WO2021044171A1

WO2021044171A1 - Pipe inspection tool

Info

Publication number: WO2021044171A1
Application number: PCT/GB2020/052138
Authority: WO
Inventors: Robin HAUGE; Joe HALLEY
Original assignee: Doosan Babcock Limited
Priority date: 2019-09-06
Filing date: 2020-09-07
Publication date: 2021-03-11
Also published as: EP4025819A1; GB201912859D0

Abstract

Pipe inspection tool for inline inspection of a pipe or pipeline, having at least one inspection device (1) for inspecting the pipe or pipeline and drive means to move the pipe inspection tool inside the pipe or pipeline, the drive means comprising at least one wheel unit (21) with a main body (6) and at least a first and a second wheel (4) connected to said main body adapted to contact the inside wall of the pipe or pipeline, the main body being adapted to rotate with respect to the longitudinal axis of the pipe inspection tool to allow the wheels to rotate and thereby generate a force on the pipe or pipeline to move the inspection tool with respect to the pipe or pipeline, wherein the rotational axis of said at least one wheel is at an angle with respect to the longitudinal axis of the pipe inspection tool, to have, in use in a longitudinal section of the pipe or pipeline, the rotational axis of said at least one wheel at an angle with the longitudinal axis of the pipe or pipeline to generate, when rotating the wheel, a force on the pipe or pipeline in both the longitudinal direction and the radial direction thereof.

Description

Pipe Inspection Tool

Background of the Invention

The invention relates to a pipe inspection tool for inline inspection of a pipe or pipeline, having at least one inspection device for inspecting the pipe or pipeline and drive means to move the pipe inspection tool inside the pipe or pipeline, the drive means comprising at least one wheel unit with a main body and at least a first and a second wheel adapted to contact the inside wall of the pipe or pipeline.

The pipe inspection tool according to the invention is specifically adapted for in line inspection for pipework. In use, such a pipe inspection tool is inserted in the pipe work to be inspected and is navigated to the part of the pipework that needs inspection. Typically, a pipe inspection tool is provided with inspection tools for Non Destructive Testing (NDT) of pipework. These inspection devices include, for instance, cameras to allow visual inspection of the inside of the pipework. Other examples of inspection devices include the use of an air pump with inflatable bladders to perform non destructive leak testing.

In the prior art, pipe inspection tools are known that have the form of a ‘pig’. A pig is an inspection tool that typically is navigated through pipework by means of pneumatic or hydraulic pressure. The use of a pig includes, inserting of the pig into the pipework, for instance by means of a pig launcher or launching station. Thereafter, the pressure driven flow of product in the pipeline is used to push the pig down the pipe until it reaches the area of the pipework which needs inspection.

A disadvantage of the use of pigs is that when using fluid discharge to propel a pig through the pipework, it is very difficult to control the position of the device accurately, in particular, when travelling through vertical pipework sections. A further disadvantage of the use of fluid driven pigs is the fact that certainly not all pipework is adapted for navigating a pig through the pipework by means of fluid pressure.

It is a first objective of the invention to provide a tool inspection tool for inline inspection that is provided with drive means, to allow the pipe inspection tool to travel through pipework without the need of using fluid pressure for that purpose.

A further objective of the invention is to provide a pipe inspection tool that can be used, without any modification being need, in pipes with different internal diameters.

A further objective of the invention is to provide a tool inspection tool for inline inspection that is provided with drive means which allow the pipe inspection tool to navigate through pipeline obstacles such as T-junctions and bends.

A related further objective is to provide a tool inspection tool for inline inspection that is provided with drive means which allow the pipe inspection tool to avoid being stuck inside the pipework and which provide the possibility for the tool to rotate with respect to the pipe wherein the pipe inspection tool is used to improve the movability of the pipe inspection tool inside the pipework.

Yet a further objective of the invention is to provide a pipe inspection tool that is provided with an umbilical or tether with a reduced diameter to limit the restrictions that the presence of the umbilical or tether have on the overall movability of the pipe inspection tool through pipework.

Summary of the invention

According to a first aspect of the invention, the invention relates to a pipe inspection tool for inline inspection of a pipe or pipeline, having at least one inspection device for inspecting the pipe or pipeline and drive means to move the pipe inspection tool inside the pipe or pipeline, the drive means comprising at least one wheel unit with a main body and at least a first and a second wheel connected to said main body adapted to contact the inside wall of the pipe or pipeline, the main body being adapted to rotate with respect to the longitudinal axis of the pipe inspection tool to allow the wheels to rotate and thereby generate a force on the pipe or pipeline to move the inspection tool with respect to the pipe or pipeline, wherein the rotational axis of said at least one wheel is at an angle with respect to the longitudinal axis of the pipe inspection tool, to have, in use in a longitudinal section of the pipe or pipeline, the rotational axis of said at least one wheel at an angle with the longitudinal axis of the pipe or pipeline to generate, when rotating the wheel, a force on the pipe or pipeline in both the longitudinal direction and the radial direction thereof.

Brief description of the drawings

A possible embodiment of the invention will be described below, making reference to the drawings, wherein

Figure 1 is a schematic view of part of the pipe inspection tool according to the invention in a T-Junction of pipework,

Figure 2 is a detailed view of the front and of the pipe inspection tool according to the invention,

Figure 3 shows the connection of one wheel to a wheel unit for the inspection tool according to the present invention,

Figure 4 shows in three stages, the possibility of the tool according to the present invention, to change direction in the pipework,

Figure 5 shows a camera module for the pipe inspection tool according to the present invention, Figure 6 shows a leak detection module for the pipe inspection tool according to the present invention,

Figure 7 shows an umbilical carriage for an umbilical for the pipe inspection tool according to the present invention, and

Figure 8 shows schematically, the assembly of modules forming a pipe inspection tool according to the present invention.

Detailed description

The present invention relates to a pipe inspection tool. The pipe inspection tool according to the invention is specifically adapted for the inspection of pipework of thermal power plants, nuclear power plants and for the petrochemical industry. Therefore, the pipe inspection tool as described with reference to the embodiment shown in the attached drawings is intended to be capable of navigating through DN65 to DN40 pipework incorporating bends, T-Junctions, Reducing T Junctions, and reducers of these pipe sizes.

Furthermore, the pipe inspection tool is intended to be capable of navigating through up to 160m pipework length. Moreover, the pipe inspection tool is intended to be capable of performing a leak test between two inflatable bladders located on the inspection tool device, capable of visually inspecting the internal bore of the pipework with a resolution of 0.1mm, and capable of being navigated using a visualisation software system which accurately visualises the device location when navigating through a mock up test facility.

It should be understood however, that the specific drive means of the inspection tool could also advantageously be used for other types of pipe inspection devices.

Figure 1 shows part of a possible embodiment of the pipe inspection tool 1 of the invention, in a T-junction of pipework. The pipe inspection tool 1 comprises a first or front wheel unit 21 , which comprises a plurality of wheels 4 to contact the inside wall 40 of the pipework. The individual wheels 4 are pushed outwards by means of spring loaded arms 5, which are attached to the main body 6 of the wheel unit 21. In use, the main body 6 rotates around the longitudinal axis of the pipe inspection tool 1 , wherein the combination of the spring loaded arms 5 and the wheels 4 are used to exert a force on the inside wall 40 of the pipe work to move the pipe inspection tool 1 through the pipework to a determined destination. Further details of the wheel unit 21 will be described with reference to figure 2.

The wheel unit 21 is attached to the forward end of a first tubular element 31. This first tubular element 31 forms the external structure of the pipe inspection tool 1. The subsequent tubular elements 31 , 32,., 39 (see figure 8) of the pipe inspection tool 1 will connect the various modules that form the pipe inspection tool 1 , and act as a central conduit for routing the cabling and hoses for all systems present in the tool 1.

For the tubular elements 31 - 39 corrugated stainless steel tube is used to provide a balance between flexibility and structural integrity for the pipe inspection tool 1. Due to the presence of the corrugated surface of the tubular elements 31 - 39, the tubular elements 31 - 39 can comfortably navigate tight bends and return to its straight resting orientation without deforming. This means that the corrugated stainless steel tubular elements 31 - 39 are able to deflect in any direction making the navigation and retrieval of the pipe inspection tool 1 easier and the tool less likely to get jammed or stuck during the navigation and retrieval. Despite the flexibility of the tubular elements 31 - 39 in their longitudinal direction, the tubular elements 31 - 39 will be torsion resistant in their radial direction.

As shown in Figure 1 , the trailing end of the first tubular element 31 is connected to a linear actuator 10. The linear actuator 10 is used to manipulate the forward end of the first tubular element 31 comprising the wheel unit 2 to navigate through T-junctions and bends. The linear actuator 10 will actuate a cable present inside the pipe inspection tool 1 that is attached to a lever which will manipulate the orientation of the wheel unit 21 , at the forward end of the tubular element 31. The specific functioning of the linear actuator will be described in more detail with reference to figure 4.

Figures 2 and 3 show in detail the wheel unit for moving the pipe inspection tool 1 inside the pipe or pipeline and the functioning of said wheel unit.

Figure 2 shows in detail front wheel unit 21 , in a perspective view. The wheel unit 21 comprises a main body 6 which has essentially a triangular shape. The main body 6 is adapted to be positioned in the centre of a pipe during movement of the pipe inspection tool 1 through pipework. The forward facing surface of the wheel unit 21 is provided with a camera 15 for obtaining images which help the manoeuvring of the tool 1 through pipe work.

The wheel unit 21 further comprises three wheels 4, which each have the form of a sphere. The wheels 4 are connected to the main body of the wheel unit 21 by means of spring loaded arms 5. These arms 5 are connected with a first end to the main body and can be moved in the direction of the main body 6 against the force of a spring. The springs are adapted to force the wheels 4 outwards, with constant force. The second end of the arms 5 is provided with a rotational axis to allow the wheels 4 to rotate with respect to the arms 5.

The main body 6 of the wheel unit 21 is adapted to rotate around the longitudinal axis of the pipe inspection tool 1. For this purpose the wheel unit comprises an electrical motor, in particular a DC motor. Since the arms 5 are connected to the main body 6, the arms 5 and the connected wheels 4 will follow the rotation of the main body 6. Because of the spring loaded arms 5, the wheels 4 will be forced against the inside wall 40 of the pipe in which the inspection tool is inserted (see figure 1). This means that if the wheels 4 are rotated using the electrical motor, the wheels 4 will exert a force against the inside wall 40 of the pipe. As shown in figure 3, the rotational axis for the wheels 4 are at an angle of 45° with respect to the longitudinal axis L of the pipe inspection tool 1.

A first technical effect of the above mentioned features is that the pipe inspection tool 1 according to the invention can be used for inspecting pipework with different diameters. After insertion of the tool 1 in the concerned pipe, the wheels 4 of the wheel unit 21 will move outwards and therefore the tool 1 will adapt to the specific internal diameter of the pipe to be inspected.

A second technical effect of the mentioned features is that once the pipe inspection tool 1 is inserted in a pipe and the wheels 4 are rotated, the force exerted on the pipe wall 40 is directed in a direction transverse to the rotational axis of the wheels. This is schematically shown in figure 3. In other words, the force exerted by the wheels 4 on the inside wall of the pipe will be at an angle of 45° with respect to the centre line of the pipe. This means that the force exerted on the inside wall, will have a first component FI in the longitudinal direction of the pipe and a second component Fr in the radial direction of the pipe.

With reference to figures 2 and 8, it is noted that in the example of the drawings, the pipe inspection tool 1 comprises in total four wheel units 21-24: one at either end of the pipe inspection tool (wheel units 21 and 24), and two intermediate wheel units 22 and 23.

The adjacent wheel units 21 , 22 and 23, 24 will be mirrored so that they rotate in opposite directions with respect to the longitudinal axis of the pipe inspection tool 1. This means, for instance for the wheel units 21 and 22, that when the wheels 4 are rotated, the longitudinal component FI of the force exerted on the inside wall of the pipe by means of the wheels 4 of wheel unit 21 will be directed in the same direction as the longitudinal component FI of the force exerted on the inside wall of the pipe by means of the wheels 4 of wheel unit 22. However, the respective, the longitudinal component FI of the force exerted on the inside wall of the pipe will be opposite for the wheel units 21 , 22. This means that as a result, the tool 1 will move inside the pipe, but not rotate with respect to the pipe. The opposite directed radial component Fr exerted by both wheel units 21, 22 will generate a torsional load on the pipeline inspection tool 1. This is not a problem, in view of the fact that the pipeline inspection tool 1 comprises an assembly of corrugated tubular elements 31 - 39 which are torsion resistant.

The assembly of wheel units 21 - 24 can selectively be used to move the pipe inspection tool 1 through a pipe, along the longitudinal axis of the pipe and, if needed, to rotate the pipe inspection tool 1 with respect to the pipe, without any rotational limitation. If the wheel units 21 - 24 are rotated in a first direction to have the longitudinal component FI of the force exerted on the inside wall of the pipe in the same direction and to have the radial component Fr of the wheel units neutralised, the pipe inspection tool 1 will not rotate and move a first direction within the pipe. Reversing the direction of rotation of the wheels will propel the tool 1 in the opposite direction in the pipe.

Rotating the wheels 4 to have the radial component Fr of the force exerted on the inside wall of the pipe in the same direction will cause the pipe inspection tool 1 tool to rotate with respect to the tool. This means that the user, by controlling the rotation of the wheels 4, can choose between: moving the tool 1 within the pipe, rotating the tool within the pipe or move and rotate the tool 1 at the same time. This feature is important for both navigation and inspection purposes.

A further advantage of using the wheel units 21 - 24 is that, as the point of rotation is at the centre of the pipe, the motor size can be maximised to ensure that the largest motor size that could fit within the pipework can be utilised. This ensures that the maximum propulsion power can be achieved, in view of the internal diameter of the pipe for which the tool is adapted.

It should be noted that when not being driven in the forwards or backwards direction the assembly of the wheels and the DC motor will act as a break and maintain the inspection device in a stationary location, including when traversing vertical pipework. It should be noted that in figures 2 and 3 wheels 4 are shown, which have the form of a sphere. It is possible to use other shapes and forms for the wheels 4. For instance, the wheels 4 could essentially have the form of a flat element, having an external spherical contact surface. This shape would allow for a shorter rotational axis for the wheels 4, which could decrease the width of the spring loaded arms 5.

In the example of figure 2 and 3, the angle of 45° between the rotational axis for the wheel 4 and the longitudinal axis L of the pipe inspection tool 1 is present between the second end of the spring loaded arms 5 and the wheels 4. In an alternative embodiment, not shown in the figures, the angle of 45° between the rotational axis for the wheel 4 and the longitudinal axis L of the pipe inspection tool 1 could be present between the first end of the spring loaded arms 5 and the main body 6 of the wheel units 21 - 24. A combination of angular inclinations at both ends of the spring loaded arms 5 could also be used to obtain the same result.

In the example of figures 2 and 3, each wheel unit 21 - 24, comprises three wheels 4. The skilled person will realize that it would be possible to provide some of the wheel units, or alternatively, each wheel unit 21 - 24 with a different number of arms 5 and wheels 4. Each wheel unit 21 -24 should at least comprise two wheels 4 and could have, for instance, two, three, four or even more wheels 4.

In the example of figure 2 and 3, each of the wheels is at an angle of 45° between the rotational axis for the wheel 4 and the longitudinal axis L of the pipe inspection tool 1. The skilled person will realize that it would be possible to orient some of the wheels, or alternatively, each wheel 4 at an alternative angle. Each of the wheels 4 should have its rotational axis preferably at an angle between 5° - 45° with respect to the longitudinal axis L of the pipe inspection tool 1. For completeness, it is noted that the referred angles in the present text refer to the smallest angles defined between the rotational axis of the wheels 4 and the longitudinal axis of the pipe inspection tool 1. and/or the pipe or pipeline in which the pipe inspection tool 1 is inserted.

In figure 4 the subsequent stages of the pipe inspection tool 1 navigating through a T-junction are shown. In first instance, as shown in figure 4a, the pipe inspection tool 1 moves forwards through the horizontally positioned pipe 41 until the forward end of the pipe inspection tool 1 arrives at the entrance of the vertically positioned pipe 42.

Thereafter, the linear actuator 10 is used to manipulate the forward end of the first tubular element 31 comprising the wheel unit 21 to allow the forward end to enter the vertically positioned pipe 42. This is shown in figure 4b.

As explained above, with reference to figures 2 and 3, rotating the subsequent wheel units 21 in the same direction will cause the pipe inspection tool 1 to rotate and therefore be able to rotate the angle of direction of the front wheel unit 21 towards any bends or through T-Junctions. The linear actuator 10 will be actuated by the pipe inspection tool 1 operator by viewing the visual images of the front camera 15 of the front wheel unit 21 and manipulating the bend of the front wheel assembly 21 as required. The ability to rotate the pipe inspection tool 1 through 360° with respect to the pipe 41 , 42 wherein the pipe inspection tool is deployed, will allow navigation in any direction.

One the forward end of the pipe inspection tool 1 has entered the vertically positioned pipe 71 , the pipe inspection tool 1 can continue to move forward in a linear direction towards a determined destination. This is shown in figure 4c.

It should be noted that linear actuators, such as the linear actuator 10 according to figure 1 , offer both push and pull functions and can accurately control the orientation of the forward end of the pipe inspection tool 1. This will ensure fast and accurate navigation through bends and T-Junctions. With reference to specifically figures 5 and 8, the pipe inspection tool 1 according to the example of figures 1-8 further comprises a camera module 50, with an inspection camera 51 which is used in combination with a mirror 52.

As shown in figures 5 and 8, the camera module 50 is attached in between the corrugated tubular elements 33 and 34. The camera 51 is typically a COTS CMOS camera. The mirror is typically positioned with a 45° angle with respect to the direction of travel of the pipe inspection tool 1.

The camera module 50 allows for visual inspection of the internal surface of the pipe which is inspected. The camera module 50 will further comprise a linear actuator (not visible in figure 5) which is used to manipulate the distance from the front of the camera lens to the mirror to ensure that the camera can be focussed to the pipe internal bore surface across the various pipe diameters and as noted above.

With reference to figures 2 and 3 it is noted that rotating the wheel units 21 - 24 in the same direction will cause the pipe inspection tool 1 to rotate and therefore be able to record visual inspection of the internal pipe surface through 360°.

LED lights will be suitably located on the camera module 50 to provide the required light level for the camera 51.

In an alternative embodiment, not shown in the drawings, a Contact Image Sensor array is used, like to the devices used in document scanners. A short linear array in contact with the pipe could capture a ring shaped area of the pipe internal surface by the pipe inspection tool 1 being commanded to rotate without translating.

Further overview cameras will be installed along the length of the pipe inspection tool 1 such as the camera 15 in the front wheel unit 21. Similar cameras (not shown in the drawings) will be provided in the rear end of the pipe inspection tool 1 inspection and additional positions if needed to form inspection volume oversight cameras to support navigation and for aligning the device to welds and T-Junctions in the pipework to be inspected.

With reference to specifically figures 6 and 8, the pipe inspection tool 1 according to the example of figures 1-8 further comprises a leak test module 60, with a local air pump 61 , which cooperates with bladder seals 62 and 63, positioned at a distance from the leak test module 60, at opposite ends thereof.

As shown in figures 6 and 8, the leak test module 60 is attached in between the corrugated tubular elements 36 and 37. The camera bladder seals 62 and 63 are respectively positioned in between corrugated tubular elements 35-36 and 37-38.

A local air pump 61 is used to inflate the inflatable bladder seals 62 and 63, at selected positions to perform leak testing of the concerned pipe length. The presence of the local air pump 61 removes the need to run air hoses in the umbilical, reducing the size of the umbilical and removing the risk of hoses snagging on bends and reducing the flow rate of the air hoses.

The local air pump 61 is used to inflate the seals 62 and 63 and to pressurise the volume between the bladders 62, 63. The leak test module 60 will further comprise absolute pressure sensors (not shown in the drawings) which will be located within the pressurised volume between the bladders 62 and 63 and will be utilised to monitor the pressure in this volume and allow a pressure decay test to be performed to determine if leaks are present within the volume between the bladders 62, 63.

It is further noted that the inflatable seals 62, 63 can also be used as a friction brake to hold the whole pipe inspection tool 1 in place.

To facilitate the combined power and control of the pipe inspection tool 10, the device comprises multiple microcontrollers which are distributed around the pipe inspection tool 10 to power and control all the electrical motors inside the tool, the air pump, solenoid valves, the oversight cameras, the inspection camera and the mirror. The microprocessors that are used for this purpose are for instance Raspberry Pi Zero Linear Actuators.

To provide power and control data for microcontrollers, Ethernet cables are used. The technical effect of these measures is that utilising local microcomputers removes the need for instrumentation and control cables from the umbilical. This means that the actual size of the umbilical can be reduced.

The advantage of having an umbilical with a reduced size is that the navigation and retrieval of the pipe inspection tool can be improved. In practise, when a large umbilical is travelling though several bends, the navigation and retrieval of the attached pipe inspection tool becomes extremely difficult. Therefore, the umbilical should be minimised as far as reasonably practicable. In addition, running hoses the length of the umbilical would likely result in snagging and reduced flow rate in the hoses.

In order to further improve the navigation of the pipe inspection tool 10, according to the invention, additional DC motors and wheel units are proposed to be located along the length of the pipe inspection tool tether/umbilical to assist with the transportation of said umbilical/tether. A possible embodiment of an additional umbilical carriage is shown in figure 7.

Figure 7 shows an umbilical carriage 70 comprising a front wheel unit 71 and a rear wheel unit 72. Both wheel units are attached to the opposite ends of a corrugated tubular element 73. In the centre thereof, the carriage 70 further comprises a support element 74 to support and guide the load of the carriage 70 during movement of the carriage 70 through the pipe. The wheel units 71 and 71 are similar in build up and functioning as the wheel units 21-24 of the pipe inspection tool 1 , described with reference to figures 2 and 3. The corrugated tubular element 73 is similar to the tubular elements 31 - 39 used for the pipe inspection tool 1, as described with reference to figure 1. The carriage 70 comprises a DC motor for driving the wheels of the wheel units 71 and 72. The DC motor for each individual carriage 70 will be linked to the control of the lead motor, provided in the tool inspection device 1. This to ensure that the travel of each motor is the same and the distance travelled by the tool inspection tool 1 and each of the carriages 70 is the same.

Additional carriages can be added with fixed distances between subsequent carriages 70. For instance, an additional carriage could be added every five meters of umbilical.

At the end of an intervention with the pipe inspection tool 1 , the tool 1 will have to be removed from the pipe work. The standard method for retrieval of the pipe inspection tool 1 will be to utilise the wheel units 21 - 24 and motors to power the tool 1 out of the pipework. It is noted that when reversing the direction of rotation of the wheels 4, the direction of travel will be reversed.

A back-up retrieval method, in the event of a fault or power failure with the wheel units 21 - 24, is to utilise a cable, such as a Kevlar® cable, and winch to retrieve the device. The cable will be attached to the pipe inspection tool 1 , running the full length of the umbilical/tether. The power to the motor being turned off or cut will result in the motors being free to rotate and therefore, the wheels 4 of the different wheel units 21 -24 can rotate. This will avoid the wheels continuing to operate as brakes. Since the wheel can freely rotate, the pipe inspection tool 1 will rotate out of the pipework when tension is applied to the cable.

Figure 8 shows a schematic overview of a possible embodiment of the pipe inspection tool according to the invention. The pipe inspection tool 1 comprises subsequently (from left to right in figure 8):

A front wheel assembly 21 , a corrugated tubular element 31 , a linear actuator 10, a corrugated tubular element 32, a second wheel assembly 22, a corrugated tubular element 33, a camera module 50, a corrugated tubular element 34, a third wheel assembly 23, a corrugated tubular element 35, a first bladder seal 62, a corrugated tubular element 36, a leak test unit 60, a corrugated tubular element 37, a second bladder seal 63, a corrugated tubular element 38, a forth wheel unit 24, a corrugated tubular element 39, and a first umbilical carrier 70.

Claims

1. Pipe inspection tool for inline inspection of a pipe or pipeline, having at least one inspection device for inspecting the pipe or pipeline and drive means to move the pipe inspection tool inside the pipe or pipeline, the drive means comprising at least one wheel unit with a main body and at least a first and a second wheel connected to said main body adapted to contact the inside wall of the pipe or pipeline, the main body being adapted to rotate with respect to the longitudinal axis of the pipe inspection tool to allow the wheels to rotate and thereby generate a force on the pipe or pipeline to move the inspection tool with respect to the pipe or pipeline, wherein the rotational axis of said at least one wheel is at an angle with respect to the longitudinal axis of the pipe inspection tool, to have, in use in a longitudinal section of the pipe or pipeline, the rotational axis of said at least one wheel at an angle with the longitudinal axis of the pipe or pipeline to generate, when rotating the wheel, a force on the pipe or pipeline in both the longitudinal direction and the radial direction thereof.

2. Pipe inspection tool according to claim 1 , wherein the rotational axis of the at least one wheel is at an angle with respect to the longitudinal axis of the pipe inspection tool, to have in use in a longitudinal section of the pipe or pipeline, the rotational axis of the at least one wheel at an angle with the longitudinal axis of the pipe or pipeline between 5° and 45°.

3. Pipe inspection tool according to claim 1 or 2, wherein the rotational axis of the at least one driven wheel is at an angle with respect to the longitudinal axis of the pipe inspection tool between 5° and 45°.

4. Pipe inspection tool according to claim 1 , 2 or 3, wherein the at least first and second wheels are connected to the main body of the wheel unit by means of spring loaded arms to urge the wheels outwards.

5. Pipe inspection tool according to claim 4, wherein the spring loaded arms are connected with a first end thereof to the main body of the wheel unit, the wheels being connected to the second end of the spring loaded arms.

6. Pipe inspection tool according to claim any of the preceding claims, wherein the at least one wheel unit comprises three wheels adapted to contact the inside wall of the pipe or pipeline.

7. Pipe inspection tool according to any of the preceding claims, wherein the rotational axis of each of the wheels is at an angle with respect to the longitudinal axis of the pipe inspection tool, to have in use in a longitudinal section of the pipe or pipeline, the rotational axis of each driven wheel at an angle with the longitudinal axis of the pipe or pipeline between 5° and 45°.

8. Pipe inspection tool according to one of the preceding claims, wherein the pipe inspection tool comprises at least a first and a second wheel unit, each unit comprising at least one wheel with a rotational axis at an angle with respect to the longitudinal axis of the pipe inspection tool to have, in use in a longitudinal section of the pipe or pipeline, the rotational axis of the at least one wheel at an angle with the longitudinal axis of the pipe or pipeline to generate, when rotating the driven wheel, a force on the pipe or pipeline in both the longitudinal direction and the radial direction thereof, the configuration of the first wheel unit and the second wheel unit being mirrored, to have the radial forces generated by the first and the second wheel unit acting in opposite directions, when generating with the first and second unit longitudinal forces in the same direction.

9. Pipeline inspection tool according to any of the preceding claims, wherein the contact surface of the wheels adapted to contact the inside wall of the pipe or pipeline has a spherical shape.

10. Pipeline inspection tool according to claim 9, wherein the wheels are ball shaped.

11. Pipe inspection tool according to any of the preceding claims, wherein at least part of the pipe inspection tool comprises a tubular section, the tubular section comprising a torsion resistant corrugated tube.

12. Pipe inspection tool, according to claim 11 , wherein the pipe inspection tool comprises, in its longitudinal direction, a plurality of modules, wherein adjacent modules are connected by means of a torsion resistant corrugated tube.

13. Pipe inspection tool according to any of the preceding claims, wherein the at least one inspection device for inspecting the pipe or pipeline comprises a camera inspection device.

14. Pipe inspection tool according to any of the preceding claims, wherein the at least one inspection device for inspecting the pipe or pipeline comprises a leak test device.