Abstract: Process for lining a pipe with thermoplastic polymer using non-crosslinked, expandable thermoplastic liner which is uniformly heated after insertion into the pipe.

Abstract: Heating apparatus particularly useful for installing heat expandable plastic pipe liner comprising a radiant heater and air circulation means for the uniform distribution of heat about the circumference of the plastic pipe.

Abstract: A pipe fitting of organic polymeric material such as polyethylene is provided wherein said pipe fitting is of unitary construction and includes a first tubular body portion of substantially uniform internal and external diameters integrally connected to a tapered heat-expandable tubular body portion having an external diameter at its terminal end less than the external diameter of the first tubular body portion. A method for making said pipe fitting also is provided which includes placing a tubular structure of organic polymeric material into a mold having a molding surface corresponding to that of said pipe fitting and cold-forming said tubular structure by pressing said tubular structure in said mold.

Abstract: A core element preferably of plastic material is provided wherein one embodiment of the core element comprises (1) a tubular body member and (2) a tubular coupling member of water-degradable material disposed within one end of the tubular body member and extending axially outwardly therefrom, and (3) a tubular coupling member of water-degradable material disposed within the other end of the tubular body member and also extending axially outwardly therefrom, including also diametrically opposed lug members extending radially outwardly from the tubular coupling member that engage a slot disposed in the wall of the tubular body member whereby the tubular coupling member may be moved into and out from the tubular body member as in a telescoping manner.