toward the pipe elements, and may be located midway between the opposite ends of the segments. The second and third contact points are located at opposite ends of the coupling segments.