High-density polyethylene (HDPE) liners are often used for pipeline rehabilitation. This paper describes ongoing research in which steel sleeves were welded on the outside surface of a steel pipe lined with a HDPE and then tested in the laboratory. Recommendations were made to establish welded joints using stitch welds of length equal to the minimum length specified by the applicable codes, with a center-to-center spacing of three times the weld length. A waiting period may be necessary between consecutive stitch welds, particularly for small-diameter pipes. In a second series of tests, the material performance of a liner strengthened by butt-fused HDPE rings was evaluated. The overall stiffness of the liner increased with the addition of the butt-fused rings. Tension tests were performed on dog bone-shaped samples extruded from the stiffened liner. The butt-fusion process used to attach the stiffening rings increased the average tensile strength and average elasticity modulus of the material in the fusion region.


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  • Accession Number: 00723366
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jun 28 1996 12:00AM