Method for forming and sealing pipe liners
US6299803A · kind A · utility
Inventor
Key dates
| Filing date | Oct 21, 1999 |
| Grant date | Oct 9, 2001 |
| Priority date | — |
| Expiry date | Oct 21, 2019 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2101/12
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method for producing temporarily deformed pipe liners from a continuously extruded thermoplastic round pipe, or thermoplastic round pipe extruded in segments of 20 to 50 feet in length and butt-fused together to obtain a pipe liner segment of a length greater than the conduit to be lined; annealing the pipe liner before deformation in a stress release chamber to relieve stresses induced in the extrusion process; collapsing the pipe liner to a flattened shape by means of internal vacuum and subsequently bending deformable portions of the flattened shape toward a back-up portion thereof, and without elongation, maintaining diameter and wall thickness; applying a sealant material on the outer pipe liner surface to seal the gap between the pipe liner and conduit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.