NL8900564A - METHOD AND APPARATUS FOR SKIPPING CABLES. - Google Patents

Description

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Method and device for installing a replacement pipe in an existing underground pipe.

The invention relates to improvements and their methods and devices for installing a replacement pipe section within an existing underground pipe, such as a pipeline section to be repaired or replaced.

In particular, the invention relates to the installation of a replacement pipe section within main sewers intersecting house connections, within other main pipelines intersecting side pipe conduits, within pipeline sections which may include curves and sharp bends, and within yet other pipeline sections intersected by house connections where the connections of side pipes are difficult to find after a new pipe section has been installed within the existing pipeline section.

Several methods have been proposed for repairing underground pipelines such as sewer lines and the like, keeping the existing pipeline underground in place by installing a flexible membrane or plastic sheathing inside the existing pipe or by introducing a new plastic pipe in the existing pipe.

In one known method, pipes are lined with a flexible plastic such as polyethylene. According to this method, the cladding is installed through input wells spaced along the pipeline, making the method expensive.

In another method, for example, shown in U.S. Patents 3,927,164 and 4,064,211, a flexible tube is turned inside out and inflated and blown into a pipe section from one end of the section. This method is expensive because special equipment, extensive heating and expensive materials are required.

The aforementioned methods, and most others, use a flexible or semi-flexible coating, which is not capable of withstanding a significant external 8900922: - 2 - hydrostatic pressure or ground pressure. Therefore, the existing pipe cannot be properly repaired, since when the part of the existing pipe is broken off, the coating may collapse due to external pressure of any size, such as pressures exceeding, for example, 27 kPa.

U.S. Patent 4,394,202 and U.S. Patent 2,794,758 disclose methods of introducing flexible tubing into an existing pipeline as a casing membrane for that pipeline. U.S. Patent No. 4,394,202 describes a method of attaching the flexible tube to the existing pipeline using an expandable short section of adhesive coated rigid plastic. The methods of U.S. Pat. Nos. 4,394,202 and 2,794,758 have the same drawbacks as mentioned above with respect to other methods using flexible membrane material, in that they provide the necessary hoop strength for resistance to external soil and hydraulic pressures lack.

Others have suggested introducing a rigid pipe within the existing pipeline to be repaired. For example, in published British Application No. 2,084,686, an oversized round rigid plastic pipe is flattened or otherwise sized at the site and then introduced cold and stiff into the existing pipeline through a large excavation at a manhole. After introduction, the plastic tube is expanded using heat and internal pressure. The plastic pipe is expanded against the existing pipe.

According to British Patent 1,580,438, an existing underground pipe is lined with a plastic casing, which is made of a plastic material such as polyethylene or polypropylene with a plastic memory (plastic memory). The casing is manufactured in a non-round "0" shape to fit within the existing pipe, then introduced in its non-round shape into the existing pipe and then expanded to a round state under heat and pressure against the existing pipe.

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Published European Patent Application 0,000,576 proposes the introduction of a semi-rigid plastic pipe insert within an existing pipe. The semi-rigid plastic tube has sufficient hoop strength to withstand all or at least part of the external pressures that can be applied to it.

Most of the foregoing and other known methods using rigid or semi-rigid pipes for insertion into an existing underground pipe have a common drawback: because of their stiffness or near-rigidity, they must be fed into straight or nearly straight existing pipelines . This means, for example, with regard to underground sewer lines, such methods are limited to use on main sewers as they usually have straight pipeline sections between manholes. Most, if not all known methods 15 are not suitable for use in repairing the many house connections extending from the main sewers to buildings. Often such side pipes have bends or bends through which a rigid or semi-rigid plastic pipe cannot penetrate. Also, such side pipes are usually inaccessible through manholes at both ends, and therefore known lining method or replacement pipe installation methods requiring manholes or other access forms at both ends are excessively expensive. Most known underground replacement pipe installation methods require large excavations at one end of the side pipe to be re-coated or repaired to provide room for introduction of the straight rigid plastic replacement pipe. Such a large excavation adjacent to a building for which the side conduit serves, or at the other end where the side conduit arrives at the main sewer, is often impractical and usually expensive.

In addition, most known methods of recoating or repairing existing underground pipelines require access to the pipeline section to be repaired at both ends of the section. This is not possible with a side conduit which, by definition, crosses a main conduit at a point not usually accessible through a manhole.

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For the foregoing reasons, the known methods of recoating and repairing underground pipelines are simply not applicable to house connections.

Another drawback in the use of known methods for repairing and repacking existing pipeline sections crossed by house connections using straight rigid or semi-rigid pipes is that once the pipe is in place within the existing pipeline section, the it is very difficult to determine the exact positions where they cross pipes 10 to the main pipeline in order to be able to cut access openings in the replacement pipe to allow access to the side pipes. This is especially the case when the replacement tube is sufficiently thick and therefore has sufficient hoop strength to withstand self-characteristic hydraulic and ground pressures.

For the foregoing reasons, there is a need for improved methods, devices and equipment to allow for the repair of existing underlying pipeline sections, and in particular house connections and other pipeline sections with bends and curves, and pipeline sections that do not easily accessible from both ends of the pipeline section to be repaired.

Accordingly, the main objects of the invention are to provide the following: 1. A new and improved replacement pipeline product for installation in an existing underground pipe, which is particularly suitable for use in repairing and replacing existing house connections that are not straight and of main lines crossed by house connections; 2. a new and improved method of manufacturing a pipeline article for repair and replacement, which is particularly suitable for installation in existing underground pipes that are not straight or that are crossed by side pipes; 3. a method of installing a new or substitute pipeline section in an existing 8900922 / - 5 underground conduit, and in particular in a conduit that is not straight or intersected by house connections; 4. a device and tool for manufacturing a pipeline product for replacement purposes such as the aforementioned; 5. a device and tool for installing a pipeline product as aforementioned in an existing underground pipe and in particular in a pipe which is not straight or which is crossed by side pipes; and 10 6. a device and tool for reforming a new or replacement thermoplastic pipe section installed in an existing underground pipe, and in particular a home connection, after the new or replacement pipe section is installed in a 15 folding state has been introduced, by reforming it to a stable round shape within the existing conduit.

The invention relates to a new and improved repair and replacement pipeline product, which is particularly suitable for installation in an existing underground pipe such as a house connection with bends and bends, and a series of closely related methods, devices and tools for manufacturing the article, installing the article into an existing conduit, straight or curved, and reshaping the article into a round shape after it has been collapsed into the existing line. The article, methods, devices and tools of the invention are particularly intended for use in installing the article in house connections and other existing underground pipes with access at only one end of the pipe or with bends or bends, or in pipes crossed by side pipes.

According to one aspect of the invention, a replacement pipeline product is made of a thermosetting plastic material such as PVC, extruded in the first 6900922 / - 6 instance and formed into a unique folded and flat shape, such that it retains a folded memory when re-heated, that it can be easily applied to a coil for storage and use, that it has a reduced cross-sectional size for easy insertion into an existing underground pipe, without excavation or damage to the plastic material through manholes, cleaning or other small vertical openings and all around sharp bends can be introduced into deep pipelines, and that, despite their flat folded condition, a hot fluid can be passed therethrough for reheating along its entire length.

In accordance with another aspect of the invention, the aforementioned plastic pipe product is installed in, for example, an existing curved side pipe, by reheating the plastic pipe to a flexible state, and then retracting the hot flexible folded plastic pipe into the existing side pipe. with a pull cable and either a pulley arrangement anchored temporarily at the junction of the side conduit and the main conduit or with a cable leather from the closest manhole in the main conduit. The folded installed pipe is then heated along its entire length by passing a hot fluid therethrough, plugging or restricting its front end, and injecting a fluid, such as air, under pressure into the other end to reform the pipe and to expand to a round shape. While continuing to apply internal pressure to the reformed round pipe, it is allowed to cool and thereby stabilize its round shape.

In accordance with another aspect of the invention, various means are provided for plugging or restricting the front end of the plastic pipe to allow passage of a hot fluid therethrough in the folded state and yet expanding and reforming the folded pipe into enable a round shape by applying an internal fluid pressure.

In accordance with another aspect of the invention 8900922 / - 7 - means are provided to cover or seal an inlet end of the folded pipe to allow internal fluid, depressurization into the folded pipe when introduced into a existing underground pipeline.

In accordance with another aspect of the invention, there is provided a unique pulley and cable device which can be pushed through a side conduit to its intersection with the main pipeline and temporarily anchored there by maintaining tension at both ends of the cable . One end of the cable is anchored to the front end of the folded pipeline to be installed; then the opposite end of the cable is pulled to pull the folded plastic pipe into an existing side conduit in a heated bendable condition.

In accordance with another aspect of the invention, various means are provided for heating the opposite ends and various other sections of the plastic pipe article to allow reworking of selected sections of the pipe for clamping, insertion of plugs, or for keeping it sufficiently flexible along the entire length of the pipe for insertion into an existing pipe that is not straight.

The foregoing and other objects, features and advantages of the invention will become more apparent from the following detailed description, with reference to the accompanying drawings, in which; Figure 1 is a cross section of a conventional thermoplastic pipe, such as a PVC pipe, used in accordance with the invention in its expanded round state; Figure 2 is a perspective view of the thermoplastic pipe of Figure 1 and of the device for reducing the pipe from its round state to a collapsed, folded state for storage on a spool; Figure 3 is a cross-section of the thermoplastic pipe of Figure 2 after it has been folded, taken according to 89 00922. - Line III-III of Figure 2; Figure 4 is a schematic view showing a method of installing the folded and coil-stored thermoplastic pipe of Figures 2 and 3 from a manhole within a main sewer, with the folded thermoplastic pipe stored on a roll and again is heated before installation in the underground pipe to be repaired; Figure 5 is a schematic sectional view showing a detail of the device for expanding the folded thermoplastic pipe of Figures 2 and 3 and rounding it after it has been fed into the existing main pipeline shown in Figure 4; Figure 6 is a schematic sectional view showing an alternative construction for expanding and rounding the folded thermoplastic pipe after its introduction into an existing conduit; Figure 7 is a schematic cross-section through a typical house connection extending from a building to a main sewer, illustrating a method of installing the thermoplastic pipe in an existing house connection according to the invention; Figure 8 is a section through a preferred embodiment of the thermoplastic pipe of Figure 1 when folded for installation in an existing underground conduit; Figure 9 is a schematic side view of an apparatus for manufacturing the thermoplastic pipe of Figure 1 in a folded form as shown in Figure 8; Figure 10 is a vertical view of the gauge of the device of Figure 9 on an enlarged scale as used in the manufacture of the thermoplastic pipe in the form shown in Figure 8; Figure 11 is a vertical view of a single calibration plate of the calibration device of Figure 10 as viewed from line XI-XI of Figure 10; Figure 12 is a plan view of a folded 83 00 922 / - 9 end portion of the thermoplastic pipe of Figure 8 with an attached end clamp for use in drawing the pipe into an existing conduit and limiting the pipe end to internal negative pressure application. of the pipe for expansion; Figure 13 is a section on line XIII-XIII of Figure 12; Figure 14 is a somewhat schematic plan view of a cable and pulley device of the invention, also shown in Figure 7, for drawing the folded thermoplastic pipe of Figure 8 into a side conduit, showing the device in the operative position thereof; Figure 15 is a view similar to Figure 14, but with the device of Figure 14 in a collapsed condition for insertion into a side conduit; Figure 16 is a somewhat schematic side view of the device of Figures 14 and 15; Figure 17 is a side view of a plugging tool used for plugging an end of a length of the thermoplastic pipe shown in Figure 8 after the end has been rounded, for use in transferring fluid, heat and fluid pressure to the interior of the thermoplastic pipe; Figure 18 is a vertical front view of the tool of Figure 17; Figure 19 is a view of an end of the thermoplastic pipe with the plugging tool of Figures 17 and 18 inserted into the pipe and clamped in place with a chain clamping member; Figure 20 is a view of the chain clamping member of Figure 19 for its application to the pipe and plug of Figure 19; Figure 21 is a cross-sectional view along line XXI-XXI of Figure 19, showing the chain clamping tool of Figure 35 19 and Figure 20 showing the thermoplastic pipe end 89 00922

Claims (1)

- 10 - clamps onto the stuffing tool of Figures 17-19; Figure 22 is a somewhat schematic longitudinal section through a front end portion of the thermoplastic pipe of Figure 8, the end clamps of Figures 12 and 13 being mounted on the pipe end and the rest of the pipe being expanded and rounded, and a cutting tool conforming has been introduced into the rounding pipe end portion with the invention to separate the clamped end from the rest of the pipe; Figure 23 is a sectional view of the pipe and cutting tool of Figure 22 taken along line XXIII-XXIII of Figure 22; Figure 24 is a somewhat schematic side view of an end heater used to heat an end portion of the thermoplastic pipe to rework the end portion, with the heater shown installed on a folded end portion of the thermoplastic pipe of Figure 8; Figure 25 is a perspective view of an inflatable end-capping tool used for plugging or restricting the end portion of the thermoplastic pipe in place of the end clamp of Figures 12 and 13 to expand and round the folded thermoplastic pipe possible; Figure 26 is a shortened vertical view, partially in section, of the inflatable pipe of Figure 25; Figure 27 is a schematic view illustrating installation of the inflatable plugging tool of Figures 25 and 26 in the thermoplastic pipe when expanded and rounded; Figure 28 is a schematic view similar to that of Figure 27, but showing the pipe of Figure 27 after it has been refolded with the inflatable plug inside it in a deflated state; Figure 29 is a schematic view showing the use of the inflatable plugging tool of Figures 25 8900922 / - 11 - and 26 during installation of the thermoplastic pipe in a side conduit? Figure 30 is a schematic view illustrating another application of the inflatable plugging tool of Figures 25 and 26; Figure 31 is a schematic view further illustrating the use of the inflatable plugging tool of Figures 25 and 26 according to the method illustrated in Figure 30; Figure 32 is a schematic view illustrating yet another use of the inflatable plugging tool of Figures 25 and 26 for expanding and rounding the folded thermoplastic pipe after it has been inserted into an existing underground conduit; Figure 33 is a schematic view of a portion of a main pipeline and an intersecting side pipeline, illustrating an alternative method of drawing the thermoplastic pipe of Figure 8 into a side pipe to be repaired; Figure 34 is a schematic view of an end portion of the folded thermoplastic pipe of Figure 8, illustrating a method of detaching the pull cable from the front end of the pipe after it has been introduced into an underground conduit; Figure 35 is a schematic view similar to that of Figure 34 illustrating yet another method of detaching the tensile cable from the thermoplastic pipe after it has been introduced into an existing underground conduit; Figure 36 is a section through the junction of a main pipeline and a side pipeline after the thermoplastic pipe of Figure 8 has been installed and expanded within the main pipeline to be repaired, using a method for determining and cutting an opening through the newly installed thermo - 35 plastic pipe for restoring communication between the 89 00922 - 12 - side pipe and the main pipeline is illustrated; Figure 37 is a schematic side view illustrating a method and device for folding a thermoplastic pipe that is manufactured in a round manner for insertion into an existing underground pipe, Figures 38A-E are schematic cross-sections taken respectively are along lines XXXVIIIA-XXXVIIIA to XXXVIIIE-XXXVIIIE of Figure 37; Figure 39 is a somewhat schematic side view of a releasable end clamp with attached pull cable and release line, for use in clamping the front end of the folded pipe of Figure 8 during its installation; Figure 40 is a plan view of the end clamp of Figure 39; and Figure 41 is a plan view of the release wedge portion of the clamp of Figure 39. In Figure 1, the numeral 10 designates a type of pipe used to renew, repair or replace underground pipeline sections such as sewer pipes or the like. according to the present invention. A feature of the pipe is that it is formed from a thermoplastic material such as PVC and more particularly from a material which is usually rigid and thick-walled to have sufficient hoop strength to resist external ground and hydraulic pressures to which it is exposed. can be exposed underground. Such a thermoplastic pipe can be made flexible when heated to temperatures of, for example, 105 ° C (200 ° F) or more, in the case of PVC pipe. A feature of the pipe 10 is that it is rigid in construction at typical above-ground and underground ambient temperatures but becomes flexible and processable to various guises when heated or re-heated. Another feature of such thermoplastic material is that it has a memory, that is, if it is made in a special shape such as a round tubular shape and then later heated and flattened or folded and then cooled to store it in are 9900922 · '