Patent Application
20200109810
The present invention relates to a device and method for repairing and sealing an opening in a pipe, such as underground sewer pipe and the like.
As the infrastructure of major cities and towns in the developed world age, the sewer systems weaken. Pipe degradation, system blockage, water infiltration, and sewer leakage are major problems that aging sewer systems experience. As these problems persist, the sewer system may eventually experience total failure and entire sections of the sewer system may collapse. As a result, sinkholes may form and sewers may back up into homes and places of business. One method of addressing this critical infrastructure problem is the use of pipe lining techniques to rehabilitate existing sewer systems.
Cured-in-place pipelining is one such technique that includes rehabilitating an existing sewer system by creating a new pipe within an existing pipe. A liner, impregnated with a resinous material capable of curing and hardening, is inverted or pulled into a damaged pipe. The liner is pressed toward the wall of the existing pipe, and the resinous material is allowed to cure and harden. The result is a replacement pipe having the older pipe or “host pipe” on the exterior. The cured-in-place pipe acts to alleviate the problems caused by structural defects and blockages in the existing sewer system.
Mainline sewer pipes are normally lined from manhole to manhole. In sewer systems where the main pipes have been rehabilitated with a cured-in-place pipe, unsealed connections at service and lateral pipe junctions (collectively referred to herein as “lateral pipes” or “lateral pipe lines”) create problems. An unsealed connection is generally a product of installing a pipe liner within the main pipe and over the lateral pipe junction, then using a cutting tool on the pipe liner at the connection to reinstate service to the lateral pipe. Current methods for cutting/reinstating service to lateral pipes are described for example in U.S. Pat. No. 7,131,791 (Whittaker et. al.), which is incorporated by reference. In some cases, however, it may be desirable to leave the lateral pipe sealed off without reinstating service. In these cases, lining over the lateral junction opening may not be sufficient to seal off the lateral pipe. One reason is because liners typically need to be constrained against a surface to prevent them from overstretching. Overstretching a liner during installation may cause the resin to ring out of the liner with gravity pulling the resin to the bottom of the liner. The overstretched portion of the liner does not have sufficient resin to cure and harden into a rigid cured-in-place pipe leaving the section of liner vulnerable to water infiltration.
Further, considerable difficulty has been encountered in attempting to obtain an adhesive bond between the liner tube and the interior of the pipe being repaired. The interior of the pipe being repaired is often greasy or oily even after high pressure water jetting is performed. Attempts have been made to wash the interior of the pipe line with some success, but washing the interior of the pipe line is often only partial and not reliable. In some types of pipes, such as polyethylene pipes, an adhesive bond cannot be maintained between the resin impregnated liner and the polyethylene pipe even if the pipe is free from grease and oils. It is also difficult to produce a dry pipeline as most procedures for producing an adhesive bond require dry substrates.
Even in those instances where the interior of the pipe line is suitable for accepting a liner, shrinkage of the liner can occur, which creates a gap that allows ground water to flow around the liner and eventually infiltrate the pipe line. For example, thermoset resins are used in cured-in-place pipe applications to form the liner to the interior of the pipe line. These thermoset resins tend to shrink during the curing process, thus creating a gap between the liner and the pipe. Even the slightest shrinkage in the liner can be problematic.
A primary object of the present invention is the provision of an improved device and method for sealing an opening in a first pipe using a sealing member made from a hydrophilic or other impermeable compressible material.
A further object of the present invention is the provision of an improved device and method for sealing off a lateral pipe junction opening using a sealing member made from a hydrophilic or other impermeable compressible material.
A further object of the present invention is the provision of a device and method for preventing ground water from infiltrating a pipe line near the juncture between a main pipe line and a lateral pipe line.
A further object of the present invention is the provision of a device and method for repairing a section of a pipe, sealing a lateral pipe junction opening, and preventing entry of ground water from a damaged portion of the pipe being repaired.
A further object of the present invention is the provision of an improved device and method for placing a sealing member across a lateral pipe junction opening which creates a clean surface against which a pipe liner may be pressed to prevent overstretching the liner.
A further object of the present invention is the provision of a device and method for repairing pipe and sealing a lateral pipe junction opening using a hydrophilic sealing member or the like which is economical to manufacture, durable in use, and reliable in operation.
According to one feature of the present invention, an assembly is provided for repairing and sealing an opening in a first pipe which may be the juncture opening between two pipes, such as a main pipe line and a lateral pipe line. The assembly includes a main liner member, a bladder, and a sealing member. The main liner member is made of a resin absorbent material which is impregnated with a curable resin before being positioned in the first pipe. The sealing member may be a gasket made from an impermeable compressible material, such as a hydrophilic material. The sealing member is secured to the liner using bands, snaps, adhesive, or other suitable means. The sealing member surrounds a portion of the main liner member and is positioned between the host pipes and the liner assembly in operation. The main liner is moved through the main pipe line to a position where the sealing member and the main liner extend across the opening. The bladder is expanded to urge the liner and a portion of the sealing member against the main pipe, then the resin in the liner cures and hardens to permanently seal the opening. The combination of the structural repair and hydrophilic material creates a long-term compression seal between the host liner and new short pipe liner. The assembly can be positioned with a launcher assembly, inverted into the main pipe, or positioned using so-called “pull-in-place” or “push-in-place” applications.
According to another feature of the present invention, a method is provided for repairing and sealing an opening in a first pipe using a repair assembly. The opening may be the junction opening between two pipes, such as a main pipe line and a lateral pipe line. The assembly includes a resin impregnated main liner member, a bladder, and a sealing member. In use, the assembly is positioned in a first pipe at the opening to be sealed. The main liner member and sealing member extend across the opening then the bladder assembly is inflated to urge portions of the sealing member and liner into contact with the interior walls of the first/main pipe line. After the main liner member cures and hardens, the bladder may be deflated and removed from the pipe leaving the main liner member and sealing member to seal off the opening.
Referring to
Launcher device 12 includes side walls 18, an end cap 20, and an end wall 22, all of which form a launcher device cavity 48. Extending through end cap 20 is an air inlet 30 which is connected to an air hose 32.
As can be seen in
A sealing member 56 such as a gasket is used to seal the juncture opening between the pipes 50, 52. The sealing member 56 is positioned about a portion of the liner 38. The sealing member 56 may be made of a hydrophilic material capable of swelling in response to being exposed to water or other liquid. However, other materials for the sealing member 56 found suitable include neoprene rubber, hydrophobic material, other similar gasket materials such as urethane or silicone rubber, and like impermeable compressible materials. The ground water, as designated by the arrows 90 in
In addition to sealing the lateral junction opening, the sealing member 56 provides a surface for the liner 38 to cure against. This is helpful in instances where the inside wall of the pipe 50 is dirty or where there is a hole, crack, opening, or damage to the pipe 50 that would prevent the liner 38 from making contact with the inside wall of the pipe 50. As explained above, it is desirable for the liner 38 to be contained by or compressed against a surface as the bladder 34 expands and pushes the liner 38 outward. If not constrained, the liner 38 could become overstretched at the opening causing resin to ring out of the liner 38 resulting in a weak and uncured liner 38 at the opening.
It should be noted that some embodiments do not require a bladder 34. In these embodiments the liner 38 includes a fluid impermeable coating so that fluid can be introduced directly into the liner 38 after the liner is positioned at the lateral juncture opening to urge the liner 38 and sealing member 56 toward the walls of the pipe. Further, it should be noted that although certain sealing members 56, 56A are described above with respect to different embodiments for positioning the assembly, either sealing member 56, 56A may be used in any of the embodiments described herein.
Having thus described the invention in connection with the preferred embodiments thereof, it will be evident to those skilled in the art that various revisions can be made to the preferred embodiments described herein without departing from the spirit and scope of the invention. It is my intention, however, that all such revisions and modifications that are evident to those skilled in the art will be included with in the scope of the following claims.
This application is based upon U.S. Provisional Application Ser. No. 62/742,092 filed Oct. 5, 2018, the complete disclosure of which is hereby expressly incorporated by this reference.
| Number | Date | Country | |
|---|---|---|---|
| 62742092 | Oct 2018 | US |
