Liner pipe for repair of a host pipe
AssigneeIpex Inc.
InventorJoseph E. F. Goncalves
Life of this patent
Estimating the term…
Abstract
This invention relates to liner pipes and to their use in the repair of pipes, preferably in the trenchless reconstruction of underground pipes such as sewer lines. The liner pipe of the present invention comprises two layers, an outer layer comprised of flexible thermoplastic material and an inner layer comprised of rigid thermoplastic material. When heated, the inner layer becomes sufficiently pliable to allow the cross-sectional shape and size of the liner pipe to conform to the inner cross-sectional shape and size of a host pipe. Because of its structure, the liner pipe of the present invention at least partially overcomes some of the disadvantages of prior art liner pipes relating to ease and expense of installation.
Claims12
A liner pipe for repair of a host pipe;
- the liner pipe having a hollow inside;
- a length defining a longitudinal axis;
- and a cross-sectional shape and size in a plane transverse to the longitudinal axis;
- the cross-sectional shape and size of the liner pipe being such that the liner pipe can be fed through the host pipe;
- the liner pipe comprising an inner layer and an outer
- the outer layer being comprised of flexible thermoplastic material;
- and
- the inner layer being comprised of rigid thermoplastic material which, when softened by heating to attain a flexibility similar to that of the outer layer, becomes sufficiently pliable to allow the cross-sectional shape and size of the liner pipe to conform to an inner cross-sectional shape and size of the host pipe.
A method for using a liner pipe to repair a host pipe having a section to be repaired,
- said method comprising:
- feeding a liner pipe into a position in the host pipe so that the liner pipe covers substantially the entire section to be repaired;
- wherein the liner pipe has a hollow inside, a length defining a longitudinal axis, a cross-sectional shape and size in a plane transverse to the longitudinal axis which allows the liner pipe to be fed through the host pipe, an outer layer comprising flexible thermoplastic material, and an inner layer comprising rigid thermoplastic material;
- heating the inner layer of the liner pipe to an extent whereby the inner layer of the liner pipe is softened and attains a flexibility similar to that of the outer layer;
- conforming the cross-sectional shape and size of the liner pipe to an inner cross-sectional shape and size of the host pipe while the inner layer is softened;
- and
- cooling the liner pipe so that the inner layer becomes rigid.
Dependencies are inferred from the claim text.