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Title:
METHOD AND SYSTEM FOR APPLYING A COATING OF MATERIAL TO A PIPE
Document Type and Number:
WIPO Patent Application WO/2019/165502
Kind Code:
A1
Abstract:
A method and system (10) for applying a coating of a material to a pipe (12) has a formwork (20) made of two or more parts (34a), (34b) arranged to be releasably coupled together. The parts (34a), (34b) are configured to form a wall that wholly surrounds a portion of a pipe (12). An inner support (50) is arranged to support the formwork (20) on the portion of the pipe (12) wherein the formwork is self-supporting on the pipe (12). The inner support (50) is at one axial end of the formwork and extending coaxially with the outer wall. Settable material (14) is pumped into the formwork (20) at the formwork (20) is traversed along the pipe.

Inventors:
SHANAHAN, Darren (2C Warwick Street, West Leederville, Western Australia 6007, 6007, AU)
Application Number:
AU2019/050167
Publication Date:
September 06, 2019
Filing Date:
February 27, 2019
Export Citation:
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Assignee:
WOODSIDE ENERGY TECHNOLOGIES PTY LTD (11 Mount Street, Perth, Western Australia 6000, 6000, AU)
International Classes:
B05B13/02; F16L58/02; B29C45/00
Attorney, Agent or Firm:
GRIFFITH HACK (Level 22, Allendale Square,77 St Georges Terrac, Perth Western Australia 6000, 6000, AU)
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Claims:
CLAIMS

1. A system for applying a coating of a material to a pipe comprising:

a formwork having two or more parts arranged to be releasably coupled together, the parts configured to wholly surround a portion of a pipe when coupled together, and wherein the formwork is self-supporting on the pipe and arranged, together with an outer surface of the portion of the pipe, to form a cavity; and

an inlet arrangement through which a settable material can flow into the formwork and the cavity onto the outer surface of the pipe.

2. A system for applying a coating of a material to a pipe comprising:

a formwork having two or more parts arranged to be releasably coupled together, the parts configured to form a wall that wholly surrounds a portion of a pipe when coupled together; and

an inner support arranged to support the formwork on the portion of the pipe wherein the formwork is self-supporting on the pipe, the inner support being formed at one axial end of the formwork and extending coaxially with the outer wall.

3. The system according to claim 1 or 2 wherein the formwork has a leading end and a trailing end and a radial wall at the leading end wherein the cavity opens onto the trailing end.

4. The system according to claim 3 wherein the formwork comprises an inner support arranged to support the formwork on the portion of the pipe.

5. The system according to claim 4 wherein the inner support is arranged to maintain the cavity substantially concentrically about the portion of the pipe.

6. The system according to claim 4 or 5 wherein the inner support lies between the leading end and a location in board of the trailing end.

7. The system according to claim 5 wherein the cavity extends from the location in board of the trailing end to the trailing end.

8. The system according to any one of claims 4-7 wherein the inner support comprises a sleeve arranged to slide along the pipe.

9. The system according to any one of claims 1-8 comprising a conditioning system

arranged to condition the material prior to the material exiting from the formwork to accelerate, retard or otherwise control or influence the setting of the settable material.

10. The system according to claim 9 wherein the conditioning system is located in or on the formwork.

11. The system according to any one of claims 1-10 comprising a skid arranged to hold a supply of the material and a conduit providing fluid communication between the supply and the formwork.

12. The system according to claim 11 comprising a traction system coupled to the

formwork and arranged to traverse the formwork along the pipe.

13. The system according to any one of claims 1-12 comprising a mould kit having a plurality of pieces at least a subset of which are capable of being assembled to form a mould between: at least a portion of coating applied to a pipe; and one or more uncoated portions of one or more coupled pipes; the mould having an inlet through which a volume of the settable material can flow onto the uncoated portions.

14. A method of applying a coating of a settable material onto a pipe comprising:

locating a formwork about a portion of a pipe;

supporting the formwork at one axial on the pipe wherein the formwork together with an outer surface of the pipe forms an annular cavity of substantial constant outer radius;

flowing a settable material through the formwork onto an outer surface of the portion of a pipe wherein the settable material on the outer surface has a

substantially uniform thickness; and

while flowing the settable material, traversing the formwork along a length of the pipe.

15. A method of applying a coating of a settable material onto a pipe comprising:

locating a formwork about a portion of a pipe;

flowing a settable material through the formwork onto an outer surface of the portion of a pipe wherein the settable material on the outer surface has a

substantially uniform thickness;

while flowing the settable material, traversing the formwork along a length of the pipe at a rate wherein the settable material when outside of the formwork is self- supporting to maintain a substantially uniform thickness on the outer surface.

16. The method according to claim 14 or 15 comprising chemically bonding the settable material onto the outer surface of the pipe.

17. The method according to any one of claims 14-16 comprising arranging the formwork to define a cavity between an inner surface of the formwork and the outer surface of the pipe and wherein the substantially uniform thickness is arranged to correspond with a radial distance between the inner surface of the formwork and the outer surface of the pipe.

18. The method according to any one of claims 14-17 comprising connecting the

formwork to a supply of the settable material.

19. The method according to any one of claims 14 to 18 comprising stopping the

depositing of the settable material prior to a junction of the pipe with another pipe or a pipe connector and forming a seal on the outer surface between an end of the settable material and other pipe or pipe connector.

20. The method according to any one of claims 14 to 18 comprising stopping the

depositing of the settable material prior to a junction of the pipe with another pipe or a pipe connector and forming a mould about an end of the settable material on the pipe and the other pipe or pipe connector and injecting a volume of the settable material into the mould.

21. The method according to claim 20 comprising, prior to forming the mould, forming a seal on the outer surface between an end of the settable material and other pipe or pipe connector.

22. The method according to any one of claims 14-21 comprising heating, cooling, or otherwise conditioning the settable material prior to the material being outside of the formwork.

23. The method according to any one of claims 14-22 comprising providing the settable material as two or more separate components and mixing the two or more separate components prior to flowing the material onto the outer surface of the pipe.

24. The method according to any one of claims 14-23 wherein locating the formwork about a pipe comprises locating the formwork about a fixed pipe in a plant or machine whereby the method facilitates the coating of a fixed pipe in a installed in a plant or machine.

Description:
METHOD AND SYSTEM FOR APPLYING A COATING OF MATERIAL TO A PIPE

A method and a system are disclosed for applying a coating of a material to a pipe. The material may have properties which aim to prevent or minimise corrosion of a pipe and/or thermally insulate the pipe.

BACKGROUND ART

In industrial processing plants in many different industries pipes are often coated with a thermal insulation material. A common thermal insulating material is mineral wool. One example of a commercially available mineral wool is that sold under the brand name ROCKWOOL. Mineral wool is wrapped around the pipe. A steel cladding may then be placed over the mineral wool.

A deficiency with this type of cladding is that water does from time to time seep in to the mineral wool. The water is retained by the mineral wool and acts to corrode the underlying pipe. If the corrosion is not detected a hole may be created causing the pipe to leak. This can be disastrous when the pipe is carrying high-pressure fluids or fluids which are inflammable or poisonous.

One way of detecting the commencement of corrosion is to strip back the cladding and insulation. This is a very expensive and time-consuming process which may also require the shutdown of at least a part of an industrial processing plant. It may be possible to rely on other techniques such as use of gamma rays or x-rays to detect underlying corrosion. However, in many situations this is not practical due to the size and complexity of the detection equipment and the difficulty in accessing pipes in an industrial processing plant.

SUMMARY OF THE DISCLOSURE

In a first aspect there is disclosed a system for applying a coating of a material to a pipe comprising:

a formwork having two or more parts arranged to be releasably coupled together, the parts configured to wholly surround a portion of a pipe when coupled together, and wherein the formwork is self-supporting on the pipe and arranged, together with an outer surface of the portion of the pipe, to form a cavity; and

an inlet arrangement through which a settable material can flow into the formwork and the cavity onto the outer surface of the pipe.

In a second aspect there is disclosed a system for applying a coating of a material to a pipe comprising:

a formwork having two or more parts arranged to be releasably coupled together, the parts configured to form a wall that wholly surrounds a portion of a pipe when coupled together, and an inner support arranged to support the formwork on the portion of the pipe wherein the formwork is self-supporting on the pipe, the inner support being formed at one axial end of the formwork and extending coaxially with the outer wall.

In one embodiment the formwork has a leading end and a trailing end and a radial wall at the leading end wherein the cavity opens onto the trailing end.

In one embodiment the formwork comprises an inner support arranged to support the formwork on the portion of the pipe.

In one embodiment the inner support is arranged to maintain the cavity substantially concentrically about the portion of the pipe.

In one embodiment the inner support lies between the leading end and a location in board of the trailing end.

In one embodiment the cavity extends from the location in board of the trailing end to the trailing end.

In one embodiment the inner support comprises a sleeve arranged to slide along the pipe.

In one embodiment the system comprises a conditioning system arranged to condition the material prior to the material exiting from the formwork to accelerate, retard or otherwise control or influence the setting of the settable material.

In one embodiment the conditioning system is located in or on the formwork.

In one embodiment the system comprises a skid arranged to hold a supply of the material and a conduit providing fluid communication between the supply and the formwork.

In one embodiment the system comprises a traction system coupled to the formwork and arranged to traverse the formwork along the pipe.

In one embodiment the system comprises a mould kit having a plurality of pieces at least a subset of which are capable of being assembled to form a mould between: at least a portion of coating applied to a pipe; and one or more uncoated portions of one or more coupled pipes; the mould having an inlet through which a volume of the settable material can flow onto the uncoated portions.

In a third aspect there is disclosed a method of applying a coating of a settable material onto a pipe comprising:

locating a formwork about a portion of a pipe; supporting the formwork at one axial on the pipe wherein the formwork together with an outer surface of the pipe forms an annular cavity of substantial constant outer radius; flowing a settable material through the formwork onto an outer surface of the portion of a pipe wherein the settable material on the outer surface has a substantially uniform thickness; and

while flowing the settable material, traversing the formwork along a length of the pipe.

In a fourth aspect there is disclosed a method of applying a coating of a settable material onto a pipe comprising:

locating a formwork about a portion of a pipe;

flowing a settable material through the formwork onto an outer surface of the portion of a pipe wherein the settable material on the outer surface has a substantially uniform thickness;

while flowing the settable material, traversing the formwork along a length of the pipe at a rate wherein the settable material when outside of the formwork is self-supporting to maintain a substantially uniform thickness on the outer surface.

In one embodiment the method comprises chemically bonding the settable material onto the outer surface of the pipe.

In one embodiment the method comprises arranging the formwork to define a cavity between an inner surface of the formwork and the outer surface of the pipe and wherein the substantially uniform thickness is arranged to correspond with a radial distance between the inner surface of the formwork and the outer surface of the pipe.

In one embodiment the method comprises connecting the formwork to a supply of the settable material.

In one embodiment the method comprises stopping the depositing of the settable material prior to a junction of the pipe with another pipe or a pipe connector and forming a seal on the outer surface between an end of the settable material and other pipe or pipe connector.

In one embodiment the method comprises stopping the depositing of the settable material prior to a junction of the pipe with another pipe or a pipe connector and forming a mould about an end of the settable material on the pipe and the other pipe or pipe connector and injecting a volume of the settable material into the mould.

In one embodiment the method comprises prior to forming the mould, forming a seal on the outer surface between an end of the settable material and other pipe or pipe connector. In one embodiment the method comprises heating, cooling, or otherwise conditioning the settable material prior to the material being outside of the formwork.

In one embodiment the method comprises providing the settable material as two or more separate components and mixing the two or more separate components prior to flowing the material onto the outer surface of the pipe.

In one embodiment locating the formwork about a pipe comprises locating the formwork about a fixed pipe in a plant or machine whereby the method facilitates the coating of a fixed pipe in a installed in a plant or machine.

BRIEF DESCRIPTION OF THE DRAWINGS

Notwithstanding any other forms which may fall within the scope of the method and system as set forth in the Summary, specific embodiments will now be described, by way of example only, with reference to the drawings in which:

Figure 1 is a schematic representation of an embodiment of the system in use applying a coating of a settable material onto a pipe in a pipe network;

Figure 2 is a view of section A -A through a portion of the coating formed on a pipe shown in Figure 1;

Figure 3 is a longitudinal section view of an embodiment of a formwork incorporated in the system shown in Figure 1;

Figure 4 is a front end view of the formwork shown in Figure 3;

Figure 5 is an enlarged view of a quarter section B-B of the formwork shown in Figure 4; Figure 6 is a schematic representation of a method of applying a coating to a pipe and a pipe network which includes a T-piece;

Figure 7 is a schematic representation of a formwork of that may be used in a further embodiment of the disclosed method and system.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

Accompanying Figures 1-6 depict an embodiment of the disclosed method and system 10 for applying a coating 12 of a settable material 14 to a pipe 16. The pipe 16 in this embodiment is shown as part of a pipe network 18 which includes a plurality of pipes 16 interconnected together.

The general idea behind embodiments of the disclosed method and system 10 is to facilitate the application of a settable material onto a pipe to provide a beneficial effect to either the pipe itself in terms of providing protection from the ambient atmosphere and/or improving the efficiency of a process which involves the transfer of a fluid or other flowable material through the pipe 16 or pipe network 18 by insulating the pipe 16 and therefore the fluid or flowable material passing through the pipe 16 from effects of the ambient atmosphere. Most notably this may constitute thermally insulating the pipe 16 and/or protecting the pipe 16 by forming a moisture or vapour barrier to prevent or otherwise minimise the risk of corrosion of the pipe 16.

In a general sense the disclosed method of applying or forming the coating 12 of the material 14 onto the pipe 16 involves locating a formwork 20 about a portion of the pipe 16 and subsequently flowing or delivering the settable material 14 through the formwork 20 onto an outer surface 22 of the portion of the pipe 16 while traversing the formwork 20 along the pipe 16. The traversing of the formwork 20 is depicted by the arrow D in Figure 1. The formwork 20 may be of a size capable of being picked up and carried by a single person of ordinary strength and subsequently pulled or traversed along a pipe manually. Since the formwork is traversed along the pipe the formwork 20 it may be considered to be a mobile formwork. This is to contrast with systems where the formwork is stationary, and a pipe is moved through the formwork.

The material 14 is delivered through the formwork 20 to have a substantially uniform thickness about the pipe 16. The formwork 20 is traversed along the length of the pipe 16 at a rate such that the material 14 is self-supporting once it has left the confines of the formwork 20 to maintain its substantially uniform thickness and form the coating 12.

It is possible to match the rate of setting of the material 14 with the speed of traversing the formwork 20 along the pipe 16 so that the material 14 once outside of the formwork 20 can support itself to maintain its substantially uniform thickness about the pipe 16.

Figure 1 also depicts a hand controller 24 coupled to both the formwork 20 and, via an umbilical 26, a skid 28. The skid 28 holds a supply 30 of the settable material 14 and a delivery mechanism such as a pump 32. The hand controller includes a trigger or other user manipulable control mechanism to control the flow of the material 14 to the formwork 20 and other systems on or associated with the application of the material 14 such as a material conditioning system (e.g. a heater, cooler, UV light source etc).

The umbilical 26 may include an internal conduit through which the material 14 flows to reach the portion of the pipe 16 surrounded by the formwork 20. In that case the handle 24 may also be formed with an internal passage that provides a path for the material 14 to flow into the formwork 20. Alternately one or more separate conduits can be used to provide a flow path for the material 14 from the supply 30 to the inside of the formwork 20. In that case, as described later, this conduit can be attached to a manifold formed about the formwork 20 to supply the material 14 to the region between the inside of the formwork 20 and the outside of the pipe 16. The hand controller 24 also provides a mechanism by which the user can pull the formwork 20 along the pipe 16. To assist in reducing a moment being applied to the formwork 20 as it is traversed along the pipe 16 two hand controllers or two handles one of which incorporates a controller may be provided at diametrically opposed locations about the formwork. In this way a user can grab both handles and/or controllers to apply the force needed to traverse the formwork 20 along the pipe 16.

With particular reference to Figures 1 and 3-5 it can be seen that in an embodiment of the system 10 the formwork 20 is made from two parts 34a and 34b (hereinafter referred to in general as "parts 34") that are arranged to be releasably coupled together. The parts 34, when coupled together, wholly surround a portion of the pipe 16. The formwork 20 is configured to be self-supporting on the pipe 16. Also, the formwork 20 is arranged, together with the outer surface 22 of the portion of the pipe 16 it surrounds, to form a cavity 36. This is an annular cavity having a substantially uniform outer radius. Each of the parts 34 is in the general form of a semi cylindrical shell.

In embodiments where the material 14 does not flow through the umbilical 26, an inlet arrangement 38 is provided on the formwork 20 through which the settable material can flow into the cavity 36 and subsequently onto the outer surface 22 to form the coating 12. This material is supplied through separate conduits 26a connected between the supply 30 and the inlet arrangement 38.

The formwork 20 has a generally cylindrical configuration. When the formwork 20 comprises two parts 34a and 34b each of the parts is arranged to extend 180° about a pipe 16. Conveniently the parts 34 can be releasably coupled together by way of radial flanges 40 and bolts 42.

With reference to its direction of travel D along the pipe 16, the formwork 20 has an outer wall 43, a trailing end 44 and a leading end 46 at opposite ends of the outer wall 43, and a radial wall 48 at the leading end 46. The cavity 36 opens onto the trailing end 44. The radial wall 48 closes off the leading end 46 so that the settable material 14 when delivered into the formwork 20 fills the cavity 36 rearward of the wall 48.

The formwork 20 has an inner circumferential surface 49 of constant inner diameter, at least for the length of the cavity 36. Accordingly, as there is no narrowing or tapering of the inner circumferential surface 49, the formwork 20 applies a constant rather than varying compression to the material 14 being delivered onto the pipe 16 as the formwork 20 is traversed along the pipe 16.

The formwork 20 is also provided with an inner support 50 which is arranged to support the formwork 20 on the pipe 16. Moreover, the inner support 50 maintains the cavity 36 substantially concentrically about the pipe 16 and therefore provides the cavity with a substantially constant outer radius. The support 50 is formed as an inner sleeve 52 which is coupled with the radial wall 48 and extends parallel to the pipe 16. An outer surface of the inner sleeve 52 adjacent the outer surface 22 of the pipe 16 may be formed as a bearing surface to facilitate sliding of the formwork 20 along the pipe 16.

Alternately, and as shown in Figure 5, a separate bearing 54, for example in the form of a NYLON bearing 54 may be attached to the inner sleeve 52 to facilitate sliding of the formwork 20 along the pipe 16. The bearing 54 also acts as a seal to prevent flow of the material 14 between the bearing 54 and the outer surface 22.

The inlet arrangement 38 includes a short nozzle 56 for connection to the umbilical 26a. Optionally the nozzle 56 can feed an internal manifold 58 which extends circumferentially about the formwork 20 adjacent the radial wall 48. The manifold 58 is provided with a plurality of openings 60 through which the settable material 14 can be fed into the cavity 36.

When the system 10 is in operation so that the material 14 is being delivered from the supply 30 through the umbilical 26 or 26a into the formwork 20, the material 14 initially flows onto a portion of the cavity that includes the inner support 50, but will subsequently flow into a portion of the cavity 36 from the trailing end of the inner support 50 to the trailing end 44. An inner circumferential surface of this portion of the cavity 36 is formed by the outer surface 22 of the pipe 16. Thus, the thickness T of the coating 12 is the radial distance from the outer surface 22 of the pipe 16 to an inner circumferential surface of the formwork 20 at the trailing end 44.

Although not shown, the system 10 may be provided with a heating or other conditioning device or system for accelerating, retarding or otherwise controlling or influencing the rate of setting of the material 14. This may include for example but is not limited to: an electric heater; a steam injection system; a cooling circuit (e.g. a cooling coil about the formwork 20) and a UV radiation source. The conditioning device or system may be located either in or on the formwork 20, in the controller 24, along a length of the conduit 26, or in the skid 28.

Figure 6 illustrates one embodiment of the disclosed method in relation to a pipe network 18 in which three lengths of pipe 16 coupled together by a flanged T-piece 62. The disclosed method of applying the coating 12 in the pipe network 18 involves initially applying a coating 12 to each of the separate lengths of pipe 16 to a location close to but stopping short of the flanged connection between the pipe 16 and the T-pieces 62. A volume of sealing material 64 is applied, for example by using a hand gun, between the end of the coating 12 and an adjacent flange. Next a mould 66 is constructed about the T- piece 62 which encompasses an end portion of the coating 12 on each of the pipes 16.

Once the mould 66 has been constructed the settable material can be delivered into the mould 66 to fully envelop the T-piece 62, flange couplings, the sealing material 64 and the end portions of the coatings 12.

The mould 66 may be constructed from a multi-component mould kit (not shown). The mould 66 is formed by assembling a plurality of pieces from the mould kit to the required shape and configuration to encompass a portion of the pipe network 18 to be coated with the material 14.

Optionally the mould 66 can be provided with a heating or other conditioning device or system as described above to aid in accelerating, retarding or otherwise controlling or influencing the setting of material 14. After sufficient time has elapsed the mould 66 can be removed leaving a fully encapsulated and coated T-piece 62 and corresponding pipe junction.

The settable material 14 may be provided as a multicomponent material for example comprising a resin and a hardener which are separately held on the skid 28 and mixed en route to or within the formwork 20. However, in other embodiments the material 14 may be a single component material capable of controlled phase change from solid to liquid/plastic and back to solid. The material 14 is not intended or required to have substantive mechanical strength so as to form for example a pressure containment structure or pseudo vessel. However, the material 14 may have a characteristic of being able to chemically bond to the outer surface 22 of the pipe 16. It is desirable for the material 14 to be relatively easily removed for example by cutting, scraping, or abrading for example by sandblasting or dry ice blasting.

Other desirable properties of material 14, and thus the subsequent coating 12 include:

• thermal insulation

• liquid impervious

• vapour impervious

• can be applied in a continuous process

• resistance to hydrolysis in hot and humid conditions

• absence of or minimal hazardous materials

• resists capillary action

• UV resistant

• able to withstand thermal cycling without cracking or degradation of the chemical bond between the material and the pipe

• able to be repaired and/or patched

• free of volatiles

• ability to be dyed or otherwise provided in different colours • on setting producing a firm and tough outer surface

• have a 30+ year life in open weather.

Example of suitable materials include but are not limited to polymers such as syntactic polymers including syntactic polyethylene, syntactic polyurethane and syntactic poly propylene.

Embodiments of the disclosed method are particularly useful for the application of insulating material to fixed pipes and pipework already installed in a plant. Embodiments are also applicable where the pipework is inaccessible from ground level and would otherwise require the erecting of scaffolding. This is distinct from applying a coating to a stand-alone or free pipe.

Examples of the application of embodiments of the disclosed method and system is in an LNG production plant, or chemical processing plant. Such plants may include many kilometres of fixed pipes through which various fluids flow. Many of the pipes are at heights which are in accessible to people standing on the ground. The disclosed method and system envisages using the handheld formwork 24 for applying a coating to pipes. In terms of occupational health and safety application of the coating utilising the disclosed method and system is akin to painting. This enables traditional harnesses, winches and platforms that painters use for painting at elevated locations to be used for when applying coatings using the disclosed system and method.

It should be recognised that by way of the disclosed method and system the coating is applied after construction of the plant. Some methods and systems are known for applying coatings to pipes prior to them being used in the construction of a plant or machine. This is much simpler than applying the coating to a fixed pipe in a constructed plant due to accessibility. Also, when applying a coating to a pipe prior to it being installed into a plant or machine there is a risk of damaging the coating during handling of the pipe. This is particularly the case with the pipes of a weight and/or length that need the use of cranes, forklift trucks, or other machines to lift and transport the pipe.

Thus, in one embodiment the disclosed method is a method for applying a coating of a material onto a fixed pipe installed in a plant or machine that comprises: locating a mobile formwork about a portion of the fixed pipe; flowing a settable material through the formwork onto an outer surface of the portion of the fixed pipe wherein the material on the outer surface has a substantially uniform thickness; and while flowing the settable material, traversing the mobile formwork along a length of the fixed pipe at a rate wherein the material when outside of the formwork is self-supporting to maintain a substantially uniform thickness on the outer surface. Whilst a number of specific method and system embodiments have been described, it should be appreciated that the method and system maybe embodied in many other forms. For example, the formwork 20 is described as comprising two parts 34a and 34b, each extending for 180° about the pipe 16. However, the formwork 20 can be made from three or more parts which are releasably coupled together to wholly surround a pipe 16.

Additionally, while the parts 34 are coupled together by use of flanges 40 and bolts 42, in alternate embodiments the parts 34 may be releasably coupled together by use of separate clamps or other means including for example magnets.

As the formwork 20 is formed from two parts 34 in one embodiment of the system 10, the manifold 58 can also be conveniently formed as two arcuate chambers extending circumferentially about and on the outside of each of the parts 34 (shown in phantom Ine 59 in Fig 1). In such an embodiment a separate conduit is connected between each of the chambers and the supply 30.

In a further variation the manifold 58 can be formed as separate arcuate chambers 59 on the outside of the radial wall 48 as shown in Figure 7. Again, in this variation a separate conduit is connected between each of the chambers 59 and the supply 30 via to deliver the material 14 into the cavity 36.

Optionally a traction device can be provided at the leading end 44 of the formwork 20 to traverse the formwork 20 at a user controllable speed, this includes traversing the formwork at a constant speed or a variable speed. This may include for example an electric motor driving a plurality of wheels or tracks which engage the outer surface 22 of the pipe 16. Further, an inside surface of the formwork 20 can be provided with a non-stick coating to prevent the material 14 from chemically bonding or otherwise adhering to the formwork 20.

Any discussion of the background art throughout this specification should in no way be considered as an admission that such background art is prior art, nor that such background art is widely known or forms part of the common general knowledge in the field in

Australia or worldwide.

In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word "comprise" and variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features of the system and method as disclosed herein.




 
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