FOR INSTALLING OVER A PROTRUSION OF AN INNER PIPE WALL

The invention relates to a three dimensional device for installing over a protrusion of an inner pipe wall.

Infrastructure pipelines that carry fluids such as potable water, gas and wastewater deteriorate over time due to their extensive use. This deterioration can lead to leaks and bursts resulting in costly damage if the pipelines are not maintained. Since these pipelines are typically located underground and provide essential utilities, maintenance and rehabilitation is preferably performed with as minimal disruption to service as possible. Several methods for performing in-situ maintenance and rehabilitation on these pipes, also known as trenchless methods, have been developed. One such method involves feeding an applicator device through the pipe to spray a material along the interior surface of the pipe. The material then hardens to form a new, interior liner surface to seal cracks and strengthen the existing pipeline. One technique for spray coating the interior surface of a pipe involves centrifugally spraying a liquid liner, or resin composition, with a hole-patterned cone. A device for applying a coating according to this technique is for example disclosed in WO 2014/105630 A1 . A method of forming a coating on the internal surface of a drinking water pipe is also disclosed in GB 2 42 634 A.

When the inner pipe wall provides a protrusion, especially a protrusion that has a geometry perpendicular to the longitudinal axis of the pipe, it might happen that the result of the spray coating process is not a continuous one with a uniform coating thickness. It might happen, that protrusions such as ferrules create localised voids or thin areas due to the current spray lining process, which cannot adequately apply the resin to areas which are next to or behind protrusions that are perpendicular to the axis of the pipe. This might be because of the resin is applied using a rotating spray head, where the liquid is injected through the centre of the spray head and is ejected tangentially from a rotating spray cone. The spray head is pulled through the pipe at a constant speed whilst resin is sprayed, therefore depositing a known thickness onto the wall with each pass. Typical total resin thickness in an in-situ spray lining process is 4 to 6 mm, applied in 2 layers. Between the two layers the spray cone and/or motor may be replaced so that the second layer is applied with the cone rotating in the opposite direction and the spray head moving also in the opposite direction.

If structural rehabilitation is to be undertaken it is essential that the installed lining is effectively continuous and always meets the required minimum thickness. This is of particular importance in the case of natural gas distribution pipelines.

US 7,707,704 discloses a fitting which pushes through an installed lining to open up a service connection. US 7,710,281 discloses a method for internally tapping a service connection after spray lining took place to form a fluid pathway between the conduit and service.

WO 2004/023025 discloses a method of applying a filling material to fill a void around a ferrule intrusion of a pipe thereby creating a smooth contour around the intrusion. The method uses a bladder that is inflated when located in the region of the pipeline where the ferrule intrusion is located. The bladder is then inflated and filling material can be applied between the bladder and the inner wall of the pipe. The bladder prevents the filling material to escape from the region where it needs to be applied. The bladder may remain in position after application of the filling material in order to allow the material to cure.

None of the above mentioned references describes a device that helps to ensure a continuous coating with a uniform resin coating thickness of an inner pipe wall through an in-situ spray lining process. Thus, there is still a need for a device that enables a continuous coating of an inner pipe wall with protrusions extending from or through that inner pipe wall through an in-situ spray lining process. The present invention provides a three dimensional device for installing over a protrusion of an inner pipe wall to enable a continuous coating of the inner pipe wall through an in- situ spray lining process, the device comprising:

- a base surface adapted in its shape to the shape of the inner pipe wall it is installed in; - an upper surface facing towards the inside of the pipe away from the inner pipe wall, wherein the top surface provides a chamfered portion, and

- a through hole for fixing the device onto the protrusion adapted in its shape to the shape of the protrusion.

Thus, the present invention relates to a three-dimensional device that is designed for being installed over a protrusion of an inner pipe wall and for enabling a continuous coating of the inner pipe wall through an in-situ spray lining process with the result of achieving a uniform resin coating thickness.

The pipe to be coated through an in-situ spray lining process may be any kind of pipe such as for example a gas pipe, e.g. a natural gas pipe, or a fluid pipe, e.g. a drinking water pipe, or any other kind of industrial pipe. The pipe section can have any kind of inner diameter. Common gas or water pipes provide an inner diameter between 75 mm and 300 mm, preferably between 100 mm and 200 mm. Those pipes provide an inner wall facing towards the inside of the pipe. The inner wall of the pipe may provide protrusions, such as for example ferrule protrusions, e.g. ferrules from service pipe entries into a main pipe. The service pipe entries into main pipe may for example occur in potable water distribution pipes or gas distribution pipes. The protrusions may also be any other protrusions or in-pipe features extending from the inner pipe wall, such as for example blanking plugs.

In-situ spray lining processes and techniques are well known in the prior art. One technique for spray coating or spray lining the interior surface of a pipe involves centrifugally spraying a liquid liner, or resin composition, with a hole-patterned cone. A device for applying a coating according to this technique is for example disclosed in WO 2014/105630 A1 . A method of forming a coating on the internal surface of a drinking water pipe is also disclosed in GB 2 42 634 A. The resin that is being ejected from the spray cone usually follows a tangential path relative to the surface of the spray cone and hits the surface of the inner pipe wall under an angle that is usually smaller than or below 90°, as will be explained in more detail below with reference to the Figures. The three dimensional device for installing over a protrusion of an inner pipe wall according to the invention provides the following features. The base surface is adapted in its shape to the shape of the inner pipe wall it is installed in. It may also conform to the shape of the inner pipe wall surrounding the protrusion. It should fit to the shape of the inner pipe wall around the protrusion. The base surface is contoured to follow the shape of the inner pipe. Thus, when the device is pushed over the protrusion against the inner pipe wall, it is ensured that the device sits flush with the surface of the inner pipe wall around the protrusion with no gaps between the base surface and the inner pipe wall. If the pipe provides an inner diameter between 75 mm and 300 mm, the shape of the base surface is adapted to follow the shape of the inner wall with any of these diameters.

The upper surface faces towards the inside of the pipe away from the inner pipe wall, wherein it provides at least one chamfered portion. The upper surface may provide a top surface extending essentially parallel to the base surface and a side surface surrounding the device and extending from the top to the base surface, wherein the side surface is chamfered. The top surface may be plain or it may follow the same curvature as the base surface. It provides the area that extends into the pipe and provides the highest point or surface of the three-dimensional device. The side surface may surround the device and may extend from the top surface to the base surface, wherein the side surface is chamfered. The chamfered extension of the side surface eliminates the perpendicular features from the protrusion which may not be reliably covered with resin.

The through hole for fixing the device onto the protrusion is adapted in its shape to the shape of the protrusion. The through hole for receiving the protrusion may extend from the top to the base surface. If the protrusion is for example a ferrule with a circular cross- section, the through hole may also provide a circular shape. The through hole may also provide any other shape that is adapted to the shape of the protrusion. The protrusion may be profiled or threaded either on the inside or the on the outside of the protrusion. The through hole may also provide features for fastening the three dimensional device according to the invention on the protrusion as will be described in more detail below.

When a three dimensional device according to the invention is installed over a protrusion of an inner pipe wall a continuous in-situ coating with a uniform coating thickness of the resin is enabled. Through the coating process the device gets fully covered with resin and is therefore not in contact with the pipe content.

The side surface may be chamfered at an angle a between 30 and 60 degrees, preferably between 40 and 50 degrees, wherein a is the angle in a cross-sectional view through the centre of the device between a vertical line through the top surface and the side surface. The chamfered side surface ensures the sprayed resin to cover all over the top and eliminate the perpendicular features which would not be reliably covered with the resin. This is because the resin that gets applied through an in-situ spray coating process usually hits the inner pipe wall with an angle that is below 90°. Thus the protrusion creates an obstacle for the resin and in an area behind the obstacle (shadow) the resin would not be applied. With the three dimensional device according to the invention, the area behind the protrusion or obstacle, a so-called shadow area, is filled with the device itself. - Thus, using the device of the present invention, resin does not need to be applied to this shadow area. The above mentioned ranges for angles of the chamfered surface have been proven to show suitable results in order to reliably coat the inner pipe wall especially the area around protrusions.

As already mentioned above, the three dimensional device according to the invention may provide features for fastening the device on the protrusion. Those features or fastening elements may for example be at least one pawl extending on the inside of the through hole of the device for locking the device onto the protrusion. If the protrusion is for example a ferrule or a blanking plug extending from the inner pipe wall, it is possible that it provides a thread on its outside. A pawl extending from the inside of the through hole may interact with the thread of the ferrule and thereby fix the three dimensional device on the ferrule or blanking plug. The pawl may be designed as pushed onto the ferrule and spring back into a thread, thereby locking the device onto the ferrule during the subsequent spraying operation. Alternative ways to grip the ferrule onto the protrusion include interference fit on the diameter of the ferrule, thread features in the through hole fitting to the threads of the ferrule, locking clips similar to cable ties, or any additional common fixing element. The three dimensional device according to the invention may either be fixed to the outside of the protrusion. If the protrusion itself also provides a through hole, it is also possible to fix the three dimensional device according to the invention on the inside of the protrusion. The at least one pawl may extend through the entire circumference of the through hole. It is also possible that the pawl is split (or the device provides a plurality of pawls extending on the inside of the through hole) in order to reduce the hoop stress during installation of the device and to allow them to settle into the thread troughs. An embodiment according to this would provide a device according to the invention with a plurality of pawls extending on one level on the inside of the through hole. If the pawl is split or several pawls are provided the single parts of the pawls may be positioned on slightly different levels. It might be advantageous to position the pawls as low down as possible (meaning as close as possible to the base surface) to ensure they engage with the first thread they come into contact with. Due to the curvature of the pipe, in another aspect the several pawls are offset from each other on slightly different levels. A full ring of pawls (e.g. 6, 7, or 8 pawls, or any other suitable number) may ensure stability and security to prevent a device from falling off the protrusion. The at least one pawl may also be adapted in its shape to the shape of the thread troughs. As already indicated above, the at least one pawl may extend on the inside of the through hole on the level of the base surface. The three dimensional device is intended for installation over protrusions with an extension into the pipe in a certain range, e.g. between 4 and 12 mm. Thus, providing at least one pawl on the level of the base surface ensures that independent of how far the protrusion extends into the pipe, a fixation of the three dimensional device on the protrusion is possible. It also ensures that the pawls engage with the first thread it comes in contact with.

It is also possible that the at least one pawl extends on the inside of the through hole on the level of the top surface. It may also be the case that the three dimensional device comprises at least one pawl on the level of the base surface and at least one pawl on the level of the top surface. Any other position of the at least one pawl between the level of the base surface and the level of the top surface is possible as well. Those pawls may also be provided in addition to any of the above mentioned positions of the pawls. It is also possible that the device comprises a plurality of pawls extending on one level on the inside of the through hole (see above stability and security).

The three dimensional device according to the invention may also comprise alternative fixing means and no pawl. It may also comprise additional fixing means in addition to the at least one pawl. The device according to the invention may for example comprise at least one rib extending from the base surface to the top surface on the inside of the through hole for centring the device relative to the protrusion of the inner pipe. The device may for example provide several guide ribs extending on the inside of the through hole from the top surface to the base surface. The at least one rib may for example provide an extension of 0.1 to 5 mm, preferably of 1 to 2 mm for service pipe applications. The guide ribs may for example provide a round shape. The guide ribs may also for example provide the same height through its extension from the top surface to the base surface. It is also possible that the guide ribs provide a smaller height on the base surface than on the top surface in order to provide easier installation.

The pawls or grip features may be designed to "bump" over and grip onto for example threads of a protrusion, therefore it may be advantageous if they provide a certain flexibility. The required flexibility may be adapted by changing the material properties and/or the design of the device. This may for example be achieved by making the whole device out of a flexible material. Possible materials for the device are mentioned below. Also, the alternative fixing means may provide a certain flexibility in order to provide required fastening forces. The three dimensional device according to the invention may provide a through hole with an essentially cylindrical shape. As already mentioned above, the device may be designed to fit over a ferrule or a blanking plug. For such a protrusion a cylindrical shape is the correct fit. If the protrusion is any other kind of in-pipe feature, the through hole may provide any other shape, like a.

The three dimensional device according to the invention may also provide an extension, the extension being designed such as to be pushed into an aperture or through hole of the protrusion. The extension may have a cylindrical shape. The extension may be positioned at the through hole, the through hole extending through the extension. The extension may also provide fixing means as described above, e.g. pawls that are designed for interact with a thread inside the aperture or through hole of the protrusion. The extension may also provide any kind of guide ribs on the outside of the extension.

The through hole may comprise an inner diameter of between 10 and 100 mm, preferably between 10 and 70 mm and more preferably between 25 and 60 mm. The diameter of the through hole may correspond to the outer diameter of the protrusion of the inner pipe wall. The above mentioned extension may comprise an outer diameter of between 10 and 70 mm and more preferably between 25 and 60 mm. It is also possible that the outer diameter of the extension is adapted to the dimension of a through hole in the protrusion.

The three dimensional device according to the invention may also comprise at least one recess that has a shape that corresponds to an according excess in an installation jig and that functions as a locating feature during the installation of the device over the protrusion. The recess may be positioned on the top surface of the three dimensional device according to the invention, or it may be positioned at the area of its top surface. The recess may also be positioned on the or at the area of the chamfered side surface, either closer to the top surface or closer to the base surface or in the middle. The device is intended for installation by a remote robot with an articulated arm. The orientation of the device is important to ensure the profiled base surface sits flush against the pipe wall. The robotic arm will therefore have a form with alignment feature which engage with the location feature to ensure the device is held in the intended orientation until installation. The device may comprise two recesses, e.g. one on each side of the device.

As mentioned above, the pawls, guide ribs and/or any additional fixing mean may need to provide a certain flexibility. This may be achieved by making the whole device out of a material with a certain flexibility and or by designing the elements accordingly. Another requirement for the material of the three dimensional device according to the invention may be that it is injection mouldable. Possible materials that can be used are high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), thermoplastic elastomers or liquid silicone rubber or a combination of the before mentioned materials. It is also possible to make the three dimensional device out of different materials, e.g. by over moulding it. The device may also be made out of separate parts that may be fixed to each other.

According to another embodiment the three dimensional device according to the invention may comprise at least one surface that is coated or that provides an additional material or layer on its surface. The coating, material or layer may provide an additional feature to the three dimensional device. It may for example function as a sealant. The surface that is coated, that provides an additional material or layer, may for example be the base surface. A devise with a coated base surface may provide the advantage of a more effective sealing between the device and the inner wall of the pipe. The coating, additional material or additional layer may also provide any other function, such as for example an adhesive function. If an adhesive is used as additional material or layer, it may be possible to use a device without any fixing elements like pawls and/or grips.

The coating, material or additional layer may for example be applied on the base surface of the device. In such a situation, the base surface may provide a recess for receiving the additional material or additional layer or coating. This will be described in more detail below with reference to the drawings.

As a coating that provides a sealing function the following materials, layers may be foreseen, e.g. a liquid gasket, a foam gasket, a rubber gasket, e.g. a silicone rubber gasket, or any other known compressible material that can be used as a gasket material. It may also be a combination of two or more of the above mentioned materials.

The invention will now be described in more detail with reference to the following Figures exemplifying particular embodiments of the invention:

Fig. 1 is a schematic drawing of a spray head for in-situ spray lining with a spray cone for applying resin;

Fig. 2 is a schematic cross-sectional drawing of a spray head in a pipe with arrows indicating the direction of the resin that gets sprayed out of the cone; Fig. 3 is a top view of the three dimensional device for installing over a protrusion of an inner pipe wall;

Fig. 4 is a side view of the three dimensional device shown in Fig. 3;

Fig. 5 is a bottom view of the three dimensional device shown in Fig. 3 and 4;

Fig. 6 is another side view of the three dimensional device shown in Fig. 3, 4 and 5; Fig. 7 is a three dimensional view from the top onto the three dimensional device shown in Fig. 3 to 6;

Fig. 8 is a three dimensional view from the bottom onto the three dimensional device shown in Fig. 3 to 7;

Fig. 9 is a three dimensional view from the top onto another embodiment of the three dimensional device according to the invention;

Fig. 10 a is a three dimensional view for the bottom onto the three dimensional device shown in Fig. 9 without gasket material;

Fig. 10 b is a three dimensional view of the bottom onto the three dimensional device shown in Fig. 9 and 10 a with gasket material;

Fig. 1 1 is a three dimensional view from the top onto another embodiment of the three dimensional device according to the invention;

Fig. 12 is a three dimensional view from the top onto another embodiment of the three dimensional device according to the invention;

Fig. 13 is a three dimensional view from the bottom onto the three dimensional device shown in Fig. 12;

Fig. 14 a to d are partial cross-sectional views of a ferrule in a pipe with a three dimensional device according to the invention installed over the ferrule, wherein the ferrule has different extensions into the pipe;

Fig. 15 a and b are cross-sectional views of a pipe with a ferrule and a three dimensional device being installed over the pipe, before and after the coating process and

Fig. 16 is a cross-sectional view of a ferrule in a pipe with a three dimensional device according to the embodiment shown in Figures 12 and 13 installed over the ferrule. Herein below various embodiments of the present invention are described and shown in the drawings wherein like elements are provided with the same reference numbers.

In Figure 1 a schematic drawing of one embodiment of a spray head or applicator 1 for an in-situ spray lining process with a spray cone 3 for applying resin is shown. An according spray head 1 is for example disclosed in the patent application WO 2014/105630 A1 . The applicator 1 comprises a stabilizer 2 that connects a coating cone 3 to a motor 4. A resin feed tube 5 connects through the centre of the motor 4 to the flow diverter 6 which is positioned centrally within the coating cone 3. The motor 4 usually includes a support structure (not shown) to arrange the motor 4 approximately in the centre of the pipe being coated. Connections to motor 4 and/or support structure may be used to move the motor 4 along the pipe during the coating process, for example by pulling the resin applicator 1 , motor first, via extraction the connections above ground at a resin source. The cone 3 may provide a plurality of holes 7 that wrap entirely around the cone 3. There are several ways of arranging the plurality of holes 7 around the cone 3. The pattern shown in Fig. 1 is just one example.

In Figure 2 a schematic cross-section of a pipe 1 1 to be coated. Inside of the pipe a spray head with a spray cone 3 is shown. The arrow A in the middle of the figure indicates that the spray cone 3 is rotating inside of the pipe 1 1 . The arrows B indicate that resin is sprayed out of the spray cone 3. The resin exists the spray cone 3 in a tangential path relative to the surface of the spray cone 3. The resin hits the inner wall of the pipe 1 1 under an angle a that is below 90°. This setting may cause some insufficiently coated areas of the inner pipe wall, since the resin gets only applied under an angle. Protrusions that for example perpendicularly extend over the inner wall may stay in the way of the resin and cause a shadow area that is not coated.

In Figures 3 to 6 top, bottom and side views of a three dimensional device 12 for installing over a protrusion of an inner pipe wall to enable a continuous coating of the inner pipe through an in-situ spray lining process are shown. In Fig. 7 and 8 three dimensional views - one from the top and one from the bottom - of the three dimensional device 12 for installing over a protrusion of an inner pipe to enable a continuous coating of the inner pipe through an in-situ spray lining process are shown. The device 12 provides a base surface 13, a top surface 14 that extends essentially parallel to the base surface 13, and a chamfered side surface 15. The device 12 also provides a through hole 16 for receiving the protrusion, wherein the through hole extends from the top surface 14 to the base surface 13. The through hole 16 is adapted to the shape of the protrusion it is installed on, here it has a cylindrical form.

As best can be seen in Figures 3 and 5, the device 12 further comprises a ring of pawls 17 extending on the inside of the through hole. The pawls 17 all have the same kind of rectangular shape and they are arranged equidistant from each other. In the embodiment shown in Figures 3 to 8 the pawls 17 are arranged in two rings of two different levels. One level is close to the base surface 13 of the device 12 and the other is close to the top surface 14 of the device 12. The pawls 17 are used for fixing the three dimensional device 12 to the protrusion in the pipe wall, e.g. to a ferrule. They need to be flexible enough in order to engage with an outer surface of the ferrule, e.g. a thread. The pawls 17 close to the base surface 13 are the ones that engage at first with the ferrule during an installation. Depending on the height of the protrusion or ferrule the second ring of pawls which is closer to the top surface 14 may or may not engage with the protrusion or ferrule.

The device 12 may also comprise, as can be seen in Figures 3, 6 and 7 a recess 18 on its top surface that has a shape that corresponds to a shape of an excess of an installation jig and that functions as a locating feature during the installation of the device over the protrusion. The recess may provide any kind of shape as long as it is adapted to the shape of the installation jig and as long as it allows for positioning the device and for easy installing the device onto the protrusion of the inner pipe wall.

In Figures 9 and 10 another embodiment of a three dimensional device 12 for installing over a protrusion of an inner pipe wall to enable a continuous coating of the inner pipe through an in-situ spray lining process is shown. The embodiment shown in Fig. 9 and 10 differs from the one in Fig. 3 to 8 in that it only provides one ring of pawls 17. The ring of pawls 17 extend on the inside of the through hole 16. All pawls 17 are arranged close to the bottom side 13 of the device 12. This is to ensure a quick and secure engagement with the outer surface of the protrusion, e.g. with a thread of a ferrule. The shape of the pawls 17 of this embodiment is adapted to the geometry of a thread of a ferrule. That means that for example the length and/or the thickness of the pawls 17 corresponds to the length and/or distance of the threads of the ferrule. The pawls 17 may be arranged all on one level. They may also be arranged offset from each other. Another difference between the embodiment shown in Figures 9 and 10 is that it provides six guide ribs 19, also extending on the inside of the through hole 16. The guide ribs 19 extend along the entire length of the through hole 16. It is also possible that they only extend over a certain distance within the hole 16. The six guide ribs 19 are arranged in two groups of three guide ribs 19, wherein the two groups are arranged on opposite sides of the through hole 16.

The difference between Figures 10 a and 10 b is that Figure 10 a shows the three dimensional device 12 from its bottom side 13. The bottom side provides a recess. The function of the recess is to receive a gasket material 25 as shown in Figure 10 b. The gasket material 25 may have the function of providing additional sealing between the three dimensional device 12 and the inner pipe wall 1 1 , when the device 12 is installed over a protrusion. Possible materials for the gasket material are mentioned in the general part of this patent application. All other features of the three dimensional device 12 according to the invention are the same as those of the device 12 shown in Figures 3 to 8 and will not be described again.

Figure 1 1 is a three dimensional view of a three dimensional device 12 for installing over a protrusion of an inner pipe wall to enable a continuous coating of the inner pipe through an in-situ spray lining process. The embodiment shown in Figure 1 1 differs from the one in Figures 3 to 8 and Figures 9 and 10 in that it only provides guide ribs 18 on the inside of the through hole and now pawls. The guide ribs extend from the top surface 14 to the base surface 13. They all have the same dimensions and are positioned equidistant from each other. All other features of the three dimensional device 12 according to the invention are the same as those of the device 12 shown in Figures 3 to 8.

Figures 12 and 13 are three dimensional views of another embodiment of the device 12 according to the invention. The device 12 provides a top surface 14 as well as a base surface 13. The base surface may also be called base ring 13. The device 12 also provides a chamfered side surface 15 extending from the top surface 14 to the base surface 13. And it provides a through hole 16 also extending from the top surface 14 towards the base surface 13. The difference between the embodiment shown in Figures 12 and 13 and those described above, is that the base surface does not extend along the entire base section of the device 12 towards the through hole 16. It only extends a certain part from the chamfered side surface towards the through hole 16. The width of the base surface or base ring 13 has to be wide enough to provide for a sufficient sealing function between the device 12 and the inner pipe wall. Another difference between the embodiment shown in the Figures 12 and 13 is that the fixing means (pawls, guide ribs or the like) are arranged on the outside of the through hole 16 and not on the inside of it. Thus, the through hole 16 is created by a cylindrical part of the device 12, which provides fixing means on its outside. By providing this embodiment it is possible, to fix the device 12 inside of an aperture or through hole of the protrusion. The cylindrical part of the device 12 with the through hole 16 may therefore extend into the aperture or through hole of the protrusion, e.g. the ferrule and may be fixed through its fixing means (see Figure 16). In Figures 12 and 13 the fixing means are guide ribs 17 being arranged on the outside of the cylindrical part of the device 12.

Figure 14 a to d show partial cross-sectional views of a ferrule 20 in a pipe 1 1 with a three dimensional device 12 according to the invention installed over the ferrule 20. The pipe may for example comprise a diameter of 100 mm. The ferrules 20 in the different drawings may for example be a British standard pipe (BSP) with an outer diameter of about 26 mm. In the drawings they extend with a different height into the pipe. In Figure 14 a the ferrule 20 extends for example 12 mm over the inner pipe wall into the pipe 1 1 , which may correspond to three times the thickness of the resin. In Figure 14 b the ferrule 20 extends for example 9 mm over the inner pipe wall into the pipe 1 1 , which may for example correspond to a bit more than two times the resin thickness. In Figure 14 c the ferrule 19 extends for example 6 mm over the inner pipe wall into the pipe 1 1 , which may for example correspond to something between one and two times of the resin thickness. And in Figure 14 d the ferrule 20 extends for example 4 mm over the inner pipe wall into the pipe 1 1 , which may for example correspond to the resin thickness. The three dimensional device 12 according to the invention is designed in such a way that the same design can be used for all of the above mentioned different situations.

According to one aspect, a reliable and continuous in-situ inline coating process with a uniform coating thickness of an inner pipe wall with protrusions can achieved as long as the protrusions are smaller than the thickness of the resin that gets applied. If the protrusion is larger than the resin thickness challenges of an uneven coating result may exist. If the protrusion, e.g. the ferrule 20 is for example exactly the high of the resin thickness that gets applied, the three dimensional device 12 according to the invention may be installed over the protrusion. Thereby the pawls 17 that are arranged on the lower end, closer to the base surface 13, engage with the thread of the ferrule 20 and securely fix the device 12 to the ferrule 20. The ferrule 20 does not extend over the top surface 14 of the device 12 into the pipe. Thus, the ferrule 20 is complete covered by the device 12 and ensures a continuous in-situ inline coating process with a uniform coating thickness of the inner pipe.

In the situation illustrated in Figure 14 c, the ferrule 20 extends more than the resin thickness over the inner pipe wall into the pipe. The situation is similar to the one described with reference to Figure 1 1 d. The ferrule 20 engages with the lower pawls 17. Thus, the device 12 is fixed through its pawls 17. The ferrule 20 is also complete covered by the device 12 and ensures a continuous in-situ inline coating process with a uniform coating thickness of the inner pipe.

In the situation illustrated in Figure 14 b, the ferrule 20 even more over the inner pipe wall into the pipe, e.g. more than double the thickness of the resin. It reaches up to the top surface 13 of the device 12. It does not extend over the top surface 13 of the device. A continuous in-situ inline coating process with a uniform coating thickness of the pipe is still guaranteed.

And finally in the situation illustrated in Figure 14 a, the ferrule 20 extends more than three times the resin thickness over the inner pipe wall into the pipe. The ferrule 20 is not complete covered by the device 12. If the extension of the ferrule 20 out of the device is below the resin thickness, it is still possible to reliably cover the ferrule protrusion with resin through an in-situ inline coating process. Thus, the three dimensional device 12 according to the invention can be used for protrusions with different heights.

The above mentioned dimensions are only mentioned as an example and are not meant to limit the scope of the invention. It still is possible to adapt the size of the device according to the invention to other diameters. It is just pointed out that a three dimensional device according to the invention of a particular size can be used for differently sized protrusions, e.g. protrusions that are completely covered by the device and also protrusions that extend over the device.

Figures 15 a and b are cross-sectional views of a pipe 1 1 with a ferrule 20 and a three dimensional device 12 being installed over the pipe 1 1 , before and after the in-situ inline coating process. A section of the wall of the pipe 1 1 can be seen. A ferrule 20 extends through the wall of the pipe 1 1 into the pipe 1 1 . The ferrule 20 is fixed through a fixing element 21 which is positioned outside of the pipe 1 1. In the embodiment shown in Figure 15 a and b the ferrule 20 extends over the device 12 but not more than the thickness of the resin. As can be seen from the Figure 15 b showing the situation after the coating process, with the device 12 according to the invention it is possible to coat all areas around the ferrule 20 with a uniform thickness of resin 22.

Figure 16 is a cross-sectional view of a pipe 1 1 with a ferrule 20 and a three dimensional device 12 being installed over the pipe 1 1 , wherein the device is a device according to the one shown in Figures 12 and 13. As can be seen, the cylindrical part of the device 12 extends into the through hole of the ferrule 20. The guide ribs 17 on the outside of the cylindrical part of the device 12 engage with the inner surface of the through hole of the ferrule 20 thereby fixing the device 12 according to the invention on the ferrule 20. The base surface 13 touches the inner pipe wall and provides a sealed connection so that no resin may enter the space between the device and the inner pipe wall.