Abstract: A restrained pipe joining system for plastic pipe is shown comprising male and female ends each having aligned circumferential grooves which form a canal for passage of a locking keystrap. The keystrap can be formed of PEEK or PEEK reinforced with glass fiber. During manufacture, the female belled end is sequentially formed over a Rieber style gasket and then over a ring-shaped casing member. The casing member is also formed from polymeric composite materials. In some cases, the casing is reinforced with an internal metal band.

Abstract: A restrained pipe joining system for plastic pipe is shown comprising male and female pipe ends, the male pipe end having an external circumferential groove and the female pipe end having an internal recess which contains a circumferential casing element, the casing element receives a non-circular click fit restraint ring which engages the external circumferential groove of the male pipe end during the make-up of the pipe ends to form a sealed and restrained pipe joint.

Abstract: A pipe belling process where a heated thermoplastic pipe end is forced over a sealing gasket on a forming mandrel, with the pipe being subsequently cooled to retain the gasket in an internal groove simultaneously formed in the pipe end. The sealing gasket is a two-component gasket with an elastic component and a plastic component. The elastic component is stretched over a portion of the plastic component during assembly with the plastic component acting as a belling ramp for the gasket during the subsequent pipe belling operation.

Abstract: A restrained pipe joining system for plastic pipe is shown comprising male and female pipe ends, the male pipe end having an external circumferential groove and the female pipe end having an internal recess which contains a circumferential casing element, the casing element receives a non-circular click fit restraint ring which engages the external circumferential groove of the male pipe end during the make-up of the pipe ends to form a sealed and restrained pipe joint.

Abstract: A method is shown for manufacturing a hardened gripping element for a sealing and restraint system used for forming a pipe joint in a fluid pipeline. Instead of machining the gripping elements used in the system from a metal stock, a special series of metal injection molding steps are utilized. A metal polymer composite mix is first formed having a metal particulate phase and a polymer phase. A green metal composite article is formed by either extruding the composite mix or molding the composite mix into a metal polymer composite article having at least one gripping surface having a plurality of gripping teeth. The green composite article is subjected to thermal debinding and sintering to produce a brown part. The brown part is selectively hardened in the range from about 42 HRC to 45 HRC to produce a finished or near finished hardened gripping element.

Abstract: A sealing gasket is shown which is designed to be used in making up a sealed pipe joint in a plastic pipeline conveying fluids, such as a water or sewer pipeline. The sealing gasket is a two-component gasket with an elastomeric component and a plastic component. The elastomeric component is stretched over a portion of the plastic component during assembly. Since the two components of the gasket are not permanently bonded to one another, the gasket can be disassembled, allowing various combination s of seal and retainer designs. The gasket can be removed and replace by another gasket after the initial installation. The hard plastic component can be provided with a gripping structure which acts as a restraint mechanism when the sealing gasket is in use.

Abstract: A mechanism for restraining pipe against both internal and external forces at a pipe or fitting connection and to join and seal at least two pipes to form a pipeline featuring an improved restraint mechanism. The restraint mechanism includes a circumferential casing and a companion grip ring, both of which are received within a mating groove provided in the belled end of a female pipe. The grip ring is made up of a series of arc-shaped gripping elements which are interconnected by discrete elastomeric segments. The gripping elements are separated by gaps so that a flexible hinge region is created by the elastomeric segments between adjacent gripping elements. The elastomeric segments provide both axial and radial spring action to the assembly.

Abstract: A restrained pipe joining system for plastic pipe is shown comprising male and female ends each having aligned circumferential grooves which form a canal for passage of a locking keystrap. The keystrap can be formed of PEEK or PEEK reinforced with glass fiber. During manufacture, the female belled end is sequentially formed over a Rieber style gasket and then over a ring-shaped casing member. The casing member is also formed from polymeric composite materials. In some cases, the casing is reinforced with an internal metal band.

Abstract: A method of manufacturing a sealing gasket is shown for use in a pipe sealing system. A pair of mating upper and lower mold plates are provided each having an exposed molding surface in the form of a spiral cavity. A length of pre-extruded elastomeric material in the shape of the near final form of the spiral mold cavity is laid into the mold cavities to substantially fill the cavities. The material may have hardened gripping elements incorporated therein. The upper and lower mold plates are closed to compress the elastomeric material within the spiral cavities and thereafter the material is cured to form a spiral strip. The spiral strip is then cut into given lengths having opposing free ends and the free ends are spliced to form completed sealing gaskets of a desired size.

Abstract: A pipe sealing gasket is shown which is designed to be received within a raceway provided within the female, belled end of a section of plastic pipe which is assembled with a mating male pipe end to form a plastic pipe joint. The gasket is a two-component gasket having a softer, elastomeric portion and a harder, plastic ring portion. A splicing technique is used to form the softer, elastomeric portion with the harder, plastic portion being injection molded over the previously formed elastomeric portion.

Abstract: A mechanism for restraining pipe against both internal and external forces at a pipe or fitting connection and to join and seal at least two pipes to form a pipeline featuring an improved restraint mechanism. The restraint mechanism includes a circumferential casing and a companion grip ring, both of which are received within a mating groove provided in the belled end of a female pipe. The grip ring is made up of a series of arc-shaped gripping elements which are interconnected by discrete elastomeric segments. The gripping elements are separated by gaps so that a flexible hinge region is created by the elastomeric segments between adjacent gripping elements. The elastomeric segments provide both axial and radial spring action to the assembly.

Abstract: A method is shown for manufacturing a hardened gripping element for a sealing and restraint system used for forming a pipe joint in a fluid pipeline. Instead of machining the gripping elements used in the system from a metal stock, a special series of metal injection molding steps are utilized. A metal polymer composite mix is first formed having a metal particulate phase and a polymer phase. A green metal composite article is formed by either extruding the composite mix or molding the composite mix into a metal polymer composite article having at least one gripping surface having a plurality of gripping teeth. The composite article is subjected to thermal debinding and sintering to produce a finished or near finished hardened gripping element.

Abstract: A pipe sealing gasket is shown which is designed to be received within a raceway provided within the female, belled end of a section of plastic pipe which is assembled with a mating male pipe end to form a plastic pipe joint. The gasket is a two-component gasket having a softer, elastomeric portion and a harder, plastic ring portion. A splicing technique is used to form the softer, elastomeric portion with the harder, plastic portion being injection molded over the previously formed elastomeric portion.

Abstract: A pipe belling process where a heated thermoplastic pipe end is forced over a sealing gasket on a forming mandrel, with the pipe being subsequently cooled to retain the gasket in an internal groove simultaneously formed in the pipe end. The sealing gasket is a two-component gasket with an elastic component and a plastic component. The elastic component is stretched over a portion of the plastic component during assembly with the plastic component acting as a belling ramp for the gasket during the subsequent pipe belling operation.

Abstract: A pipe sealing gasket is shown which is designed to be received within a raceway provided within the female, belled end of a section of plastic pipe which is assembled with a mating male pipe end to form a plastic pipe joint. The gasket is a two-component gasket having a softer, elastomeric portion and a harder, plastic ring portion. A splicing technique is used to form the softer, elastomeric portion with the harder, plastic portion being injection molded over the previously formed elastomeric portion.

Abstract: A method is shown for manufacturing a hardened gripping element for a sealing and restraint system used for forming a pipe joint in a fluid pipeline. Instead of machining the gripping elements used in the system from a metal stock, a special series of metal injection molding steps are utilized. A metal polymer composite mix is first formed having a metal particulate phase and a polymer phase. A green metal composite article is formed by either extruding the composite mix or molding the composite mix into a metal polymer composite article having at least one gripping surface having a plurality of gripping teeth. The composite article is subjected to thermal debinding and sintering to produce a finished or near finished hardened gripping element.

Abstract: A pipe sealing gasket is shown which is designed to be received within a raceway provided within the female, belled end of a section of plastic pipe which is assembled with a mating male pipe end to form a plastic pipe joint. The gasket is a two-component gasket having a softer, elastomeric portion and a harder, plastic ring portion. A splicing technique is used to form the softer, elastomeric portion with the harder, plastic portion being injection molded over the previously formed elastomeric portion.

Abstract: A pipe sealing gasket is shown which is designed to be received within a raceway provided within the female, belled end of a section of plastic pipe which is assembled with a mating male pipe end to form a plastic pipe joint. The gasket is made up of a hard plastic band having an outer circumferential surface and an inner circumferential surface, and two separated elastomer portions. A first of the separated elastomer portions forms an outer ring which circumscribes the outer circumferential surface of the hard plastic band. The second of the separated elastomer portions forms an inner lip which circumscribes the inner circumferential surface of the hard plastic band. The two separate elastomer portions are connected during the gasket molding operation by a series of spaced ribs which form a continuous body of elastomer connecting the first and second separated elastomer portions at spaced intervals.