CH683122A5 - Spare tube, method and apparatus for introducing a replacement pipe into an existing pipeline. - Google Patents

Description

1

CH 683 122 A5

2nd

description

The present invention relates to a replacement pipe for insertion into an existing pipeline, to a method and a device for its production, to a method and a device for inserting such a pipe into a pipe, to a device for storing a thermoplastic replacement pipe and to a method for later removal of such a pipe. The present invention is of particular interest for the introduction of a replacement pipe section for repairing or replacing a defective pipe within building sewer pipes which cross main sewer pipes, within other side pipes which cross main pipe pipes, within pipe sections which have curves and abrupt bends, and within others Pipe sections that are crossed by building sewage pipes, as well as side connections that would be difficult to locate after a new pipe section has been installed within the existing pipe section.

Various methods and devices have been proposed to repair underground pipelines, such as sewage pipes and the like, leaving the existing pipeline in place underground, by installing a flexible membrane or plastic liner within the existing pipe or by inserting a new plastic pipe into the existing one Pipe.

In a known method, pipes are lined with a flexible plastic, such as polyethylene. According to this method, the lining is installed through insertion openings at intervals along the pipeline, which makes the method expensive.

According to another method, e.g. in the U.S. 3,927,164 and 4,064,211, a flexible tube is reversed while being inflated and blown into a pipeline section from one end of the section. This process is expensive because it requires special equipment, extensive heating and expensive materials.

The above-mentioned methods and most others use a flexible or semi-flexible liner which is unable to withstand severe external hydrostatic or earth pressure. This means that the existing pipe cannot be properly repaired, since if a part of it breaks off, the lining may collapse of any size due to external pressure, e.g. Prints that exceed approximately 0.28 kg / cm2.

Both the U.S. Patent 4,394,202 to Thomas et al. like the U.S. U.S. Patent 2,794,758 to Harper et al. also disclose methods of inserting a flexible pipe into a flexible pipe as a lining membrane for that pipe. Thomas discloses a method of attaching the flexible pipe to the existing pipe using an expandable short section of hard plastic coated with adhesive. Both the Thomas and Harper processes have the same disadvantages as above with regard to other previously known processes using flexible membrane material, in that they do not have the circumferential strength required to withstand external earth and hydraulic pressures.

Other authors have suggested inserting a hard pipe inside the existing pipe to be repaired. For example, in the published British patent application 2 084 686 an oversized, round, hard plastic pipe is flattened or otherwise shredded at the work place and then cold and stiffly introduced into the existing pipeline through a large hollow in a manhole. After use, the plastic tube is expanded using heat and internal pressure. The plastic pipe is expanded against the existing pipe.

According to British Patent 1,580,438, an existing underground pipe is lined with a plastic lining pipe, which is made of a plastic material, such as polyethylene or polypropylene, with a practical memory. The liner tube is manufactured in a non-round "U" shape to fit inside the existing tube, then inserted in its non-round shape into the existing tube and then expanded against the existing tube under heat and pressure to a round state .

The published EP patent application 0 000 576 proposes to insert a semi-rigid plastic pipe into the interior of an existing pipe. The semi-rigid plastic tube has sufficient circumferential strength to withstand all or at least part of the external pressures that can act on it.

a. Repair of crown pipelines and pipelines with access from one end only

Most of the above-mentioned and other known methods, which use rigid or semi-rigid pipes for insertion into an existing underground pipe, have a common disadvantage: due to their stiffness or approximate stiffness, they have to be used in straight or almost straight existing pipes. This means e.g. referring to underground sewer lines, that such known methods are limited to use in main sewer pipes because they usually have straight pipe sections between manholes. Most, if not all, of these known methods are not suitable for use in repairing the numerous building sewage systems that extend from sewer mains to buildings. Such branches often have curves or bends that a rigid or semi-rigid plastic tube cannot handle. Furthermore, such side lines are usually not

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

2nd

3rd

CH 683 122 A5

4th

Accessible at one end and known liner or replacement tube inserting methods that require manholes or other access at both ends are excessively expensive. In most of the known methods for replacing underground pipe installations, large excavations are necessary at one end of the side line to be newly lined or repaired in order to make room for the use of the straight, rigid plastic replacement pipe. Such a large excavation near a building served by the side line or at the other end where the side line crosses the main line is often impractical and generally costly.

In addition, most known methods for re-lining or repairing existing subsurface pipelines require access to the pipeline section to be repaired at both ends of the section. This is not possible with a side line that by definition crosses a main line at a point that is usually not accessible through a manhole.

For the above reasons, the known methods for lining and repairing underground pipelines are simply not applicable to building waste water pipes.

b. Repair of main sewage pipes

Another disadvantage of using known methods of repairing and re-lining existing pipe sections that cross through building sewers using straight rigid or semi-rigid pipes is that once the pipe is inserted into the existing pipe section, it is very difficult to find the exact positions to locate where the service side lines cross the main pipeline so that access openings can be cut out in the replacement pipe to reach the service side lines. This is particularly the case if the replacement pipe has a sufficient thickness and therefore has sufficient circumferential strength to withstand even typical hydraulic and earth pressures.

For the reasons mentioned above, there is a need for improved methods and devices which enable the repair of existing underground pipeline sections and in particular of building sewage pipes and other pipeline sections which have bends and curves, and pipeline sections which are not easily accessible from both ends of the pipeline section to be repaired .

Accordingly, the primary objects of the present invention are to provide the following:

1. A new and improved replacement pipe for use in an existing pipeline, which is particularly suitable for use in the repair and replacement of existing building sewage pipes, which are not straight main pipes crossed by building sewage pipes;

2. a new and improved method for producing a repair and replacement pipe which is particularly suitable for use in existing underground lines which are not straight or which are crossed by side service lines;

3. a method for inserting a new or replacement pipe section into an existing underground pipe, and in particular one which is not straight or which is crossed by building sewage pipes;

4. an apparatus for producing a replacement piping product as mentioned above;

5. a device for inserting a pipeline product, as mentioned above, into an existing underground line, and in particular such a line which is not straight or which is crossed by lateral service lines; and

6. Method for removing an approximately rigid thermoplastic replacement pipe, which had been introduced into an existing pipeline, and in particular a building sewage pipe, by reshaping it into a stable, rounded shape within the existing pipe.

These objects are achieved by the present invention as defined in claims 1, 4, 8, 11, 12, 18 and 21. Preferred embodiments are claimed in the dependent claims.

In one aspect of the invention, the replacement tubing product is a thermosetting plastic material, such as PVC, which is first extruded and molded into a unique folded and flattened shape so that it retains a folded memory when heated again, making it easy for storage and the consumption can be coiled up so that it has a reduced cross-sectional size for easy insertion into an existing underground pipe, so that it can be used in deep pipes through cleaning holes or other small vertical openings as well as around sharp bends without digging or damaging the plastic material and so that despite its flattened folded state, a hot liquid can be passed through it to heat the entire length.

According to another aspect of the invention, the above replacement tube is installed in an existing curved side pipe, e.g. by reheating the plastic pipe to a flexible state, then pulling the hot flexible folded plastic pipe into the existing side line with a pull cable and either a roller arrangement, which is temporarily anchored at the intersection of the side line with the main line, or with a cable winch from the nearest manhole in the Main line

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

3rd

5

CH 683 122 A5

6

out. The folded inserted tube is then heated along its entire length by passing a hot liquid through it, clogging or restricting its leading end, and injecting a fluid such as e.g. Air into the other end under pressure to reshape and expand the tube into a rounded shape. With further application of the internal pressure to the formed rounded tube, the tube is then allowed to cool, thereby allowing it to stabilize in its rounded shape.

The invention makes it possible to obtain a unique reel and cable device which can be pushed through a service side line to its intersection with a main pipeline and temporarily anchored there by exerting tension on both ends of the cable. One end of the cable is anchored to the leading end of the folded tube to be used; then the opposite end of the cable is pulled to pull the folded plastic tube into the existing side pipe while it is in the heated, flexible condition.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings.

In the drawings

1 shows a cross section through a conventional thermoplastic pipe as a replacement pipe such as a PVC pipe, which is used according to the invention, in its expanded, rounded state.

FIG. 2 shows a perspective view of the thermoplastic tube from FIG. 1 and a device for reducing the tube from its round state to a collapsed and folded state for the purpose of storage on a coil;

FIG. 3 shows a cross section through the thermoplastic tube from FIG. 2 after it has been folded, along the line 3-3 from FIG. 2;

Fig. 4 is a schematic illustration showing a method for inserting the folded and spooled thermoplastic pipe of Figs. 2 and 3 within a sewer main from a manhole, the folded thermoplastic pipe being stored on a spool and for use in the underground repairing line is reheated;

Fig. 5 is a schematic sectional view of a detail of the device for expanding the folded thermoplastic pipe of Figs. 2 and 3 and for rounding the same after it has been inserted into the existing main pipeline as shown in Fig. 4;

6 is a schematic view, in section, of another structure for expanding and rounding the folded thermoplastic pipe after it is inserted into an existing pipe;

7 shows a schematic representation of a section through a typical building sewage pipe which extends from a serviced building to a main sewer pipe and a method for inserting the thermoplastic pipe into an existing building sewage pipe according to the invention;

Figure 8 is a cross section through a preferred form of the thermoplastic pipe of Figure 1 when folded into an existing underground conduit for installation;

FIG. 9 shows a schematic view of a device for producing the thermoplastic tube from FIG. 1 in folded form, as shown in FIG. 8;

Fig. 10 is an elevation, on an enlarged scale, of the calibrator of the device of Fig. 9 used to manufacture the thermoplastic tube of the shape shown in Fig. 8;

Figure 11 is an elevation of a single calibration plate of the calibrator of Figure 10 as seen from line II-II of Figure 10;

Fig. 12 is a view of a folded end portion of the thermoplastic tube of Fig. 8 with an attached end bracket for use in pulling the tube into an existing conduit and restricting the tube end to allow internal pressure to be exerted on the tube for expansion;

Fig. 13 is a cross section of line 13-13 of Fig. 12;

FIG. 14 is a somewhat schematic view of a cable and reel device, also shown in FIG. 7, for pulling the folded thermoplastic tube of FIG. 8 into a service side line, the device being shown in a division of labor;

FIG. 15 shows a view similar to FIG. 14, but with the device from FIG. 14 in a collapsed state for use in a service branch line;

16 is a somewhat schematic side elevation of the device of FIGS. 14 and 15;

Figure 17 is a side elevation of a closure device used to plug one end of a length of the thermoplastic tube shown in Figure 8 after the end has been rounded, for use in transferring fluid, heat and fluid pressure to the interior of the thermoplastic tube;

Fig. 18 shows a cross section through the device of Fig. 17;

Figure 19 is a view of one end of a thermoplastic tube with the closure device of Figures 17 and 18 inserted into the tube and secured in place with a chain lock;

FIG. 20 shows a view of the chain lock from FIG. 19 before it is applied to the tube and the stopper from FIG. 19;

FIG. 21 is a cross section along the line 21-21 from FIG. 19, which fastens the chain closure device from FIGS. 19 and 20, which fastens the thermoplastic pipe end to the closure device from FIGS. 17 to 19;

22 shows a somewhat schematic longitudinal section through a guide end part of the thermoplastic tube of FIG. 8 with the end clamp of FIGS. 12 and 13 applied to the tube end and with the rest of the tube expanded and rounded, and with a cutting device which is in the rounded

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

4th

7

CH 683 122 A5

8th

Deten pipe end portion is used to separate the clamped end from the rest of the tube;

FIG. 23 shows a cross section through the tube and the cutting tool from FIG. 22 along the line 23-23 from FIG. 22;

Fig. 24 is a somewhat schematic side elevation of an end heater apparatus used to heat an end portion of the thermoplastic tube to refurbish the end portion, showing the heater installed in a folded end portion of the thermoplastic tube of Fig. 8;

25 is a perspective view of an inflatable end closure device used to plug or restrict the end portion of the thermoplastic tube in place of the end clamp assembly of FIGS. 12 and 13 to enable the expanded thermoplastic tube to be expanded and rounded;

Fig. 26 is a shortened elevation, partially in section, of the inflatable tube of Fig. 25;

Fig. 27 is a schematic view showing the insertion of the inflatable plugging device of Figs. 25 and 26 into the thermoplastic tube when it is expanded and rounded;

FIG. 28 is a schematic view similar to FIG. 27, but with the tube from FIG. 27 being folded again with the inflatable plug in the deployed state inside;

29 is a schematic view illustrating the use of the inflatable closure device of FIGS. 25 and 26 during installation of the thermoplastic tube in a service side line;

30 is a schematic view illustrating another use of the inflatable closure device of FIGS. 25 and 26;

31 is a schematic view further illustrating the use of the inflatable closure device of FIGS. 25 and 26 in accordance with the methods shown in FIG. 30;

32 is a schematic view illustrating yet another use of the inflatable closure device of FIGS. 25 and 26 for expanding and rounding the folded thermoplastic tube after it has been inserted into an existing underground conduit;

33 is a schematic view of a main pipe section and a crossing service side pipe, illustrating another method of pulling the thermoplastic pipe of FIG. 8 into a service side pipe to be repaired;

Fig. 34 is a schematic view of an end portion of the folded thermoplastic pipe of Fig. 8, illustrating a method for releasing the pull cable from the leading end of the pipe after it has been inserted over an underground conduit;

35 is a schematic view similar to FIG. 34, illustrating another method of detaching the pull cable from the thermoplastic pipe after it has been inserted into an existing underground conduit;

36 is a cross section of the intersection of a main pipe and a service side pipe after the thermoplastic pipe of FIG. 8 has been installed and expanded within the main pipe to be repaired, showing a method of locating and cutting an opening through the newly installed thermoplastic pipe for the purpose Reopening the connection between the service branch line and the main pipeline is illustrated;

37 is a schematic side elevation illustrating a method and apparatus for folding a thermoplastic pipe that has been made in a round shape for use in an existing underground conduit;

38A-E are schematic cross sections along lines 38A-38A to 38E-38E of FIG. 37;

Fig. 39 is a somewhat schematic elevation of a releasable end bracket and attached pull cable and solution line for use in attaching the leading end of the folded tube of Fig. 8 during its installation;

FIG. 40 is a top view of the end bracket of FIG. 39; and

Figure 41 is a top view of the release edge portion of the clip of Figure 39.

Repair of sewage mains and the like

Referring first to FIG. 1, number 10 designates a type of pipe used to rebuild, repair, or replace underground pipe sections such as sewage pipes or the like in accordance with the present invention. A characteristic of the pipe is that it is made of a thermoplastic material, such as PVC, and in particular a material that is normally stiff and thick-walled, so that it has sufficient circumferential strength to withstand external earth and hydraulic pressures, to which it can be exposed underground. Such a thermoplastic tube can, however, after heating to temperatures of e.g. about 93 ° C (200 ° F) or above in the case of PVC pipes. A feature of the tube 10 is that it is structurally rigid at typical ambient and surface temperatures, but becomes flexible and workable to various shapes when heated or reheated. Another characteristic of such a thermoplastic material is that it has a resilience, a "memory"; i.e. if it is in a special form, e.g. a rounded tubular shape and then later heated and flattened or folded and then cooled to stabilize it in the folded form and later heated again without being tended to tend to revert to its original rounded tubular shape. Conversely, if the pipe was originally in e.g. collapsed and folded shape, such as 3 and 8 Dar5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

5

9

CH 683 122 A5

10th

then later heated and expanded under internal pressure to a rounded shape and then cooled and stabilized in this round shape, it tends to return to its original folded shape if it is subsequently heated again without hindrance. This "memory" aspect of the thermoplastic tube is used to promote certain aspects of the present invention.

A conventional and readily available pipe of the type useful for practicing the present invention is a polyvinyl chloride (PVC) pipe with standard aspect ratios (outer diameter / wall thickness) in the range of 13 to 65 which is currently used for underground pipelines such as drain pipes, water pipes etc. is available.

Although in the most preferred embodiment of the present invention the thermoplastic tube is shown in folded form as shown in Fig. 8 in the manner described with reference to the apparatus of Figs. 9 to 11, at least certain aspects of the invention can also be practiced under Use of a thermoplastic tube made in tubular or round shape. Fig. 2 illustrates the device 11 for forming the conventional PVC pipe 10, which was made in a round shape. Figure 3 illustrates a cross section of a pipe after it has been formed by flattening and folding using the apparatus of Figure 2. In particular, the PVC pipe is heated in any conventional manner, e.g. by a heating means 11a, which may be a thermostatically controlled steam chamber or a housing containing thermostatically regulated electrical heating elements. By passing the originally round tube 10 through the heater 11a, the tube is heated to a temperature sufficient to make the tube plastic or flexible. It is then flattened, or preferably folded, in the folding device 11 to reduce its overall cross-sectional dimension such that it is capable of easily entering an underground conduit that has the same or only a slightly larger inner diameter than the original outer diameter of the thermoplastic pipe. The thermoplastic tube with reduced dimensions is shown at 10a in Fig. 3.

2 schematically illustrates a tube folder, a practical tube folder and method is illustrated with reference to the device of FIGS. 37 and 38A-E. It will be seen that the round tube 10, after having passed through the heater 11a, is first flattened by a pair of opposing flattening rollers 60, 61 and then passed under a folding wheel 62 while being successively passed through three different sets of folding rollers 63, 64, 65 is worn. The pair of folding rollers 63 are arranged in cooperation with the folding bike 62 to start folding the tube 10 into a U-shape. Then, the three folding rollers 64 continue the folding process by being arranged in a semi-U shape to cooperate with the folding bike 62. Finally, a set of four folding rollers 65 is arranged in a U shape to cooperate with the folding wheel 62 to fold the tube 10 to end in a U-shape. The folded tube is then placed under a mold 66 while it is being cooled to stabilize the tube in its U-shape so that it has a U-shaped memory.

From the form 66, the folded tube can either be stored in predetermined lengths or passed through a steam tube to be reheated and made pliable directly into an existing conduit for use.

After the flattening process and before folding, however, the tube can also be wound up in a flat state in the heating chamber 18 shown in FIG. 4. Then the flat, wound tube in the heating chamber at the work station can be heated again and then pulled off the heating chamber and folded, as described, immediately before its use in the line to be repaired.

In certain applications it may also be possible to install the thermoplastic pipe in an existing pipe in a flattened state, in particular if the thermoplastic pipe in a rounded state has a significantly smaller outer diameter than the inner diameter of the pipeline to be repaired. However, under most conditions it is preferred that the thermoplastic pipe be installed in an elongated form, as shown in either FIG. 3, FIG. 8 or FIG. 38E, in an existing pipeline. Of all of the folded shapes, however, the shape of Fig. 8 is preferred for reasons set out below.

As mentioned above, the thermoplastic tube, when made in a round shape, has a memory which tends to return it to the round shape when heated after being folded. Therefore, when it is necessary to reheat the folded tube to make it flexible for use in an existing pipeline, the tube tends to return to its round shape prematurely if it is not prevented from doing so. For this reason, it is therefore preferred that the thermoplastic tube be manufactured in the desired folded shape from the beginning. Because when the folded pipe is reheated to make it pliable for use in an existing pipe, the pipe will maintain its folded shape until it is fully inserted into the existing pipe and is ready to be shaped into a round shape.

Regardless of whether the thermoplastic tube is made in a round or folded shape, the tube should be in a folded state when ready for use in the existing conduit. It is further preferred that the thermoplastic tube be wound on a storage spool during heating and thereby to be flexible, e.g. the coil 12 shown in FIG. 4.

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

6

11

CH 683 122 A5

12th

The coil 12 with the folded thermoplastic tube is stored in a housing or a “hot box” 18 which is equipped with a thermostatically regulated heating device 24 for heating the interior of the chamber and thus the coil 12 in order to make the folded tube material 10a flexible. if desired. The “hot box” 18 is preferably also equipped with an air circulation system 19 in order to prevent heat stratification within the chamber and thus to ensure that the coil with the folded tube is heated uniformly. The “hot box” 18 is preferably mounted to be transportable and is shown mounted on the flat bed of a truck 20 for transport to a work station. A smaller form of "hot box" can be wheeled and moved by hand for use in small, inaccessible service pipes, such as building sewage pipes. In either case, either powered or manually operated means are provided to rotate the spool 12 to wind the material on the spool or to pull it off the spool. The "hot box" 18 is equipped with an access opening gate 21 and can also be equipped with a waste pipe 22 and a roller 23 to facilitate the insertion of the folded thermoplastic pipe into an underground pipe through a vertical access opening, such as a manhole 16, of the existing main sewer 14. be equipped.

Main wastewater repair procedures

For this purpose, the "hot box" 18 is opened at the workplace, e.g. the manhole 16, in an underground pipe section to be repaired, such as the main sewer 14. The end of the folded pipe 10a is connected to a wire pull 26 which is made accessible from an adjacent opening in the existing pipe, e.g. another manhole (not shown) and fastened with fasteners 28 to the free or leading end of the new tube. The new tube is made flexible by heating the coil 12 in the "hot box" 18 with the help of the heating device 24. The wire pull 26 is then e.g. actuated by a winch on the next manhole downward from manhole 16 to pull flexible pleated tube 10a from spool 12 through tube 22 and around roller 23 into an existing tube 14 to the next manhole. After insertion of the folded new pipe, it is heated and expanded into a round or approximately round shape to give a pipe which is in a thick-walled, rigid form which has sufficient circumferential strength to withstand external hydraulic earth pressures.

Figure 5 illustrates one way of expanding the shredded cross-section pipe after it has been inserted into the original pipe to be repaired or replaced. According to such a method, a pair of plugs 30 and 32 are folded into the opposite ends of the

Pipe used when at least the ends are in heated, flexible form. The plug 30 is inserted at the rear end of the new pipe section, which is located at the end of the existing pipe. The plug 32 is inserted at the guide or pull end of the new pipe after loosening the wire. Each of the plugs 30 and 32 is equipped with peripheral expansion members 34 which are arranged for releasable sealing connection with the original pipe 14 and the new pipe 10a. The sealing members 34 are connected via the pressure lines 36, e.g. Inflated air pressure lines leading to regulators (not shown) above the earth. Plug 30 has an inlet line 38 for introducing an expansion medium, such as live steam or hot water, into the new pipe. Such a line is equipped with a suitable regulating valve 40 as well as a pressure meter 42 and a drain valve 44. Plug 32 has a drain line 46 which is connected to the location between the two plugs and advantageously has a valve at 48. The newly inserted folded tube, with the plugs inserted at its opposite ends, is then heated from the inside by passing live steam through the narrow passage provided on the folds of the new tube, as shown in FIG. 8. The valve 48 at the downstream end is open so that the entire length of the new pipe is heated. Valve 48 is then closed while steam under pressure continues to be introduced through plug 30 to pressurize the folded tube, thereby reshaping and expanding it into a rounded shape. If the new pipe is manufactured in the folded state, it should be cooled or allowed to cool after it has reached the round shape while the internal pressure, e.g. a cold air pressure is maintained so that the tube hardens in the round shape. This last step is not necessary if the tube was made in a round shape, unless the tube was expanded or stretched over its original diameter during the forming process.

If there are no internal passages in the folded new tube, as is the case when the new tube is folded completely flat, as shown in Fig. 3, the new tube should be heated from the outside, e.g. by passing live steam through the existing pipe before the plugs 30 and 32 are inserted into the ends of the new pipe. Then, with the tube heated over its entire length, plugs 30 and 32 could easily be inserted into its opposite ends, the valve 48 would be closed and live steam or hot water would be introduced through the plug 30 to expand the folded tube and round it To reshape shape.

Fig. 6 shows another type of apparatus instead of Fig. 5 for expanding the shredded tube. Such a device comprises a mandrel 50 with heating means 52 installed therein, which

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

7

13

CH 683 122 A5

14

able to heat the new pipe to a flexible condition. The mandrel 52 is connected to around a cable 54 or other traction means to pull it through the original pipe. When the dome is properly heated and tension is applied to the pull cable, the mandrel is pulled through the original tube, expanding the new tube to the desired diameter. With this method, the pull cable 54 would of course be inserted into the new pipe before the new pipe is folded into the existing pipe for use.

A third method for heating, rounding and expanding the new pipe involves passing hot water or steam through the existing pipe to be repaired along the already used but still folded new pipe until the desired temperature at the downstream end is reached. Then the new pipe is pressurized with hot water or steam and expanded under steam to a round shape and the desired diameter.

example

In a specific pipe reconstruction process, a conventional PVC pipe is procured which is approximately 12.7 mm (approximately 0.5 inch) smaller in its outer diameter than the inner diameter of the pipe to be repaired. The PVC pipe has standard dimensional ratios of wall thickness to outer diameter, as mentioned above. The PVC pipe is heated to at least 93 to 99 ° C (200 to 210 ° F) and reduced to the shape shown in Fig. 3, 8 or 38E. The folded tube is then stored on large spools so that it can be driven to the work site by truck. When inserted into an existing pipe or underground pipe, the new pipe is again heated, preferably in a "hot box" 18, so that it becomes flexible and is capable of being easily vertically down a deep manhole and then generally to be pulled horizontally through the existing pipe. As soon as it is installed in the existing pipe section to be repaired, the folded pipe is closed with plugs, heated and rounded. If desired, it can also be expanded beyond an original or intended round diameter to closely fit the existing pipe section.

Process for the localization of building waste water pipe connections

An advantage of expanding the freshly installed thermoplastic pipe beyond its originally intended diameter is illustrated with reference to FIG. 36, in which the existing pipe section to be repaired is crossed by at least one sewage pipe or another service side pipe. In Fig. 36, the main pipeline 70 at 72 is replaced by a service side line 74, e.g. a building sewage pipe, crossed. When the new thermoplastic pipe is inserted into the main line 70 and rounded and expanded or stretched over its original round diameter to closely contact the inner wall of the existing main line 70, a bulge or recess 76 is created at the opening or interface 72 of the service Branch line formed in the main line. This bulge 76 is actually an indicator of the exact position of the opening of the service branch line in the main line. When a television camera is passed through the main line, the exact position of the bulge or depression and thus the service branch line opening can be determined. A remote controlled cutting tool 78 can then be routed along the main line to the exact location of the bulge and used to cut the bulge 76 from the new replacement tube 80, thereby reopening access from the service side line 74 to the main line.

The rounding and expanding or stretching of the freshly installed thermoplastic pipe is carried out according to the methods described above or as subsequently described with reference to additional embodiments.

Preferred form of folded tubes

3 and 38E are suitable for use in the installation process described, the preferred form of such a folded tube 10 is shown in FIG. 8. The thermoplastic tube 10 of FIG. 8 is manufactured essentially in the folded form shown. It generally consists of a collapsed tube which is folded along a generally curved, longitudinal balloon fold 82 into a pair of superimposed legs, comprising a long leg 83 and a shorter leg 84. The long leg 83 terminates at a curved or balloon-shaped free one End 85 to define a small longitudinal passage 86 through the folded tube. The shorter leg 84 likewise ends in a curved or balloon-shaped free end 87, which likewise delimits a passage 88 in the longitudinal direction through the tube. Furthermore, the flat folded portion 82 defines a passage 89 along the interior of the fold from one end of the tube to the other.

The balloon-shaped fold and the leg ends are, as described, important to prevent the folded parts of the tube from breaking when folded, which could otherwise occur if the tube is folded flat in the manner shown in Fig. 3, especially if the tube is thick-walled is. Passages 86, 88 and 89 are also important to allow steam or other hot fluid to pass the full length of the folded pipe to reheat and thus reprocess the pipe after the folded pipe is in an existing underground conduit has been installed. Without one

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

8th

15

CH 683 122 A5

16

Such access to the interior of the folds would make reheating a slow, slow process and very difficult to accomplish.

The folded shape of the pipe from FIG. 8 is particularly suitable for use as a replacement pipe in the repair of building sewage pipes, such as a building sewage pipe 90 shown in FIG. 7, which leads from an interface 92 with a main pipe 94 into a building 96 to be operated. The installation of a replacement pipe in such building sewage pipes is particularly difficult due to the nature of such pipes. First, such side lines present difficulties due to the difficult access, because they often run under meadows, trees and bushes and are not accessible via manholes. Digging out the existing side pipe to be repaired would thus be very costly. When a new side line is inserted into an existing underground side line, access is typically practically only a single small vertical excavation adjacent to the building, as indicated at 98 in FIG. 7. Such an excavation leaves little room for maneuvering or for a large amount of equipment.

Second, building sewer pipes are typically much smaller in diameter than main pipes and often have sharp curves or bends as opposed to main pipes which are usually straight from manhole to manhole. For example, the building sewage line 90 bends at 100, making it impossible to insert a straight, rigid pipe into the existing side line. In Fig. 7, the building sewer 90, which is accessible through the vertical excavation 98 adjacent to the building 96, extends beneath a meadow 102 to the main 94 at a considerable depth below the street 104. The methods and apparatus described below , are particularly suitable for solving the unique difficulties of installing a replacement branch line in an existing underground branch line from a single, small, generally vertical access opening. Such methods and apparatus utilize the form of folded thermoplastic tube as shown in FIG. 8.

Method and device for producing thermoplastic pipes in folded form

Referring to Figs. 9, 10 and 11, e.g. the folded thermoplastic tube of FIG. 8 made using a conventional plastic tube extruder 106 which extrudes into a vacuum chamber 108. A puller 110, which includes a series of opposing pinch rollers 110, 112 downstream of the vacuum chamber, draws the extruded and molded material from the vacuum chamber under tension and feeds it into a steam pipe 114 for reheating to a flexible condition so that the resulting folded tube is in its folded shape can be wound onto a storage reel 116, which is typically arranged in the “hot box” 18 of FIG. 4.

A nozzle 118 and a mandrel 120 are arranged at the extruder outlet. There is a space 121 between about 30 and 61 cm (12 to 24 inches) between the downstream end of the nozzle 118 and the inlet to the vacuum chamber 108.

The inside of the vacuum chamber is divided into three sections by the partition walls 122, 123. All three sections are filled with water up to level 124 inside the chamber. The first or upstream section of the chamber is connected to a vacuum source 125. Although the entire vacuum chamber is under negative pressure due to this connection, the maximum negative pressure prevails in the upstream section of the chamber. A Kaiibrator 126 is arranged in the first section of the vacuum chamber. The Kaiibrator forms the extruded plastic material and holds it in the desired folded shape when the material is cooled and hardened. The water within the vacuum chamber has a cooling function and the vacuum introduced into the chamber works in conjunction with the calibrator to keep the plastic material in its desired folded shape until it is able to maintain this shape without obstruction due to cooling.

With particular reference to FIGS. 10 and 11, the calibrator comprises a series of calibration plates 128 spaced apart and held together by collecting bars 130 and spaced apart by spacers 132 between the plates on the bars. The rods are threaded at their opposite ends and secured by nuts 134. The calibration plates 128 near the inlet end of the calibrator are closer together than those further downstream due to the greater plasticity and flowability of the plastic at the inlet end and therefore the greater need to maintain the shape of the extrusion in that section of the calibrator. Optionally, the calibrator may also include a central tube 136 with openings 137 for delivering cooling water to and between the plates for faster cooling of the plastic material.

Referring to FIG. 11, each calibration plate 128 includes a precision cut opening 138 of exactly the same shape and dimension as the folded tube formed and held in the calibration plates. Each plate 128 of the calibrator has exactly the same size and shape of the opening. When comparing FIGS. 8 and 11 it can be seen that the openings 138 of the calibration plate have a short leg 138a corresponding to the short leg 84 of the folded tube and a long leg 138b corresponding to the long leg 83 of the tube and a round folded portion 138c corresponding to that in the longitudinal direction has rounded fold 82 of the tube.

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

9

17th

CH 683 122 A5

18th

In the manufacture of the tube according to Fig. 9, a raw plastic mixture, such as polyvinyl chloride, is fed into the extruder 106 through a feed hopper 107, where the material is heated to a high temperature, e.g. about 182 ° C (about 360 ° F) is heated and then extruded through the nozzle 118, where the very hot plastic material meets the mandrel 120. The nozzle and the mandrel are dimensioned in such a way that the plastic is shaped to the desired final size and shape of the desired tube. The plastic material is fed through the opening 121 into the first section of the vacuum chamber 108 and through the calibration plates. The plates form the plastic material and hold it in the shape and size which are determined by the calibration plate opening 138.

When the plastic material first enters the quay vibrator, it is very hot and rather fluid, and therefore the quay vibrating plates 128 are arranged very close together at this point to maintain the desired shape. The vacuum within the chamber holds the plastic against the outer periphery of the opening 138 when the cooling water cools the plastic material. If desired, compressed air from a source 140 can be directed down into the mandrel 120 through the internal passages 86, 88, 89 of the folded plastic mold to ensure that the plastic does not collapse completely and to maintain the tubular shape of the folded pipe . When the plastic material reaches the downstream end of quay vibrator 126, it is substantially cooled and able to maintain its own shape under tension exerted by draw rollers 110. Such rollers pull the folded plastic out of the vacuum chamber in a continuous strip. The strip moves from the calibration plates through the second and third sections of the vacuum chamber, where it increasingly hardens. When the strip 10 leaves the vacuum chamber, it is cold, rigid and essentially in the form shown in FIG. 8. The puller 110 controls the wall thickness and other dimensional parameters of the folded tube by pulling the strip or stream of material out of the extruder under tension.

From the take-off device 110, the folded strip is passed through the steam pipe 114, into which a steam source 115 is fed through an inlet opening 117, in order to heat the strip to a flexible state so that it can be wound up on the storage reel 116.

The number and spacing of the calibration plates used in the calibrator is a function of the extrusion speed as determined by the puller and the desired wall thickness of the finished tube.

As already mentioned, the coil 116 from the stored folded tube 10 can be inserted into the “hot box” 18 shown in FIG. 4 for transport using it at the work site.

Method. Apparatus and tools for installing thermoplastic pipes in side lines

Fig. 7 illustrates not only a waste water side pipe as described above, but also a method, an apparatus and tools for inserting the folded thermoplastic pipe of Fig. 8 into the side pipe. First, a vertical excavation 98 must be dug, preferably as close as possible to the building 96 served by the side lines 90, to break through and provide access to the existing side line 90.

The length of the side line to be repaired or replaced can then be determined by inserting a flexible fiberglass rod into the side line as the rod is excavated and fed through the side line until it cuts the main line 94.

When this occurs, the length of the rod can be marked within the side line at the access opening and the rod can then be withdrawn and measured to determine the length of the plastic tube 10 required for this work. Once the lengths of a series of side lines to be repaired are known, the folded tube 10 can be pre-cut to match these lengths, either at the factory or at another location away from the work site. Such pre-cut lengths can then be transported to the workstations for installation.

On the other hand, the required lengths at the work site can also be cut from the coil 142 or 12 (FIG. 4) within the “hot box” 18 that was transported to the work site. If the excavation for the side lines to be repaired is not accessible to the truck 20 on which the “hot box” 18 is mounted, the required length of plastic tube 10 on other smaller coils can be found within smaller “hot boxes” mounted on wheels ( not shown), which can be taken to the corresponding excavation sites. A smaller “mini hot box” 140 is shown in FIG. 7 and comprises a coil 142 of the folded tube 10.

Instead of pre-measuring and pre-cutting the required lengths of the folded tube 10 according to the lengths of the side lines to be repaired, the folded tube 10 can simply be heated within the “hot box” 140 and inserted into this standing side line until the new folded tube interfaces with the Main line 94 reached, and then cut from the coil.

If the folded plastic tube 10 is already pre-cut in the factory, it can be transported in these pre-cut lengths to various workstations and heated there for use in the existing side lines in a steam tube, similar to the steam tube 114 from FIG. 9.

The steam pipe can be made of canvas or metal or equivalent materials with flexible

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

10th

19th

CH 683 122 A5

20th

Fabric or equivalent threads that can be wrapped around the folded plastic tube to hold the steam within the steam tube. Such pipes are lightweight for easy transportation to a job and can be 6 meters (20 feet) in length or more. For field use, a steam hose is preferred over the metal pipe due to its lower weight.

If the sewage side pipe runs straight and its access opening is close enough to the surface during excavation or the excavation is large enough, it may be possible to simply insert the new length of folded plastic pipe 10 into the existing side pipe by pushing the new pipe 10 into the existing one Insert the tube until the leading end reaches the main line. However, this is often not possible due to the need for the new pipe to overcome a bend during excavation or along the side pipe, or both. In such cases, it is necessary to heat the normally rigid folded plastic pipe to make it longitudinally flexible to cope with the bends and to pull the new folded pipe into the side pipe instead of pushing it. The retraction of the flexible folded plastic tube into the existing side line without an access opening at the main end of the side line is associated with particular difficulties, which the present invention serves to overcome.

Pulling the new side line into the existing side line from a Zuaanasöffnuno

A method of inserting the new side line into the existing side line by pulling in requires the use of a pull cable attached to the leading end of the new side line. The cable runs over a pulley at the junction of the side line into the main line and then leads back to the entrance into the side line. By applying a pulling force to the pulling cable from the access opening at the excavation 98, the new pipe can be drawn in through the full length of the existing side line. This procedure requires the use of special tools.

First, the leading end of the new side pipe must be clamped to reduce the size of passages 86, 88, 89, as shown in Fig. 8, to the effect of the internal pressure on the folded tube after it has been inserted into the existing side pipe enable, while hot fluid must be able to flow through the folded tube, so that the tube can be heated over its entire length and thereby becomes flexible for expansion and rounding. To achieve this limitation and end clamping, end clips as shown in Figures 12 and 13 can be used. A side view of the end bracket can also be seen in FIG. 22. Referring to these three figures, end brackets 144 comprise a pair of rigid metal plates.

These plates include an upper plate 145 and an opposing bottom plate 146. Both plates have forwardly extending nose portions 147 with aligned full cable connection openings 148 which extend therethrough. Another pair of aligned openings 149 extend rearward through the lower and upper plates from cable openings 148 for receiving nut 150. Nut 150 also extends through aligned drill openings 151 through folded plastic tube 10.

To attach the end bracket 144 to the leading end of the folded plastic tube 10, the leading end of the tube is heated to make it flexible, e.g. in a final heater 152 as shown in FIG. 24. The end heater 152 includes a thin-walled rigid tube 154 which is connected at one end by an end plate 156 with a central inlet opening 157 to a steam hose connection 158. The opposite end of the heater comprises a flexible tubular fabric or other warp fabric 160 tied to tube 154 at connecting straps 162. The free end of chain 160 may be tied or wrapped around folded plastic tube 10 in such a way that steam at junction 164 of the chain can exit with the pipe so that the entire end portion of the pipe is heated to the desired temperature after injection of steam into the pipe through connection 158. The length of tube 154 can be about 60 cm (2 feet) for most purposes, although it can be longer or shorter depending on the application.

After the leading end of the tube 10 has become flexible, the plates of the end bracket 144 are applied to the end of the tube and the nut 150 is passed through the openings 151 and fastened such that the opposite plates 145, 146 an intermediate part of the folded tube to a flatter Compressed condition to reduce the size of passages 86, 87, 89 at the end of the folded tube. It should be noted that the widths of the clamping plates 145, 146 are substantially smaller than the total width of the folded tube 10, so that the passages 89 at the fold and 86 at the end of the long leg are not completely closed after the clamping force has been applied to the folded one Pipe. Thus, when the clip is attached, fluid can still pass completely through the clamped end of the tube, but the passages are small enough that internal pressure can be achieved within the folded tube to expand and round the tube.

The final heater described is also useful for other purposes, as will be apparent from the description below.

Removable end bracket

Another form of end bracket that can be used in place of the end bracket 144

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

11

21

CH 683 122 A5

22

is a releasable end bracket 250, as shown in Figs. 39-41. The clip 144 has the disadvantage that it cannot be removed from the leading end of the pipe 10 when the pipe is inserted into a blind pipe without cutting off the clamped end of the pipe using a special remote controlled cutting tool as shown in Figs 22 and 23 and described below. However, a removable end clamp 250 can be remotely detached from the clamped end of the new pipe if desired and pulled out of the existing conduit with the cable.

The releasable bracket 250 includes an upper jaw 252 which is rotatably attached to a lower jaw 256 at 254. The lower jaw 256 includes a leading end protrusion 258 with a pull cable opening 260 that extends through to secure a pull cable 262. The jaws 252, 256 have gripping ends 263, 264 to grip and compress a leading end portion 266 of the folded plastic tube 10 when that portion is hot and flexible.

A bolt 268 extends through a large opening 270, which is larger than the head 269 of the bolt, and through an aligned smaller bolt opening 272 in the lower jaw 256. The boizen opening 272 is smaller than the groove 273 and the head 269 of the bolt 268 A bifurcated wedge-shaped release member 276 has parallel arms 277, 278 that define a slot 280 and are united into a vertical wedge-shaped body 282. A flexible release cable or rope 284 is attached to the body 282 by passing through the body opening 286 is. The wedge member 276 is designed to be inserted between the head 269 of a bolt 268 and the upper surface of the upper jaw 252 with the arms 277, 278 which extend under the head and the slot 280 and receive the shaft of the bolt. Thus, the bolt head 269 is pulled against the arms 277, 278 rather than through the large upper jaw opening 270 when the bolt is tightened to clamp the jaw ends 263, 264 against the tube 10.

To release the clamp from the new pipe after the pipe has been drawn into the existing sewer using pull cable 262 and after the new pipe has been rounded except for the clamped ends, the release cable 282 is pulled. This pulls the wedge member 250 away from under the bolt head 269 (or the groove 273 if the groove end of the bolt is above the upper jaw), allowing the bolt head to fall through the large opening 270 in the upper jaw 256, thereby allowing the jaws open to release the pipe end. The wedge link and the clip can be pulled away from the side line or the main line using the corresponding pulling cables.

Bottle Zua Frog

Another tool used to pull the new folded side tube into the existing side tube from an access opening 98 is a pulley block, referred to as a "frog", as shown in FIGS. 14-16. The frog 152 comprises a cable pulling wheel 154, which is rotatably mounted within an pulley housing 156 on an axis 157. Attached to the opposite sides of the open rear end of the housing is a pair of angled legs 158. Each leg includes a front leg portion 158a and an integral rear leg portion 158b. Running from the rear leg parts 158b to the rear is a pair of flexible steel leg guide bands 160 which are bent inwards towards their rear ends 161. The pivot connections 162 of the legs 158 to the frame 156 are spring-loaded in order to force the legs outwards, as shown in FIG. 14. However, the legs can be rotated inwards into the positions shown in FIG. 15 in order to allow the legs and thus the entire device to migrate through the side line.

A pair of generally triangular shaped arms 164 are rotatably supported at the junctures of the front and rear leg portions 158a, 158b at the sprung pivot connections 166. The sprung links 166 force the arms 164 into their extended positions, as shown in FIG. 14, normal for the rear leg portions 158b when they are in their extended positions of FIG. 14. However, the arms 164 may collapse against their spring pressure into their collapsed positions, as shown in FIG. 15, again to allow the frog to reach its end point through a side line. A pull cable 168, both ends of which lead back to the access opening 98, is guided around the disk wheel 154.

When the pull cable 168 is attached but both ends of the cable lead back to the access opening 98, the frog is inserted into the existing side conduit and pushed through using a flexible fiberglass push rod (not shown). When the frog reaches the intersection of the side line and the main line, and the housing 156 and its pulley are pushed into the main line and the front legs 158a also enter the main line, the arms 164 jump outwards from their positions shown in FIG open positions, as shown in Fig. 14. In the open position of the legs, the rear leg parts 158b and their connected leg straps 160 press against the inner wall of the existing side line. At this point, both ends of the pull cable 168 are pulled to firmly anchor the frog to the junction of the side line with the main line.

While tension continues to be applied to the pull cable to anchor the frog in place, one end of the pull cable comes on

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

12th

23

CH 683 122 A5

24th

an end bracket 144 (FIGS. 12, 13) or the releasable end bracket 250 (FIGS. 39 to 41). The other end of the cable, which is still at the access opening 98, is pulled, with the heated, flexible, folded plastic tube 10 being pulled through the side line and around the bend 100, the leading end of the folded tube 10 is the crossing point of the side line reached with the main line at the frog 152. Traction can then be applied to the cable 168 to accomplish this either by hand or using a hand or power winch 170 (FIG. 7) at the inlet opening 98. Because of the triangular shape of the arms 164, the tension applied to the cable 168 prevents the frog from tipping up or down.

After the new folded plastic pipe has reached the frog in the main line, the cable connection to the pipe end clamp is released and one end of the cable is pulled through the pen, causing the frog to fall into the main line. The cable is then pulled out on the service line from the inlet opening and the frog can be withdrawn from the main line at a later time using conventional withdrawal methods. At this point, the folded plastic tube 10 is fully inserted in the side line to be repaired, with its clamped leading ends lying on the main line. The folded plastic pipe is now ready to be heated again and expanded into a rounded shape in the existing service branch line.

Before discussing the expansion and rounding process as applied to the service side lines, the method and means for releasing the pull cable 168 from the end bracket 144 so that the cable can be pulled through the frog should be mentioned. This can be done in different ways, e.g. 34 and 35.

Figure 34 illustrates what is referred to as a breakaway cable solution. In this method, a "slack" end 168a of the pull cable 168 is attached to a cord or cable 172 which can be torn with relatively little force, which in turn is wound at 173 to the leading end of the folded tube 10 which is to be inserted into the existing side line. From this slack end, the pull cord 168 is loosely pulled through the cable opening 148 in the end bracket as indicated by the loose loops 168b, 168c and then pulled through the frog's pulley. The pull end of the cable remains at the access opening to the side line. If an end bracket is not used, the cable opening 148 can be drilled directly through the folded leading end of the plastic tube. When the winch at the inlet opening pulls the cable through the frog to pull the folded new tube into the existing side line, the cord 172 exerts moderate tension on the slack end 168a of the cable. If the leading end of the folded new tube the

Frog reached, the pull end of the cable is sharply drawn, causing the cord 172 to tear and the slack end 168a of the cable to be released through the cable opening 148 so that the cable can be pulled back.

35 illustrates a similar cable release method, which is referred to as a handheld cable solution. In this method, the slack end of the cable 168 is again loosely looped twice through the cable opening 148 at the leading end of the folded new tube 10 to form the double loops 168b, 168c. Then pull cable 168 is routed through existing side line 90 to the frog and back to the access opening. The slack portion 168a of the cable must be longer than the length of the new tube 10 to be inserted. When the winch pulls the new tube into the existing side line, moderate tension is applied to the slack end 168a of the cable, allowing the folded new tube to to be drawn into the side pipe. When the new pipe is properly inserted into the existing side line, the slack end 168a at the access opening is released, making it possible to pull it free from the leading end of the newly inserted pipe through the cable opening 148.

Method and device for expanding and rounding the folded tube within the side line

With the folded new tube in place within the existing side line, the tube is ready to be expanded and rounded to replace the existing side line as a functioning service side line. At this point, the leading end of the folded new tube 10 is already constrained by an end bracket 144 or 250 so that the folded tube can be pressurized from the inside by fluid and still allow hot steam or other liquid to pass through it. This enables the entire inner length of the folded tube to be heated to a flexible state for expansion. Of course, the rear end of the newly inserted folded tube is also closed at this point to allow the introduction of hot steam or other liquid into the tube for heating and expansion. Such a closure or plug is shown in FIGS. 17 to 21.

A generally tapered plug, referred to as a "torpedo plug" 176, includes a generally tapered guide portion 178 with an opening 180 at its guide end. The tapered portion 178 extends rearward to a short cylindrical portion 182 which is covered by a rear end plate 184. The plate 184 includes an inlet opening 186 and a hose connection 188 for fastening a steam or hot water supply hose, so that hot fluids can be introduced under pressure into the interior of the folded tube. Other hose connections can also be fed through end plate 184, e.g. an air

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

13

25th

CH 683 122 A5

26

Hose connection to expand the pipe using air pressure or to maintain air pressure in the expanded pipe when the pipe is hardened in its expanded, rounded state.

When the rear end of the folded tube 10 is heated, e.g. using the end heater 152 described above to make the tube flexible, the conical portion of the torpedo plug 176 is driven into the rear end of the tube 10, as shown in FIG. 19, until the end cap 184 reaches the end edge of the touches new pipe, whereby the end of the new pipe is expanded into a rounded shape according to the outer diameter of the cylindrical plug part 182. An adjustable chain bracket 190 is used to secure the expanded end portion of the new tube to the cylindrical portion 182 of the torpedo plug to tightly secure the tube to the stopper.

Details of chain bracket 190 are shown in FIGS. 20 and 21. The chain clip includes a clip plate 192 which has a curved surface 193 surrounding the tube. The convexly curved outer surface of the plate fixes a bracket 194 between which a groove member 195 is rotatably mounted. The slot link

195 takes a threaded rod

196, which has a wrenching end 197. A chain clip 198 is attached to the opposite end of the bar. The chain is preferably a transmission chain or a Velokette or the like. The chain is equipped for an adjustable connection to an anchor bracket 199 on the outer surface of the bracket plate 192.

When the end of tube 10 is heated and flexible and the torpedo plug 176 is inserted into such an end, clamp plate 192 is placed on the rounded tube end and chain 198 is wrapped around the cylindrical tube end, by hand as tightly as possible tightened and then anchored at anchor point 199. Clamp pressure is then applied by rotating the threaded rod 196 in one direction to shorten the effective length of the clamp chain 198 using a twist key attached to the rotating end 197 of the rod. It is important that the clip can be tightened easily because the plastic tube tends to deform when heated and the clip must be tightened in place while the new tube is being heated and rounded.

When the torpedo plug is clipped in place at the rear end of the newly inserted tube, a steam hose is connected to the plug connection 188. Hot steam is conveyed through the length of the folded tube, particularly through its narrow passageways, thereby allowing the full length of the tube to be heated. At the same time, the restriction imposed by the end clamp at the leading end of the folded tube enables the tube to be from the inside up to approximately 1.75 kg /

cm2 (25 psi) is pressurized. When the tube is heated and pressurized, it expands and curves to its cylindrical shape along its entire length, except for the clamped end portion.

When the new pipe expands and is rounded to the desired dimension, usually against the inner wall of the existing side pipe, the plastic pipe is allowed to cool, while the internal pressure is maintained, for example by introducing air under pressure, thereby keeping the new pipe in its place can stabilize new rounded shape. When the new tube is stabilized, the chain clip is released from the rear end and the torpedo plug is removed.

Removal of the clamped end of the new pipe

The next step is to separate the end clamp and the still folded and clamped leading end of the new pipe from the remaining rounded part of the pipe. This is done by cutting the stapled and folded guide end from the expanded and rounded new tube as shown with reference to FIGS. 22 and 23.

22 and 23, a cutting device for cutting the folded and stapled leading end of the expanded and rounded pipe 10 in the existing pipe is shown. The cutting device comprises a power-driven cutting tool 200. The cutting tool contains a small high-power electric or air motor 202, which is arranged in a cylindrical motor housing 204 of a much smaller diameter than the inner diameter of the rounded plastic tube 10. A flexible air hose or electrical line 206 provides power to motor 202 from an external source at the opening of the existing service side line. A motor-driven shaft 208 operates a rotor 210 to which a pair of knives 212, 213 are rotatably attached to the pivot connections 214 adjacent the outer ends of the rotor.

Motor housing 204 is enclosed in an inflatable rubber boot 216 which, when expanded, centers and anchors the cutting unit in place within the rounded plastic tube. A flexible air hose 218 provides air under pressure to inflate the cuff 216.

Although the cutting blades 212, 213 shown are made of steel, they can also be made from a chain or cable. They are intended to extend outwards under centrifugal force when the rotor 210 rotates in order to separate the plastic tube 10.

In use, the cutting unit 200 is pushed down through the new plastic tube 10 after the tube has been installed and rounded. The poking can be done with a flexible fiberglass rod and with non-inflated rubber

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

14

27

CH 683 122 A5

28

cuff 216. The cutter is inserted into the existing side line until it reaches the collapsed and clamped leading end. At this point, sleeve 216 is inflated to anchor and center the cutting unit within the rounded plastic tube. With the cuff inflated, the motor 202 is started by applying force through the air hose or electrical line 206. The motor rotates the rotor 210 to activate the knives 212, 213 until they cut off the clamped and folded end of the plastic tube. The cut end falls into the main line and can later be retrieved in the usual way.

After the leading end of the pipe is cut off, the air is released from the sleeve 216 and the cutting unit is withdrawn from the rounded plastic pipe by simply pulling on the air hose 218 and the power line 216 from the entry end of the new pipe. The new side line is now installed in the existing side line and after being connected to the part of the side line leading into building 96 (Fig. 7) it is ready for service.

Other methods and apparatus for installing and expanding the new pipe in an existing side line

FIG. 33 illustrates a further method for pulling the folded plastic tube 10 through an access opening 98a into an existing side line 90a, which crosses a main tube line 94a at an intersection 92a. At a certain distance from the intersection 92a, the main line 94a has a manhole 216 for access to the main line. A cable winch 218 is installed at manhole 216. The leading end of a pull cable 220 is inserted into the existing side line 90a at the access opening 98a and pushed down in the side line to the crossing point 92a with the aid of a flexible fiberglass rod, the leading end of which is equipped with a gripper for holding the leading end of the pull cable.

The leading end of the bumper is also bent so that when it reaches the intersection, the rod can be guided around the sharp corner into the main line. At this point, the bumper continues to push pull cable 220 through the main line, as shown at 220a, until the leading end of the pull cable reaches manhole 216. The lead end of the cable is attached to the winch cable at 219. The rear end of the pull cable 220, which is still located at the access opening 98a of the side line 90a, is attached to the leading end of the folded tube 10 using one of the cable release methods described above. The new pipe, after e.g. was heated in the "hot box" 18 to become flexible, pulled into the existing side line 90a by means of the winch cable 220 using the winch 218 at the manhole 216. The pulling continues until the leading end of the new tube 10 reaches the intersection 92a. Then pull cable 212 is released from the leading end of the new tube using one of the techniques described above. The new tube is now ready for expansion and rounding within the existing side line 90a using any of the rounding methods described above or any other method described below.

Inflatable Stonfen method for rounding pipes

Another method and device for expanding the newly installed plastic pipe within an existing service branch line is shown in FIGS. 25 to 29. This method is known as the inflatable plug method. The inflatable plug 222 used in this method is shown in FIGS. 25 and 26. It is used in place of end bracket 144 (Figs. 12 and 13) or end bracket 250 (Figs. 39 through 41) to seal or restrict the inaccessible leading end of the new plastic pipe so that this pipe can be pressurized, rounded and expanded . The plug is designed to be able to maintain an air pressure of at least 1.75 kg / cm2 (25 psi), to expand to an outer diameter equal to the size of the inner diameter of the rounded new pipe, but not to burst when it passes through the new pipe is unobstructed. The plug should also be designed to withstand a temperature above 93 ° C (200 ° F).

The inflatable plug should be made from a single layer of flexible material if a suitable material can be found that meets the specifications above. However, no such material has yet been found. A two-layer construction of the plug is therefore currently used. The stopper consists of an outer canvas or other fabric hose 224, which is folded, closed and sewn at its leading end 225. The outer hose 224 has an expanded diameter corresponding to the desired inner diameter of the new tube in a rounded state. The rear end 226 of the canvas hose remains open. An inner tube or bladder 228 made of expandable rubber is arranged inside the canvas tube. The total length of the plug can vary between about 30 cm and 6 m (1 to 20 feet), depending on the application. The rear end of the outer canvas hose and the inner rubber hose are combined around a pipe stem 230 which provides an air hose connection 232 for an air or steam supply hose 234 for the purpose of supplying fluid under pressure to the interior of the inner hose. The rear ends of the outer and inner tubing are wrapped around a pipe trunk 230

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

15

29

CH 683 122 A5

30th

collected and tightly tied by a band clamp 236 to prevent fluid under pressure from appearing from the inner tube.

The inflatable plug, as described, is typically used when inserting and rounding new service side lines, so the end clips and end cutters described above do not have to be used. A typical method of using the inflatable plug is as follows:

The required length of folded plastic tube for a given existing service line is heated and rounded in the store using, for example, the steam hose described above. The hose 234 for pressurizing the plug is inserted through the length of the rounded plastic tube with the inflatable plug attached until the plug is at the leading end of the rounded plastic tube.

At this point the pre-cut length of the rounded plastic tube is reheated and folded again for field use with the uninflated plug and the connected air hose folded inside. Fig. 27 shows the insertion of the air tube and attached uninflated plug 222 into the rounded plastic tube 10. Fig. 28 illustrates the refolding of the tube 10 with the uninflated plug 222 and the tube 234 inside the folded tube.

At the work place, the plastic pipe is heated and inserted into the side pipe to be repaired while it is folded and flexible. When fully inserted, the folded plastic tube, with the plug still uninflated, is heated by passing steam through the tube. When the entire length of the installed plastic pipe is heated, the plug is inflated via the air hose 234 to inflate the plug and so the still hot, flexible leading end of the plastic pipe 10 surrounding the plug to completely plug the leading end of the plastic pipe . After the plug is inflated, the plastic tube is pressurized upstream of the plug, e.g. with compressed air, rounded and expanded, the air being supplied through a hose 236 which leads into the torpedo plug 176 at the rear end of the new tube at the access opening 98.

After the new plastic tube has been completely rounded and expanded to the desired diameter within the existing side line 90 and then left to cool, the plug 222 is freed of air and pulled out on the new rounded tube 10 through its air hose 234. The newly installed plastic side line is now ready for service.

Other methods of using the inflatable plug

30 to 32 illustrate some other methods of using the inflatable plug just described.

A slight variation of the methods illustrated in Figures 27-29 is the use of the inflatable plug as a sliding plug during the tube rounding process. According to this variation, and referring to Fig. 30, the inflatable plug 222 and its air tube are inserted into the pre-rounded plastic tube 10 and folded with the tube as above, but the plug is about 15 cm (6 inches) or so from the leading end 238 of the tube inserted remotely, allowing the leader to be folded as compactly as possible for ease of use in the existing side line. The folded tube 10 with the uninflated plug 222 inside is folded as previously installed in the existing side pipe. The rear end of the new tube is closed with a torpedo plug 176, with an air hose 234 extending through a seal in the torpedo plug.

With the uninflated inflatable plug 222, the folded tube is heated with steam from the inside over the entire length in order to make the tube flexible. Air hose 234 is pulled tight where it extends from torpedo plug 176 and clip 240 is attached to the hose approximately 30 cm (12 inches) behind the rear end of the torpedo plug. When the folded new tube is hot, the inflatable plug is inflated. In addition, the folded new tube between the inflated plug 222 and the torpedo plug 176 is pressurized with compressed air which is introduced through the torpedo plug through an air line 236. Pressurizing the new tube forces the inflated plug 222 to slide against the leading end 238 of the new tube until it is stopped by the clip 240 being pushed against the rear end of the torpedo plug. At this point, the leading end, like the rest of the newly installed pipe, is completely rounded. The inflated plug 222 is now cleared of air and removed from the newly installed pipe.

Fig. 32 illustrates another method of using the inflatable plug 222 to close, round and expand the new tube within an existing side line or other line, which is only accessible from one end.

According to this method, the new pipe is inserted into the side pipe in a folded state using one of the insertion techniques described above and without a leading end clamp or inflatable plug to seal or narrow the leading or downstream end. However, at least about 3 m (about 10 feet) of additional length of the folded plastic tube is left exposed to the access end of the existing side pipe. The folded tube is heated from the inside with steam in order to make it flexible over the entire length. When it is hot, an outer bracket 242

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

16

31

CH 683 122 A5

32

attached to the folded tube about 3 m (10 feet) downstream of torpedo plug 176. Then the top approximately 3 m (10 feet) of plastic tubing between the bracket and the torpedo plug are rounded by introducing steam from line 236 through the torpedo plug into the top 3 m (10 feet) of the folded tube. The rounded 3 m (10 feet) of the tube are then allowed to cool in the rounded state.

The torpedo plug 176 is then removed and the inflatable plug 222 is inserted in an at least partially uninflated state for ease of insertion into the rounded section of the new tube. The torpedo plug 176 is reinserted into the end of the rounded section of the new tube with the air hose 234 from the inflatable plug extending therefrom. Now clamp 242 is removed from the new tube and inflatable plug 222 is deflated. The inside of the new pipe is heated with steam over its entire length in order to make it flexible again. When the new tube is hot, the inflatable plug 222 is partially inflated. The internal pressure within the new tube, caused by steam or air pressure, is increased and the partially inflated plug 222 is conveyed through the new tube, which at this point is partially deployed and rounded. When the inflatable plug 222 reaches the downstream or leading end of the new tube, it is fully inflated to close the end. The new pipe is now placed under fluid pressure, completely rounded and cooled and thus stabilized in its rounded shape. When the new tube is cured, the inflated plug 222 is deflated and pulled out of the fully rounded tube.

Sealing of the removed pipe end

A method and means are also provided for sealing the space between the new rounded pipe and the existing pipe, wherever such pipes intersect another opening, be it a manhole or another pipe. A typical pipe intersection is located at the downstream end of a building sewer where it opens into the main sewer.

The seal is simply a compressible rubber sleeve that surrounds the crossing end of the folded new tube. It is typically 1/4 to 1/2 inch thick, but can be of any reasonable thickness. Typically it is 30 to about 60 cm (12 to 24 inches) long, but can be of any length desired.

When the leading end of the folded new pipe is installed and accessible, e.g. in the case of a manhole, the sleeve can be slipped over the folded end of the new tube before such an end is rounded. Then the sleeve is also rounded while the pipe end is being rounded. The new tube is expanded during the rounding process until the rubber sleeve is pressed tightly between the new tube and the existing tube to form the liquid-tight seal. Another method is used to seal the distant and inaccessible, downstream ends of building sewers. A rubber-lined rubber sleeve is used. The leading end of the folded new tube is heated, unfolded and rounded before use in the existing tube. The glue-lined sleeve is applied to the rounded end and the end with the attached matte is folded again. The folded new tube is then inserted into the existing tube using one of the methods described above.

The use of the expandable plug described above is the preferred method for rounding and expanding the distal end to be sealed. With such a plug, the expansion and thus the sealing is more complete and safer than with the other methods described.

Procedure for removing installed thermoplastic replacement pipes from an existing underground pipe

As already mentioned, it is preferred that the thermoplastic tube 10 is manufactured in the folded form shown in FIG. 8. After first being cooled and cured in such a folded form, the thermoplastic pipe retains resilience to such a form which tends to return the pipe to such a folded form whenever it is heated and relaxed again. This "memory" for its folded shape can be used to advantage if a damaged section of such a pipe is removed from an existing underground pipe.

To remove a damaged thermoplastic pipe from inside an existing pipe, the damaged pipe is heated by passing fresh steam through the pipe and, if possible, around the outside thereof. When the damaged pipe section to be removed is hot, it collapses to its original folded shape. This collapse and refolding can be accelerated by connecting a vacuum pump to the inside of the pipe to reduce its internal pressure. When collapsed and folded, the hot plastic pipe can be pulled out of the existing pipeline with a cable winch whose pull cable is attached to an accessible end of the collapsed pipe.

Heating and molding a thermoplastic tube for use

Heating the folded thermoplastic pipe to facilitate its use, especially where there are bends in the existing pipe

5

10th

15

20th

25th

30th

35

40

45

50

55

60

65

17th

33

CH 683 122 A5

34

or pipe has to be managed or the new pipe has to be inserted down through a small deep vertical hole is important. Several methods of heating for insertion have been described, including using a "hot box" or a long steam pipe. Another method is to heat the interior of the existing pipeline into which the thermoplastic pipe is to be inserted. According to this method, a short section of the pipe, which is in steam connection, is attached to the rear end of the existing pipe to be repaired. A streamline closure at the rear end of the steam pipe section is wrapped around the folded new pipe when inserted through the steam pipe connection into the existing pipe to heat the new pipe during use. This method can also be used to advantage with the other heating methods described.

The flattened, folded shape of the rigid thermoplastic tube shown in Figs. 3 and 8 is also important because such shape gives the tube certain properties which are different with other tubes which are collapsed or partially collapsed, only for the purpose of theirs entire diameter dimensions for the purpose of insertion into an existing pipe cannot be achieved. First, the flattened, folded shape shown, when heated and made flexible, can be conveniently and compactly stored on a spool in long or short lengths. The coil in turn can be used for storage, reheating and feeding the pipe into a pipe. Second, the tube shape shown, when heated and made flexible, is capable of being in a conduit around a sharp bend from a small vertical access opening, e.g. a manhole to be used and is capable of installing sharp bends in the existing pipeline itself. For example, a rigid PVC pipe with a typical wall thickness to diameter ratio within the above range, when heated to a flexible condition, has a minimum bend radius to rounded outer diameter ratio of between 1 and 2. That is, a typical rigid PVC pipe with a diameter of about 10 cm (4 inches), if it is flexible, flattened and folded as shown in Fig. 3 or 8, a curve with a radius between about 10 and 20 cm (4 and 8 inches), depending on the wall thickness, can be mastered without damaging the pipe walls. Such a minimal bend radius is unattainable with other known forms of rigid thermoplastic tubes when in their flexible condition.

Third, the folded forms of Figs. 3 and 8, when heated and made flexible, can, despite the above properties, be quickly reformed to a round shape and hardened to make them structurally rigid and sufficiently strong to be external to the earth and withstand hydraulic pressure. The installed thermoplastic pipe of the present

Invention is therefore truly a replacement pipe, not just a liner for a damaged existing pipe.

Claims (21)

Claims 1. Replacement pipe for insertion into an existing pipe, characterized by a length of a plastic pipe (10) which is approximately rigid at ambient temperature in a state of reduced overall cross-section which is smaller than the inner diameter of the existing pipe, the pipe ( 10) has a resilience for this condition and is capable of being made flexible at a predetermined temperature and expanded to an approximate tube shape of the desired dimension. 2. Replacement pipe according to claim 1, characterized in that it consists of polyvinyl chloride. 3. Replacement tube according to claim 1 or 2, characterized in that the tube (10) has a collapsed and longitudinally folded shape, which has a first and second leg (83, 84) which on a rounded, bulged folding part (82) are connected, the first and second legs (83, 84) ending in rounded, bulging ends (85, 87) which delimit passages (86, 88, 89) and one of these legs is longer than the other, so that the bulged end of the shorter leg is behind and above the bulged end of the longer leg, whereby the total thickness of the collapsed and folded tube is reduced to a minimum. 4. A process for producing a replacement tube according to one of claims 1 to 3, characterized in that a thermoplastic tube material is extruded in a hot and plastic state through a nozzle in order to bring the plastic material into a tube shape of the desired dimension, the resulting hot, leads tubular, plastic material in a plastic state through a Kaiibrator (126), which is dimensioned and designed such that the hot, tubular, plastic material is brought into the desired shape of reduced overall cross-section and held therein and the thermoplastic material then in this mold is cooled to harden it in this mold. 5. The method according to claim 4, characterized in that the hot, plastic material in the Kaiibrator (126) is exposed to a partial vacuum. 6. The method according to claim 4 or 5, characterized in that the tubular plastic material is brought to a collapsed and folded in the longitudinal direction. Process according to one of claims 4 to 6, characterized in that the hardened tube is heated, e.g. with steam to make it pliable and then it is wound onto a storage reel in collapsed and folded form. 8. Device for performing the method according to one of claims 4 to 7, characterized 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 18th 35 CH 683 122 A5 36 by extruding means (106) for extruding a thermoplastic material in the hot plastic state to a length of a tube (10) with an approximately tubular diameter of the desired size, by a quixer (126) and cooling means (136) for deforming and maintaining the extruded thermoplastic material in a desired form of reduced overall cross-section, in which all dimensions are smaller than those of the tubular shape. 9. The device according to claim 8, characterized by an additional pressure medium to preserve the shape of the extruded material in the Kaiibrator (126). 10. The device according to claim 9, characterized in that the pressure medium is a vacuum (108) which acts on the outside of the tube. 11. Device for storing a thermoplastic replacement tube according to one of claims 1 to 3 in the state of reduced overall cross-section characterized by a coil (12), a housing (18) which with openings (21) for winding and pulling the tube (10 ) in the form of a reduced overall cross-section, heating means (24) for heating the interior of the housing to a temperature at which the coiled tube becomes flexible, and air circulation means (19) to distribute the heat approximately evenly through the interior of the housing. 12. A method for inserting a replacement pipe according to one of claims 1 to 3, into an existing pipe, characterized in that the replacement pipe (10) is transported in the state of reduced overall cross-section to an inlet opening (16) of the existing pipe (14) , heated a length of the replacement pipe (10) in this state to make it longitudinally flexible, inserting a leading end of the replacement pipe (10) into the existing pipe (14) while the replacement pipe (10) is in the heated, flexible state , the replacement pipe (10) is inserted within the existing pipe (14) at the desired location, the replacement pipe (10) rounds out from its shape of reduced overall cross-section to a pipe shape by the action of heat and internal pressure on the replacement pipe (10) and it then cools to stabilize it in its tubular shape. 13. The method according to claim 12, characterized in that the existing pipeline is a lateral pipeline (90) which is connected to a main pipeline (94), and the replacement pipe (10) into the lateral pipeline (90) from an access point ( 98) is introduced against the main pipeline (94), and the replacement pipe in the existing pipeline is brought into position by means of rollers (23) and cables (26), so that one end of a cable device is pulled in one direction from the inlet opening away from the main pipe, a second end of the cable device is caused to pull the leading end of the replacement pipe (10) towards the main pipe. 14. The method according to claim 12, characterized in that the ability of a fluid to flow from an opening at the leading end of the replacement tube (10) is restricted before an internal pressure is applied to expand the replacement tube (10) to allow fluid pressure to build up within the replacement tube (10) and to allow hot fluid to flow internally through the length of the replacement tube (10), and then to place a hot fluid in the replacement tube (10) from a hanging end at a temperature and pressure sufficient to expand the replacement tube (10) from a reduced overall cross-sectional condition to a round shape. 15. The method according to claim 14, characterized in that the fluid flow from the leading end of the replacement tube (10) is restricted by plugging the leading end with a flexible, foldable and inflatable plug (30) which is in the state of reduced overall within the replacement tube (10) -Cross-section is attached. 16. The method according to claim 12, characterized in that the replacement tube (10) is rounded with sufficient heat and internal pressure to form recesses (76) in the replacement tube (10) according to the position of the lateral connections, the recesses are located and a Part of the replacement tube (10) at the recess (76) is removed to create inlet openings for a lateral connection. 17. The method according to claim 12, characterized in that the leading end of the replacement tube (10) is also brought into a round shape, an expandable sealing sleeve (216) is fastened around the rounded leading end of the replacement tube, the leading end is folded again before the replacement tube is inserted, and that After use, the replacement pipe heats, rounds and expands to press the sealing sleeve tightly between the replacement pipe and the existing pipeline. 18. Device for performing the method according to one of claims 12 to 17, characterized by - Storage means for a length of substantially rigid thermoplastic replacement tube, which has a leading end and a hanging end and is in the state of reduced overall cross-section, the substantially rigid, thermoplastic replacement tube (10) in the rigid state of reduced overall Cross-section is stored in which it is bent and layered on itself, the storage means having an enclosure for enclosing the stored tube; - Heater for heating the interior of the enclosure to put the rigid tube in a flexible condition; Means for withdrawing the leading end of the flexible tube from the enclosure in the state of reduced overall cross-section; - insert means for inserting the leading end of the replacement pipe into the existing pipe, 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 19th 37 CH 683 122 A5 while the replacement pipe is heated and flexible; and - Pressure fluid to expand the replacement tube used from its reduced overall cross-section to a round shape in the existing pipeline, including restricting means at the leading end of the replacement tube end of reduced overall cross-section to allow passage of a heated fluid through the length of the Allow replacement pipe of reduced overall cross-section to increase the internal pressure within the pipeline and means to introduce a heated fluid into the pipe from its rear end. 19. The apparatus according to claim 18, characterized in that the pressure means comprises a flexible and inelastic tubular jacket which is closed at the leading end, and an inner tubular elastic inflatable bladder within the jacket, the bladder being expanded under fluid pressure to fit the jacket into a to bring rounded tubular shape, and connecting means at a rear end of the bladder for connecting the interior of the bladder with a source of fluid pressure. 20. The apparatus of claim 18, characterized in that it includes heating means for heating an end portion of the replacement tube (10) to a flexible, workable condition to facilitate the insertion of an end plug restricting fluid flow. 21. A method for removing an approximately rigid thermoplastic replacement pipe according to one of claims 1 to 3, which had been introduced into an existing pipeline, characterized in that the replacement pipe (10) is heated in order to make it flexible and to cause it to at least partially return to its form of reduced overall cross-section, which is smaller than the inner diameter of the existing pipeline, and in this form the replacement pipe (10) is removed from the existing pipeline while being kept flexible. 5 10th 15 20th 25th 30th 35 40 45 50 55 60 65 20th