Abstract: Methods of manufacturing a continuous pipe from thermoplastic materials are provided. The methods include the steps of providing an endless mandrel having a releasable surface, the endless mandrel configured for rotation, forming an inner liner layer on the releasable surface of the endless mandrel, forming an intermediate layer on the inner liner layer, forming an outer layer on the intermediate layer, thereby forming a continuous pipe and cutting the continuous pipe into segments. The method is characterized in that the inner liner layer is made of a thermoplastic material, the intermediate layer is made of commingled thermoplastic material and glass fiber reinforcement material, and the outer layer is made of a thermoplastic material.

Abstract: A reinforcement liner and methods of manufacturing the liner are disclosed. The liner includes a fabric (100) material having first and second fibers (112, 122). The second fibers comprise chopped fibers in substantially parallel alignment for being positioned substantially about the circumference of a pipe, so the fabric can be elongated in a direction parallel to the second fibers. The liner may includes a stitching material (130) that is used to couple the first and second fibers together. The stitching material is preferably an elastic yarn.

Abstract: An invention is disclosed which relates to a process for producing a glass reinforced potable water pressure pipe having an ultra thin inner layer of thermoplastic resin that is made via a continuous mandrel concept and which is ideally suited for use with potable water.

Abstract: A bellows is disclosed which includes a tube having plurality of raised circumferential convolutes formed in the surface of the tube, wherein at least one of the convolutes being formed so that a portion of the convolute is substantially even with the surface of the tube.