A combination seal and restraint system capable of both joining and sealing a female plastic pipe to a mating male plastic pipe having an interior surface and an exterior surface, the seal and restraint system comprising: a sealing ring formed as an elastomeric body, the sealing ring being integrally installable within a groove formed in a belled end of the female pipe during the manufacture of the belled pipe end; a companion restraint mechanism for the elastomeric sealing ring which allows movement of the mating male pipe relative to the belled end of the female pipe in a first longitudinal direction but which restrains movement in a second, opposite relative direction, the restraint mechanism comprising a ring shaped housing which is also integrally installable within the belled pipe end in the same groove as the sealing ring during manufacture and which has a circumferential interior region and a companion gripping insert which is contained within the circumferential interior region of the housing, the gripping insert having an exterior surface and an interior gripping surface with at least one row of gripping teeth (35,37, 39,43); wherein the gripping insert exterior surface has a sloping profile which contacts a mating interior region of the housing, whereby contact with the exterior surface of a mating male plastic pipe causes the gripping insert to ride along the male surface at an angle while the row of gripping teeth (35,37, 39,43) on the gripping insert internal surface engage the exterior surface of the mating male plastic pipe; wherein the gripping insert is a ring shaped member having at least one circumferential slit in the circumference thereof which allows the gripping insert to be temporarily compressed and installed within the circumferential interior region of the housing in snap-fit fashion after the ring shaped housing has been integrally installed within the belled pipe end during manufacture of the female pipe; and wherein the housing has a rear wall region which is substantially perpendicular to a longitudinal axis of the female pipe, the rear wall region being in contact with the elastomeric body of the sealing ring as a mating male pipe is inserted into a mouth opening of the female plastic pipe; wherein the housing exterior surface has at least one row of biting teeth for biting an internal diameter of the female plastic pipe, the biting teeth being located on a region of the exterior surface which is forward of a vertical central axis of the housing. a sealing ring formed as an elastomeric body, the sealing ring being integrally installable within a groove formed in a belled end of the female pipe during the manufacture of the belled pipe end; a companion restraint mechanism for the elastomeric sealing ring which allows movement of the mating male pipe relative to the belled end of the female pipe in a first longitudinal direction but which restrains movement in a second, opposite relative direction, the restraint mechanism comprising a ring shaped housing which is also integrally installable within the belled pipe end in the same groove as the sealing ring during manufacture and which has a circumferential interior region and a companion gripping insert which is contained within the circumferential interior region of the housing, the gripping insert having an exterior surface and an interior gripping surface with at least one row of gripping teeth (35,37, 39,43); wherein the gripping insert exterior surface has a sloping profile which contacts a mating interior region of the housing, whereby contact with the exterior surface of a mating male plastic pipe causes the gripping insert to ride along the male surface at an angle while the row of gripping teeth (35,37, 39,43) on the gripping insert internal surface engage the exterior surface of the mating male plastic pipe; wherein the gripping insert is a ring shaped member having at least one circumferential slit in the circumference thereof which allows the gripping insert to be temporarily compressed and installed within the circumferential interior region of the housing in snap-fit fashion after the ring shaped housing has been integrally installed within the belled pipe end during manufacture of the female pipe; and wherein the housing has a rear wall region which is substantially perpendicular to a longitudinal axis of the female pipe, the rear wall region being in contact with the elastomeric body of the sealing ring as a mating male pipe is inserted into a mouth opening of the female plastic pipe; wherein the housing exterior surface has at least one row of biting teeth for biting an internal diameter of the female plastic pipe, the biting teeth being located on a region of the exterior surface which is forward of a vertical central axis of the housing.