Abstract: A ring-shaped seal has projections on an outwardly facing surface in the form of tubes which have a longitudinal axis oriented perpendicular to a plane containing the ring. The seal is received within a channel defined by segments attached end to end forming a coupling for coupling pipe elements in end to end relation. The segments have pockets which receive the projections. The projections support the segments in spaced apart relation to allow the pipe elements to be inserted into the coupling without loosening or disassembling it. The projections deform when the segments are drawn toward one another by adjustably tightenable fasteners and allow the segments to engage and capture the pipe elements in end to end relation.

Abstract: A mechanical pipe coupling is formed of segments attached end to end to surround a central space. Each segment has a circumferentially extending cavity facing the central space flanked by arcuate keys which project toward the central space. Two arcuate shoulder surfaces are positioned on each segment. The arcuate shoulder surfaces face the central space and are positioned in spaced relation on opposite sides of the cavity between the cavity and the arcuate keys. The arcuate shoulder surfaces are angularly oriented with respect to an axis perpendicular to a plane containing the segments. The coupling is used to couple pipe elements having a circumferential ring located at the ends of the pipe elements. The angular orientation of the arcuate shoulder surfaces provides flexibility to the joint. A method of joining pipe elements having circumferential rings is also disclosed.

Abstract: A seal used with crimp-type couplings to provide a fluid tight joint has a ring that surrounds a point. The ring has a multiplicity of cross sections. Each cross section may have the same shape and area at every position along the entire length of the ring. Each cross section has a centroid. The ring is divided into portions. Each portion subtends an angle measured about the point. Each portion is characterized by the distance from the point to the centroids of the cross sections within the portion. Centroids of the cross sections in a first portion are positioned at the same distance from the point. Centroids of the cross sections in another portion are positioned at respective points different from the distance associated with the first portion. By offsetting the centroids leak paths are intentionally created before the joint is crimped to prevent false indications of a crimped joint.

Abstract: Mechanical pipe couplings for joining pipe elements in end to end relation have arcuate keys which engage circumferential grooves in the pipe elements and radially projecting stiffening ribs aligned with the keys. At the end of the keys on opposite sides are camming surfaces which are formed by a thinning of the key. The camming surfaces may be concave, convex, or angularly oriented surfaces and serve to guide the keys into grooves when the keys are not directly aligned with the grooves.

Abstract: A ring-shaped seal has projections on an outwardly facing surface in the form of tubes which have a longitudinal axis oriented perpendicular to a plane containing the ring. The seal is received within a channel defined by segments attached end to end forming a coupling for coupling pipe elements in end to end relation. The segments have pockets which receive the projections. The projections support the segments in spaced apart relation to allow the pipe elements to be inserted into the coupling without loosening or disassembling it. The projections deform when the segments are drawn toward one another by adjustably tightenable fasteners and allow the segments to engage and capture the pipe elements in end to end relation.

Abstract: A mechanical pipe coupling is formed of segments attached end to end to surround a central space. Each segment has a circumferentially extending cavity facing the central space flanked by arcuate keys which project toward the central space. Two arcuate shoulder surfaces are positioned on each segment. The arcuate shoulder surfaces face the central space and are positioned in spaced relation on opposite sides of the cavity between the cavity and the arcuate keys. The arcuate shoulder surfaces are angularly oriented with respect to an axis perpendicular to a plane containing the segments. The coupling is used to couple pipe elements having a circumferential ring located at the ends of the pipe elements. The angular orientation of the arcuate shoulder surfaces provides flexibility to the joint. A method of joining pipe elements having circumferential rings is also disclosed.

Abstract: A coupling installed by crimping has an angularly oriented conical surface at an open end surrounded by a ring which receives a pipe element. Dies move radially toward the coupling on jaws of a crimping tool and engage the conical surface along a single line of contact to effect a crimp which secures the coupling to the pipe. The radially applied force has radial and axial components. The radial component effects the crimp, the axial component deforms a channel in the coupling in which a seal is located. The seal is deformed between the coupling and the pipe to effect a fluid tight joint. The coupling may have a circumferential rib which projects radially outwardly. Registration dogs engage the coupling and provide a reaction surface against the axial force component.

Abstract: Mechanical pipe couplings for joining large diameter pipe elements in end to end relation have arcuate keys which engage circumferential grooves in the pipe elements and radially projecting stiffening ribs aligned with the keys. Key surfaces have angular orientations between 5° and 30°. At the end of the keys on opposite sides are camming surfaces which are formed by a thinning of the key. The camming surfaces may be concave, convex, or angularly oriented surfaces and serve to guide the keys into grooves when the keys are not directly aligned with the grooves.

Abstract: Mechanical pipe couplings for joining pipe elements in end to end relation have arcuate keys which engage circumferential grooves in the pipe elements and radially projecting stiffening ribs aligned with the keys. At the end of the keys on opposite sides are camming surfaces which are formed by a thinning of the key. The camming surfaces may be concave, convex, or angularly oriented surfaces and serve to guide the keys into grooves when the keys are not directly aligned with the grooves.