The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 14, 2002
Filed:
May. 31, 2000
David L. Buckley, Monrovia, CA (US);
Air Logistics Corporation, Pasadena, CA (US);
Abstract
A method of prestressing and reinforcing damaged pipes includes using a resin impregnated substrate, or a fiberglass fabric coated with a resin, to wrap a damaged area of the pipe. In order for the substrate to compress the pipe, the pipe is wrapped tightly. The compressed pipe has a negative hoop stress when the pipe is not under internal pressure. This negative hoop stress offsets the hoop stress due to the internal pressure from the fluid flow, so that the maximum hoop stress of the pipe is not exceeded. In an effort to provide this tightness, a pressurized portion of resin is introduced between the substrate and the pipe. A bladder may be inserted between the pipe and the substrate to contain a functional amount of prestressing resin injected under pressure. The resin used for prestressing can be the same as or different from the resin used to impregnate or coat the fiberglass strips.