RU2025635C1 - Method and device for mounting new pipe inside existing pipe line - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: pipe is used in the flattened state and in the contracted form for storage of contracted form memory at which its maximum size is lesser that the inner diameter of the existing pipe line. The new pipe is heated throughout its entire legth in its contacted form to flexible state in the longitudinal direction. Then front end of new pipe is inserted into the existing pipe line in the heated flexible state, after which it is rounded off converting its contracted form into tubular form by heating and applying internal pressure simultaneously to flattened and bent pipes. Then new pipe is cooled down for its stabilization in the tubular form. Method is effected with the aid of device for mounting new pipe inside existing pipe line. EFFECT: enhanced reliability. 11 cl, 45 dwg

Description

 The invention relates to methods and equipment for mounting a replaceable section of a pipeline inside an existing underground pipeline, for example, a section of a pipeline, if necessary, to repair or replace it.

 For the repair of underground pipelines, such as sewer lines, etc. devices, while maintaining the existing pipeline in its place underground, various methods and equipment were proposed based on installing a flexible membrane or plastic sleeve inside an existing pipe, or installing it in an existing one the pipe of a new plastic pipe.

 In the known method, the pipes are lined with elastic plastic, such as polyethylene. According to this method, the sleeve is installed through pits located at intervals along the pipeline, which leads to an increase in the cost of the process.

 According to the method [1], the flexible pipe is turned inside out after it is filled with gas and driven into the pipeline section from one end of the section. This method is expensive because it requires special equipment, prolonged heating and expensive materials.

 The above processes and most other processes use an elastic or semi-elastic sleeve that is not able to withstand any perceptible external hydrostatic or atmospheric pressure. Thus, an existing pipe cannot be properly repaired.

 Known methods [2] and [3] of installing elastic tubing in an existing pipeline as a facing membrane for this pipeline. Thomas's patent describes a method for attaching flexible tubing to an existing pipeline using a stretchable short section of hard plastic coated with a binder. Both the method proposed by Thomas and the method proposed by Harper have the same disadvantages that were mentioned above in relation to other known methods that use elastic membrane material, which consists in the fact that they have insufficient necessary ring strength in order to withstand external pressure from soil and hydraulic pressure.

 Other authors, if necessary, repair suggested installing a rigid pipe inside the existing pipeline. For example, in a round rigid plastic pipe having a repair size, they are flattened or otherwise crimped at the site of the repair work and inserted in the cold state and in a rigid form into the existing pipeline through large excavation pits in the hole. After installation, the plastic pipe is expanded by heating and internal pressure. A plastic pipe is pressed against an existing pipe.

 The closest technical solution to the described method and device for mounting a new pipe inside an existing pipeline and a method of eliminating a cut of a new pipe is [5].

 In the method of mounting a new pipe of hard thermoplastic material at ambient temperature in an existing pipeline, in which the new pipe is installed in an abbreviated form in an existing pipeline on its inlet channel, in which the maximum size is smaller than the inner diameter of the existing pipeline, and which (pipe) can expand to the tubular shape of the desired outer diameter substantially the same as the inner diameter of the existing pipe, insert the front end of the new pipe into uyuschy conduit positioned, a new pipe in the existing pipe, the new pipe attached roundness by converting it from the reduced form into the tubular form by heating.

 A device for mounting a new pipe inside an existing pipeline contains means for storing a rigid thermoplastic pipe for replacement having a front end and a rear end in an abbreviated form, and storage of a rigid thermoplastic pipe for replacement in an abbreviated form, in which the pipe is bent and layered on itself, the means to extract the front end of the tapered seamed pipe, mounting means for mounting the front end of the new pipe into the existing pipe.

 In a method of eliminating a cut-off of a new, substantially rigid thermoplastic pipe that is inserted into an existing pipe, the new pipe is made in an abbreviated form to preserve memory in relation to such a flattened and folded shape.

 The disadvantage is that a thin-walled pipe made of plastic has a thermal memory only for a round shape.

 The description of the invention further states that the flattened pipe can be wound on a bobbin. It will remain in its flattened form, but since plastic materials with thermal memory regain their original shape if they are heated to the softening temperature after deformation, the pipe can again take its round shape by heating, which is used when applying the method according to the invention.

 When a pipe is made flattened, it does not expand during heating to give it flexibility before insertion instead of a replacement one. If the pipe has a circular shape memory, it will expand during heating to make it bend (flexible). Thus, it will be difficult to install it in an existing pipeline.

 The technical results from the use of this invention are to provide the following: a new and improved product for the replacement of pipelines for installation in an existing underground pipeline, which is suitable for the repair and replacement of existing sewer pipelines of buildings that are not linear, and main pipelines intersected by sewer pipelines of buildings; a new and improved method of manufacturing a pipeline product for repair and replacement, in particular suitable for installation in existing underground pipelines that are not straight or intersected by sewer pipelines of buildings; a method for installing a new or replaceable section of a pipeline in an existing underground pipeline and, in particular, in a pipeline that is not straight or that is intersected by sewage pipelines of buildings; devices and equipment for the manufacture of a replaceable pipeline product in accordance with the foregoing; devices and accessories for installing the piping product described above into the existing sub-piping pipeline and, in particular, such a pipeline that is not straight or that intersects the side auxiliary pipelines; devices or accessories for converting a new or replaceable section of a thermoplastic pipe installed in an existing underground pipeline and, in particular, the sewer pipe of a building, after a new or replaceable section of the pipeline was installed in a bent state, by giving it a stable round shape inside the existing pipeline.

 In FIG. 1 shows a thermoplastic pipe, for example polyvinyl chloride, which is used in accordance with the invention in an expanded rounded state; FIG. 2 shows a perspective view of the thermoplastic pipe shown in FIG. 1, and devices for transforming a pipe from its circular state into a flattened and folded state for storage on a coil; in FIG. 3 - thermoplastic pipe, after it was folded (section AA in figure 2); in FIG. 4 - shows the installation process of the folded and wound onto the coil thermoplastic pipe shown in FIG. 2 and 3, inside the sewer line from the hatch, the folded thermoplastic pipe being stored on the drum and re-heated for installation in a relocated underground pipeline; in FIG. 5 is a schematic view of a detail of a device for dispensing a folded thermoplastic pipe shown in FIG. 2 and 3, and giving it a round shape after it has been inserted into the main line, as shown in FIG. 4; in FIG. 6 is a schematic illustration of an alternative structure for dispensing and rounding a folded thermoplastic pipe after it is installed in a pipeline; in FIG. Fig. 7 shows a schematic diagram of the sewer pipe of a building passing from the building it serves to the main sewer line (illustrates the method of installing a thermoplastic pipe in the sewer pipe of a building in accordance with the invention; Fig. 8 is a thermoplastic pipe shown in Fig. 1 in the folded state for installation in an underground pipeline; in Fig. 9 - a device for manufacturing the thermoplastic pipe shown in Fig. 1, in the folded form shown in Fig. 8; in Fig. 10 - a calibration device , shown in Fig. 9 is a vertical section; in Fig. 11 is a vertical section of the calibration plate of the calibration device shown in Fig. 10 (section BB in Fig. 10); in Fig. 12 is a folded end portion of the thermoplastic pipe shown Fig. 8 is a top view with an end gripper attached to it for use when pulling the pipe into the pipeline and to narrow the end of the pipe so as to allow internal pressure to be supplied to the pipe for distribution; in FIG. 13 is a cross-section BB in FIG. 12; in FIG. 14 is a traction drum device, a top view shown in FIG. 7 to retract the folded thermoplastic pipe shown in FIG. 8 into an auxiliary branch, this device being in its working position; in FIG. 15 is the same as in FIG. 14, but with a device in a flattened state for installation in an auxiliary branch; in FIG. 16 is the same as in FIG. 14 and 15, side view; in FIG. 17 is a plugging tool of a tool used to seal the end of the long thermoplastic pipe shown in FIG. 8 is a side view, after the end has been given a round shape, for use in supplying the medium, heat and pressure of the medium to the interior of the thermoplastic pipe; in FIG. 18 is a section GG in FIG. 17; in FIG. 19 is an end of a thermoplastic pipe with a plugging tool shown in FIG. 17 and 18 inserted into the pipeline and clamped in place by the chain clamping means; in FIG. 20 is a view of the chain clamping means shown in FIG. nineteen; before applying it to the pipeline and plugging shown in FIG. nineteen; in FIG. 21 is a section DD in FIG. 19 illustrating the chain clamping tool of FIG. 19 and 20, pressing the end of the thermoplastic pipe to the plugging tool shown in FIG. 17-19; in FIG. 22 is a front end portion of the thermoplastic pipe shown in FIG. 8 is a longitudinal section, with the end clamp shown in FIG. 12 and 13, superimposed on the end of the pipe, and with the rest of the pipe extended and round in shape, and with a cutting tool, in accordance with the present invention, inserted into the rounded end portion of the pipe to cut the clamped end from the rest of the pipe; in FIG. 23 is a section EE in FIG. 22; in FIG. 24 is a side view of the end heating device used to heat the end portion of the thermoplastic pipe to reprocess the end section, the heating tool being shown mounted on the folded end section of the thermoplastic pipe shown in FIG. 8; in FIG. 25 is a perspective view of an air-inflated end plugging tool used to plug or narrow an end portion of a thermoplastic pipe in place of the end clamping means shown in FIG. 12 and 13, to ensure the distribution and rounding of the folded thermoplastic pipe; in FIG. 26 is a perspective view showing a vertical projection of a blown pipe shown in FIG. 25, partially in section; in FIG. 27 is a schematic view illustrating the installation of the inflatable plugging tool of FIG. 25 and 26, in a thermoplastic pipe, when it is in an expanded state and is given a round shape; in FIG. 28 is a schematic view similar to FIG. 27, but which illustrates the pipe shown in FIG. 27, after it was crumpled again, with the inflatable tube in the deflated state inside; in FIG. 29 is a schematic view illustrating the use of the inflatable plugging tool of FIG. 25 and 26, when installing a thermoplastic pipe in an auxiliary branch; in FIG. 30 is a schematic view illustrating yet another use of the inflatable plugging tool of FIG. 25 and 26; in FIG. 31 is a schematic view further illustrating the use of the inflatable plugging tool of FIG. 25 and 26 in accordance with the method illustrated in FIG. thirty; in FIG. 32 is a schematic view illustrating yet another use of the inflatable plugging tool of FIG. 25 and 26, for expanding and rounding a folded thermoplastic pipe after it has been inserted into an existing underground pipeline; in FIG. 33 is a schematic view of a portion of a main pipeline and an intersecting auxiliary branch pipe, illustrating an alternative method of pulling the thermoplastic pipe shown in FIG. 8, into a repaired auxiliary branch; in FIG. 34 is a schematic view of an end portion of a folded thermoplastic pipe shown in FIG. 8 illustrating one method of disconnecting a traction cable from a front end of a pipe after it has been inserted into an underground pipeline; in FIG. 35 is a schematic view similar to that shown in FIG. 34 illustrating yet another method for disengaging a traction cable from a thermoplastic pipe after it has been inserted into an underground pipeline; in FIG. 36 is a section at the intersection of the main pipeline and the auxiliary branch of the pipeline after the thermoplastic pipe shown in FIG. 8, installed and distributed inside a repaired main pipe, and illustrating a method for splitting and cutting a hole in a newly installed thermoplastic pipe to resume communication between the auxiliary branch and the main pipe; in FIG. 37 is a schematic side view in vertical section illustrating a method and apparatus for folding a thermoplastic pipe that has been made round for installation in an existing underground pipeline; in FIG. 38-42 are schematic sections, respectively, F-F-F-L in FIG. 37; in FIG. 43 is a schematically removable end clamp and an attached traction cable and free conduit for use in clamping the front end of the folded pipe shown in FIG. 8, when installing it, side view; in FIG. 44 is an end clamp of FIG. 42, top view; in FIG. 45 is a free wedge portion of the clamp shown in FIG. 42, top view.

 Repair of sewer highways, etc. devices.

In FIG. 1, 10 denotes the type of pipe that is used to restore, repair, or replace underground sections of pipelines, such as sewer pipelines or the like. devices in accordance with the present invention. A characteristic feature of the pipe is stiffness and thickness so as to have sufficient annular strength to withstand the external pressure of the soil and the hydraulic pressure that it can be exposed to when working underground. Such thermoplastic pipe can become more flexible when heated to temperatures of the order of ^{200 °} F (93,5 ° ^C) or higher in the case of PVC pipe. A characteristic feature of the pipe 10 is that it is structurally rigid at normal ambient temperatures on the surface of the earth and underground, but becomes flexible and workable with the possibility of giving it various shapes when heated or reheated. The second characteristic feature of such a thermoplastic material is that it has a "memory", that is, if it is made in the form of a specific shape, such as a round tubular shape, and after that it is heated and flattened or folded, and then cooled to stabilize it in its folded form, and then re-heat without restriction, it will strive to return to its original tubular shape. Conversely, if the pipe is manufactured initially, for example, in a flattened and folded form, as shown, for example, in FIG. 3 and 8, after that, heat and distribute under the influence of internal pressure to a round shape, and then cool and stabilize in a round shape, the pipe will tend to return to its original folded shape if it is then heated again without restriction. This side associated with the memory of the thermoplastic pipe is used to provide advantages in some aspects of the present invention.

 The most suitable in this invention is a pipe made of polyvinyl chloride (PVC) with standard geometric ratios (outer diameter / wall thickness) in the range of 13-65, currently used for underground pipelines, such as drainage pipelines, water pipelines, etc.

 Although in a most preferred embodiment of the present invention, the thermoplastic pipe is folded as shown in FIG. 8, by the method described with respect to the device shown in FIGS. 9-11, at least some aspects of the invention can also be practiced using a thermoplastic pipe made in the form of a tubular or round shape. FIG. 2 illustrates a device 11 for re-shaping a polyvinyl chloride pipe 10 that has been manufactured in a circular shape. FIG. 3 illustrates the cross section of a pipe after its shape has been restored by flattening and folding using the device of FIG. 2. In particular, the polyvinyl chloride pipe is heated by any known method, for example by means of a heating means 11a, which may be a thermostatically controlled steam box or a casing in which thermostatically controlled electric heating elements are located. Due to the passage of the round pipe 10 through the heating box 11a, the pipe is heated to a temperature sufficient to become plastic or flexible. It is then flattened or folded in a folding device 11 to reduce the overall cross section, so that the pipe can easily be pulled into an underground pipe having the same or slightly larger inner diameter than the original outer diameter of the thermoplastic pipe. The thermoplastic pipe or reduced folded size is shown at 10a in FIG. 3.

 Although the assembly 11 in FIG. 2 schematically illustrates a means for folding a pipe, a practical device for folding a pipe, and a method are illustrated in more detail with respect to the device shown in FIG. 37 and 38-41. It can be seen that the round pipe 10, after being passed through the heater 11a, is first flattened using a pair of opposite flattening rolls 60, 61 and then passed under the folding wheel 62, while gradually supporting three different sets of folding rolls 63-65. A pair of folding rolls 63 is mounted together with the folding wheel 62 in order to start folding the pipe 10 to give it a U-shape. Then, with the help of three folding rolls 64, the folding process is continued, placing them in the form of a semi-U-shape for interaction with the folding wheel 62. And finally, a set of four folding rolls 65 is set in the form of the letter U for interaction with the folding wheel 62 s the purpose of completing the folding of the pipe 10 into a U-shape. Thereafter, the folded tube is passed through the restrictive mold 66 while it is being cooled in order to stabilize the tube and its U-shape so that it retains a U-shaped memory. After mold 66, the folded pipe can either be stored as lengths of predetermined lengths, or it can be passed through a steam pipe to reheat and give flexibility for direct insertion into an existing pipeline.

 After the flattening process and before folding, the pipe can be wound onto the drum in a flat state in the hot box 18 shown in FIG. 4. Then the flat pipe wound on the drum can be heated again in a hot box at the place of work and then pulled out of the hot box and folded, as described previously, just before installation in the restored pipeline.

 It is possible to mount a thermoplastic pipe into an existing pipe in a flattened state, in particular if the thermoplastic pipe in its circular state has a smaller outer diameter compared to the inner diameter of the pipeline being repaired. However, in most cases, it is preferable to install the thermoplastic pipe into the pipeline in a longitudinally folded form, as shown in one of FIG. 3, FIG. 8 or in FIG. 42. However, of all the folded forms, the form shown in FIG. 8 is preferred.

 A round thermoplastic pipe has a memory that tends to return it to its round shape if it is reheated after folding. Thus, when it is necessary to reheat the pipe in order to make it flexible for installation in the pipeline, the pipe will tend to return to its circular cross-section, possibly prematurely if not limited. For this reason, it is preferable to produce a thermoplastic pipe in the first case in a folded form. When the folded pipe is reheated in order to make it flexible for installation in the pipeline, the pipe will tend to retain its folded shape until it is fully inserted into the pipe and ready for conversion to a round shape.

 Regardless of whether the thermoplastic pipe is made in a round or folded form, the pipe must be in a folded form when it is ready to be installed in the pipeline. It is also preferred that the thermoplastic pipe is wound on the drum while it is heated and therefore made flexible on the drum, such as drum 12 shown in FIG. 4.

 The thermo-plastic tube drum 12 is stored in a casing or “hot box” 18 equipped with a thermostatically controlled heater 24 for heating the interior of the hot box and, thus, the drum 12, for receiving the folded tubular material 10a, which can become flexible if necessary. Preferably, the hot box 18 is also provided with an air circulation system 19 to prevent stratification of the heat inside the hot box and thereby guarantee uniform heating of the drum with the wound pipe. The hot box 18 is preferably mounted for portability, and is shown mounted on a flat base of a truck 20 for transport to a work site. A smaller hot box can be mounted on wheels and manually moved for use when servicing small inaccessible pipelines, such as sewer pipelines in buildings. In any case, either a drive means or a manual means is provided for rotating the drum 12 to wind the material onto the drum or unwind from the drum. The hot box 18 is provided with an access door 31 and can be equipped with a downpipe 22 and a roll 23 to facilitate the installation of the folded thermoplastic pipe into the underground pipe through a vertical access opening, such as the hatch 16 in the sewer line 14.

 The hot box is transported to an opening at a place of work, such as a hatch 16, in an underground section of a pipeline, such as a sewer line 14, to be repaired. The end of the deflated pipe 10a is connected to the pull cable 26, accessible from the side of an adjacent hole in the pipeline, such as another hatch (not shown), and connected by clamping means 28 to the free or front end of the new pipe. The new pipe is made flexible by heating the drum 12 in the hot box 18 by means of a heater 24. After that, the traction cable 26 is activated by, for example, a winch in the next hatch along the hatch 16 to pull the flexible folded pipe 10a from the drum 12 through the drain pipe 22 and around the drain roll 23 into the conduit 14 to the next hatch. After installing the folded new pipe, it is heated and distributed to a round or essentially round shape in order to obtain a pipe that turns into a thick-walled rigid shape having sufficient annular strength to withstand external hydraulic and ground pressures.

 FIG. 5 illustrates a method of dispensing a pipe of a reduced size after being dragged into a relocated or replaceable original pipe. A pair of plugs 30 and 32 are inserted into the opposite ends of the folded pipe when at least these ends are in a heated flexible state. The plug 30 is installed at the rear end of a new pipe section, which is located on the inlet side of the existing pipeline. The plug 32 is installed in the front or traction end of a new pipe after disconnecting the traction cable. Each of the plugs 30 and 32 is provided with spherical expansion spacer elements 34 mounted for the seals capable of being disconnected with the original pipe 14 and a new pipe 10a. Gasket elements 34 are inflated using pressure lines 36, such as compressed air lines leading to a control means (not shown) above the ground. The plug has an inlet channel 38 for introducing into the new pipe an expansion medium, such as hot water vapor or hot water. Such a channel is equipped with a control valve 40, as well as a manometer 42 and a safety valve 44. In the plug 32 there is an output channel 46, communicating with the space between the two plugs and equipped with a valve 48.

 The newly installed folded pipe with the plugs installed at the opposite ends is heated inside by passing sharp water vapor through small passages formed by the folds of the new pipe, visible in FIG. 8. The valve 48 on the outlet side is open so that the new pipe heats up over its entire length. Then, the valve 48 is closed, while continuing to supply through the plug 30 pairs of pressure in order to create pressure in the folded pipe, causing it to change and expand with the formation of a round shape. If the new pipe is fabricated, it should be cooled or allowed to cool after it has reached a round shape, while maintaining internal pressure, such as cold air pressure, so that the pipe cures in its round shape. This last operation is not necessary if the pipe is made round, if the pipe is not expanded or extended beyond the boundaries of its original diameter during the conversion process.

 If no internal channels are provided in the folded new pipe, such as would have been possible if the new pipe was folded completely flat, as shown in FIG. 3, the new pipe should be heated externally, for example, by passing sharp water vapor through an existing pipe before plugs 30 and 32 are inserted into the ends of the new pipe. Then, after heating the new pipe along its entire length, plugs 30 and 32 could be easily inserted into its opposite ends, valve 48 should be closed and sharp steam or hot water should be introduced through plug 30 to expand the folded pipe and turn the pipe into a round shape.

 In FIG. 6 illustrates another type of device for expanding a deflated pipe. Such a device comprises a mandrel 50 provided with a heating means 52 capable of heating a new pipe, bringing it into an elastic state. The mandrel 52 is connected to the traction cable 54 or other means for drawing it through the source pipe. After heating the mandrel and as a result of the tension of the traction cable, the mandrel is pulled through the original pipe, distributing a new pipe to the required diameter. Using this method, the traction cable 54 should be inserted into a new pipe before the new pipe is folded for entry into the pipeline.

 The third method of heating, rounding and expanding the new pipe involves treating the existing pipe to be repaired with hot water or water vapor next to the installed but still folded new pipe until the required temperature is reached at the output end. After that, the new pipe is subjected to pressure using hot water or water vapor and expanded under the influence of pressure until it takes a round shape and to the required diameter.

In a particular pipeline reconstruction method, a polyvinyl chloride pipe is obtained which is half an inch smaller in outer diameter than the inner diameter of the pipe being restored. A PVC pipe is characterized by standard geometric relationships between wall thickness and outer diameter. PVC tubing is heated to at least ^about 200-210 F (93,5-88,0 ° ^C) and lowered to the shape shown in FIG. 3, FIG. 8 or FIG. 42. The folded tube is then stored on large drums so that it can be transported by truck to the place of work. During installation in the pipeline or underground channel, the new pipe is again heated, preferably in the hot box 18, so that it becomes flexible and can be easily dragged, usually vertically down through a deep hatch and then horizontally through the pipeline. Immediately after installation in the pipeline section, the folded pipe is closed with a stopper, heated and round-shaped. If necessary, it can be expanded beyond its original or design diameter so that the pipe fits snugly into the pipeline section.

 The advantage of distributing the newly installed thermoplastic pipe outside its original design diameter is illustrated with respect to FIG. 36, where the repaired section of the existing pipeline is intersected by at least one sewer pipe of the building or another auxiliary branch. In FIG. 36, the main pipeline 70 intersects at point 72 with an auxiliary branch 74, such as a sewer pipe of a building. After installing a new thermoplastic pipe in line 70, it is given a circular shape and is expanded or extended beyond its original round design diameter to fit snugly with the inner wall of existing line 78, a bulge or recess 76 forms in the hole or in the insertion point 72 of the auxiliary branch into the line. This bulge 76 is an indication of the exact location or entry of the auxiliary branch into the trunk. By passing the television camera through the trunk, it is possible to determine the exact location of the bulge or recess and thus the passage of the auxiliary branch. After that, along the highway to the location of the exact location of the bulge, you can skip the cutting tool 78 with remote control and use it to cut the bulge 76 from the new pipe 80, thereby again forming a message between the auxiliary branch 74 and the highway.

 Although flattened and folded thermoplastic pipes shown in FIG. 3 and 41 are suitable for use in the described mounting methods, a preferred shape of such a folded pipe 10 is shown in FIG. 8. The thermoplastic pipe 10 shown in FIG. 8 is a flattened pipe with longitudinal folds in the form of a curved convex longitudinal fold 82, in the form of a pair of overlapping legs, including a long leg 83 and a short leg 84. The long leg 83 ends with a curved or convex free end 85, in order to limit a small longitudinal channel 86 in a fanfold pipe. The shorter leg 84 also ends with a curved or convex free end 87, which forms a longitudinal channel 88 in the pipe. In addition, the peeling-off portion 82 forms a channel 89 along the inner cavity of the rebate from one end of the pipe to the other.

 The convex folds and leg ends described above are important to prevent splitting of the folded portions of the pipe during folding, which might otherwise occur if the pipe was flattened in the manner shown in FIG. 30 in particular if the pipe is thick-walled. Channels 86, 88, and 89 allow water vapor or other hot medium to pass along the entire length of the folded pipe to reheat and reprocess it after the folded pipe is installed in an underground pipe. Without such access to the internal cavities of the folds, re-heating would be long, slow down the process and it would be very difficult to provide.

 The folded shape of the pipe shown in FIG. 8 is suitable for use as a new pipe in the repair of sewer pipelines of buildings, such as the sewer line of building 90, shown in FIG. 7, passing from the intersection 92 from the main highway 94 into the serviced building 96. Installation of a new pipe in such sewer pipelines of buildings is difficult due to the features of such pipelines. Firstly, such branches are associated with difficult access problems, as they often pass under the playgrounds, trees and bushes and are inaccessible from the hatch. If repairs were necessary, digging up the branch would be very expensive. When installing a new branch into an underground branch, access is usually practiced only from a single small vertical soil, next to the building, as indicated in pos. 98 in FIG. 7. Such excavation leaves little room for maneuvering or for a large amount of equipment.

 Secondly, the sewer pipelines of buildings have a significantly smaller diameter compared to highways and have sharp curves and bends, unlike highways, which, as a rule, are straight from one inspection well (hatch) to another. For example, the sewer pipe 90 of the building contains a bend in the form of poses. 100, which makes it impossible to insert a straight rigid pipe into the existing branch. In FIG. 7, the sewer pipe 90 of the building, having access by opening 98 near the building 96, passes under the lawn 102 to the highway 94. The methods and equipment described below are suitable for solving the problems associated with installing a new branch pipe into the underground pipeline branch from the only small, mostly vertical opening. Such methods and devices are based on the use of the finished form of the sealed thermoplastic pipe shown in FIG. 8.

 According to FIG. 9-11, the sealed thermoplastic pipe shown in FIG. 8, is weaved from a conventional plastic pipe in an extruder 106, extruding the pipe into a vacuum box 108. Traction means 110, consisting of a series of opposed compression rolls 111, 112 after the vacuum box, pulls the extruded and molded material from the vacuum box under tension and feeds it into the steam pipe 114 for heating to a flexible state so that the resulting folded pipe can be wound in its folded shape onto the storage drum 116, which can be placed in the hot box 18 shown in FIG. 4.

 Matrix 118 and punch 120 are located at the exit of the extruder. Between the output side of the matrix 118 and the entrance to the vacuum box 108 there is a gap 121 of the order of 12-24 inches.

 The vacuum box is divided from the inside by partitions 122, 123 into three compartments. All three compartments are filled with water to level 124 inside the box. The first or first downstream compartment of the box is connected to a vacuum source 125. Although the entire vacuum box is under vacuum due to such a connection, the largest vacuum occurs in the first compartment of the box along the way. Calibration means 126 are provided in the first compartment of the vacuum box. Calibration means form and store the extruded plastic material in its necessary folded form after cooling the material, and therefore curing it. The water inside the vacuum box performs a cooling function, and the vacuum created in the box, together with the calibration means, maintains the plastic material in its necessary folded form until, by cooling, it is able to maintain this form without constriction.

 According to FIG. 10 and 11, the calibration means includes a series of calibration plates 128 mounted at certain distances from each other and assembled together by means of connecting rods 130 and separated from each other by spacers 132 between the plates on the rods. The rods are threaded at their opposite ends and fastened with nuts 134. The calibration plates 128 are closer to the inlet end of the calibration means closer to each other than the downstream plates due to the greater ductility and fluidity of the plastic material at the inlet end portion and therefore due to the greater need to maintain the shape of the extrusion in this part of the calibration device. The calibration means optionally also includes a central tube 136 with openings 137 for supplying cooling water to the plates and between them for faster cooling of the plastic material.

 According to FIG. 11, each calibration plate 128 includes a precision bore 138 of a precise external shape and the outer size of a folded pipe molded and provided by calibration plates. Each plate 128 of the calibration device has exactly the same size and the same hole shape. The hole 138 of the calibration plate comprises a short leg 138a corresponding to the short leg 84 of the folded pipe, and a long leg 138b corresponding to the long leg 83 of the pipe, and a rounded folding part 138c corresponding to the longitudinal rounded fold 82 of the pipe.

In the manufacture of the pipe shown in FIG. 8, a crude mixture of plastics material, eg PVC, is introduced into the extruder 106 via hopper 107, where the material is heated to a high temperature, e.g., about 360 ^° F (182 ° ^C) and then extruding it through a die 118 where very hot plastic material in contact with a needle 120. The matrix and the needle are sized to give the plastic materiel the required final size and shape to produce the required pipe. Plastic material is introduced through the gap 121 into the first compartment of the vacuum box 108 and through the calibration plates. The plates provide the molding of plastic material and the preservation of its shape and dimensions, determined by the holes 138 of the calibration plates.

 When the plastic material first enters the calibration device, it is very hot and quite liquid, and therefore the calibration plates 128 are located very close to each other in this place in order to maintain the desired shape. The vacuum inside the box presses the plastic material to the outer periphery of the hole 138, as cooling water cools the plastic material. If necessary, compressed air supplied from the source 140 to the needle 120 can be passed through the internal ducts 86, 88, 89 of the folded plastic shape to ensure that the plastic material is not completely flattened, retaining the tubular shape of the folded pipe. By the time the plastic material reaches the output end of the calibration means 126, it has cooled significantly and is able to maintain its own shape under the tension created by the draw rolls 110. Such rolls pull the folded plastic material from the vacuum box into a continuous strip. From the calibration plates, this strip passes through the second and third chambers of the vacuum box, where it gradually cures. By the time the strip 10 leaves the vacuum box, it has been cooled, has rigidity and practically has the shape depicted in FIG. 8. Traction means 110, while pulling the strip or material flow from the extruder under tension, controls the wall thickness and other geometric parameters of the folded pipe.

 From the traction means 110, a folded strip is fed through a steam pipe 114, to which a water vapor source 115 is supplied through an inlet 117 to heat the strip to a flexible state so that it can be wound onto a storage drum 116.

 The number of calibration plates and the distance between them depend on the speed of extrusion.

 The drum 116 with the folded tube 10 stored thereon can be installed in the hot box 18 shown in FIG. 4, for transportation and use at the work site.

 FIG. 7 not only illustrates the sewer branch described previously, but also the method, apparatus and tool for installing the sealed thermoplastic pipe shown in FIG. 7, in the branch. Firstly, it is necessary to vertically dig 95 soil as close as possible to building 96 served by branch 90 in order to provide access to branch 90.

 After that, you can determine the length of the branch to be repaired or replaced by passing a flexible fiberglass rod in the branch at the opening point and pushing this rod through the branch until it intersects with line 94. When this happens, the length of the rod inside the branch can be mark in the hole through which access is provided, and after that the rod is pulled out and measured in order to determine the length of the plastic pipe 10 necessary for the work. When the length of the series of repaired branches is known, the folded pipe can be previously cut into such segments, either at the production site, or at some distance from the place of work. After that, pipe blanks can be transported to the installation site.

 Alternatively, these segments can be cut at the place of work from the drum 116 or 12 (figure 4) inside the hot box 18, delivered to the place of work. If pits dug in the ground for repaired branches are not available for the truck 20 on which the hot box 18 is mounted, the plastic pipe 10 of the required length can be stored on other, smaller, drums in the smaller hot-mounted boxes (not shown) mounted on wheels, rolled up to the corresponding pits in the ground. The smaller “new hot box” 140 is shown in FIG. 7 with a drum 142 enclosed therein with a folded tube 10.

 Alternatively, instead of pre-measuring and pre-cutting the folded plastic pipe 10 into the required lengths corresponding to the lengths of the branches to be repaired, the folded pipe can be heated inside the hot box 140 and introduced into the existing branch until the folded pipe reaches the intersection with the highway 94, and cut the zeppm on the drum.

 If the folded plastic pipe 10 is pre-cut to the desired length at the factory, then it can be transported in the form of pre-cut segments to various sections of the work, and there it can be heated for installation in an existing branch in a steam pipe similar to the steam pipe 114 shown in FIG. 9. The steam pipe can be made of tarpaulin or metal, or equivalent materials, with ends of elastic fabric or similar materials that can be tied around a folded plastic pipe in order to hold water vapor inside the steam pipe. Such pipes are lightweight in terms of ease of transportation to the place of work and may be 30 feet (9.1 m) long or more. For field conditions, a canvas tarpaulin steam pipe is preferred over a metal pipe given their weight.

 If the sewer branch is straight and the access to it during excavation is close enough to the surface, or the opening is quite large, then in this case it may be possible to place a folded plastic pipe 10 of the required length into the branch by pushing a new pipe into the pipeline until until the front end reaches the highway. However, this will often be impossible due to the need for a new pipe to pass through a bend at the opening site or along a branch, or both. In such cases, it is not necessary to heat a rigid folded plastic pipe under normal conditions to give it longitudinal flexibility for bending and pulling a new folded pipe into a branch instead of pushing it.

 One way to install a new branch into an existing branch by pulling is to use a pull cable attached to the front end of the new branch. The cable bends the block at the junction of the branch with the trunk and then returns back to the entrance to the branch. Due to the application of traction to the traction cable from the side of the access hole at the opening point of pile 96, a new pipe can be dragged through the entire length of the branch. This method requires the use of a special tool.

 The front end of the new branch must be clamped securely in order to limit the through passages 86, 88, 89 shown in FIG. 8, in order to provide the possibility of creating internal pressure in the folded pipe after it is introduced into the branch, allowing the passage of hot medium through the folded pipe, so that it can warm up along its entire length and thereby become flexible for distributing and adopting a circular cross section. To ensure this limitation and clamping of the end, the end clamping means shown in FIG. 12 and 13. A side view of the end clamping means is also shown in FIG. 22. The end clamping means 144 includes a pair of rigid metal plates — an upper plate 145 and an opposing lower plate 146. Both plates have forward projecting end portions 147 with connecting holes 148 for the traction cable passing through them. Another pair of coaxial holes 149 are made in the lower and upper plates behind the cable hole 148 under the clamp bolt 150. The bolt 150 also passes through the coaxially drilled holes 151 in the folded plastic pipe 10.

 To install the end clamp 144 on the front end of the folded plastic pipe 10, the front end of this pipe is heated to give it flexibility, for example, in the heater 152 shown in FIG. 24. The end heater 152 comprises a thin-walled rigid pipe 154 closed on one side by an end plate 156 provided with a central inlet 157 with a connection 159 for a steam hose. The opposite end of the heater comprises a wrapper 160 of flexible tarpaulin or other suitable fabric wound around the pipe 154 in the form of a connecting tape 162. The free end of the wrapper 160 can be knotted or wrapped around a folded plastic pipe 10 so that water vapor can pass at the junction 164 wrappers with the pipe, so that the entire end of the pipe is heated to the required temperature when water is supplied to the pipe through the connection 158. The length of the pipe 152 can be approximately two feet (0.61 m), although it may be longer and ducted depending on the specific case.

 After the front end of the pipe 10 has become flexible, the end clamp plates 144 are laid on the end of the pipe and a bolt is passed through the bolt holes 151 so that the opposite plates 145, 146 compress the middle part of the folded pipe to a more flattened state so that reduce the free section of the channels 86, 87, 89 at the end of the fanfold pipe. The width of the clamping plates 145, 146 is smaller compared to the total width of the folded pipe 10, so that the channels 89 on the fold and 86 on the end of the long leg do not completely overlap when the clamping force is applied to the folded pipe. Thus, when applying the clamp, the medium can still completely pass through the clamped end of the pipe despite the fact that these channels are small enough so that an internal pressure sufficient to distribute the pipe and adopt a circular cross-section can be created inside the folded pipe.

 Another form of end clamp that can be used in place of end clamp 144 is the disengaged end clamp 250 of FIG. 43-45. The clip 144 has the disadvantage that it cannot be removed from the front end of the pipe 10 after being installed in a dead pipe without cutting off the clamped end of the pipe using a special cutting tool with a remote actuator shown in FIG. 22 and 23 and described below. However, the detachable end clamp 250 can be separated remotely from the clamped end of the new pipe and pulled out of the pipeline using a cable.

 The detachable clip 250 comprises an upper jaw 252 pivotally mounted in pos. 254 to the lower jaw 256. The lower jaw 256 contains a front end protrusion 258 with a hole for the traction cable 260 passing through it to attach the traction cable 262. Jaws 252, 256 contain gripping ends 263, 264 for gripping and crimping the front end portion 266 of a folded plastic pipes 10 when it is heated and in a plastic state.

 The bolt 268 passes through the hole 270, larger than the head 269 of the bolt, and through the smaller bolt hole 272 coaxially with it, in the lower lip 256. The bolt hole 272 is smaller in size than the nut 273 and the head 269 of the bolt 268. The bifurcated removable wedge element 276 has parallel shoulders 277, 278 defining a slot 280 and connected to a vertical wedge-shaped body 282. A flexible removable cable or rope 284 is attached to the body 282 by passing it through an opening 286 in the body. The wedge element 276 is designed to wedge between the head 269 of the bolt 265 and the upper surface of the upper jaw 252 with shoulders 277, 278 extending below the head and slot 280, under the body of the bolt. Thus, the bolt head 269 is attracted to the levers 277, 278 to a greater extent than is passed through the large hole for the upper jaw 270 when the bolt is tightened so as to press the ends 263, 264 of the jaw against the pipe 10.

 To disconnect the clamp from the new pipe after drawing it into the sewer branch using the traction cable 262 and after the new pipe has taken a circular cross-section, with the exception of the end, it is pulled by the removable cable 284. This allows you to remove the wedge element 276 from the lower head 269 of the bolt (or nuts 273 if the nut end of the bolt is located above the upper jaw), allowing the bolt head to fall out through the large hole 270 in the lower 256 and thereby allowing the jaws to open to release the end of the pipe. The wedge element and clamp can be pulled out of the branch or line using the appropriate pull ropes.

 Used when pulling a new folded branch into an existing branch from the access hole 98, the block-cross device (crosspiece) 152 includes a cable drum 154 rotatably mounted in the drum casing 156 on the axis 157. Attached to the opposite sides of the open rear end of the pulley casing is attached a pair of corner struts 158. Each strut comprises a front portion of a strut 158a and an associated rear or tail portion of a strut 158a. From the tail sections of the strut 158, a pair of flexible steel guide rails 160 of the strut backwardly curled inward at their rear ends 161. Swivel joints 162 of the struts 158 to the housing 156 are spring-loaded to push the racks outward, as shown in FIG. 14. However, these racks can rotate inward to the positions shown in FIG. 16 in order to enable the uprights and thus the entire device to move through the branch.

 A pair of triangular-shaped brackets 164 are pivotally connected to the joints of the front and rear sections of the struts 158a, 158b in spring-loaded swivel joints 166. The spring-loaded joints 166 force the brackets 164 to take their elongated positions shown in FIG. 14, perpendicular to the rear portions of the uprights 158b when they are in their elongated positions (see FIG. 14). However, the brackets 164 may, under the action of spring pressure, occupy their compressed positions shown in FIG. 15, again providing the ability to move the cross in the branch to its destination. Traction cable 168 with both ends extending in the direction of the access hole 98 moves around the drum 164.

 With the pull cable 168 attached, but with both ends leading to the access hole 98, the crosspiece is mounted on a branch and pushed along it with a flexible push rod of fiberglass (not shown). When the crosspiece reaches the point of intersection of the branch with the trunk, so that the casing 156 and the drum connected to it are advanced into the trunk, as well as the front struts 158a, the brackets 164 come out from their positions shown in FIG. 15 to their open positions depicted in FIG. 14. With the racks open, the rear sections of the racks 158c and the yokes 160 of the racks connected to them are pressed against the inner wall of the branch. At this point, both ends of the pull cable 168 are pulled for rigidly securing the cross to the connection between the branch and the trunk.

 Continuing to apply tension to the traction cable so that the crosspiece remains in place, one end of the traction cable is connected to end clamp 144 (Fig. 12-13) or detachable end clamp 250 (Fig. 43-45). The second end of the cable, while in the access hole 98, is pulled by pulling a heated flexible folded plastic pipe 10 through the branch and around the bend 100 until the front end of the folded pipe 10 reaches the intersection of the branch with the main pipe at the crosspiece 152. Traction the force can be applied to the cable 168 so that it can be pulled out either manually or by means of a manual electric winch 170 (FIG. 7) from the access hole 98. Due to the triangular shape of the brackets 164, traction applied to the cable 168 prevents the crosspiece from tipping over.

 After a new folded plastic pipe reaches the cross in the line, the cable connection with the pipe end clamp is loosened and the end of the cable is pulled through the drum, lowering the cross in the line. The cable is then pulled out of the auxiliary pipeline through the access hole, and the crosspiece can be removed from the trunk using known extraction methods. At this point, the folded plastic pipe 10 is fully inserted into the repaired branch with its clamped front end in the trunk. The folded plastic pipe is ready for reheating and dispensing to a circular cross section in the branch.

 FIG. 34 illustrates what is called the tearing compartment of a cable. In this method, the “weak” end 168a of the traction cable 168 is attached to a relatively low tensile tear rope or cable 172, which, in turn, is attached at 173 to the front of the folded pipe 10 inserted into the branch. From this weak end, the traction cable 168 is loosely thrown in a loop through the cable hole 142 in the end clamp, as can be seen from the free loops 168b, 168c, and then passed through the drum of the crosspiece. The traction end of the cable remains in the hole for access to the branch. If you do not use the end clamp, the cable hole 148 can be drilled directly through the seamed front end of the plastic pipe. When the winch mounted at the access hole pulls the cable through the crosspiece to the winch with a folded new pipe into the branch, the rope 172 maintains the average tension at the weak end of the cable 168a. When the front end of the folded new pipe reaches the cross, they pull sharply on the pull end of the cable, breaking the rope 172, and disconnect the weak end 168a of the cable through the cable hole 142 so that the cable can be removed.

 FIG. 35 illustrates a similar method for separating a cable (manual cable release). In this method, the weak end portion of the cable 168 again in the form of a double loop is freely passed through the cable hole 148 at the front end of the folded new pipe 10 to form double loops 168b, 168c. After that, the traction cable 168 is passed through a branch 90 to the crosspiece and back to the inlet. The weak portion of the cable 168a should be longer compared to the inserted new pipe 10. When the winch pulls the new pipe into the branch, medium tension is applied to the weak end of the cable 168a, allowing the folded pipe to be drawn into the branch. When the new pipe has fully entered the branch, the weak end of the cable 168a is loosened at the inlet opening, allowing it to be freely removed from the front end of the newly inserted pipe through the cable opening 148.

 When the folded new pipe is in place inside the existing branch, it is ready to distribute and give it a circular cross-section in order to replace the branch as a functioning house branch. At this point, the front end of the seam pipe 10 is already bounded by an end clamp 144 or 250, so that the seam pipe can be influenced by the internal pressure of the medium and still allow hot water vapor or other medium to pass through it. This allows you to heat the folded pipe along its entire inner length to an elastic state for distribution. At this point, the rear end of the newly installed fanfold pipe is also sealed so as to allow the supply of hot water vapor or other medium to the pipe for heating and distribution. Such a locking means or plug is illustrated in FIG. 17-21.

 The cone-shaped plug (torpedo plug) 176 comprises a conical front portion 178 with an opening 180 at its front end. The conical portion 178 extends from the rear to a short cylindrical portion 182 that is covered by the rear end plate 184. The plate 184 includes an inlet 186 and a sleeve connection 188 for connecting a supply sleeve with steam or hot water, so that hot pressurized media can be introduced into the seam pipe. Other hose connections can be made through the end plate 184, such as a hose connection for supplying air, to distribute the pipe under the influence of air pressure, or to maintain the air pressure in the expanded pipe when it is cured in an expanded, scraped state.

 When heating the rear end of the folded pipe 10 by using the previously described end heater 152, in order to make this end flexible, the conical portion of the torpedo plug 176 is inserted into the rear end of the pipe 10, as shown in FIG. 19 until the end cap 184 abuts against the edge of the new pipe, thereby distributing the end of the new pipe until it adopts a circular cross section in accordance with the outer diameter of the cylindrical portion 182 of the plug. To clamp the expanded end section of the new pipe to the cylindrical section 182 of the torpedo tube, a suitable chain clamp 190 is used to seal the pipe to the tube.

 Details of the chain clamp 190 are shown in FIG. 20 and 21. The chain clamp includes a clamp plate 192 with a curved surface 193 mating with the pipe. The convex-curved outer surface of the plate carries a bracket 194, between which a wrench element 195 is pivotally mounted. A wedge element 195 includes a threaded rod 196 provided with an end for a wrench 197. The clamp chain 198 is connected to the opposite rod. The chain is a transmission chain, a bicycle chain, or the like. The chain is adapted for adjustable connection with the strut 199 on the outer surface of the clamping plate 192.

 After the end of the pipe 10 is heated and it becomes flexible and a torpedo plug 176 is inserted into it, the clamp plate 192 is placed on the end of the pipe, which is given a circular cross section, and the chain 198 is wound around the cylindrical end of the pipe, tightened as tight as possible by hand and then fastened to the strut 199. After that, by pressing the threaded rod 196 in the direction of reducing the useful length of the clamping chain 198 using a wrench tool acting on the end of the rod 197 processed under a wrench, apply pressure. It is important that the clamp is easily sealed, because the plastic pipe tends to deform when heated, and the clamp must be sealed during heating of the new pipe and giving it a circular cross section.

Thanks to the torpedo plug pressed in place at the rear end of the newly installed pipe, the steam hose is connected to the plug connection 198. Hot water vapor is passed along the length of the folded pipe, in particular through small channels in it, providing heating of the pipe along its entire length . At the same time, the constriction created by the end clamp at the front end of the seamed pipe allows an internal pressure of up to about 25 psi (1.75 kgf / cm ² ) to be created in the pipe. When the pipe is heated and pressurized, it is distributed and assumes its cylindrical shape along its entire length, with the exception of its clamped end portion.

 When a new pipe is handed out and given a circular cross-section to its desired size, typically in the direction of the inner wall of the existing branch, the plastic pipe is allowed to cool while maintaining internal pressure by, for example, supplying air under pressure, thereby allowing the new pipe to stabilize in its newly acquired round shape. After stabilization of the new pipe, the chain clamp is separated from the rear end of the pipe and the “torpedo” plug is removed.

 The next step is to remove the end clamp and the folded and clamped front end section of the new pipe from the rest of the circular part of such a pipe. This is achieved by cutting the clamped and folded front end from the expanded and round-shaped new pipe, as shown in FIG. 22 and 23.

 In FIG. 22 and 23 depict cut-off means for cutting the folded and clamped front end of the expanded and round-shaped pipe 10 in the pipeline. The cutting device includes a driving cutting tool 200. The cutting tool includes a small high-speed electric or pneumatic motor 202, enclosed inside a cylindrical housing 204 of significantly smaller diameter compared to the inner diameter of a round-shaped plastic pipe 10. Energy is supplied to the engine 202 via a flexible air hose or electric power wire 206 from a remote source at the inlet to the house branch. The drive shaft 208 of the engine carries a rotor 210, to which a pair of cutting or rotating blades 212, 213 are pivotally connected in swivel joints 214 adjacent to the outer ends of the rotor.

 The engine housing 204 is enclosed in an inflatable rubber sleeve 216, which, when expanded, centers and locks the cutting unit in place inside the plastic pipe that has restored its round shape. A flexible air hose 218 is supplied with pressurized air to inflate the sleeve 216.

 Although the rotating blades 212, 213 are depicted in the form of steel, they could also be made of chain or cable. They must be pulled out under the influence of centrifugal force during rotation of the rotor 210 so as to beat off and cut off the plastic pipe 10.

 In use, the cutting assembly 200 is pushed through a new plastic pipe 10 after the pipe has been installed and is round in shape. The pushing can be carried out using a flexible fiberglass rod (fiberglass rod) and using a deflated rubber sleeve 216. The knife is pushed into the existing branch until it reaches a flattened and clamped front end. At this point, the sleeve 216 is inflated to fix and center the cutting unit inside the round-shaped plastic pipe. After pumping the sleeve, the engine 202 is provided with energy by supplying energy to it through an air sleeve or an electric wire 206. The engine 206 rotates the rotor 210 to drive the rotating blades 212, 213 until the blades cut off the clamped and folded end of the plastic pipe. The cut end falls into the trunk and can later be removed by known methods.

 After cutting the front end of the pipe, the sleeve 216 is lowered and the cutting unit is removed from the round pipe by pulling on the air sleeve 218 and the power wire 206 from the inlet end of the new pipe. A new branch is installed in the branch and after that it is connected to the section of the branch leading to the building 96 (Fig. 7), it is ready for operation.

 In FIG. 33 illustrates an alternative method of pulling a folded plastic pipe 10 through an opening for access 98a into an existing branch 90a intersected with a main pipe 94a at an intersection 92a. At a certain distance from intersection 92a, there is an inspection well (hatch) 216 for access to the highway in line 94a. A cable winch 218 is located in the hatch 216. The front end of the traction cable 220 is inserted into the branch 90a in the access hole 98a and the branch is pushed to the intersection 92a by a flexible fiberglass rod, the front end of which is provided with a grip for gripping the front end of the traction cable.

 The front end of the push rod is also bent so that when it reaches the intersection, it can be guided around an acute angle into the trunk. At this point, the pushing rod continues to push the traction cable 220 through the highway indicated by pos. 220a, until the front end of the traction cable reaches the hatch 216. The front end of the traction cable is connected to the winch cable 219. The rear end of the traction cable 220, located in the hole for access 98a to branch 90a, is connected to the front end of the folded pipe 10 s using one of the previously described cable release methods. After heating the new pipe, for example, in a hot box 18, to give it flexibility, it is pulled into the branch 90a using a winch cable 219.

 Currently, a two-layer cork is used. The cork consists of an outer pipe 224 made of canvas or other fabric, folded, cut and stitched near its front end 225. The outer pipe 224 has an expanded diameter corresponding to the required inner diameter of the new pipe after it is given a round shape. The rear end 226 of the tarp pipe remains open. The expandable rubber inner tube or chamber 228 is placed inside the canvas sheet. The full length of the cork can range from approximately one foot (0.3 m) to 6 m, as the case may be. The rear ends of the outer tarpaulin pipe and the inner rubber pipe are assembled around the tubular shaft 230, which connects 232 air hoses for air or hoses 234 for supplying water vapor in order to supply pressure medium to the inner pipe. The rear ends of the outer inner pipe are assembled around the tubular rod 230 and tightly fixed with a yoke clamp 236 to prevent leakage of the pressurized medium from the inner pipe.

 An inflatable plug is used when installing house branches and rounding them, so there is no need to use the end clamps and end cutting tools previously described. A typical way to use an inflatable cork is as follows.

 The folded plastic pipe of the required length for the house branch is heated and subjected to rounding in workshop conditions. Sleeve 234 for sealing a tube is installed through the length of the rounded plastic pipe with an inflatable tube attached until the tube is installed in the front end of the rounded plastic pipe.

 The pre-cut section of the rounded plastic pipe is again heated and folded using an deflated plug, an air sleeve is folded from the inside for use in the field. In FIG. 27 shows the installation of an air sleeve and an attached deflated plug 222 in a rounded plastic pipe 10. FIG. 28 illustrates the re-folding of the pipe 10 by means of a deflated plug 222 and a sleeve 234 inside the folded pipe.

 At the place of work, the plastic pipe is heated and inserted while it is folded and flexible into the restored branch. After the final installation, the folded plastic pipe is heated using a cork, while deflated, by passing water vapor through the pipe. After heating the installed plastic pipe along its entire length, the cork is inflated by means of an air sleeve 234 in order to expand the cork and, thus, while the hot, flexible front end section of the plastic pipe 10 enclosing the cork, to completely clog the front end section of the plastic pipe. After the plug is inflated, the plastic pipe in front of the plug is subjected to pressure using, for example, compressed air, round it and stretched by supplying air through the sleeve 236 leading to the torpedo plug 176 at the rear end of the new pipe in the hole 98 for access.

 After completely rounding the new plastic pipe and stretching it to the required diameter inside the existing branch 90 and allowing it to cool, the plug 222 is lowered and pulled out of the newly rounded pipe 10 using its air sleeve 234. The newly installed plastic branch is ready to work.

 A slight deviation from the method illustrated in FIG. 27-29, is the use of an inflatable tube as a sliding tube in the process of giving the pipe a round shape. According to FIG. 30, the inflatable plug 222 and its air sleeve are installed in a pre-rounded plastic pipe 10 and folded with a pipe so that the plug is positioned approximately six inches (15.1 cm) from the front end 238 of the pipe, thereby allowing the front end to be folded as tight as possible for easy installation in the branch. The folded pipe 10 with the deflated plug 222 inside is installed in a folded state into an existing branch. The rear end of the new pipe is sealed with a torpedo plug 176 with a torpedo plug through the seal of the air sleeve 234.

 After pumping out the inflatable plug 222, the folded pipe is heated from the inside along its entire length with water vapor to give it flexibility. The air sleeve 234, where it comes out of the torpedo plug 176, is tightly pulled onto the sleeve, clamp 240 is placed approximately 12 inches behind the sleeve and the torpedo plug. When the folded new tube is hot, inflatable tube is inflated. Additionally, the folded new pipe between the inflatable plug 222 and the torpedo plug 176 is subjected to the pressure of the compressed air supplied through the torpedo plug through the air pipe 236. The pressure in the new pipe causes the inflated plug 222 to slide towards the front end 238 of the new pipe until it stops under the action of the stop clamp 240 against the rear end of the tube-torpedoes. At this point, the front end, like the rest of the newly installed pipe, will be fully rounded. The inflated plug 222 is now lowered and pulled out of the newly installed pipe.

 In FIG. 32 illustrates yet another method of using an inflatable plug 222 to plug, round, and stretch a new pipe inside an existing branch or other pipe that is accessible on one side only.

 According to this method, a new pipe is installed in a branch in a folded state using one of the above installation techniques and without clamping the front end or the inflatable plug to seal or limit its front or output end. However, at least about 10 feet (3.1 m) of excess length of the folded plastic pipe is left protruding from the accessible side into the branch. The folded pipe is subjected to steam heating from the inside to give it flexibility along the entire length of the pipe. When the pipe is hot, an outer yoke 242 is placed on the seamed pipe approximately 10 feet (3.1 m) after the torpedo plug 176. After that, approximately the top 10 feet (3.1 m) of the plastic pipe between the yoke and the stopper - a “torpedo” is rounded by supplying water vapor from a pipe 236 through a “torpedo” plug to the upper portion of a 10-foot (7.1 m) folded pipe. The rounded portion of the 10-foot pipe is then able to cool in its rounded state.

 The torpedo plug 176e is removed and the inflatable plug 222 is installed in an at least partially inflated condition for easy installation in the round-shaped part of the new pipe. The torpedo plug 176 is again installed at the end of the rounded part of the new pipe with an air sleeve 234 from the inflatable plug passing through it. The yoke 242 is removed from the new pipe and the inflatable plug 222 is lowered. The new pipe is heated with water vapor inside again over its entire length to give it flexibility. When the new pipe is hot, the inflatable tube 222 is partially pumped with air. The internal pressure inside the new pipe, which can be created by water vapor or air, is increased and the partially inflated plug 222 is pushed through the new pipe, which at this point is partially unfold and partially rounded. When the inflatable plug 222 reaches the downstream or front end of the new pipe, it is fully inflated to lock the end. The new pipe is subjected to the pressure of the medium, completely give it a round cross section, it is cooled and thus stabilized in its round cross section. After curing the new pipe, the inflated plug 222 is lowered and removed from the fully rounded pipe.

 To seal the space between the new rounded pipe and the pipe when the pipes cross another hole, regardless of whether it is a manhole or another pipe, methods and appropriate means are provided. A typical pipe intersection is the distal end of the sewer pipe at the point where it runs into the sewer line.

 The seal is a compressible rubber sleeve covering the intersected end of a seamed new pipe. It usually has a thickness of 1 / 4-1 / 6 inches (6-4 mm), but can have any acceptable thickness. It usually has a length of 12-24 inches (0.31-0.62 m), but can be of any desired length.

 After installing the front end of the folded new pipe and with access, such as a hatch, this sleeve can be dragged through the folded end of the new pipe before this end is rounded. While giving a circular cross section to the end of the pipe, a circular cross section is also attached to the sleeve. The new pipe is dispensed during the rounding process until the rubber sleeve is tightly pressed between the new pipe and the existing pipe to form an impermeable seal. To seal the remote and inaccessible distant ends of the sewer pipelines of buildings, another method is used. To do this, use a rubber sleeve coated with glue. The front end of the folded new pipe is heated, flattened and given a circular cross-section before being installed in the pipeline. A sleeve coated with glue is applied to the rounded end, and this end is again folded with a sleeve attached to it. After that, a new pipe is installed in the pipeline using one of the previously described methods.

 The use of the expandable plugs previously described is the preferred method of imparting a round cross-section (rounding) and dispensing a sealed distal end. With the help of such a cork, the distribution and, consequently, the seal are more complete and more definite in comparison with the other methods described.

 The thermoplastic pipe 10 is preferably fabricated in the folded form shown in FIG. 8. Being initially cooled and cured in such a folded state, the thermoplastic pipe retains a memory of a shape that tends to return it to such a folded configuration, whenever it is reheated and not limited. This memory in its folded form can be advantageously used when removing a damaged pipe section from an underground pipeline.

 To remove the damaged thermoplastic pipe from the pipeline, the damaged pipe is heated by passing sharp steam through it and, if possible, around its outer surface. In the hot state, the damaged portion of the pipe to be removed is flattened to its original folded configuration. This flattening and re-folding can be accelerated by connecting a vacuum pump to the internal cavity of the pipe to reduce its internal pressure. After flattening and folding, the hot plastic pipe can be pulled out of the existing pipeline using a cable winch with a pull cable fixed to the accessible side of the flattened pipe.

 The heating of a thermoplastic thermoformed pipe in the case of installation, in particular where bends should occur in the pipe or pipe, or when a new pipe must be passed through a small, deep vertical hole, is important. Some heating methods for mounting have been described before, including using a hot box or a long steam pipe. Another way is to heat the inside of the existing pipeline into which the thermoplastic pipe is to be installed. According to this method, a short section of the pipe provided with a steam connection is connected to the rear end of the existing pipe being repaired. A tarpaulin at the rear end of the steam pipe section is wrapped around a folded new pipe, since it is passed through the steam pipe connection into the pipeline in order to heat the new pipe during the installation of the steam pipe. This method can also be advantageously used with the other methods described.

 The flattened, folded shape of the rigid thermoplastic pipe shown in FIG. 3 and 8, because this form provides the pipe with some properties unattainable with other pipes that can be flattened or partially flattened solely to reduce their overall transverse dimensions for installation in the pipeline. First, the flattened, folded form shown in the drawings, when heated and given flexibility, can be conveniently and compactly stored in the form of long and short segments on the drum. The drum, in turn, can be used to store, reheat and feed the pipe into the pipeline.

 Secondly, the shape of the illustrated pipe after heating and giving it flexibility allows the installation of the pipe in the pipe with a sharp bend from a small vertical access hole, such as a hatch, and allows its installation in sharp bends in the pipe itself. For example, a rigid PVC pipe with the usual ratio between wall thickness and diameter within the previously mentioned range, after flattening and folding to the specific shape shown in FIG. 3 or 8, and heated to a flexible state, will have a ratio between the minimum bending radius and the rounded outer diameter between 1 and 2. That is, a regular rigid PVC pipe with a diameter of 4 inches (100 mm) after giving it flexibility, flattening and folding, shown in FIG. 3 or 8, can turn into a curve with a radius of 4-8 inches (10-10 cm) depending on the wall crack without damaging the pipe walls. Such a minimum bending radius is unattainable with other known forms of rigid thermoplastic pipes when in flexible states.

 Thirdly, despite these signs, after heating and giving flexibility, the folded pipe shapes shown in FIG. 3 and 8 can be easily turned into a round pipe and cured to give the pipe structural rigidity and sufficient strength to withstand the external pressure of the soil and the hydraulic pressure of the medium. Thus, the installed thermoplastic pipe is actually a working pipe, and not just a lining for a damaged existing pipe.

Claims (11)

 1. The method of installation of a new pipe of rigid thermoplastic material at an ambient temperature inside an existing pipeline, in which a new pipe is installed in an existing pipeline on its inlet channel in a reduced form, the maximum size of which is smaller than the inner diameter of the existing pipeline and which can expand to the required outer diameter, the same as the inner diameter of the pipeline, insert the front end of the new pipe into the pipeline, position the new pipe in the pipeline and attach roundness of a new pipe by converting it from a shortened shape to a tubular shape by heating, characterized in that a pipe made in a flattened and shortened shape is used with the possibility of preserving the memory of such a reduced state, in which its maximum size is smaller than the inner diameter of the pipe, and the new the pipe along its entire length in its shortened form to a flexible state in the longitudinal direction, insert the front end of the new pipe into the pipeline in its heated flexible state, round off -hand tube by conversion from its reduced form by a tubular heating and internal pressure at the same time, after which a new pipe is cooled in order to stabilize it in a tubular form.  2. The method according to p. 1, characterized in that in the case where the pipeline is a branch connected to the main pipeline, a new pipe is inserted into the branch from the access point in the direction of the main pipeline, and the new pipe is positioned in the pipeline by means of a pulley and cable by retracting the first end of the cable from the access point in the direction from the main pipeline and the second end of the cable pulls the front end of the new pipe into the main pipeline.  3. The method according to claim 1, characterized in that they limit the possibility of fluid flowing from the hole in the front end of the new pipe before applying internal pressure to convert the new pipe in order to create fluid pressure inside the new pipe and allow the hot medium to pass inside the new pipe through its entire length, and then the heated medium is fed into the new pipe from the rear end at a temperature and pressure sufficient to expand the new pipe from its flattened and bent state into a round one.  4. The method according to claim 3, characterized in that the flow of medium from the front end of the new pipe is limited by installing a flexible bendable and inflated plug in the front end of a flattened and folded new pipe.  5. The method according to p. 1, characterized in that the new pipe is made of a flattened shape by extruding the thermoplastic material of the pipe in a hot plastic state through a matrix to turn it into a tubular shape of the required size, the resulting hot tubular thermoplastic material in a plastic state is fed before any substantial cooling through the holes of a number of calibration plates, in which the holes have such dimensions and configurations as to flatten, fold and form tubular plastic into a folded shape, while exposing the plastic to a vacuum and a temperature higher than that which would give the thermoplastic material a memory, cool the flattened and folded pipe while pulling it through the calibration plates to cure the pipe in a flattened and folded shape, reheat the flattened and folded pipe to give it longitudinal flexibility, but lower than the temperature, which changes the storage characteristics of the thermoplastic material, and install a flexible pipe in its flattened and fold bath in the form of conditions allowing its storage in multiple layers.  6. The method according to p. 1, characterized in that the new pipe is rounded off with sufficient heat and internal pressure to form sections with recesses corresponding to the location of the branches, and these sections are removed to form a place for access to the branch.  7. The method according to claim 1, characterized in that the front end of the new pipe is rounded, a stretchable sealing sleeve is fixed around the rounded front end of the new pipe, the front end is re-folded before installing the new pipe, and after installing the new pipe at the heating place, round and expand the new pipe for tightly pressing the sealing sleeve between the new pipe and the existing pipeline.  8. A device for mounting a new pipe inside an existing pipeline, comprising means for storing a rigid thermoplastic pipe having a front end and a rear end in an abbreviated form, and a storage in which the pipe is curved and layered, means for removing the front end of the tapered folded pipe, and an assembly means for installing the front end of the new pipe into an existing pipeline, characterized in that the storage means includes a casing surrounding the stored pipe, mounting means, For retracting the front end of a new pipe into an existing pipeline in its heated and flexible state, the device is equipped with means for heating the inner part of the casing to convert the rigid pipe into a flexible state, with means for extracting the front end of the bent flattened folded pipe from the casing, and with pressure means for expanding the installed a new pipe from its reduced form into a rounded shape into an existing pipeline, including a constricting means at the front end of the flattened side of the pipe I passing heated fluid along the length of the collapsed and folded tube to increase the internal pressure within the tube and means for supplying a heated fluid into the tube from its rear end.  9. The device according to claim 8, characterized in that the pressure means includes a flexible inelastic tubular shirt closed at the front end, an inner tubular elastic inflatable chamber in the specified shirt, and the chamber is configured to expand under the action of pressure of the medium to give the shirt a round forms, and at the rear end of the chamber, means for connecting the inside of the chamber to a medium (liquid) pressure source.  10. The device according to claim 8, characterized in that it includes means for heating the end section of the new pipe to a flexible working state to facilitate the input of the medium flow limited by the end cap.  11. A method of eliminating a cut of a new rigid thermoplastic pipe that is inserted into an existing pipeline, the new pipe being made in an abbreviated form while preserving the memory of such a flattened and folded shape, characterized in that the section of the new pipe is heated to a temperature at which the new pipe becomes flexible, to return the pipe at least partially in a reduced form having dimensions smaller than the inner diameter of the existing pipeline, and remove the new pipe in at least partially reduced form e of the existing pipeline while maintaining the new tube in a flexible state.

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