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Process and prepressing pipe for laying a pipeline in the earth

  • US 4,552,485 A
  • Filed: 10/22/1982
  • Issued: 11/12/1985
  • Est. Priority Date: 10/23/1981
  • Status: Expired due to Fees
First Claim
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1. Pipe for use in laying a prepressed pipeline in the earth comprising:

  • a load bearing shell having an inner surface;

    an at least substantially even outer surface and first and second longitudinal force transferring end faces;

    a layer of polymeric material adjacent to said inner surface, said layer characterized by a first average thickness over a substantial portion of said pipe between said end faces and end portions of greater thickness proximate said end faces; and

    a plurality of flexible projections extending from said layer into said shell for anchoring said layer to said shell.

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