CN1070568C - How to Repair Underground Drains - Google Patents

Abstract

A method of repairing a damaged (fractured) portion of a subterranean tubular comprises: impregnating one or more layers of fibrous material with a hardenable plastic compound; winding the thus produced liner on a radially expandable hose; feeding the hose to the damaged part; expanding the hose and liner so that the liner engages the inner surface of the pipe; after the compound hardens, the hose is retracted and the tubing is withdrawn. A polyethylene film is inserted between the outer surface of the hose and the inner surface of the lining layer to increase friction, so that the hose rotates when being expanded. The hose is expanded to force the compound out of the periphery of the liner to adhere the liner to the pipe and at least partially fill the crack. The compound also extrudes from the axial end of the liner to form a smooth transition between the inner face of the pipe and the outer face of the liner.

Description

How to Repair Underground Drains

This invention relates to improvements in the repair of defective liquid piping, and more particularly to improvements in the repair of drains, and more particularly to improvements in the repair of cracked or otherwise damaged drains buried in soil or other material.

German Patent No. 3922351A1 discloses a method for integrally repairing part of an underground pipe using a resin-impregnated single-layer fiber material liner. The liner is wrapped around a radially expandable hose which expands from the inside to compress the liner against the inner surface of the defective portion of the pipe. The edge portions of the liner wound on the expandable carrier overlap each other to ensure that the wound liner remains a cylindrical body after expansion is complete. This arrangement is or should be such that when the process of expanding the hose and coiled liner is complete, the liner edges overlap each other at an angle of approximately 90°.

The hose wrapped around the liner remains stationary during the expansion process, that is, while the liner expands radially outwardly into contact with the inner surface of the defective portion of the pipe. The overlapping edge portions of the liners rub against each other and frictionally engage each other, while the hose and the liner wound thereon are subjected to the radial expansion of pressurized fluid entering the hose. In addition, radial expansion of the hose provides an expanding motion of the liner relative to the hose. Accordingly, the resin that saturates the wound liner does not squeeze out at the periphery and/or axial ends of the expanded liner. In any event, the amount of resin extruded radially outwardly and axially from the liner is negligible, so that the forces that expand the liner act on the inner surface of the pipe are minimal. Some radial compression of the resin-soaked single-ply liner occurs only at the completion of the expansion process, and the expanded hose continues to apply pressure to the expanded liner, that is, only when the damaged portion of the pipe is used for expansion. When the anvil or support of the liner is used, the single liner is reduced in thickness and some resin is squeezed out.

The shortcoming of aforementioned prior art scheme is, the damaged part of pipeline (the damaged part of pipeline is generally one or more cracks. Make transported flowable material such as untreated sewage leak from underground pipe into the soil around the pipe ) must withstand very significant radially outward stresses imposed by the expanded tubular liner, prone to additional damage such as widening of cracks or complete fragmentation of the pipe. In addition, the amount of resin extruded from the tubular liner when the expansion process is completed is relatively small, therefore, the resin extruded from the liner (if extruded) cannot fill the crack and cannot guarantee the bonding of the expanded liner to the pipe damage part of the adjacent inner surface.

It is an object of the present invention to provide a simple, cheap and reliable method of repairing defective subterranean sewage or the like pipes.

Another object of the present invention is to provide a method that ensures a high percentage of hardenable plastic compound (such as epoxy resin) is extruded from the tubular liner even before the expansion process, thereby reliably sealing a strip or The multiple cracks also allow the expanded liner to reliably adhere to the inner surface of the damaged or defective portion of the pipe.

It is a further object of the present invention to provide a novel and improved method of forming a liner impregnated with a hardenable sealing and bonding compound.

Another object of the present invention is to provide a novel and improved method of expanding a tubular liner and its carrier so that the liner can be positively engaged and securely held within a subterranean drainpipe or other defective portion of pipeline On the surface.

Another object of the present invention is to provide a new and improved method of uniformly saturating a liner with a hardenable sealing and bonding compound.

Another object of the present invention is to provide a method which ensures the impregnation and setting of the fibrous material within a short time interval.

Another object of the present invention is to provide a new and improved method of radially expanding one or more hoses each wrapped around a respective liner.

Yet another object of the present invention is to provide a method according to which two or more holes, cracks or similar imperfections in a pipeline can be simultaneously sealed using a single liner when the pipeline is buried in the ground.

Another object of the present invention is to provide a new and improved apparatus for carrying out the above method.

Another object of the present invention is to provide a new and improved mechanism for feeding a carrier and a liner wound around the carrier into a defective pipeline.

Another object of the present invention is to control the friction between the radially expandable carrier and the liner wrapped around the carrier.

A method according to the present invention for patching or repairing from within at least one selected portion of an at least partially buried pipeline such as a drainpipe, said at least one selected portion having at least one crack or similar defective area requiring sealing or filling. This improved method has the steps of: impregnating a liner containing at least one layer of fibrous material with a hardenable plastic substance (such as a compound, hereinafter referred to as compound); A hose or similar hollow tubular carrier to form a tubular shell with an overlapping portion and first and second axial ends, a significant friction is formed between the carrier and the tubular shell, so that the radial expansion of the carrier simultaneously drives the diameter of the tubular shell Expanding in a radial direction, with sliding of overlapping portions of the tubular shell in radial expansion; introducing the carrier and the tubular shell into at least a selected portion of the pipeline; expanding the carrier and the tubular shell therein thereby causing the tubular shell to contact the pipeline at least one selected portion of, (a) causing concomitant flow of hardenable compound into at least one defective region; (b) rotating the carrier relative to the conduit; contracting the expanded carrier so that the contracted carrier is aligned with the expanded separating the tubular shell; withdrawing the shrunk carrier from the shell; and curing the hardenable compound, the expanding step further comprising extruding the hardenable compound from at least one axial end of the expanded tubular shell. compound.

The expansion step preferably expands the tubular carrier from the inside with a gas or a liquid. The winding step may include forming the impregnated liner into a tubular shell having an axial length, the carrier extending beyond both axial ends of the tubular shell.

The step of creating friction between the carrier and the tubular shell may comprise placing a suitable film, for example a polyethylene film, between the liner and the carrier. The step of arranging the film is or may be performed after the soaking step and before the winding step. The winding step of the method may also include forming the film into a tube surrounding and extending axially beyond the carrier.

Additionally, the step of creating friction between the carrier and the tubular body may also include introducing a multilayer film (eg, a multilayer polyethylene film) between the liner and the carrier. The winding step may also include forming the multilayer film into a tubular body surrounding the carrier and having axial ends extending beyond the tubular body, and the method preferably further includes the step of securing the ends of the tubular body to the carrier to prevent radial During the expansion process, the tube body is unwound to expose the carrier.

The winding step may comprise forming the liner into a helix having a number of turns, for example a helix having a number of full turns plus a fraction of a turn. If the liner has a number of overlapping layers of fibrous material, the winding step may comprise forming the liner into a helix having a number of turns each having two or more layers.

The expansion step may include introducing a fluid into the carrier at a pressure that is a function of a number of parameters, including the degree of expansion of the carrier required to press the tubular body against the inner surface of the conduit with a predetermined force, and the degree of expansion of the liner. The nature of the layer fibers. Yet another parameter may be the circumferential length of the liner being wound.

The range of lining fiber materials that can be selected is glass fiber, carbon fiber and KEVLAR (trademark) fiber.

The soaking step may comprise: applying a hardenable plastic compound to a plurality of aggregated or separate layers of fibrous material; overlapping said layers of fibrous material with each other, confining the overlapping layers of fibrous material and the applied plastic compound to a cladding such as polyethylene In the cladding of the film; and exerting an external force on said cladding in a direction in which the plastic compound penetrates into the fibrous material layer, preferably allowing the plastic to permeate the entire liner. Said cladding is light-transmissive, and the step of applying force may comprise spreading the plastic compound in the cladding by means of at least one tool resembling a rolling pin.

The novel features of the invention are set forth with particularity in the claims. However, a more in-depth understanding of the improved method itself, its features and advantages, can be obtained by perusal of the detailed description of the particular preferred embodiment, which is illustrated in conjunction with the accompanying drawings.

The perspective view shown in Figure 1A depicts the step of applying a hardenable plastic compound on half of a layer of fibrous material covered with an incomplete cladding of light-transmitting plastic film which in turn covers a flat the bottom plate;

The front view shown in Figure 1B shows that the other half of the layer of fibrous material is folded over the above-mentioned half to form a multilayer lining;

The front view shown in Figure 1C shows the layers of the liner contained within the plastic film wrap and also shows a rolling pin being used to spread the plastic compound in the wrap and saturate the liner.

Fig. 1D shows the situation when Fig. 1C completes the spreading step;

The axial sectional view shown in Fig. 1 E shows that a radially expandable and contractible hose carrier is surrounded by a tubular shell made of a coiled liner, with a plastic film in between, so that on the outer surface of the carrier and by the coiled Significant friction is formed between the inner surfaces of the tubular shell formed by the surrounding lining;

Figure 2A shows a front view similar to Figure 2a, but on a soft, small first layer of fibrous material. applying a non-uniform plastic compound, the first layer of fibrous material is covered with a plastic film, and the plastic film is covered with a base plate;

Figure 2B shows the addition of a separate second layer of fibrous material on top of the first layer of fibrous material of the structure of Figure 2A, also having a non-uniform coating of hardenable plastic compound on the second layer of fibrous material;

Figure 2C shows the manner in which the plastic compound is dispersed into the layer of fibrous material shown in Figure 2B by means of rolling pins applying force through the transparent plastic film cladding;

Figure 2D shows the structure of Figure 2C after the step of dispensing has been completed, the cladding has been opened to reveal the resulting double layer of fibrous material liner impregnated with hardenable plastic compound;

Figure 2E shows a portion of a radially expanded tubular shell made of the liner shown in Figure 2D adhered to the inner surface of the defect area of a selected portion of a pipe of ceramic or other suitable material;

Figure 3A shows an axial sectional view showing a portion of a defective pipe and a carrier in a contracted state surrounding a tubular shell of fibrous material with a friction-friendly plastic spaced between the carrier and the tubular shell in a ready radial direction. an expanded condition so as to force the tubular shell against the inner surface of the defective pipe section;

Fig. 3B is an enlarged end view sectional view seen along the arrow direction of line IIIB-IIIB in Fig. 3A;

Figure 3C is a cross-section of a radially expanded tubular shell, helically shaped, made of a multi-layer liner of fibrous material, the expanded tubular shell sealingly engages the inner surface of the defective pipe section, and the plastic compound fills the pipe part of the crack;

Figure 4A is an axial cross-sectional view similar to Figure 3A, but showing the carrier and tubular shell in a radially expanded state in the damaged pipe section;

Figure 4B is an enlarged cross-sectional view of the structure shown in Figure 4A;

The axial cross-sectional view shown in Figure 5 shows the defective portion of the pipe and the expanded tubular shell in the pipe; and

Fig. 6 is an axial cross-sectional view of the pipeline, a row of carriers respectively located in different defective parts of the pipeline.

Now compare Fig. 1, a square or rectangular bottom plate 3, its length is L, and width is B, and height is H, and a light-transmitting plastic film 2, preferably polyethylene film, covers on it. The width of the film 2 is equal to or at least slightly greater than the length L of the base plate 3, while the length of the film is at least equal to but preferably at least slightly greater than 2B. The membrane 2 is covered by an elongated layer of fibrous material comprising a first part or first half 1A of that part of the membrane which completely covers the top surface of the base plate 3, and which is integral with the first part 1A and which covers the base plate 3. The second part or half 1B of the film 2 on the right. The size of the base plate 3, the width of the film 2 and the full length of the layer of fibrous material including the parts 1A, 1B are selected to ensure that the selected (defective) parts of the underground pipeline 12 are satisfactorily repaired (see, for example, Figs. 3A, 3B and 4A), the underground pipeline can be, for example, a drainage pipe which is at least partially buried underground to a predetermined depth. Figure 1A also shows the application of a stream of hardenable plastic compound 14 to the exposed upper surface of portion 1A of the layer of fibrous material.

When the application of the stream of plastic material 14 to the portion 1A is complete, the portion 1B is folded over the portion 1A so that the two overlapping portions form a double-layer lining, and a selected amount of optional coating is also applied to the folded portion 1B. Hardened Plastic Compound 14. The plastic compound 14 coating may but need not be uniform, but the total amount of plastic compound used should be at least sufficient to completely penetrate the fibrous material liner comprising sections 1A and 1B. The lining thus obtained has a length equal to or approximately B and a width L.

The next step is to fold the uncovered part of the film 2 over the plastic compound 14 on the top surface of the part 1B so that the film 2 forms a cladding completely enclosing the liner and the two coatings of plastic compound. Manually using a rolling pin-like tool 4 on the top surface of the light-transmitting cladding formed by the film 2 to spread the plastic compound 14 in the two parts 1A and 1B so that the two parts become substantially infiltrated (i.e. saturated) Layers 1A', 1B' of fibrous material of hardenable plastic compound 14 (FIG. 1D). At the same time, the tool 4 makes the two sides of the base plate 3, that is, the joint 1E between the layers 1A' and 1B' and the side parallel to the 1E side, reasonably accumulate a large amount of plastic compound (shown by 5 in FIG. 1C). The length B of the liner including layers 1A', 1B' is equal to or approximately (preferably at least slightly greater than) the length of the defective portion of the pipe 12, and the width L of the liner exceeds the perimeter of the inner surface of the defective portion of the pipe to be repaired For example, the width L of the liner in Figure 1D can be equal to or approximately twice the circumference of the inner surface 12a of the defective portion of the pipe 12. The height H of the bottom plate 3 is selected so that the hollow hose carrier 6 can move to FIG. 1E shows the position in which the carrier covers and is at a distance from the underlayer comprising layers 1A', 1B'.

A preferred hardenable plastic compound 14 is epoxy resin. The use of a light-transmitting film 2 is recommended here because it enables the operator to observe the beginning, middle and final stages of the dispersion of the compound 14 within the cladding formed by the film 2 shown in Figures 1C and 1D. For example, the operator can detect and eliminate air bubbles, isolated impermeable fiber bundles and/or other defects that can be eliminated by using tool 4 to drive the plastic compound to the corresponding portion of the light-transmitting cladding. This can be eliminated by driving air bubbles (or other entrained gas bubbles) into the accumulated plastic compound 5 near the splice joint 1E between the layers 1A', 1B' and near the opposite side of the base plate 3.

When the integrated step of spreading and infiltration is completed, the envelope formed by the film 2 is opened, so that the adhered overlapping layers of fibrous material 1A', 1B' (infiltrated with plastic compound) become accessible and can be wound on the circumference of the carrier 6 , and then keep it in the contracted state shown in Figure 1E.

Before describing Fig. 1E, it is necessary to describe, with reference to Figs. 2A to 2D, a series of different steps in the preparation of a multilayer liner which can be wound on an expandable and contractible carrier of the type shown at 6 in Fig. 1E.

As shown in FIG. 2A, a separate layer 1a of fibrous material covers that part of the transparent film 2 which covers the top of the base plate 3. As shown in FIG. A uniform or non-uniform coating of hardenable plastic compound is applied to the exposed upper side of the individual fiber material layer 1a. A separate second layer of fiber material 1b is placed on top of the plastic compound 14 coating on the first layer 1a, and the second layer 1b is also coated with a uniform or non-uniform coating of hardenable plastic compound 14 (Fig. 2B). The film 2 is folded over the double lining thus obtained to form a cladding completely enclosing the lining comprising the layers 1a, 1b and the two coatings of the plastic compound 14, the hardenable plastic compound being spread therein with the tool 4 Comes to penetrate every part of every layer of the double liner. Some of the plastic compound is squeezed out of the liner to form a pool of plastic compound 5 enclosed in the envelope of folded film 2 . The cladding is then opened (FIG. 2D) exposing the backing layer so that the backing layer comprising layers 1a' and 1b' of fibrous material impregnated with plastic compound can be wound on a carrier 6 of the type shown in FIG. 1E.

As shown in Figure 2E, the plastic component of the radially expanding tubular shell has hardened, the tubular shell is adhered to the inner surface 12a of the pipe 12, and a certain amount of hardened plastic compound or filler 10 has penetrated and sealed the pipe 12 Cracks in the wall13. Reference numeral 11 denotes a ring of hardened plastic compound at the relevant axial end of the radially expanded and stabilized tubular shell 1d, such ring being formed between the inner surface 12a of the duct 12 and the outer surface of the expanded tubular shell 1d It provides a reliable seal against the penetration of the conveyed fluid medium (such as sewage). In addition, the ring 11 also forms a smooth transition between the inner surface 12a and the inner surface of the expanded tubular shell 1a.

As shown in Figure 1E, the transfer device that makes the radially expandable and contractible carrier 6 move into and out of the selected part of the pipeline 12 has a cylindrical metal core 15 on which the carrier 6 is enclosed. Two pairs of feet 8 carrying rollers 9 (see also FIGS. 3A and 3B ). The carrier 6 can be made of firm pressure-resistant and wear-resistant elastic material, for example, it can be a length of rubber hose or a hose made of elastic plastic. The elastic material of the carrier 6 may, but need not always be reinforced in any known manner, depending on how the carrier is configured to expand toward the inner surface 12a of the duct 12 and force the expanded tubular shell 1D into proper engagement with the inner surface 12a of the duct to be repaired. The amount of stress that must be withstood.

For example, the axial end 16 of the carrier 6 can be hermetically fixed to the adjacent part of the cylindrical core 15 with a woven strip 16 or other suitable material, ensuring that the annular chamber 6a between the carrier and the core is kept away from the atmosphere. Hermetically separated. The medium used to expand the carrier between the two sealed axial ends 16 may be a liquid or a gas such as air. The input means for pressurized fluid into the annular chamber 6a has a tube 17 connected to a suitable source of pressurized fluid and fitted with one or more valves for regulating the delivery of fluid into the chamber 6a or the removal of spent fluid from the chamber. The valve of 6a (not pictured).

Each lining layer 1d or 1D may consist of coarse fiberglass and a layer of fiberglass without adhesive, the latter being sewn to the former with polyester threads. Very good linings can consist of one or more layers, each layer consisting of a first layer (550 grams of glass fiber per square meter) and a second layer (such as cloth or mat) with a second layer of 450 grams per square meter glass fiber. The thickness of the liner 1d or 1D need not exceed 1 mm. E-CR glass is preferred because this material can withstand the corrosive effects of the fluid conveyed in the pipeline 12 being repaired.

As previously mentioned, the hardenable plastic compound 14 may be an epoxy resin that cures at ambient temperature or that must be heated to initiate or accelerate curing. Plastic compounds may contain one or more additives to enhance or impart certain desired properties. For example, the plastic compound may contain a suitable coupling agent to enhance the adhesion of the liner 1d or 1D to the wetted inner surface 12a of the pipe 12. This is particularly important when the method of the present invention is used to repair pipelines which are at least partially buried in the ground and used to transport sewage and/or other liquids. It is also advantageous to add at least a small amount of degassing agent to the plastic compound to reduce the possibility of gas bubbles forming in the tubular shell 1d or 1D. Each of the additives mentioned above may be a commercially available variety.

Fiber-reinforced plastics are stronger if they have a higher percentage of oriented fibers. This also applies to fiberglass, carbon filaments and KEVLAR(TM) fibers. The fibers and filaments described above are preferably used in the lining to be formed into the tubular shell 1d or 1D. Stronger or very strong but also thin tubular shells are preferred, since such tubular shells can withstand the stresses of widening the crack 13 in the damaged section of the underground pipeline. It should be remembered that the displaced tubular shell reduces the effective inner diameter of the repaired portion of the pipe 12 and thus constitutes an impediment to flow. A thin or extremely thin tubular shell that still seals the defective portion of the subterranean pipeline 12 constitutes little or no obstruction to flow and thus does not affect or significantly affect the flowable substances (such as sewage) flow.

When appropriate detection means (TV camera 18 as shown in Figure 6) have determined that there is a defective section in the underground pipeline, a liner (1A'+1B) impregnated with a suitable hardenable plastic compound 14 of the required size 'or 1a'+1b') is wound on the shrunken carrier 6, so that the formed tubular shell 1d or 1D constitutes a helix having at least a little more than one full turn, preferably at least two full turns plus A helix that is part of another turn. Each turn can consist of single layer, double layer or multiple layers. A winch or another suitable transfer device is used to transfer the carrier 6 and the tubular shell 1d or 1D wound thereon in the underground pipeline 12, so that the tubular shell is delivered to the defective part of the pipeline and viewed by a television camera 18 correctly positioned on the screen. The winch can be replaced by a motorized camera that automatically transports the carrier 6 in the underground pipeline 12 and stops the movement of the tubular shell when it is correctly positioned in the defective part of the pipeline to be repaired. The tube 17 is connected to a source of pressurized air or liquid (FIG. 6) by means of a hose 117, and the flow of pressurized fluid into and out of the chamber 6a in the carrier 6 is controlled by one or more valves. When the outer surface of the expanded tubular shell comes into sealing contact with the inner surface 12a of the duct 12, the expansion of the carrier 6 and the tubular shell thereon is complete. In and on the confined and expanded tubular shell 1d or 1D, the intervals required for the solidification of the plastic compound 14 can be selected in advance with a high degree of precision. Therefore, if this interval is shorter (for example when filling chamber 6a with hot gas or hot liquid), so, after short or very short time just can make carrier 6 shrink and withdraw from the pipeline 12 that is repaired like this .

It has been found that if the membrane 7 between the carrier 6 and the tubular shell 1d or 1D wound thereon comprises one, but preferably multiple (for example two) layers of a suitable film, such as a polyethylene film, very good results can be achieved. satisfactory effect. The two ends of the film 7 (wound on and bounded by the entire carrier 6) are hermetically connected to the corresponding axial ends of the carrier to ensure that when the carrier and the tubular shell (1d or 1D) surrounding the carrier expand radially, the wound The membrane will not be completely unwound. The means for sealing the wound film 7 at both axial ends of the carrier 6 can be strips, tapes, etc. coated with adhesive, or the innermost layer or each layer of the wound film 7 can also be fixed to the bottom of the roller 9. on foot 8.

In order to form the lining 1A'+1B' or 1a'+1b' into a tubular shell 1D or 1d, the carrier 6 can be guided so that it occupies the supporting film 2, the lining 1A'+1B' or 1a'+1b' and the membrane 7 A position on the front end face of the bottom plate 3, so that the carrier 6 is adjacent to the adjoining edge portion of the liner. The carrier 6 is then rolled along the top of the liner away from or towards the viewer of Figure 1D or 2D so that the liner forms a tubular shell 1D and 1d that closely follows the contour of the shrunk carrier. The membrane 7 can be wound on the carrier 6 before the liner is transformed into the tubular shell 1D or 1d in this way. Since the rollers 9 are outside the axial ends of the carrier 6, they do not form a hindrance during the transformation of the liner into a tubular shell. A suitable transport trolley for the carrier 6 may have a tubular metal core 15 (or of other suitable material) and four rollers 9, two at each axial end of the metal core. When installing and choosing the diameter of the roller 9, the carrier 6 and/or the tubular shell 1D or 1d thereon must not contact the inner surface 12a of the pipe 12 (see FIG. 1E ). In FIG. 1E , the distance D is between the outer surface of the tubular shell 1D and the top surface of the bottom plate 3 .

Once the step of winding the liner on the carrier is completed, the carrier 6 is ready to be moved into the pipe 12, either by means of a winch or by means of a motor driven television camera. The insertion of the carrier 6 takes place in a channel, for example in one of the channels 112 described in FIG. 6 .

When the carrier 6 and the tubular shell 1D or 1d thereon are removed from the bottom plate 3 in FIG. 1E , the film 2 is folded so that its surface in contact with the hardenable plastic compound 14 is located inside the formed laminate. The laminate is lifted off the base plate 3 and disposed of in an ecologically acceptable manner. The pool or soft part of the plastic compound hardens in a short time (eg 2-3 hours) in order to simplify the handling of the laminate including the folded together film 2 and the contents therein.

The carrier 6 with the tubular shell thereon is ready to be moved into the pipe 12, ie into the defective part of the pipe. Such moving in is carried out by transfer device, and transfer device comprises pipe 15 and roller 9 thereof, and the transfer process of carrier 6 is observed on the screen of television camera 18 when moving in. Pressurized gas or liquid is then introduced into the chamber 6a through the tube 17 to expand the carrier 6 and the tubular shell thereon. The expansion of the tubular shell 1d or 1D causes the overlapping parts of the layers 1A', 1B' or 1a', 1b' to slide relative to each other. For example, if the inner diameter of the duct 12 is 400 mm, the outer diameter of the carrier 6 in the unexpanded state may be around 350 mm, that is, significantly smaller than the inner diameter of the duct. The circumference of the tubular shell 1d or 1D may be about 350mm×π×2=2200mm, that is to say, the unexpanded tubular shell 1d or 1D is a spiral with 2 full turns. The circumference of the inner surface 12a of the pipe 12 having an inner diameter of 400 mm is 1256 mm. Thus, when the tubular shell 1d or 1D expands into contact with the inner surface 12a, the overlap of its turns is reduced from 2 to 1.75 (2200:400π=1.75). The calculation of the circumference of the unexpanded tubular shell takes into account the internal diameter of the defective pipe and the degree of overlap of the turns required for the expanded helically wound tubular shell.

As shown in FIG. 3A , the carrier 6 and the tubular shell are located within the defect of the pipe 12 . The defect comprises a joint between two adjoining sections of pipe 12 which has two cracks 13, one in each section. The carrier 6 is not yet expanded, that is to say there is still a gap between the outer surface of the tubular shell 1d and the inner surface 12a of the pipe. A membrane 7 is placed between the not yet expanded carrier 6 and the outer surface of the tubular shell 1d.

The pipe may have additional cracks 13 as shown in Figure 3B. These gaps can be sealed by a second tubular shell 1d or 1D, or by replacing the tubular shell 1d shown in Figures 3A and 3B with a longer tubular shell 1d or 1D.

As shown in Figure 3C, when the expanding step is complete, the expanded helically wound tubular shell 101d has two full turns and a portion of a third turn. The degree of overlap between the outer full turn and part of the third turn is indicated by the angle α. Each turn of the expanded tubular shell 101d has two layers. Part of the turn is adjacent to the inner surface 12a of the pipe 12 with three slits 13 . Each crack 13 is filled with a mass of hardened plastic compound 10 .

Using a tubular shell 1d, 1D or 101d having a first thickness to repair a first selected defective portion of the pipe 12, and repairing a second selected defective portion of the same pipe with a tubular shell having a second different thickness, the above case It also belongs to the scope of the present invention. Tubular shells with different thicknesses can be made from the same material (eg layers 1A+1B in Figure 1A or layers 1a, 1b in Figure 2B) by choosing the dimensions of the layers. Thus, the coiled tubular shell may have one, two, three, four or more full turns (if necessary) plus a portion of the next turn. In order to expand a thinner or thicker tubular shell 1d, 1D or 101d it is not necessary to vary the pressure in chamber 6a. Tubular shells with different thicknesses can also be produced by lining with the desired number of layers, each layer impregnated with a hardenable plastic compound. For example, referring to Fig. 2B, layer 1b is added on layer 1a, and a third layer can be added on top of layer 1b to increase the thickness of the liner shown in Fig. 2D, thereby increasing the tubular shape shown in Fig. 2E. Shell 1d thickness. In many cases, the size of the liner can be selected such that the circumference of the expanded tubular shell is equal to twice the circumference of the inner surface 12a of the pipe 12 to be repaired plus a part of the third turn, the circumference of which To the length of 100mm. Thus, a tubular case 101d as shown in Fig. 3C can be obtained.

When selecting the pressure of the gas or liquid in the chamber 6a during and immediately after expansion of the carrier 6 and its upper tubular shell, consideration must be given to avoid further damage to the defective duct 12 . Therefore, the pressure in the chamber 6a is limited to a pressure still sufficient to ensure that the tubular shell reliably expands to contact the inner surface 12a of the pipe 12 and infiltrates some hardenable plastic compound 14 in the crack 13 without causing cracks or any significant pressure. The widened minimum pressure on.

The magnitude of the friction force between adjacent turns of the tubular shell 1d, 1D or 101d can be calculated in advance, especially if the circumferential length (eg 100mm) of the complete turns and the additional turns is known in advance. During the expansion of the carrier 6 and the tubular shell, the overlapping parts of the helical tubular shell will slide relative to each other. The movement of adjacent turns of the multilayer tubular shell occurs only or actually only in the weight zone 20 between the outermost (partial) turn portion and the adjacent full turn 19 of the tubular shell. Since the friction force can be calculated in advance, especially when the tubular shell is expanded in a pipe 12 with a standard inner diameter and the tubular shell has a standard axial length, in order to ensure that the predetermined expansion of the tubular shell does not cause further damage to the defective part of the pipe The calculation of the pressure of the fluid in chamber 6a is rather simple. In addition, a precisely calculated pressure is established in the chamber 6a, which ensures that the outer surface of the expanded tubular shell bears against the inner surface 12a of the defective part of the pipe 12 with a predetermined force. The pressure of the fluid in chamber 6a is chosen such that adjacent turns of the helical tubular shell slide relative to each other during expansion of carrier 6 and that the expanded tubular shell bears against inner surface 12a with a preselected force.

Due to the entry of pressurized fluid into the chamber 6a, the carrier 6 will rotate about its axis during expansion. The degree of angular displacement of the carrier 6 during the expansion step is a function of the difference in diameter between the contracted carrier and the expanded carrier. It can be said that the carrier is screwed into the defective part of the pipe 12 by itself. The rotation of the carrier 6 during the expansion process can be attributed to the significant friction between the outer surface of the carrier and the inner surface of the membrane 7 (the inner surface of the membrane 7 can be the inner surface of a single layer membrane 7, or it can be inserted between the carrier and the tubular shell. The innermost inner surface of the membrane 7). The fully expanded carrier 6 and the tubular shell 1d thereon are shown in Figures 4A and 4B. The membrane 7 can be said to constitute a link preventing the rotation of the carrier 6 relative to the adjacent turns of the tubular casing and the latter relative to the former.

Expansion of the tubular shell 1d, 1D or 101d along with the carrier 6 causes some reduction in the thickness of the tubular shell, at least in part due to the sliding of adjacent turns of the helical tubular body relative to each other. This causes some of the plastic compound to extrude radially outward from the expanded tubular shell into the surrounding duct 12 at the defective site. in addition. The plastic compound is extruded from the axial end of the tubular shell to form a smooth transition zone 11 (Fig. 2E).

The carrier 6 is kept in the expanded state until after the plastic compound has hardened in the turns of the tubular shell, in the slits 13 and in the transition zone 11 . As mentioned above, the time required for the plastic compound 14 to harden can be selected virtually arbitrarily by appropriate choice of additives to the basic components (eg epoxy resin) and/or by appropriate choice of the temperature of the expanded tubular shell at the completion of the embedding step.

Once the plastic compound 14 has hardened, the carrier 6 can be shrunk by discharge of pressurized fluid through the tube 17 and withdrawn from the tube 12 . Separation of the shrunken carrier 6 from the expanded tubular shell is not problematic since the membrane 7 adheres to the shrinking carrier and is easily separated from the hardened plastic compound of the expanded tubular shell.

The carrier 6 is then ready to be rolled out of the repaired pipe 12 and put into re-use or stockpiling. The transition zone between the axial end of the expanded tubular shell and the repaired conduit 12 (shown as 11 in FIG. Sewage) has little or no resistance to flow. The hardened plastic compound increases the stability of the expanded tubular shell, reliably sealing the axial ends of the tubular shell and the crack 13 at the periphery of the tubular shell.

The flow of fluid through conduit 12 is preferably blocked during repair work. Since the core 15 of the transfer device transferring the carrier 6 presents little resistance to the flow of fluid through the pipe repair portion, the plastic compound within and on the expanded tubular shell, once cured, initiates the flow of fluid. In FIG. 4A the fluid levels (FL) in the repaired pipe 12 and core 15 are plotted just after the repair work has been completed and the carrier G has not been withdrawn.

The use of polyethylene films 2 and 7 is recommended here, since this allows the use of the epoxy resin in a physiologically acceptable manner and also allows the hardened epoxy resin to be concentrated and disposed of in an ecologically acceptable manner. The operator therefore does not need to come into contact with the flowable plastic compound at any stage of forming the tubular shell and/or moving into the job.

Figure 5 shows the removed tubular shell 1d at the completion of the work of withdrawing the carrier. The ring of hardened plastic compound at the axial end of the expanded tubular member 1d forms a smooth transition region 11 between the inner surface 12a of the tubular shell 1d and the inner surface 12a of the duct 12, as shown in FIG.

Fig. 6 shows the pipeline 12 completely buried in the ground between two adjacent wellbores 112 which allow access to adjacent parts of the pipeline. It often happens that several locations of the tubing 12 between two wellbores 112 are defective and each location must be repaired with a separate tubular casing of required axial length. In Fig. 6, there are four expanded carriers 6 in the pipe section between two wellbores 112 (the transfer device thereof is omitted and not shown). The hose 117 supplies pressurized gas or liquid to the chamber 6a of each carrier 6 and outputs used fluid from the chamber 6a, and the hose 117 is fed from one of the wellbores 112 and connected to a suitable source of pressurized fluid . It can be seen that the hose 117 leading to the chamber 6a of the carrier 6 on the far right in FIG. The two carriers adjacent to the left wellbore 112, and so on. Prior to feeding the four carriers shown in the figure into the conduit 12, the hose 117 may be fed into or through selected carriers. The video camera 18 is advanced with the newly introduced carrier 6 (and the tubular shell thereon) to facilitate proper positioning of the tubular shell in the selected defective portion of the pipeline 12, and the video camera 18 is then retracted through one of the shafts 112 Go to the illustrated position where the next carrier 6 is ready to be loaded. Carriers 6 can be expanded one after the other, that is to say, during feeding into the following carrier, thereby shortening the time required to complete the repair work between two wellbores 112 . The expansion of each carrier independently of the others is possible because each chamber 6a can receive pressurized gas or liquid through a separate hose 117 . Thus, a particular tubular shell may harden while other tubular shells are being fed into or expanded in the defective portion of the conduit 12 . This is of great importance for rapid completion of restorations that require entry and expansion of two or more tubular shells. Another tubular shell that has already been advanced and expanded does not interfere with the advancement and expansion of another tubular shell or shells.

The use of polyethylene films and membranes is recommended in many cases because the friction between the outer surface of the expandable carrier of elastic material and the adjacent face of the polyethylene film is greater than the innermost part of the helical tubular shell 1d, 1D or 101d saturated with plastic compound The friction between the turns and the membrane 7 is added to the friction between the tubular shells. The dimensions of the membrane 7 are chosen such that the initial overlap between turns of the membrane is sufficient to prevent direct contact between the tubular shell and the carrier when the carrier is being expanded to bring the tubular shell against the inner surface 12a of the pipe 12 . Thus, during radial expansion of the carrier 6, adjacent turns of the helically wound membrane 7 can slide relative to each other, but continue to form the outer surface of the expanding carrier and the helical lining forming the tubular shell 1d, 1S or 101d. Barriers to contact between the innermost turns of a layer. Since the end of the turn of the membrane 7 immediately adjacent to the outer surface of the carrier 6 does not slide relative to the carrier, whereas the overlapping parts of the membrane 7 slide relative to each other during the expansion of the carrier, the carrier is forced to Rotating in the conduit, the degree of angular displacement of the expanded carrier is dependent upon the difference in circumference of the outer surface of the carrier before and after the expanding step, as previously described. Rotation of the carrier 6 in the conduit 12 (during carrier expansion) is desirable and advantageous because it ensures that the turns of the helically wound tubular shell slide relative to each other, and the tubular shell during radial expansion The density of the tubular shell is increased by abutting against the inner surface of the duct 12 . The hardenable plastic compound 14 is thus extruded radially outwardly from the peripheral surface of the expanding tubular shell into sealing contact with the inner surface 12a of the pipe 12 and penetrates into the crack 13, forming a reliable seal once the plastic compound has cured .

It is desirable and advantageous to extrude at least some hardenable plastic compound on the circumferential surface and axial ends of the radially expanding tubular shell, since this avoids excessive pressure on the inner surface 12a of the duct 12 . This reduces the possibility of further damage to the pipe 12 (such as widening of the crack 13), because the very high percentage of hardenable plastic compound required at the transition zone 11 and at the crack 13 during the radial expansion of the carrier 6 can be removed from the tubular Squeeze out of the shell.

Without further analysis, for the gist of the invention described above, it is easy for others to use the existing knowledge to make various adaptation changes in various occasions, but it will not exceed the characteristics of the invention, which are my contribution to this profession. The basic and specific aspects of the contribution, therefore, such adaptation changes will not go beyond the scope defined by the claims of the present application.

Claims (17)

1. A method of repairing from within at least one selected portion of a pipeline at least partially buried in the ground, said at least one selected portion having at least one crack or a similar defective area, the method having the steps of: applying a hardenable plastic compound saturating a liner comprising at least one layer of fibrous material; winding the saturated liner on a radially expandable and contractible carrier to form a tubular shell having overlapping portions and first and second axial ends; the support and the tubular shell Significant friction is established between them, so that the radial expansion of the carrier causes the tubular shell to expand radially at the same time and with the relative sliding of the overlapping parts relative to each other; the carrier and the tubular shell are sent into at least one selected part of the pipeline; expanding the carrier and tubular shell within and toward the at least one selected location, concomitantly producing (1) a flow of hardenable plastic compound towards said at least one defect region, (2) rotation of the carrier relative to the conduit; shrinking the carrier separates the shrunk carrier from the expanded tubular shell; withdrawing the shrunk carrier from the tubular shell; and curing the hardenable plastic compound, wherein said expanding step further includes compressing said overlapping portions against each other, A hardenable plastic compound is extruded from at least one axial end of the expanded tubular shell. 2. The method of claim 1, repairing at least one selected location of an at least partially buried pipeline having a predetermined internal diameter, wherein said winding step comprises winding the saturated liner on a tubular carrier , the carrier has an outer diameter substantially smaller than the outer diameter after said expanding step comprising internally expanding the tubular carrier with a pressurized fluid. 3. 3. The method of claim 2, wherein said winding step includes forming the impregnated liner into a tubular shell, the length of which is selected such that said carrier extends beyond both axial ends of the tubular shell. 4. 3. The method of claim 1, wherein said step of establishing friction includes introducing a polyethylene film between said liner and carrier. 5. 4. The method of claim 4, wherein said feeding step is performed after said soaking step and before said winding step. 6. 4. The method of claim 4, wherein said winding step includes forming said film into a tube that surrounds and extends axially beyond the carrier. 7. 2. The method of claim 1, wherein said step of establishing friction includes introducing a multilayer polyethylene film between said liner and carrier. 8. The method according to claim 7, characterized in that: the winding step further comprises making the multilayer polyethylene film into a tube body, the tube body surrounds the carrier and exceeds the carrier in the axial direction, and the tube body The two axial ends are fixed on the carrier to prevent unwinding of the tube body during the radial expansion of the carrier. 9. The method of claim 1 wherein said winding step includes forming said liner into a helical shape having a plurality of turns. 10. 9. The method of claim 9 wherein said helix has a number of full turns plus a fraction of a turn. 11. 2. The method of claim 1, wherein said liner comprises a plurality of overlapping layers of fibrous material, and said winding step includes forming said liner into a helix having a plurality of turns. 12. The method of claim 1, wherein said expanding step includes introducing fluid into the carrier at a pressure that is a function of a number of parameters including the pressure required to press the tubular shell against the conduit with a predetermined force. The degree of carrier expansion required and the nature of the fiber material in the liner. 13. 13. The method of claim 12, wherein the other said parameter is the circumferential length of the liner being wound. 14. The method according to claim 1, characterized in that: the fiber material of the liner is selected from glass fiber, carbon fiber and KEVLAR (trademark) fiber. 15. The method of claim 1, wherein said step of impregnating comprises applying a hardenable plastic compound to a plurality of layers of fibrous material; laying said plurality of layers of fibrous material on top of each other; The layer and the applied plastic compound are contained within an envelope of polyethylene film; and an external force is applied to said envelope in a direction to cause the plastic compound to penetrate the layer of fibrous material. 16. The method of claim 15, wherein said film is light transmissive. 17. 15. The method of claim 15, wherein said step of applying external force manually spreads the plastic compound in the cladding using a rolling pin.

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