Abstract: A method for belling the ends of thermoplastic pipes including the steps of delivering the pipes successively to an initial location adjacent conveyor means including a continuously driven endless belt, and transferring the pipes successively from the initial location onto the conveyor means in a spaced relationship with each pipe disposed for movement by the conveyor means in a direction transverse to the length of the pipe and in a spaced relationship through heating and belling stations.

Abstract: Marker posts, useful for delineating traffic paths, e.g., on highways, airports and parking areas, capable of being impacted and run over by vehicles at sub-zero ambient temperatures, with the post returning to its normal upright position. The posts are extruded tubular bodies of polyethylene modified by an additional polymer selected from the group consisting of ethylene-vinyl acetate copolymers and ethylene-ethyl acrylate copolymers.

Abstract: A plurality of extrusion dies are operated from the same source of heat-plastified polymeric material, e.g., from a single barrel extruder, via a distribution manifold which includes forwardly diverging flow passages each leading to a different one of the dies. The flow passages of the manifold have equal flow capacities and compensation for differences between the extrusion dies is accomplished by equipping each die assembly with a replaceable flow control insert, the inserts being so dimensioned that the pressure differential across each die assembly, including the insert, is the same.

Abstract: Method and apparatus for belling an end of a length of thermoplastic pipe by thermally softening the end of the pipe, inserting an expansible belling head into the softened end, expanding the belling head to accomplish shaping of the thermoplastic material, cooling the pipe, and then separating the pipe from the belling head.

Abstract: A pipeline expansion joint having a smooth bore, for use with pipelines into which flow slurries containing solids in suspension, comprises a first sleeve open at both ends and having a tapered portion formed in the inner wall of one of its ends extending at a small angle with the axis of the first sleeve and over a substantial portion of the length of the first sleeve from its inside diameter to substantially its outside diameter, and a second sleeve also open at both ends and having a first portion of substantially the same inner diameter as the outer diameter of the first sleeve and telescopically mounted on the above-mentioned one end of the first sleeve, a second portion of the same diameter as the first sleeve, and an intermediate portion expanded at a small angle with the axis of the second sleeve over a substantial portion of its length from the second to the first portion of such second sleeve.

Abstract: Polyvinyl chloride pipe capable of being coiled and uncoiled under conditions involved in installing under ground by plowing in, and having characteristics meeting requirements necessary for use in natural gas distribution, and compositions and methods for producing such pipe.