A first projection is formed on the outer periphery of a bulb part, a second projection is formed on the socket rear end of the bulb part, a tapered part is formed with a decreasing diameter from the inner periphery of a heel part to the inner periphery of the second projection, and a third projection is formed on the tapered part. A first dimension B from the first projection to the third projection in an inclination direction opposite to an inclination direction G of the tapered part is smaller than a second dimension C from the first projection to the second projection in a radial direction A.

A first projection is formed on the outer periphery of a bulb part, a second projection is formed on the socket rear end of the bulb part, a tapered part is formed with a decreasing diameter from the inner periphery of a heel part to the inner periphery of the second projection, and a third projection is formed on the tapered part. A first dimension B from the first projection to the third projection in an inclination direction opposite to an inclination direction G of the tapered part is smaller than a second dimension C from the first projection to the second projection in a radial direction A.

A pipe coupling assembly for coupling a first end portion of a first pipe with a second pipe includes a socket formed on an end of the second pipe and a locking ring. The socket includes a rim defining an end opening through which at least a portion of the first end portion is inserted, the rim including a rim sealing surface adapted to form a liquid-tight seal around the first end portion. The socket also includes a sleeve portion having an exterior surface and an interior surface defining an interior space for receiving the first end portion, the interior surface comprising at least two socket sealing surfaces adapted to form a liquid-tight seal around the first end portion. The locking ring is adapted to cause the rim sealing surface to compress to form a liquid-tight seal around the first end portion.

A pipe coupling assembly for coupling a first end portion of a first pipe with a second pipe includes a socket formed on an end of the second pipe and a locking ring. The socket includes a rim defining an end opening through which at least a portion of the first end portion is inserted, the rim including a rim sealing surface adapted to form a liquid-tight seal around the first end portion. The socket also includes a sleeve portion having an exterior surface and an interior surface defining an interior space for receiving the first end portion, the interior surface comprising at least two socket sealing surfaces adapted to form a liquid-tight seal around the first end portion. The locking ring is adapted to cause the rim sealing surface to compress to form a liquid-tight seal around the first end portion.

A gasket for preventing the separation of a pipe joint formed between plastic pipes such as pipes manufactured from PVC. The invention provides a restrained pipe joint including a first pipe including a bell with a spigot entryway and a substantially V-shaped annular groove. The annular groove includes a front radial wall and a rear radial wall and a gasket seated in the annular groove. The gasket includes an inner radial face, an opening defined by the inner radial face and an outer radial face with a front radial section located adjacent to the front radial wall of the annular groove and a rear radial section located adjacent to the rear radial wall of the annular groove. A plurality of restraining segments is at least partially embedded in the gasket, each restraining segment including a toothed inner face and a smooth, sliding front radial face arranged to slide against the front radial wall of the annular groove and facilitate wedging of the segment between the plastic pipes.

A polymer pipe has a length between a first end and a second end. The length and the first end have a first diameter and the second end is a belled end having a second diameter larger than the first diameter. An insert device is received within the second end and has an annular body and a spline groove formed in the annular body and facing radially inward. The insert device is pre-installed in the belled end during the belling process.

A polymer pipe has a length between a first end and a second end. The length and the first end have a first diameter and the second end is a belled end having a second diameter larger than the first diameter. An insert device is received within the second end and has an annular body and a spline groove formed in the annular body and facing radially inward. The insert device is pre-installed in the belled end during the belling process.

A joint structure for connecting lengths of pipe uses a plurality of teeth to engage the surface of at least one end of the adjacent lengths of pipe to connect the ends. A deformable member applies forces to the plurality of teeth to engage the surfaces. In an aspect, the plurality of teeth are releasable. In another aspect, the plurality of teeth are permanently engaged into the surfaces.

A joint structure for connecting lengths of pipe uses a plurality of teeth to engage the surface of at least one end of the adjacent lengths of pipe to connect the ends. A deformable member applies forces to the plurality of teeth to engage the surfaces. In an aspect, the plurality of teeth are releasable. In another aspect, the plurality of teeth are permanently engaged into the surfaces.

A joint structure for connecting lengths of pipe uses a plurality of teeth to engage the surface of at least one end of the adjacent lengths of pipe to connect the ends. A deformable member applies forces to the plurality of teeth to engage the surfaces. In an aspect, the plurality of teeth are releasable. In another aspect, the plurality of teeth are permanently engaged into the surfaces.