FIELD OF THE INVENTION

The field of the invention relates to a self-propelling pipe maintenance device and method.

BACKGROUND

Maintaining pipes in systems such as vacuum or abatement systems can be challenging. This is particularly so, where there are large pressure differences between the exterior and interior of a pipe and where a pipe is transporting hazardous or noxious fluids. Furthermore, where the network of pipes is complex and involves joints and bends, there may be places where deposits build up and where leaks may occur that are difficult to access in a conventional manner. This makes both the diagnosis and alleviation of issues difficult.

It would be desirable to provide a pipe maintenance device that is able to access different locations along the interior of a pipe network.

SUMMARY

A first aspect provides a self-propelling pipe maintenance device comprising: a self-propelling portion comprising two gripping elements separated by a propelling element; said two gripping elements each comprising a radially expandable body configured when pressurised to move between a radially compact state and a radially expanded state; said propelling element comprising a longitudinally expandable body configured when pressurised to move between a longitudinally compact state and a longitudinally expanded state; and a pressure control apparatus configured to independently control a pressure within each of said expandable bodies to enable movement of said self-propelling device along a pipe.

Maintaining pipes within vacuum or abatement systems where hazardous and/or noxious fluids, which may contain particles, liable to be deposited on surfaces and which may be transported at low pressures can be challenging. Providing a self-propelling device able to use pneumatic power to propel itself along the interior of a pipe network allows the different parts of the pipe network to be accessed, monitored and/or cleaned. The self-propelling devices uses multiple expandable bodies that are controllably and independently linked to a reduced or increased pressure source. This allows the device to propel itself by sequencing the expansion or contraction of the expandable bodies by linking them to the appropriate pressure source.

The device is formed of gripping elements that have expandable bodies that are configured under increased pressure to expand in the radial direction and thus, grip the interior surface of the pipework and anchor that portion of the device in position. There is also a longitudinally expandable body that acts as a propelling element and when expanded pushes the two gripping elements apart. In this way be sequential anchoring of the respective gripping elements and expanding and contracting of the propelling element the device can be propelled along the pipework.

It should be noted that although this device is suitable for cleaning and/or monitoring any type of pipework, it is particularly applicable to a shared vacuum and abatement system, where the vacuum manifolds may be longer than 50m and comprised of multiple sections, making their maintenance onerous.

In some embodiments, said pressure control apparatus comprises a plurality of fluid transfer channels for independently supplying fluid received at a plurality of ports to each of said expandable bodies.

The pressure within the respective expandible bodies may be controlled by supplying fluid received at a plurality of ports to the respective expandable body along fluid transfer channels. In this way, the pressure in the respective expandible bodies is controlled without the need for complex control circuitry or active devices within the self-propelling portion of the maintenance device. The pressure control apparatus is linked to the self-propelling portion of the device via tubes and remains external to the pipe.

In some embodiments, said plurality of ports are located on an end surface of said self-propelling maintenance device.

It may be convenient to locate the ports at one end of the pipe maintenance device allowing pneumatic tubing to be connected to this end and follow the device along the pipework. This end may be an end of one of the gripping elements.

In some embodiments, said pressure control apparatus comprises a plurality of controllable valves, a high pressure source and a low pressure source, said pressure control apparatus being configured to selectively couple one of said high pressure or low pressure sources to respective ones of said plurality of ports.

The control of the movement of the self-propelling pipe maintenance device may be done at a pressure control apparatus external to the pipework and configured to supply the lower or higher pressure fluid to a respective expandible body. In some embodiments the higher pressure source is a compressor and the lower pressure source a vacuum pump.

In some embodiments, said pressure control apparatus is configured to isolate a section of pipe between said two gripping elements such that said section may be tested for leaks, by increasing a pressure within each of said radially expanding bodies.

Although the gripping elements may be individually expanded to grip the pipe to enable movement of the device along the pipework, in some cases they may both be expanded and in this arrangement a section of pipe between the gripping elements is sealed from the other pipework by the expandible bodies. This allows the portion between these bodies to be independently manipulated and leak tests to be performed.

In some embodiments, said pressure control apparatus comprises a fluid flow path linking a port in an exterior surface of said pipe maintenance device between said two gripping elements and said pressure control apparatus, said pressure control apparatus being configured once said section of said pipe has been isolated to decrease a pressure within said fluid flow path such that said pressure within said isolated section of said pipe is decreased; said pipe maintenance device further comprising a gas sensor in fluid communication with said fluid flow path.

Following isolation of the section of the pipe to be leak tested the pressure in a fluid flow path that provides fluid communication between the isolated section of the pipe and the pressure control apparatus may be decreased perhaps by connecting a lower pressure source such as a vacuum pump to the fluid flow path. This allows fluid within the isolated section of pipe to be sucked through the path towards the lower pressure source.

In some embodiments the device further comprises a gas sensor in fluid communication with this fluid flow path this gas sensor being sensitive to a gas that can be used in a leak test. This may be an inert gas such as helium or nitrogen that is applied to the environment surrounding the exterior of the pipe the gas sensor being able to detect trace amounts of such a gas and therefore able to determine whether there is a leak in the section of the pipe that has been isolated. In this regard, the section of the pipe that may be isolated in a leak test may be a section with a joint in it or it may be a section where a monitoring device such as a camera carried by the self propelling pipe maintenance device has detected a flaw. This allows the port to be sealed externally to the device when a leak test is not being performed. In other embodiments, said pressure control apparatus comprises a fluid flow path linking a port in an exterior surface of said pipe maintenance device between said two gripping elements and said pressure control apparatus; and said pressure control apparatus comprises a source of leak test gas, said pressure control apparatus being configured once said section of said pipe has been isolated to couple said leak test gas source to said fluid flow path such that said leak test gas is supplied to said isolated section of pipe.

In some cases rather than detecting a leak from the exterior of the pipe to the interior the pressure control apparatus may have a source of the leak test gas and it may be configured to connect this to the longitudinally expandable element and open the port such that the isolated section of pipe fills with the leak test gas. In this case, a gas sensor exterior to the pipe will detect any trace quantities of this leak test gas and determine whether or not there is a leak.

In both of the leak test examples, the port in the device is coupled or isolated from an external pressure source or leak test gas source by valves in the pressure control apparatus which is coupled to the self-propelling portion of the device and located externally to the pipe being tested. This avoids the valves being within the often harsh environment of the pipe and protects the valves and prolongs the lifetime of the device.

In some embodiments, said self propelling pipe maintenance device further comprises a pipe surface cleaning element extending from said self-propelling device and configured to contact an inner surface of said pipe, such that said cleaning element moves along said inner surface with movement of said device.

The self-propelling pipe maintenance device may also be used to clean sections of the pipes. In this regard, it may have a cleaning element such as a brush or a scraper attached to an outer surface and configured to move along the interior surface of the pipe with the device. This allows the self-propelling device to remove debris from particles in the fluid being transported by the pipes that may have deposited on the interior surfaces of the pipes.

In some embodiments, said self-propelling pipe maintenance device further comprises a particulate removal device in proximity to said cleaning element.

In addition to removing deposits from the interior surface of the pipe, the self- propelling pipe maintenance device may be configured to in effect vacuum up the particulate matter by connecting a particulate removal device in proximity to the cleaning element. The particulate removal device may be coupled to a lower pressure source and comprises a filter mechanism, such that fluid is sucked into the particulate removal device and the particulates collected by the filter.

In some embodiments, said pressure control apparatus is configured to cause oscillating movement of said cleaning device by periodically pressurising and de pressurising said longitudinally expandable body.

In order to aid the cleaning process, in some cases an oscillating movement may be imparted to at least a portion of the device that holds the cleaning element. This may be done by anchoring the device with one of the gripping elements and expanding and contracting the longitudinally expandible body thereby making the cleaning element move to and fro along a particular portion of the pipe.

In some embodiments, said pressure control apparatus is configured to enable movement of said self-propelling device along said pipe by: increasing a pressure in said radially expandable body of one of said gripping elements such that said radially expandable body moves to said radially expanded state where said body contacts and grips an interior of said pipe, while maintaining a lower pressure in the radially expandable body of the other of said gripping elements; increasing a pressure in said longitudinally expandable body of said propelling element such that said propelling element moves to said longitudinally expanded state thereby propelling said other of said gripping elements along said pipe; increasing a pressure in said radially expandable body of said other of said gripping elements such that said radially expandable body moves to said radially expanded state where said body contacts and grips an interior of said pipe, and reducing a pressure in the radially expandable body of said one of said gripping elements such that said one of said gripping elements is free to move along the pipe; and decreasing a pressure in said longitudinally expandable body of said propelling element such that said propelling element moves to said longitudinally compact state thereby propelling said one of said gripping elements along said pipe.

The arrangement of three or more expandible bodies, two of them radially expandible and operable to grip an interior surface of the pipe and a central expandible body that is longitudinally extendable and able to vary a distance between the two gripping elements enables with appropriate sequencing of the expansion and contraction of these bodies, the device to propel itself along the pipework.

In some embodiments, said self-propelling device comprises a mount for mounting a camera and a light.

Having a self-propelling device that is able to move along the interior of pipework enables different portions of the interior of the pipework to be accessed and in some cases, a camera and a light may be mounted on the device such that a remote inspection of the interior of the pipework can occur.

In some embodiments, said two gripping elements comprise substantially rigid end elements separated by said radially expandable body and a bendable elongate member.

The two gripping elements may be formed of radially expandible bodies and an elongate member. The elongate member holds the two gripping elements longitudinally at a particular distance from each other such that expansion of the expandible body is constrained to a radial direction. The elongate member is flexible in a direction perpendicular to its length but resists stretching or compression so that it maintains a distance between the two rigid elements and yet can bend allowing the device to travel around the contours within the pipe network.

In some embodiments, said two gripping elements comprise substantially rigid end elements, said substantially rigid end elements comprising an outer envelope, at least a portion of said outer envelope being spherical.

Having an outer envelope of the substantially rigid elements that is at least partially spherical also helps enable movement along a curved and complex pipework.

In some embodiments, said rigid end elements each comprise a truncated sphere.

A second aspect provides a method of propelling a pipe maintenance device according to any preceding claim along a pipe, said method comprising: increasing a pressure in said radially expandable body of one of said gripping elements such that said radially expandable body moves to said radially expanded state where said body contacts and grips an interior of said pipe, while maintaining a lower pressure in the radially expandable body of the other of said gripping elements; increasing a pressure in said longitudinally expandable body of said propelling element such that said propelling element moves to said longitudinally expanded state thereby propelling said other of said gripping elements along said pipe; increasing a pressure in said radially expandable body of said other of said gripping elements such that said radially expandable body moves to said radially expanded state where said body contacts and grips an interior of said pipe, and reducing a pressure in the radially expandable body of said one of said gripping elements such that said one of said gripping elements is free to move along the pipe; and decreasing a pressure in said longitudinally expandable body of said propelling element such that said propelling element moves to said longitudinally compact state thereby propelling said one of said gripping elements along said pipe.

Further particular and preferred aspects are set out in the accompanying independent and dependent claims. Features of the dependent claims may be combined with features of the independent claims as appropriate, and in combinations other than those explicitly set out in the claims.

Where an apparatus feature is described as being operable to provide a function, it will be appreciated that this includes an apparatus feature which provides that function or which is adapted or configured to provide that function.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described further, with reference to the accompanying drawings, in which:

Figure 1 shows an isometric view of a pipe maintenance device according to an embodiment;

Figure 2 shows a side view of the pipe maintenance device;

Figure 3 shows a cross section through the pipe maintenance device with the fluid transfer channels shown;

Figure 4 schematically shows the pipe maintenance device and pressure control apparatus associated with it according to an embodiment;

Figure 5 shows a flow diagram illustrating steps of a method according to an embodiment; and

Figures 6 and 7 show a pipe maintenance device with a camera and light module at one end and with a cleaning mechanism attached. DESCRIPTION OF THE EMBODIMENTS

Before discussing the embodiments in any more detail, first an overview will be provided.

A device for monitoring, cleaning and/or leak checking pipes is provided. The device is self-propelling. The propulsion is provided by two or more inflatable bladders that can be inflated to grip the internal surface of the pipe. Appropriate sequencing of the inflation and evacuation process of the bladders along with increasing and decreasing the distance between the bladders by evacuating or pressurising a flexible longitudinally expandable element, allows the device to move along the pipes. The pipes include but are not limited to those used for vacuum and abatement systems e.g. vacuum forelines and pump exhaust lines. The device may also provide support for supplying a leak test gas, in some cases an inert gas, in some cases helium, to the inside of the pipes to enable outboard leak checking. Alternatively inboard leak testing may be performed by evacuating a sealed portion of the pipe and applying the leak test gas to the outside and checking for any of the leak test gas inside the pipe.

Figure 1 shows an isometric view of a pipe maintenance device according to an embodiment. The pipe maintenance device comprises two gripping elements 10 comprised of rounded substantially rigid elements 1 separated by radially expandable bodies in the form of inflatable bladders 12 which expand in the radial direction when pressurised such that they can grip and seal to the pipe that they are within.

The end of the device comprises a plurality of ports 20 in this case 3 which are connectable to high and/or pressure sources and comprise fluid transfer channels for connecting to the inflatable bladders 12 and the longitudinally expandable propelling section 6, which in this embodiment comprises flexible longitudinally expandable element. Each of these expandable bodies can be individually pressurised or depressurised to control their configuration. In that regard, when pressurised the inflatable bladders 12 expand radially and grip the pipe, while the longitudinally expandable element 6 expands longitudinally pushing the two gripping elements apart.

In this embodiment, the front rigid element 1 is a truncated sphere the curved surface easing its progress around corners. The truncated sphere has a lip at the end not shown on which the inflatable bladder 12 fits and is held in position by a tie shown schematically as 11. In this embodiment, the left-hand side of the figure shows bladder 12 in an unpressurised deflated state such that this portion of the device is free to move within the pipe. The right-hand portion 12 is inflated and will grip the interior of the pipe allowing the longitudinally expandable section 6 to push the front of the device along the pipe when inflated, while the rear of the device is held in place. Once the expandable device 6 is fully expanded the bladder 12 of the front gripping section may be inflated and grip the pipe and the rear gripping section 10 may be deflated and deflation of the longitudinally expandable element 6 will then pull the rear section along the pipe. The procedure may then be repeated.

There are ports 20 on the end portion of the pipe maintenance device and these may be connected to controllable pressure sources. Each port 20 is in fluid communication via fluid transfer passages with a different one of the expandable bodies. The two fluid transfer passages that link to the longitudinally expandable element 6 and second inflatable bladder 12 may comprise flexible pipes that pass through the first inflatable bladder 12. The passage to the second inflatable bladder 12 may be a flexible pipe (see Figure 3) that travels around the longitudinally expandable element 6 between the two ports 22.

Figure 2 shows a side view of the pipe maintenance device according to an embodiment with the right-hand inflatable body 12 inflated.

Figure 3 shows a section through the device of Figure 2 through the lines A to A. From Figure 3 it can be seen that the two truncated spheres of the gripping elements 10 are held together by an elongate member 14 which elongate member is flexible in the lateral direction but is not easy to stretch or compress and thus, holds the two truncated spheres 1 at a set distance from each other. This means that inflation of the expandible body or bladder 12 does not push the two truncated spheres 1 away from each other but rather pushes the bladder radially outwards towards the walls of the pipe. The inflatable bladder 12 will then contact the wall and seal with it.

This embodiment shows the lips at the edge of the truncated spheres which hold the edge of the inflatable body 12 and may be held in place using a fixing mechanism such as a cable tie 11. The longitudinally expandible member 6 may have a number of forms provided that expansion in the radial direction is inhibited while expansion in the longitudinal direction is allowed.

The arrangement of the curved truncated spheres 1 , the bladders 12 and flexible elongate member 14 along with the flexible longitudinally expanding member 6 allows for the self-propelling pipe maintenance device to flex along the longitudinal direction and follow the bends and curves of a complex pipe network system.

This cross section also shows how two of the ports 20 are linked via channels 23, 24 within the truncated spheres and flexible pipes 26 that are within the inflatable bladder 12 and adjacent to the flexible longitudinally expandable element 6 to their respective expandable bodies. There is a further channel not shown that links the third port 20 to the right-hand inflatable bladder 12. This provides the independent control of the state of inflation of these respective bodies by the coupling of the appropriate pressure source to the respective port 20. Although three ports 20 are shown in this figure to provide independent channels to each of the expandable bodies, in some embodiments there may be a further port 20 that is coupled via fluid transfer channels to a port in an exterior of the pipe maintenance device between the gripping elements and may be used for leak testing, this is shown in more detail in Figure 7.

In some embodiments there may be a brush or scraping mechanism arranged around an exterior portion of the device such that it scrapes along the interior surface of the pipe as the self-propelling pipe maintenance device travels along the pipe. This may be in association with some evacuating and filtering mechanism to remove the particulates that are scraped from the pipe. This is shown in more detail in Figures 6 and 7.

Figure 4 schematically shows the pressure control apparatus that may be used for controlling the pressure and thus, the state of the various expandible bodies within the self-propelling pipe maintenance device. In this example, there is a vacuum pump E2 that provide the lower pressure source and a compressor E1 that proves the higher pressure source. There are valves V1 , V2 and V4 which connect either the compressor or the vacuum pump to a further respective valve V8, V5 or V7. These are linked to the three ports on the self-propelling pipe maintenance device which are in respective fluid communication with the two inflatable bladders of the two gripping devices and the longitudinally extendible portion of the propelling portion of the device. By the suitable control of the compressor, vacuum pump and valves the inflation and deflation of the expandable bodies can be independently controlled and sequenced in a way that allows the self-propelling pipe maintenance device to move along the pipe, isolate sections of the pipe and/or oscillate a cleaning mechanism along a surface of a pipe.

In this embodiment there is a further external port which is in fluid communication with a fluid flow path that opens in a port (31 in Figure 7) on the exterior surface of the device between the two gripping elements. There are valves V3 and V6 which couple to this fluid flow path and these valves are used in a leak test. To perform the leak test, a portion of the pipe to be tested is identified and the pipe maintenance device is moved such that the portion of pipe is located between the two gripping elements. The radially expandable bodies of the gripping elements are then inflated by coupling the compressor E1 via valves V1 , V8 V4 and V7 to respective expandable bodies. This isolates the section of pipe to be tested. A leak test gas may then be introduced to an area around the exterior of this section of the pipe and valves V6 and V3 opened so that the isolated section is coupled to the vacuum pump E2 and fluid is evacuated from the isolated region past gas sensor I2 which senses when the leak test gas is present. Any leak in the pipe will allow the leak test gas to enter the sealed section and be detected by sensor I2.

In an alternative embodiment, valves V3 and V6 may be used to couple a source of leak test gas (not shown) rather than the vacuum pump to the fluid flow path coupled to port 31 of Figure 7. In this way control of the valves V3 and V6 may be used to introduce a leak test gas into the sealed section of pipe and a sensor exterior to the pipe may be used to test for this gas and any leaks.

Figure 5 shows a flow diagram schematically illustrating steps in a method according to an embodiment. The first portion of the embodiment relates to control of the pressure within the different expandable bodies to allow the device to move along the pipe. At the initial step S10 the bladder in the rear gripping element furthest from the desired direction of travel is inflated such that it grips the pipe. The bladder in the front gripping element is left uninflated so that it is free to move. At the next step S20 the longitudinally expandable element in the propelling element are inflated to push the two gripping devices apart. As the rear gripping element is fixed to the pipe the front one moves forward along the pipe.

At the next step S30, the longitudinally expandable element in the front gripping element is inflated while that in the rear gripping element is deflated meaning that the front of the pipe maintenance device is now fixed to the pipe, while the rear section is free to move. At step S40 the longitudinally expandable element are deflated by connecting the lower pressure source such as the vacuum pump E2 of Figure 4 to the longitudinally expandable element and this results in the longitudinally expandable element deflating and compressing longitudinally so that the two gripping elements are pulled together. As the front gripping element is now fixed to the pipe the rear one moves along the pipe towards the front one.

At D5 it is determined if the pipe maintenance device should continue to move. If it should then the sequence S10 to S40 is repeated. If not it is determined if a leak test for example is to be performed. This may occur where the device is at a junction between two pipes.

If the answer to the leak test query at D6 is yes then at step S50 the longitudinally expandable element in the central propelling element are at least partially inflated to move the gripping elements away from each other to either side of the portion to be leak tested. At step S60 both gripping elements are inflated and then at step S70 a source of a leak test gas is coupled via a fluid flow path to a port in the pipe maintenance device opening onto the exterior of the pipe maintenance device between the two gripping elements. The isolated region of the pipe is then filled with a leak test gas. This allows the exterior of the pipe network to be tested for traces of the leak test gas and a leak to be detected or otherwise.

Once this is completed or if it is determined at D6 that no leak test is to be performed that at step D7 it is determined whether or not it is desired to clean this portion of the pipe. If the answer is no then we return to determining whether the maintenance device should move further while if the answer is yes then one of the bladders of the gripping elements is inflated at step S80 and then the longitudinally expandable element of the propelling element is periodically inflated and deflated at S90 to oscillate the cleaning brush backwards and forwards along a surface of the pipe.

In addition to this there may be a particulate removal mechanism associated with the cleaning brush, which mechanism may be linked to a low pressure source and have a filter associated with it, such that fluid including the particles are sucked into the filter and the particles are collected while the fluid is expelled.

Figure 6 shows an isometric view of a pipe maintenance device with a cleaning mechanism comprising a brush 30 and particulate removal device 33 extending from one end of the pipe maintenance device. It should be understood that the cleaning mechanism could located on any portion of the pipe maintenance device, but by mounting it at one end, it can be detachably mounted, so that where cleaning is not required it may be removed.

The cleaning mechanism is configured such that brush 30 scrapes along the interior of the pipe as the device moves along the pipe dislodging deposits of particulates. In this embodiment the brush 30 is a porous flexible, cylindrical brush that is pulled along the walls of the pipe as the maintenance device travels along the pipe. In this embodiment there is a particulate removal mechanism 33 that sits within the cylindrical brush 30 and in some cases may extend beyond it. This device has longitudinal slots and is coupled to a low pressure source and filter. Thus, fluid including particulates brushed from the walls are sucked through the slots by the lower pressure within the cylinder and pulled along an umbilical pipe towards a filter (not shown) where they are collected.

In this embodiment there is also a light/camera combination 40 attached to the other end of the device and operable to illuminate and capture images of the pipe as the pipe maintenance device moves along it.

The light and camera 40 may be used to detect regions in the pipework where deposits are particularly heavy and a cleaning routine may be applied at these points. This cleaning routine may involve the left-hand gripping element being inflated to grip the pipe and the longitudinally expandable element 6 may be inflated and deflated to provide oscillating movement to brushing mechanism 30. The particulate removal mechanism 33 within the brushing mechanism 30 captures particulates dislodged from the pipe walls. In this way debris may be both dislodged from the walls of the pipe and removed from the system.

Although the self-propelling pipe maintenance device is shown with only the right- hand gripping element 10 in an inflated state, there may be occasions where both of the inflatable bodies 12 of the two gripping elements are inflated which allows both ends of the device to seal to the pipe and provides an isolated section of the pipe which can then be leak tested either by evacuating the portion between the two gripping elements 10 and passing a leak test gas, in some cases an inert gas around the surfaces of the apparatus and testing for traces of the inert gas within the pipe, or by supplying the leak test gas to the sealed portion and testing for the gas outside of the pipe.

Figure 7 shows a leak test gas port 31 that provides fluid communication between a fourth external port 20 and the exterior of the maintenance device between the two gripping elements. This port 31 is coupled to the external port 20 via internal fluid transfer passages 26 and 27. These provide a separate fluid flow path to those connecting the lower pressure sources and higher pressure sources to the expandable bodies. This allows the port 31 to be sealed externally to the device when a leak test is not being performed. When a leak test is to be performed then the port may be coupled to a leak test gas source such that a leak test gas for example, helium is admitted to the sealed portion of the pipe between the gripping elements. A sensor external to the pipe may monitor for the gas to determine if a leak is present or not. Alternatively, the port 31 may be coupled to the lower pressure source and the sealed portion of the pipe may be evacuated and the external area around the portion of pipe to be tested supplied with a leak test gas, the gas evacuated from the pipe may be tested by a gas sensor to determine the presence or absence of the leak test gas.

In this way leak testing of the pipe can be performed. This may be done around the joint of a pipe for example where the two inflatable bodies are on either side of the joint such that the joint is within the sealed section. Alternatively it may be at a section of the pipe where the camera has detected a flaw.

It should be noted that although Figure 7 shows the leak test port 31 and associated fluid passages 26, 27, the passages linking the other three external ports 20 to the respective expandable bodies such as fluid passages 23, 24 and 26 shown in Figure 3 are present but are not shown to make the figure clearer.

Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the invention is not limited to the precise embodiment and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents.

REFERENCE SIGNS

1 rigid portion of gripping element

6 longitudinally expandable body

10 gripping element 12 inflatable bladders 14 bendable elongate member 20 external ports 22 connecting ports

23, 24, 27 internal fluid transfer passages 26 flexible pipe fluid transfer passages

30 brush

31 leak test port 33 particulate removal mechanism 40 camera/light combination E1 compressor E2 vacuum pump I2 gas sensor

V1 , V2, V3, V4 three-way valves V8, V5, V6, V7 two-way valves