Abstract: A pipe joining system and pipe joint are shown m which two sections of molecularly oriented pipe are joined using heat shrinking techniques. A first section of pipe is provided having a straight, pre-formed socket with an internal diameter and with an end opening having enough clearance to allow a mating spigot section having a given external diameter to be inserted into the socket end opening. After the spigot end is inserted to a given depth, the socket is heated sufficiently so that the internal diameter of the socket end comes into contact with the external diameter of the spigot end, the molecularly oriented pipe being in a rubbery state and exhibiting a low elastic modulus which allows the socket end to conform tightly to the spigot end external diameter without deforming the spigot end.

Abstract: A sealing gasket is shown which is used to seal the belled end opening of a female ductile iron pipe to a mating male pipe having an interior surface and an exterior surface. The sealing gasket has an annular gasket body made of a resilient elastomeric material which is bonded to a hard plastic reinforcing band. The annular gasket body is installed within a raceway provided in the mouth region of the female ductile iron pipe so that an outer circumferential region forms a seal with the female pipe mouth region and an inner circumferential region forms a sealing surface for the exterior surface of the mating male pipe. The reinforcing band has a circumferential body which is made of a synthetic polymer which has a greater hardness than the elastomeric material of the remainder of the gasket body.

Abstract: A pipe joining system and pipe joint are shown m which two sections of molecularly oriented pipe are joined using heat shrinking techniques. A first section of pipe is provided having a straight, pre-formed socket with an internal diameter and with an end opening having enough clearance to allow a mating spigot section having a given external diameter to be inserted into the socket end opening. After the spigot end is inserted to a given depth, the socket is heated sufficiently so that the internal diameter of the socket end comes into contact with the external diameter of the spigot end, the molecularly oriented pipe being in a rubbery state and exhibiting a low elastic modulus which allows the socket end to conform tightly to the spigot end external diameter without deforming the spigot end.

Abstract: A pipe joining system and pipe joint are shown in which two sections of plastic pipe, particularly molecularly oriented pipe, are joined. A first section of plastic pipe has a female, belled pipe end with a mouth opening and having an exterior surface, an interior surface and having an interior circumferential recess formed in the belled pipe end adjacent the mouth opening on the interior surface thereof. A second section of plastic pipe having a mating male plastic pipe end has an interior surface and exterior surface. The exterior surface has a circumferential groove formed at one circumferential location thereof which is alignable with the interior recess formed within the mouth opening of the belled pipe end as the pipe joint is made-up. The circumferential groove is formed during the manufacture of the plastic pipe by expanding the pipe against a restraining element located in the interior of an expansion mold.

Abstract: A pipe joining system and pipe joint are shown in which two sections of plastic pipe, particularly molecularly oriented pipe, are joined. A first section of plastic pipe has a female, belled pipe end with a mouth opening and having an exterior surface, an interior surface and having an interior circumferential recess formed in the belled pipe end adjacent the mouth opening on the interior surface thereof. A second section of plastic pipe having a mating male plastic pipe end has an interior surface and exterior surface. The exterior surface has a circumferential groove formed at one circumferential location thereof which is alignable with the interior recess formed within the mouth opening of the belled pipe end as the pipe joint is made-up. The circumferential groove is formed during the manufacture of the plastic pipe by expanding the pipe against a restraining element located in the interior of an expansion mold.

Abstract: A manhole assembly for a manhole having generally cylindrical sidewalls defined between an outside surface and an inside surface separated by a wall thickness and having a wall opening communicating the outside and inside sidewall surfaces of the manhole for insertion of a mating pipe. The wall opening defines a peripheral surface relatively perpendicular to the outside and inside sidewall surfaces which receives a ring shaped elastomeric gasket. The gasket has one or more retaining rings which are encapsulated within the material of the gasket body and which allow the gasket to be obliquely inserted within the wall opening of the manhole and to be subsequently snap-fitted into position on the peripheral surface, whereby the gasket is securely retained in a locked-in position with respect to the wall opening in the sidewall of the manhole.

Abstract: An energy recovery system for a pipe manufacturing process is shown. A compression or injection molding operation is used to form a sealing gasket which is used in the subsequent pipe manufacturing operation. A Stirling engine cycle is used to recover heat during the gasket manufacture. The Stirling engine is driven by waste heat from the mold members or other associated parts of the injection or compression molding apparatus. The recovered waste heat is used to subsequently heat the female pipe end which is being belled in the pipe manufacturing process.

Abstract: A method for joining molecularly oriented pipe in which a coupling is provided which is formed of a material other than molecularly oriented pipe, such as ordinary PVC pipe. The coupling if formed as a tubular body with a combination sealing and restraint mechanism located in each of two opposing end openings of the coupling that seal and restrain mating plain spigot ends of the molecularly oriented pipe. Because the coupling is made of a material such as ordinary PVC, the sealing and restraint mechanisms can be installed in internal grooves provided in the coupling interior during normal pipe belling operations without introducing unacceptable levels of stress or strain into the product.

Abstract: A combination sealing and restraint system for an as-cast ductile iron fitting is shown for both sealing and preventing separation of an iron pipe fitting and a mating male pipe. A ring-shaped body is installed within a mating groove provided in a mouth region of the as-cast fitting after the fitting has been cast at the manufacturing plant. The ring-shaped body carries a gripping member with teeth on an inner surface thereof which are initially angled away from an outer surface of a mating male pipe. The teeth are forced into engagement with the exterior surface of the mating male pipe as the pipe joint at the fitting is assembled. The teeth are oriented to allow movement of the male pipe in a first direction relative to an end opening of the fitting during assembly, but to resist movement in a opposite direction after the fitting joint has been assembled. The ring-shaped body also includes a relatively flexible portion formed of an elastomer which forms a sealing member with the mating male pipe.

Abstract: A combination sealing and restraint system for an as-cast ductile iron fitting is shown for both sealing and preventing separation of an iron pipe fitting and a mating male pipe. A ring-shaped body is installed within a mating groove provided in a mouth region of the as-cast fitting after the fitting has been cast at the manufacturing plant. The ring-shaped body is formed of an injection molded elastomeric material and carries a series of gripping segments which have teeth on an inner surface thereof which are designed to engage an outer surface of a mating male pipe. The teeth are oriented to allow movement of the male pipe in a first direction relative to an end opening o f the fitting during assembly, but to resist movement in a opposite direction after the fitting joint has been assembled. The gripping segments are mechanically bonded to the elastomeric body of the gasket during the injection molding operation.

Abstract: A method and apparatus for restraining pipe against internal forces at a pipe or fitting connection and to join and seal at least two pipes to form a pipeline is shown featuring an improved restraining/sealing mechanism. The restraining/sealing mechanism includes a relatively rigid gripper ring and a companion sealing ring which are received within one or more mating grooves provided in the belled end of a female pipe. The gripper ring and sealing ring can be combined or attached, or they can be separate members located in the same retaining groove or separate grooves in the female belled pipe end.

Abstract: A system is shown for locating hidden pipelines, particularly underground pipe used in a plastic pipeline such as for municipal water and sewer applications. An RFID tag is associated with the pipeline prior to installation of the pipeline into the ground. This can be done by associating the RFID tag with a sealing gasket which is subsequently installed at a sealing joint location of the pipeline. The tag can also be associated with the pipeline itself by installing the tag on a section of pipe. The location of the subsequently buried pipeline can be determined by interrogating the RFID tag with a suitable reader, the reader being located at an above ground location.

Abstract: An energy recovery system for a pipe manufacturing process is shown. A compression or injection molding operation is used to form a sealing gasket which is used in the subsequent pipe manufacturing operation. A Stirling engine cycle is used to recover heat during the gasket manufacture. The Stirling engine is driven by waste heat from the mold members or other associated parts of the injection or compression molding apparatus. The recovered waste heat is used to subsequently heat the female pipe end which is being belled in the pipe manufacturing process.

Abstract: An apparatus 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 restraining and sealing mechanism. The restraining and sealing mechanism includes a circumferential housing and a companion sealing ring which are received within a mating groove provided in the belled end of a female pipe. The circumferential housing has an interior region which contains a gripping ring insert. The sealing ring and housing are integrally located within a belled pipe end during belling operations.

Abstract: A pipe sealing gasket is shown which is designed to be received within a groove provided within a socket end of a thermoplastic pipe in a pipe sealing system. The sealing system includes a male, spigot pipe end which is joined to a mating female belled pipe end. The belled pipe end has an internal groove adjacent a mouth region thereof which is simultaneously formed under temperature and pressure as the mouth region is forced over a forming mandrel and about a sealing gasket located on the forming mandrel so that the sealing gasket is prelocated within the internal groove. The sealing gaskets of the invention have a specially designed sealing capability to seal volume ratio.

Abstract: A pipe sealing gasket is shown which is designed to be received within a groove provided within the belled, socket end of a plastic pipe. The sealing gasket has a body formed of resilient material and has a retainer ring embedded therein which circumscribes the gasket body. The groove in the plastic pipe is preformed during the manufacture of the plastic pipe and the gasket is installed thereafter. The gasket nominal diameter exceeds the internal diameter of the belled pipe end. The retainer ring is placed within the body of the sealing gasket at a precisely determined location which most effectively retains the ring in position while withstanding the forces of the assembly of the pipe joint.

Abstract: A combination sealing and restraint system for an as-cast ductile iron fitting is shown for both sealing and preventing separation of an iron pipe fitting and a mating male pipe. A ring-shaped body is installed within a mating groove provided in a mouth region of the as-cast fitting after the fitting has been cast at the manufacturing plant. The ring-shaped body carries a gripping member with teeth on an inner surface thereof which are initially angled away from an outer surface of a mating male pipe. The teeth are forced into engagement with the exterior surface of the mating male pipe as the pipe joint at the fitting is assembled. The teeth are oriented to allow movement of the male pipe in a first direction relative to an end opening of the fitting during assembly, but to resist movement in a opposite direction after the fitting joint has been assembled. The ring-shaped body also includes a relatively flexible portion formed of an elastomer which forms a sealing member with the mating male pipe.

Abstract: A pipe sealing gasket is shown which is designed to be received within a groove provided within a belled, socket end of a plastic pipe. The groove in the plastic pipe is preformed during manufacture and the gasket is installed thereafter. The gasket nominal diameter exceeds the internal diameter of the belled pipe end. A special installation tool is used to pull the gasket from an initially deformed, elliptical shape to a normal cylindrical shape. The installation tool uses only one fluid cylinder for power and can be hand installed and operated.

Abstract: A manhole assembly for a manhole having generally cylindrical sidewalls defined between an outside surface and an inside surface separated by a wall thickness and having a wall opening communicating the outside and inside sidewall surfaces of the manhole for insertion of a mating pipe. The wall opening defines a peripheral surface relatively perpendicular to the outside and inside sidewall surfaces which receives a ring shaped elastomeric gasket. The gasket has one or more retaining rings which are encapsulated within the material of the gasket body and which allow the gasket to be obliquely inserted within the wall opening of the manhole and to be subsequently snap-fitted into position on the peripheral surface, whereby the gasket is securely retained in a locked-in position with respect to the wall opening in the sidewall of the manhole.

Abstract: A pipe sealing gasket is shown which is designed to be received within a groove provided within the belled, socket end of a plastic pipe. The sealing gasket has a body formed of resilient material and has a retainer ring embedded therein which circumscribes the gasket body. The groove in the plastic pipe is preformed during the manufacture of the plastic pipe and the gasket is installed thereafter. The gasket nominal diameter exceeds the internal diameter of the belled pipe end. The retainer ring is placed within the body of the sealing gasket at a precisely determined location which most effectively retains the ring in position while withstanding the forces of the assembly of the pipe joint.