Patent Application
20240418295
Water is typically provided to residential and commercial buildings through a large diameter main pipe (i.e. “water main”) which runs along or below a street, with smaller diameter water service lines running to each individual building. Periodically, the water main or mainline must be replaced for various reasons, such as failure due to age or other damage. Various methods have been utilized to replace these pipes, such as trenchless technology, without the need for open trenches. Trenchless replacement methods include pipe bursting, relining, and horizontal directional drilling. Pipe bursting and relining require that the water service to each home or business be shut off before the pipe is burst or relined. Such water shut off creates a big inconvenience for the customers while the work is done, which may take several days. Furthermore, pipe bursting creates pressure in the soil, which results in surface deformation, such as bumps and/or holes in the streets, and may damage other, nearby underground utilities.
Horizontal directional drilling often has problems with maintaining accuracy and maintaining the proper grade. Directional drilling also is done at a distance spaced away from the pipe to avoid hitting and damaging the old pipe, which requires additional surface or area above ground to do the work. Horizontal directional drilling also creates underground fluid pressure, leading to humps in roadways and driveways, and damage to existing utilities.
Therefore, there is a need for an improved process for installing new water mains without disrupting the existing water main.
Accordingly, a primary objective of the present invention is the provision of a non-disruptive underground pipe replacement process.
Another objective of the present invention is the provision of a process for replacing an existing or old water main or other underground pipe with a new pipe in close proximity to the old water main.
A further objective of the present invention the provision of a water main or pipe replacement process which minimizes worktime, the water shut off time, and any inconvenience to water customers.
These and other objectives become apparent from the following description of the invention.
A method of replacing an underground pipe, such as a water main, without disruption of the main service, includes a first step of drilling a series of substantially vertical boreholes downwardly from the ground surface to a distance adjacent to the old or existing main, such that an edge of the main is exposed. Then, a pilot hold is directionally bored adjacent the main so as to intersect the series of downward bores. The pilot hole is then back reamed to a larger diameter to accommodate the new pipe, which is pulled behind the reamer head. The old or existing main remains functional until the new pipe is installed. The new pipe is adjacent, and substantially parallel to the old/existing pipe. After the water/liquid/fluid supply to the old pipe is shut off, the old pipe is retained in the ground, and can be re-purposed for other uses.
An existing underground pipe 10, such as a water main, is buried beneath the surface of the ground 12. The first step in replacing the existing or old main 10 involves drilling a series of spaced apart, substantially vertical, sight relief holes 14 downwardly from the surface 12, so as to expose an outer edge of the old main and adjacent the bottom of the holes 14. Liquid may be provided during this drilling process to lubricate the drill, so as to form a slurry with the soil in the sight relief holes 14.
The second step in the pipe or main replacement process is to drill a pilot hole using a horizontal directional drilling pilot stem 16, with the pilot hole being spaced relatively close to the existing main 10 and extending substantially parallel with the old main 10. The pilot stem 16 passes through the sight relief holes 14 to assure accurate drilling of the pilot hole. Support hooks 18 extend downwardly through each relief hole 14 to support the stem 16 during the drilling step. The soil slurry functions as a dampening agent to prevent the pilot stem 16 from whipping or jumping out of the support hooks 18. The slurry also lubricates the support hooks 18 to minimize friction and to prevent overheating and abnormal wear on the hooks by the pilot stem 16.
Next, a back reaming tool 20 attached to the stem 16 is pulled in the opposite direction to back ream the pilot hole to an enlarged diameter minimally larger than the outside diameter of the new pipe or main pipe 22. The new pipe 22 is connected to the reaming tool 20 by a connecting rod 21, such that the reaming tool 20 and new pipe 22 are pulled through the enlarged hole in a single step, as the reaming tool enlarges the pilot hole ahead of the path new pipe 22.
The enlarged hole extends along the existing, old water main 10, through the sight relief holes 14. The reaming tool 20 does not contact the existing main 10. The new main 22 is pulled into place behind the reaming tool 20 as the enlarged hole 24 is formed. Additional liquid or fluid can be used during the reaming step to produce additional slurry. The slurry is expelled, in part, upwardly out of the sight relief holes 14 during the reaming step. After the new pipe 22 is in place, additional slurry can be vacuumed out of the relief holes 14, which can then be filled with soil or other desired material.
The support hooks 18 are removed during the back reaming process, just before the reaming tool 20 reaches each support hooks 18.
As the pilot stem 16 reaches each sight relief hole 14, the depth and line of the bore stem 16 can be measured, so as to maintain the proper grade along the existing main 10. The hooks 18 are supported above the ground in any convenient manner, such as by tripods 26. A lifting mechanism 28 is provided for each hook 18, to allow the vertical position of the hook 18 to be adjusted, as needed, to maintain the proper line and grade of the pilot stem 16.
The pilot hole drilling and enlarged hole reaming steps are generally described in the inventor's prior U.S. Pat. Nos. 6,732,816, 7,581,600, and 8,641,326, which are incorporated herein by reference. The pilot drilling and reaming steps are performed without shutting off fluid flow through the existing main 10, so as to maintain water (or other liquid or fluid) service to each building through the existing service lines 30 extending from the existing main 10. After the new main 22 is installed, service is temporarily shut off to allow the service lines 30 to be connected to the new main 22. Then, service is restored after minimal downtime.
The new pipe 22 runs substantially parallel to the old pipe 10, with the old and new pipes being closely spaced to one another. For example, the new pipe 22 may be within inches of the old pipe 10. As seen in
With the present invention, the old main 10 is not removed or destroyed. The old main 10 can be repurposed for use with new utilities, such as fiber optics or other underground, pipe usage. Alternatively, the ends of the old main 10 can be capped or temporarily plugged, until further use is needed for the old main.
The non-disruptive underground pipe or main replacement process of the present invention also has the benefit of staying within the property casements, or right of way owned by the water company, since the new pipe 22 is placed adjacent, preferably within inches, of the old pipe 10. This new method also reduces the number of employees needed to do the work, which is beneficial when times are difficult for hiring workers and reduces labor costs for the installation job.
The process of the present invention can be utilized for existing or old water mains, as well as for underground pipes conveying other fluids, both liquids or gasses.
The “scope” of the present disclosure is defined by the appended claims, along with the full scope of equivalents to which such claims are entitled. The scope of the disclosure is further qualified as including any possible modification to any of the aspects and/or embodiments disclosed herein which would result in other embodiments, combinations, subcombinations, or the like that would be obvious to those skilled in the art.
This application claims priority under 35 U.S.C. § 119 to provisional patent application U.S. Ser. No. 63/508,970 filed Jun. 19, 2023. The provisional patent application is herein incorporated by reference in its entirety, including without limitation, the specification, claims, and abstract, as well as any figures, tables, appendices, or drawings thereof.
| Number | Date | Country | |
|---|---|---|---|
| 63508970 | Jun 2023 | US |
