Patrick R Ledoux

51122111, May 12, 1992

Dec 12, 1990

7/626536

Patrick LeDoux - New Orleans LA

Pipe Liners, Inc. - Metairie LA

B29C 3500

425384

Apparatus for inserting a generally U-shaped liner into a pipe and reforming the U-shaped liner into a generally cylindrical cross-section to line the pipe includes winches for pulling the U-shaped liner through the pipe, pigs for cleaning the pipe, manifolds to connection at opposite ends of the pipe and wedge-shaped expansion members for initially mechanically reforming the ends of the liner projecting from the pipe. The wedge-shaped members include bores for communicating fluid at elevated temperature and pressure within the liner for setting the liner in generally cylindrical configuration against the pipe wall. A flaring tool is used to flare the opposite ends of the liner.

49851969, Jan 15, 1991

Oct 30, 1987

7/114949

Patrick LeDoux - New Orleans LA

Pipe Liners, Inc. - Metairie LA

B29C 6338
B29C 5308

264516

Method is provided for lining a pipe wherein a thermoplastic liner is initially formed in a cylindrical shape with a diameter slightly larger than the internal diameter of the pipe. The liner is temporarily deformed at an elevated temperature to a different cross-section, preferably U-shaped, to reduce it overall cross-sectional dimension to facilitate insertion into the pipe to be lined. Once inserted, the pipe liner is re-heated and pressurized so that the shape memory characteristics of the thermoplastic material causes the liner to return to its original cylindrical shape. Pressure within the liner is increased in two stages to cause the liner to conform to the interior surface of the pipe. An expansion pig may also be employed to ensure even more exact conformance. After expansion, ends of the liner which extend beyond the pipe are flared into engagement with the pipe flanges.

49988719, Mar 12, 1991

Jan 19, 1989

7/298754

Patrick R. Ledoux - New Orleans LA

Pipe Liners, Inc. - Metairie LA

B29C 5308

425140

Apparatus is provided for lining a pipe wherein a thermoplastic liner is initially formed in a cylindrical shape with a diameter slightly larger than the internal diameter of the pipe. The liner is temporarily deformed at an elevated temperature to a different cross-section, preferably U-shaped, to reduce its overall cross-sectional dimension to facilitate insertion into the pipe to be lined. The deformation occurs with substantially comparable elongation of the pipe lining along its opposite sides thereby precluding variations in wall thickness and stress in the pipe. Once inserted, the liner is pressurized and reheated first to a temperature below its crystallization temperature to round the lining in the pipe and subsequently, further pressurized and reheated to a second temperature higher than the crystallization temperature to cause the liner to retain its original round shape.

49869515, Jan 22, 1991

Apr 29, 1988

7/188468

Patrick R. Ledoux - New Orleans LA
Luc R. Fourgaut - Huegeville, FR

Pipe Liners, Inc. - Metairie LA

B29C 6338
B29C 5308

264516

Method is provided for lining a pipe wherein a thermoplastic liner is initially formed in a cylindrical shape with a diameter slightly larger than the internal diameter of the pipe. The liner is temporarily deformed at an elevated temperature to a different cross-section, preferably U-shaped, to reduce its overall cross-sectional dimension to facilitate insertion into the pipe to be lined. Once inserted, the pipe liner is reheated to the crystallization temperature of the thermoplastic material to cause the liner to return to its original cylindrical shape. Pressure within the liner is also increased in two stages to cause the liner to conform to the interior surface of the pipe. An expansion pig may also be employed to ensure even more exact conformance. After expansion, ends of the liner which extend beyond the pipe are flared into engagement with the pipe flanges. Service fluid under pressure is introduced into the liner to maintain the liner in its cylindrical shape.

53425707, Aug 30, 1994

Aug 9, 1990

7/564708

Patrick R. Ledoux - New Orleans LA

Pipe Liners, Inc. - St. Rose LA

B29C 4926

264566

A method producing deformed pipe liners from continuously extruded thermoplastic material by collapsing and bending deformable portions of the tube toward a back-up portion thereof and without elongation to maintain diameter and wall thickness, and apparatus to carry out said method and characterized by at least one back-up roller and at least one shaping roller folding the deformable portion along a line of symmetry and juxtaposing a fold of the tube to the back-up portion, all at raised temperature followed by reduced temperature on a rail conforming to the deformed tube configuration.

48633658, Sep 5, 1989

Jul 27, 1987

7/077883

Patrick R. Ledoux - New Orleans LA

Pipe Liners, Inc. - Metairie LA

A01J 2100

425343

A method producing deformed pipe liners from continuously extruded thermoplastic material by collapsing and bending deformable portions of the tube toward a back-up portion thereof and without elongation to maintain diameter and wall thickness, and apparatus to carry out said method and characterized by at least one back-up roller and at least one shaping roller folding the deformable portion along a line of symmetry and juxt posing a fold of the tube to the back-up portion, all at raised temperature followed by reduced temperature on a rail conforming to the deformed tube configuration.

6299803, Oct 9, 2001

Oct 21, 1999

9/422426

Patrick Ledoux - Baton Rouge LA

B29C 6334

264 35

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.

50911376, Feb 25, 1992

Nov 21, 1990

7/616926

Patrick R. Ledoux - New Orleans LA

Pipe Liners, Inc. - Metairie LA

B29C 6338
B29C 5308

264516

A method is provided for lining a pipe wherein a thermoplastic liner is initially formed in a cylindrical shape with a diameter slightly larger than the internal diameter of the pipe. The liner is temporarily deformed at an elevated temperature to a different cross-section, preferably U-shaped, to reduce its overall cross-sectional dimension to facilitate insertion into the pipe to be lined. The deformation occurs with substantially comparable elongation of the pipe lining along its opposite sides thereby precluding variations in wall thickness and stress in the pipe. Once inserted, the liner is pressurized and reheated first to a temperature below its crystallization temperature to round the lining in the pipe and subsequently, further pressurized and reheated to a second temperature higher than the crystallization temperature to cause the liner to retain its original round shape.