Brian Alester George

US Patent:

60589787, May 9, 2000

Filed:

Jul 17, 1996

Appl. No.:

8/682389

Inventors:

Stephen Paletta - Briarcliff Manor NY
Brian George - Annandale VA
David A. Fletcher - Armonk NY

International Classification:

F16L 55162

US Classification:

138 98

Abstract:

A method and apparatus for relining, repairing or reconstructing existing infrastructure pipeline systems that are new, structurally deficient or experiencing an excessive amount of exfiltration or infiltration, or converting new or damaged pipelines into dual-containment pipelines. A plurality of stock, high density polyethylene lining pipes having a cylindrical cross-section with a diameter up to 36 inches and lengths of 40-50 feet are joined together to a job specific length. The lining pipe is then heated to its flex temperature and gradually deformed to a reduced diameter. At the job site, the deformed lining pipe is inserted into the existing pipe and a controlled, pressurized environment is created therein for a period of time dependent on the pipe's length. Pressurized steam is first inserted to provide heat and internal pressure to expand the pipe. Then, compressed air is inserted to cool the pipe while maintaining the internal pressure to complete the expansion and set the pipe.