Liner for lateral pipe line

Abstract

Systems and methods for forming and deploying a pipe liner in a pipe main having a service lateral. The line is formed from three pieces of material. The piece of material forming the front top and of the main liner and the front of the lateral line has a cutout at the joint to reduce bunching, which can result in non-uniform liner thickness and may form obstructions at the joint.

Claims

1. A liner configured for trenchless installation in a pipe having a service lateral, the liner comprising: a main pipe liner portion comprising a bottom and an opposing top comprising a front top and an opposing back top; and a service lateral liner portion attached to said main pipe liner portion, said service lateral liner portion comprising opposing lateral sides and a front and opposing back; wherein a first contiguous piece, a second contiguous piece, and a third contiguous piece form said main pipe liner portion and said attached service lateral liner portion when assembled together; wherein said first contiguous piece comprises said opposing lateral sides and said bottom; wherein said second contiguous piece comprises said front and said front top and an amount of material is removed at the joint between said front and said front top to form a cutout in said second contiguous piece; and wherein said third contiguous piece comprises said back and said back top.

2. The liner of claim 1, wherein said liner is a cured-in-place pipe liner.

3. The liner of claim 1, wherein said service lateral liner portion is attached to said main pipe liner portion at a non-perpendicular angle.

4. The liner of claim 3, wherein said first contiguous piece is in the configuration of a hexagonal center generally corresponding to said bottom and having two elongated rectangular arms attached at opposing sides of said hexagonal center and generally corresponding to said lateral sides.

5. The liner of claim 4, wherein said first contiguous piece is generally symmetrical around a midline through said hexagonal portion.

6. The liner of claim 5, wherein the angle from said midline to the major axis of each of said arms is said non-perpendicular angle.

7. The liner of claim 3, wherein said second contiguous piece is in the configuration of a trapezoidal element corresponding to said front top and attached to a generally rectangular arm corresponding to said front.

8. The liner of claim 7, wherein said cutout is disposed at the joint between said generally rectangular arm and said trapezoidal element.

9. The liner of claim 3, wherein said third contiguous piece is in the configuration of a trapezoidal element corresponding to said back top and attached to a generally rectangular arm corresponding to said back.

10. The liner of claim 1, wherein said first contiguous piece, said second contiguous piece, and said third contiguous piece are made from fabric.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 depicts a diagram of a prior art cured-in-place pipe (“CIPP”) liner installation process.

(2) FIGS. 2A and 2B provide a diagram of a service lateral liner.

(3) FIG. 3 depicts an embodiment of a CIPP liner for a service lateral according to the present disclosure.

(4) FIG. 4A depicts embodiments of front and back pieces for a CIPP liner for a service lateral according to the present disclosure.

(5) FIG. 4B depicts an embodiment of a bottom/side piece of a CIPP liner for a service lateral according to the present disclosure.

(6) FIG. 4C provides a set of perspective drawings of an embodiment of an assembled CIPP liner for a service lateral comprised of a plurality of connected pieces according to the present disclosure.

(7) FIG. 4D depicts a cutaway diagram of an embodiment of a CIPP liner for a service lateral according to the present disclosure.

(8) FIG. 5A depicts an alternative embodiment of a CIPP liner for a service lateral according to the present disclosure.

(9) FIG. 5B depicts an alternative embodiment of a bottom and side piece of a CIPP liner for a service lateral according to the present disclosure.

(10) FIG. 5C depicts a cutaway diagram of an alternative embodiment of a CIPP liner for a service lateral.

(11) FIG. 6 depicts an embodiment of a CIPP liner for a service lateral having a cutaway area according to the present disclosure.

(12) FIG. 7 depicts a graph of an embodiment of a cutaway area for use with a CIPP liner according to the present disclosure.

DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

(13) The following detailed description and disclosure illustrates by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the disclosed systems and methods, and describes several embodiments, adaptations, variations, alternatives and uses of the disclosed systems and methods. As various changes could be made in the above constructions without departing from the scope of the disclosures, it is intended that all matter contained in the description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

(14) Described herein, among other things, is a CIPP liner including a branch liner for a service lateral which is designed to limit or inhibit material bunching. An embodiment of such a liner is depicted in FIG. 2A. In the depicted embodiment of FIG. 2A, a main liner 109 is disposed within a main 101 having at least one service lateral 103. The main liner 109 includes a lateral liner 201 inverted within the main liner 109. To install the lateral liner 201, the main liner 109 is positioned so that the joint between the main liner 109 and lateral liner 201 is situated at the joint 203 between the main line 101 and the service lateral 103. Next, pressure is applied to cause the branch liner 201 to invert into the service lateral 103. This is depicted in FIG. 2B. This installation has the advantage of providing a seamless and jointless liner between the main 101 and lateral 103, reducing the problems caused by spaces between the liner 109 and main 101.

(15) In FIG. 3, an embodiment of such a liner 109 is shown. In the depicted embodiment of FIG. 3, the liner 109 is constructed of three different pieces 301, 303A and 303B, which are assembled to form the liner 109. In the depicted embodiment, the lateral sides A of the service liner 201 and the bottom portion B of the main liner 109 comprise a first contiguous piece 301 of liner material. The front D of the service liner 201 and the front top C of the main liner 109 comprise a second contiguous piece 303A of liner material. The back E of the service liner 201 and the back top F of the main liner 109 comprise a third contiguous piece 303B of liner material. The relative directional terms “front,” “back,” and “lateral sides” should be understood with respect to the axial length of the main 101, as in, for example, FIG. 3.

(16) The depicted liner 109 is configured for use with a service lateral that connects to the main 101 at a non-perpendicular angle θ. In the depicted embodiment, θ is about sixty degrees as measured from the axis of main 101.

(17) Pieces 301, 303A, and 303B are further depicted in FIGS. 4A and 4B. As shown in FIG. 4B, the first piece 301 comprises a generally hexagonal center B with two generally rectangular arms A attached thereto and extending therefrom at opposing sides of the hexagon, the piece 301 being generally symmetrical at a midline 407. The angle θ between the midline 407 and the major length of the arms A is about the same as the angle θ of the lateral 103 to the main 101. As shown in FIG. 4A, the second piece 303A is comprised of a generally rectangular arm D corresponding to the front D of the lateral liner 201, and connected to a generally trapezoidal element C corresponding to the front top C of the main liner 109. The third piece 303B is also comprised of a generally rectangular arm E corresponding to the back side E of the lateral liner 201, and is connected to a generally trapezoidal component F corresponding to the back top F of main liner 109.

(18) To assemble the liner 109, the rectangular arms A of piece 301, shown in FIG. 4B, are folded towards each other, forming the sides A of the lateral liner 201. The hexagon B forms the bottom B of the main liner 109. Piece 303B is folded 401 at about the connection point between the rectangle E and the trapezoid F, and piece 303A is likewise folded 403 at about the connection point between rectangle D with trapezoid C. The three pieces 301, 303A and 303B are sewn together to form the depicted liner of FIG. 3. FIG. 4C depicts perspective drawings of the assembled liner 109 showing the corresponding connection of pieces 301, 303A, and 303B. Similarly, FIG. 4D depicts a cutaway diagram of the assembled liner 109.

(19) In the depicted embodiment of FIGS. 3 and 4A-4D, the angle θ between the service lateral 103 and the main line 101 is non-perpendicular. If the fold 403 is made in piece 303A to assemble the liner 109, trapezoidal portion C is at an acute angle to the rectangular portion D. This acute angle causes the material of piece 303A around the fold 403 to crinkle, or bunch up. This in turn can result in non-uniform thickness, and may form an obstruction at the joint between the main 101 and service lateral 103. It is thus desirable to prevent or inhibit bunching up of the felt material of the liner tube 109.

(20) To do this, an amount of material is removed 405 at the folding point 403. The amount and shape of the material to be removed 405 varies with the angle and size of the piece, and is generally configured in the shape of two opposing arcs joined at their end points, or a “football” shape. This shape 405 is shown in FIG. 4A, and is shown in more detail in FIG. 6. In the depicted embodiment, the shape 405 of the removed material is defined by two circular arcs, arc.sub.top and arc.sub.bottom. In the depicted embodiment, arc.sub.top is defined as that portion of the circular arc defined by Equation 1 located above the x-axis (positive y-value).

(21) $\begin{array}{cc}y=\left(\sqrt{\frac{25}{64}{L}^2-x^2}\right)-\frac{3}{8}L\mathrm{where}L\mathrm{is}\mathrm{the}\mathrm{length}\mathrm{of}\mathrm{the}\mathrm{chord}\mathrm{at}\mathrm{the}x\text{-}\mathrm{axis}& \mathrm{Equation}\left(1\right)\end{array}$
In the depicted embodiment, the shape of arc.sub.bottom is defined as that portion of the circular arc defined by Equation 2 located below the x-axis (negative y-value).

(22) $\begin{array}{cc}y=-\left(\sqrt{\frac{25}{64}{L}^2-x^2}\right)-\frac{3}{8}L\mathrm{where}L\mathrm{is}\mathrm{the}\mathrm{length}\mathrm{of}\mathrm{the}\mathrm{chord}\mathrm{at}\mathrm{the}x\text{-}\mathrm{axis}& \mathrm{Equation}\left(2\right)\end{array}$
Illustrative examples of these two arcs, having an L=4, are shown in FIG. 7.

(23) By removing the football-shaped portion 405, bunching is inhibited because the fabric which would normally crinkle or bunch up is no longer present. This allows the piece 303A to be assembled in an acute angle with reduced risk of improper curing or forming an obstruction. It should be noted that the length L of the chord defining the midpoint of the shape 405 is generally less than the width W of the rectangular portion D of the piece 303A. This allows for at least some amount of fabric to remain connecting portions C and D together.

(24) While this technique is perhaps most applicable to an acute angle θ, due to the propensity for bunching with such an angle, it is also useful with any angle, including a perpendicular angle. As shown in the depicted embodiment of FIG. 5, a liner 109 with a lateral 201 at a generally perpendicular angle may also use the formulae described in Equations 1 and 2 to cut out an amount of fabric 405 at the folding point 403 in order to reduce or inhibit bunching during assembly. FIG. 5B depicts an embodiment of a first piece 301 for use in assembling a perpendicular lateral liner 201, and FIG. 5C depicts a cutaway diagram of an assembled liner 109 having perpendicular lateral 201.

(25) This structure reduces or eliminates the problem of bunching, as the structures defined by the formulae set forth herein and/or by related mathematical formulae as would be understood by one of ordinary skill in the art, reduce the amount of liner material used to form the lateral joint, resulting in a smoother, continuous connection with less material bunching, reducing or eliminating weak points caused by prior art systems.

(26) While the invention has been disclosed in conjunction with a description of certain embodiments, including those that are currently believed to be the preferred embodiments, the detailed description is intended to be illustrative and should not be understood to limit the scope of the present disclosure. As would be understood by one of ordinary skill in the art, embodiments other than those described in detail herein are encompassed by the present invention. Modifications and variations of the described embodiments may be made without departing from the spirit and scope of the invention.