GB2569190A

GB2569190A - Service head adaptor assembly

Info

Publication number: GB2569190A
Application number: GB1720615.2A
Authority: GB
Inventors: Richard Utting Jeffrey
Original assignee: Radius Systems Ltd
Current assignee: Radius Systems Ltd
Priority date: 2017-12-11
Filing date: 2017-12-11
Publication date: 2019-06-12
Anticipated expiration: 2037-12-11
Also published as: GB2569190B; GB201720615D0

Abstract

A service head adaptor assembly 1 is fitted onto a service pipe, where the service pipe comprises a metallic host pipe 100 that is lined with an interior lining pipe 102. The service head adaptor assembly comprises a body 2, a clip 4 and a tapered plug 3. The body forms a fluid-tight seal with the host pipe, and has a bore with a first diameter portion 207 accommodating an end of the lining pipe and a second, larger, diameter portion 206 accommodating an end of the host pipe. The clip has an inner surface which attaches onto an outer surface of the lining pipe to prevent axial movement of the lining pipe with respect to the host pipe. The tapered plug is inserted into the end of the lining pipe to apply a radial force to expand the lining pipe to bear against an interior surface of said body. In use the lining pipe is cut to the required length, and the clip is attached to the outer surface of the lining pipe. The body is then attached and sealed to the host pipe, and the tapered plug inserted into the lining pipe.

Description

SERVICE HEAD ADAPTOR ASSEMBLY [0001] This invention relates to the field of a service head adaptor assembly for safely joining a lining pipe to a host pipe. In particular, the invention relates to a service head adaptor assembly suitable for use with polyolefin lining systems for renovating fuel gas pipelines for example with the use of flexible twin wall polyolefin liners such as those described in GB2290121 and GB2300684.

BACKGROUND [0002] To reduce disruption to the building fabric of a dwelling it is preferred to internally line existing utility pipelines rather than remove and replace them when they reach the end of their life, or become damaged. The old pipe, herein referred to as the “host pipe” serves as a conduit and a guide for the new lining pipe. This method entirely mitigates the need to remove floors, or break masonry, in replacing a pipeline used, for example, to provide gas and water supplies to a dwelling.

[0003] Several known methods are available to line a host pipe in this way, for example the use of liquid resin coatings, lining with polyolefin materials, and lining with cured in place pipe.

[0004] Corrugated polyolefin pipes, for example as described in GB2290121 and GB2300684, when appropriately designed in terms of their cross-sectional profile and their material selection, have been found to be suitable for the lining of old metallic service pipes (host pipes) into dwelling houses. The advantage of such corrugated lining pipes is their ability to pass through tight radius elbows in the construction of the original metallic pipe, with bending radii as low as one diameter. This allows a lining pipe, having a smaller diameter than the original, to be inserted with a known geometry and properties that can be assessed and quantified in engineering terms. So, for example the pressure retaining properties of the lining pipe can be assessed along with the hydraulic flow properties.

[0005] A service head adaptor is required in the house to connect the lining pipe to the metallic host pipe and to valves that are used in the property for the supply of fuel gas. The service head adaptor has several functions and examples of known service head adaptors are found in GB2290121, GB2467536 and GB2479918. The following features are key:

• The service head adaptor must make a connection to the existing metallic host pipe. The connection is normally threaded but can be a compression connection.

• The service head adaptor must provide an outlet connection, normally a screw thread, to enable valves or other metal pipes to be joined thereto.

• The polyolefin lining pipe must be securely retained within the service head adaptor forming a gas tight seal to prevent gas leaking into the annulus formed after the lining pipe has been inserted into the host pipe.

• Ports may be provided in the fitting to permit annular sealant materials to be injected (optional).

• The service head adaptor must be sufficiently fireproof to meet local fire regulations. In the United Kingdom, the requirement is to survive a fire at 850°C for 30 minutes with minimal leakage occurring (e.g. less than 0.14 SCMH natural gas at 75 millibar source pressure).

[0006] Known service head adaptors generally comprise multiple parts which interconnect to form a relatively large assembly which can require alterations to the dwelling in which the assembly is being fitted, or simply be impractical to fit in a confined space.

[0007] Furthermore, the use of multiple component parts, to form a service head adaptor increases the risk of leaks in the completed assembly as the number of seals, which can fail either due to user error, in the event of a fire or from corrosion, increases with complexity. The same problem applies to any screw heads, compression fittings, etc. along which fluid can leak.

[0008] It is therefore an object of the present invention to provide a service head adaptor which mitigates the above-described problems.

BRIEF SUMMARY OF THE DISCLOSURE

In accordance with an aspect of the present invention there is provided a service head adaptor assembly adapted to be fitted onto a service pipe, where the service pipe comprises a metallic host pipe that is lined with an interior lining pipe, the adaptor assembly comprising:

a) a body that is adapted to form a fluid-tight seal with the host pipe, the body having an interior surface and a bore therethrough, the bore having a first diameter portion capable of accommodating an end of said lining pipe and a second, larger, diameter portion capable of accommodating an end of said host pipe;

b) a clip having an inner surface adapted to be attached onto an outer surface of the lining pipe in order to substantially prevent axial movement of the lining pipe with respect to the host pipe, in use; and

c) a tapered plug insertable into said end of said lining pipe so as to apply a force to radially expand at least a part of said lining pipe to bear against said interior surface of said body.

[0009] The claimed service head adaptor assembly is smaller than those of the prior art which makes the installation more practical to achieve in constrained space areas of a dwelling. In prior art service head adaptor assemblies, a lower portion of the adaptor body has to be fitted to the service pipe first, with the end of the lining pipe next being cut to length. Then a series of grip rings or seals and possibly an upper portion of the adaptor body are fitted, which adds to the size and axial length of the assembly. Use of the claimed clip to axially fix the lining pipe with respect to the host pipe enables the lining pipe to be cut to length before the adaptor body is fitted (the clip maintains the relative axial positions of the lining pipe and host pipe, resisting the axial compressive force of the advancing adaptor body).

[0010] In an embodiment, the tapered plug has a non-circular cross section, which may be an oval or elliptical cross section.

[0011] The tapered plug having a non-circular cross section may cause ovalization or other deformation of the lining pipe as the plug is initially inserted without causing significant radial expansion. This will cause the lining pipe to be pinched between the advancing plug and the body of the service head adaptor assembly in two or more places around its circumference, thus increasing the frictional resistance to movement of the lining pipe. As the tapered plug is advanced further, the lining pipe is radially expanded, without being compressed axially due to the increased frictional resistance to movement. In this way, the lining pipe can be radially compressed into the adaptor body without being axially compressed which may collapse the profile of the lining pipe.

[0012] In another embodiment, the tapered plug has one or more radially-extending formations on an exterior surface thereof.

[0013] Radially-extending formations on the exterior of the tapered plug may be incorporated on their own or in conjunction with the non-circular cross section described above to achieve a similar pinching effect.

[0014] In another embodiment, the tapered plug has a radially-extending flange at one end thereof.

[0015] This allows the top of the tapered plug to sit flush with the opening of the bore of the body with the radially expanding flange abutting the axial end of the lining pipe. This keeps the assembly relatively compact and may provide additional resistance to movement and leaks when the assembly is installed as the plug is in frictional contact with the interior surface of the body.

[0016] In an embodiment, the tapered plug comprises one or more elastomeric seals on an exterior surface thereof, the elastomeric seal or seals being capable of forming a fluidtight seal against said body and/or against said lining pipe. The seals are not essential; in some embodiments, the lining pipe itself can function as the seal.

[0017] The addition of elastomeric seals to the tapered plug affords an extra degree of protection against unwanted leaks of fluid from the assembly.

[0018] In an embodiment, the taper of said tapered plug comprises a tapered leading edge.

[0019] This may allow for more radial expansion of the lining pipe, with a larger portion of the tapered plug expanded to a larger diameter, enhancing the fluid tight seal.

[0020] Alternatively, the taper of said tapered plug comprises a taper extending along the longitudinal axis of the plug. In this embodiment, the taper extends along all or most of the length of the plug, rather than being present only at the leading edge.

[0021] In some circumstances, it may be easier for a user to insert a plug that is tapered along the longitudinal axis of the plug, as this will make the force required to insert the plug increase progressively and will decrease the possibility of collapsing the lining pipe.

[0022] The tapered plug may be made from a thermoplastic material, for example polyoxymethylene (acetal).

[0023] Forming the tapered plug from a thermoplastic allows the plug to be produced at low cost, optionally using 3D printing, whilst maintaining the appropriate physical and mechanical properties required to meet appropriate regulations for such components.

[0024] In an embodiment, the clip is generally C-shaped.

[0025] Using a generally C-shaped clip allows a user to fit the clip to the exterior of the lining pipe without needing to use a large force to deform the clip. In some circumstances, the user will be attaching the clip with only one free hand so if only a minimal amount of force is required to deform the clip such that the gap in the clip is temporarily larger than the diameter of the lining pipe this will make installing the service head adaptor assembly easier.

[0026] The clip may be attachable to the outer surface of the lining pipe by a snap fit.

[0027] Using a snap fit allow the user to easily push the clip into place by pushing the gap in the clip into the side of the lining pipe and allowing it to snap into place.

[0028] In an embodiment, in use, the clip abuts a formation on said interior surface of said body and/or an end of the host pipe in order to substantially prevent axial movement of the lining pipe with respect to the host pipe.

[0029] The clip that holds the lining pipe in place is used in the completed assembly to prevent axial movement of the lining pipe with respect to the body and the host pipe. In some circumstances an annular sealant may be applied, sometimes at high pressure, to the annular region between the interior of the host pipe and exterior of the lining pipe. Using the clip helps keep the lining pipe in place throughout this process. At the end of the lifetime of the service head adaptor assembly, the clip will again prevent the lining pipe from falling into the host pipe when the body of the service head adaptor assembly is removed.

[0030] In an embodiment, the clip comprises an interior surface having a recess therein capable of receiving a correspondingly-shaped formation on the exterior surface of the lining pipe.

[0031] Adapting the interior surface of the clip such that it corresponds to the formations on the lining pipe enhances the ability of the clip to hold the pipe in place as well as helping the user fit the clip in the correct place such that the lining pipe ends in the correct location in the body of the service head adaptor assembly.

[0032] In an embodiment, the clip comprises an exterior surface having a formation thereon capable of engaging with said formation on said interior surface of said body. Preferably, the formation on the exterior surface of the clip defines a flow channel to permit axial fluid flow past the clip, in use.

[0033] Adapting the exterior surface of the clip such that it corresponds to the formations on the interior surface of the body enhances the structural integrity of the service head adaptor assembly by increasing the contact area between the exterior of the clip and the internal surface of the body and minimising empty space from the internal structure of the service head adaptor assembly. Use of flow channels reduces the material cost of the clip and also permits sealant material or the like to travel axially over the clip as desired.

[0034] In an embodiment, the interior surface of the body comprises a recess into which the exterior surface of the lining pipe can be radially expanded and/or compressed thereinto by said tapered plug.

[0035] In some circumstances the exterior of the lining pipe is corrugated or formed with some repeating shape pattern. The ridges and/or grooves that make up the external shape of the lining pipe could be radially expanded into recesses in the interior surface of the body. This further enhances the fluid tight seal of the service head adaptor assembly and helps prevent unwanted axial movement of the lining pipe with respect to the body of the assembly and the host pipe.

[0036] In an embodiment, at least part of the second diameter portion of the body is internally threaded.

[0037] In some circumstances the exterior of the host pipe will be externally threaded, therefore threading at least some of the interior of the second diameter portion of the body permits quicker and easier fitting.

[0038] In an embodiment, at least part of the first diameter portion of the body is externally threaded. This provides an easy connection for further components to be added (for example a valve, not described here).

[0039] In another embodiment, the body has a unitary construction.

[0040] In the known prior art, the body commonly comprises at least two parts which need to be connected to each other to complete the service head adaptor assembly. Having the body comprise a unitary construction will remove the need to have fireproof metal to metal seals or washers which increase the size, cost and installation time of the assembly. Furthermore, the coupling of the two or more parts of the body could apply a torsional or axial force to the lining pipe, leading to damage and leaks, this eventuality has been completely mitigated by the use of a unitary construction.

[0041] In another embodiment, the body includes one or more ports through which filler or sealant material can be introduced.

[0042] If filler material is to be added into the annular region between the exterior of the lining pipe and the interior of the host pipe to provide a better seal, having at least one port in the body of the assembly facilitates this.

[0043] According to a further aspect of the invention, there is provided a method of attaching the adaptor assembly of any of the preceding paragraphs to a service pipe, the method including the steps of:

a) cutting the lining pipe so that a length of lining pipe protrudes from the host Pipe;

b) attaching said clip to the outer surface of the lining pipe in order to substantially prevent axial movement of the lining pipe with respect to the host pipe;

c) attaching and sealing the body to the host pipe such that the end of the lining pipe extends into the bore of the body;

d) inserting the tapered plug into the body and into said end of said lining pipe so as to apply a force to radially expand at least a part of said lining pipe to bear against said interior surface of said body.

[0044] This method of installing a service head adaptor assembly is advantageous as it makes the installation more practical to achieve in constrained space areas of a dwelling. In prior art methods of attaching a service head adaptor assembly, a lower portion of the adaptor body must be fitted to the host pipe first, with the end of the lining pipe next being cut to length. Then a series of grip rings or seals and possibly an upper portion of the adaptor body are fitted, which adds to the size and axial length of the assembly. Use of the claimed method by which a clip is axially fixed to the lining pipe with respect to the host pipe enables the lining pipe to be cut to length before the adaptor body is fitted (since the clip maintains the relative axial positions of the lining pipe and host pipe, resisting the axial compressive force of the advancing adaptor body).

[0045] In an embodiment, the body is attached to the host pipe via the thread on of the second diameter portion of the body.

[0046] Using a threaded portion on the interior of the second diameter portion of the body is faster and more efficient compared to prior art which may require extra components or materials to attach the body to the lining pipe.

[0047] The method may further comprise the step of applying a filler or sealant material between the exterior surface of the lining pipe and an interior surface of the host pipe.

[0048] If a leak occurs at some position on the lining pipe, the host pipe may fill with fluid making a leak into the dwelling more likely. By filling the volume between the lining pipe and the host pipe with a filler material this eventuality may be mitigated.

[0049] The method may comprise the step of inserting the plug using a tool which does not impart a rotational force to the assembly, for example a screwjack, mallet or hammer. Avoiding the application of rotational force to the pipe is desirable as such forces can result in damage to the pipe due to twisting which can lead to collapse of the pipe form.

[0050] In an embodiment the radial expansion of at least a part of said lining pipe is an expansion of the internal diameter thereof by 2% to 4%.

[0051] In an embodiment, said application of force expands said exterior surface of said lining pipe into recesses in the interior surface of said body.

[0052] Expanding the lining pipe into the recesses of the interior surface of the body will form a seal between the two components as well as increasing the friction and resistance to movement of the two parts with respect to each other.

[0053] The application of force may compress the material of said lining pipe.

[0054] The method may include the step of forming a fluid tight seal between the lower portion of the plug and said lining pipe.

[0055] An embodiment comprises the step of forming a fluid tight seal between the upper portion of the plug and said body.

[0056] Forming fluid tight seals where possible provides a further layer of protection against unwanted leaks in the service head adaptor assembly.

[0057] In an embodiment, at least upon initial insertion of the tapered plug, during application of said radially-expanding force the lining pipe is ovalized, and one or more foci of the ovalized lining pipe abut recesses in the interior surface of said body substantially preventing axial displacement of said lining pipe with respect to said body.

[0058] Ovalizing the lining pipe during the initial insertion of the tapered plug is useful in this method as it substantially prevents the axial movement of the lining pipe by pinching it between the host pipe and the tapered plug, preventing the collapse of the lining pipe.

[0059] After insertion of the tapered plug into the body, the tapered plug may be flush with and not substantially protruding from the body.

[0060] Ensuring that the plug does not substantially protrude from the body ensures that further components and/or fittings can be applied to the service head adaptor assembly with ease.

BRIEF DESCRIPTION OF THE DRAWINGS [0061] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:

Figure 1A shows a perspective view of a body for a service head adaptor assembly according to an embodiment of the invention;

Figure 1B shows a plan view of the body;

Figure 1C shows a perspective view of another embodiment of the body

Figure 2A shows a tapered plug for a service head adaptor assembly according to an embodiment of the invention;

Figure 2B is a cross-sectional view of the plug, showing a non-circular cross section;

Figure 2C shows an embodiment of the tapered plug having radially formations proximate the leading edge;

Figure 2D is a side view of an embodiment of the plug having a tapered leading edge;

Figure 3A is a perspective view of a clip for a service head adaptor assembly according to an embodiment of the invention;

Figure 3B is a perspective view of another embodiment of the clip;

Figure 4 is a cross-sectional view of the assembled service head adaptor assembly attached to a service pipe;

Figure 5 is a cross-sectional view of the service head adaptor assembly showing the tapered plug being inserted into the body.

DETAILED DESCRIPTION [0062] In this specification, the following terms may be understood in view of the below explanations:

[0063] The term “C-shaped” includes C-shapes, U-shapes and any substantially circular, elliptical or ring shape with a discontinuity or gap in its circumference.

[0064] The term “fluid” may refer to any matter which can flow, and includes both liquids and gases.

[0065] The term “tapered” may refer to any gradual reduction in radial diameter along an axial length.

[0066] The term “formation” includes a protrusion, bump or other raised feature, a recess, groove, or a localised increase or decrease in radial diameter.

[0067] The term “snap-fit” may refer to a component which has features that can interlock with the features of another component. The features can then be held in contact by hoop or torsional strain or a lever/ pin based mechanism or similar means.

[0068] The term “unitary construction” includes a construction comprising a one-piece, integrally-formed component as well as an assembly of more than one component integrated together.

[0069] Figures 1A - 1C show a body (2) having a generally cylindrical or tubular shape with a bore (210) therethrough and which is made from a hard, strong metallic material with a high melting point, such as mild steel electroplated with zinc. Casting materials, such as iron, may alternatively be used.

[0070] Figure 2A - 2D show a tapered plug (3), having a generally cylindrical, or tubular shape, with a bore (300) therethrough and which is made from a hard plastics material such as acetal.

[0071] Figures 3A and 3B show a clip (4) which is generally C-shaped, formed from a resilient plastics material which preferably can be resiliently deformed by a human without tools. The material preferably has a long lifetime (at least greater than 50 years), The tapered plug (3) and the clip (4) may be 3D printed allowing for complex geometries with reproducible dimensions. Alternatively, the clip and/or tapered plug may be machined or injection moulded.

[0072] Referring to Figures 1B and 1C, a bore (210) extends along a longitudinal axis (900) inside body (2). The body (2) comprises a first diameter portion (201), a second diameter portion (202), with a larger diameter than the first diameter portion (201) and a third diameter portion (203) with a diameter intermediate that of the first and second diameter portions.

[0073] The body (2) is a unitary construction, consisting of a continuous piece of material which does not require any excess seals or fireproof washers, each of which would be additional, potentially expensive safety critical components which increase installation time and add to the potential for failure of the assembly. The service head adaptor assembly may therefore be smaller, easier to manufacture and install than those that make up the present state of the art.

[0074] The body (2) has one or more port holes (206) extending from the exterior of the body through to the interior surface of the body. The one or more port holes (206) may be oriented orthogonally from the longitudinal axis (900). The port holes (206) may be threaded, such that they can be sealed with grub nuts.

[0075] The internal surface of the first diameter portion (201) of the body is formed of two sections, a first (201 A) adapted to accommodate corrugations (or similar formations) (102) on the exterior of the lining pipe (101), shown in Figure 4 and a second section (201B) in which the interior surface is smooth to accommodate the flange of the tapered plug. The interior surface of the second diameter portion (202) of the body (2) is threaded and adapted to attach to a host pipe (100). The internal surface of the third diameter portion (203) of the body (2) defines a generally cylindrical chamber (204) which is adapted to accommodate the clip (4).

[0076] The external surface of the body (2) may be laser marked, cast, dot marked or engraved with text describing the manufacturer, batch number, and appropriate lining pipe size, as shown in Figure 1C.

[0077] Figure 1C shows the exterior of the body (2) which has two portions with different diameters which correspond with the first internal diameter portion (201), the second internal diameter portion (202) and in some embodiments (see figure 1B) the third internal diameter portion (203). The exterior of the first diameter portion (201) is at least partially threaded. The external thread is suitable to enable a valve or other standard component to be easily fitted thereto. In other embodiments (not shown), instead of an external thread, a spigot tail or flange face may be provided (for welding or other method of fixing).

[0078] The body (2) has one or more flat indentations or other formations (205) on its exterior surface which provide a flat surface where a user can apply a gripping tool. These indentations or formations may be formed such that they have a high coefficient of friction with said tools such as having small corrugations or other means which may increase the coefficient of friction and tool - body contact area.

[0079] Figure 2A shows an embodiment of the tapered plug (3). The tapered plug (3) has a first portion (301) which has a tapered leading edge. In another embodiment of the tapered plug (not shown), the full axial length of the first portion (301) is tapered.

[0080] Said first portion may also have one or more grooves (309) about its external diameter, which can receive O-rings or other seals. The tapered plug (3) has a flange (302) with a larger external diameter than that of the first portion (301). The flange (302) may also have one or more grooves (309) about its external diameter.

[0081] Figure 2B shows the leading edge of the tapered plug which has a non-circular cross section which may be an oval or elliptical cross-section, for example where x > y. Other non-circular shapes (not shown) are envisaged wherein two or more points around the circumference of the leading edge of the first portion (301) of the plug have a larger radius relative to the rest of the leading edge.

[0082] As seen in Figure 2C, the tapered plug (3) has two radially extending formations (304) on its leading edge. In some embodiments, there may be one or two or more of these radially extending formations (304).

[0083] In some embodiments, the tapered plug (3) has a circular cross section and comprises said radially extending formations (304) and in other embodiments said plug has a non-circular cross section which may be an oval or elliptical cross section with or without said radially extending formations (304). In either case, what is achieved at the leading edge of the tapered plug (3) is that less than the whole circumference of the leading edge contacts the lining pipe into which the plug is inserted. Instead, contact is made only at, for example, two points at the leading edge (in the embodiment illustrated in Figure 2B). These two points may be the outer extremes of the non-circular cross section. Alternatively, the two points may be the outer extremes of the formations (304).

[0084] Referring to Figure 3A, the clip (4) has an internal surface, an external surface, internal formations (403) and external formations (404). The internal formations may be grooves, corrugations or otherwise repeating or non-repeating formations which have a complementary shape to the lining pipe corrugations (102). The external formations (404) may be radially and axially-extending protrusions or other formations. The gaps between the external formations (404) provide flow channels for sealant, as will be described in more detail later.

[0085] Figure 3B shows another embodiment of the clip in which the clip is large enough to attach to two of the lining pipe corrugations (102). Other embodiments have an internal surface capable of accommodating one or two or three or more of lining pipe corrugations (102).

[0086] Figure 4 shows a cross sectional view of the assembled service head adaptor assembly (1), wherein the body (2), the tapered plug (3) and the clip (4) are assembled on the end of a host pipe (100) and lining pipe (101).

[0087] The clip (4) is adapted to fit inside the chamber (204) in the third diameter portion (203) of the body (2). The clip (4) is adapted to snap fit onto one of the lining pipe corrugations (102). The external formations (404) on the clip (4) are shaped to complement formations on the inside of the body which define the chamber (204). The height of the generally cylindrical chamber (204) is such that, when the body (2) is fully screwed onto the end of the host pipe (100), the clip (4) is not axially compressed.

[0088] The clip (4) is such that when it is snap-fitted to the lining pipe (101), the lining pipe (101) cannot be axially translated with respect to the host pipe (100). Downward (as drawn in Fig 4) axial translation of the lining pipe (101) is prevented by the clip (4) abutting the end surface of the host pipe (100), into which the clip (4) cannot fit. Upward (as drawn in Fig 4) axial translation of the lining pipe (101) is prevented by the clip (4) abutting a formation on the internal surface of the body (2), in this case the reduced diameter at the interface of the first diameter portion (201) and third diameter portion (203).

[0089] In practice, the service head adaptor assembly (1) is fitted to a service pipe as follows. Firstly, the lining pipe (101) is trimmed such that it protrudes from the host pipe (100) by a predetermined length. The clip (4) is then fitted to the base of the protruding lining pipe (101) such that the clip (4) abuts the end surface of the host pipe (100), preventing the lining pipe (101) from falling into the host pipe (100).

[0090] Next, the body (2) is fitted over the lining pipe (101) and clip (4) with the internally threaded portion of the body (2) attaching to the externally threaded portion of the host pipe (100), forming a fluid tight seal. The clip (4) is accommodated in the chamber (204) inside the third diameter portion (203) of the body (2).

[0091] Next, and as shown in Figure 5, the tapered plug (3) is inserted into the bore (210) of the body (2). This may be done with the use of a tool which does not impart rotational stress on the service head adaptor assembly. The plug (3) is inserted into the longitudinal bore (210) through the body (2) at the opposite end to that which is attached to the host pipe (100). The bore (210) also contains the portion of the lining pipe (101) which is protruding from the host pipe (100).

[0092] As can be seen in figure 5, due to its non-circular shape (or due to formations on the exterior of the tapered plug) the leading edge of the tapered plug (3) pinches the lining pipe (101) at two or more points as it is inserted. This pinching force substantially prevents axial translation of the lining pipe (101), which might otherwise be pushed axially by the incoming plug, possibly collapsing or otherwise damaging the end of the lining pipe (101).

[0093] As the tapered plug (3) is progressively inserted, the plug will begin to radially expand the end of the lining pipe (101). During this radial expansion, the corrugations (102) or other formations on the exterior of the lining pipe (101) will be forced into the grooves (207) in the interior of the body (2) forming a fluid tight seal. When fully inserted, the tapered plug (3) is axially flush with the opening of the bore (210) at the end of the body (2) into which the tapered plug (3) was initially inserted, as shown in Figure 4.

[0094] In some embodiments, the material of the lining pipe will be compressed between the tapered plug (3) and the interior of the body (2), as well as radially expanding its diameter.

[0095] Once the tapered plug is fully inserted, the annular volume between the host pipe (100) and the lining pipe (101) can be filled with a sealant. The sealant is provided at high pressure through one of the sealable port holes (206) in the body (2) of the assembly (1). Gaps between the formations (404) on the exterior of the clip (4) form flow channels for the sealant so that it can pass axially over the clip (4) in order to properly fill the volume between the host pipe (100) and lining pipe (101). After the sealant has been injected, the bores are closed with grub screws.

[0096] The clip (4) and the grooves (207) in the body (2) hold the lining pipe (101) in place, substantially preventing movement due to the forces applied by the incoming high pressure sealant.

[0097] The method described above has several advantages over those presently used as the state of the art. First, the method requires less labour in terms of reducing the amount of time taken to install the assembly as well as the assembly being smaller and weighing less, reducing transportation costs. Second, the method provides a safer seal as there are fewer screw threads and pressure fittings through which fluid may leak. Third, the clip allows the user to perform the installation without the risk of losing the lining pipe down the host pipe.

Reference numerals

Service head adaptor assembly

100 Host Pipe

101 Lining pipe

102 Lining pipe corrugations

Body

201 First diameter portion

202 Second diameter portion

203 Third diameter portion

204 Chamber to accommodate clip

205 Grip formations

206 Port holes

207 Grooves

210 Bore

Tapered plug

300 Bore

301 First diameter

302 Flange

304 Radially extending formations

309 Grooves

310 Elastomeric seals

Clip

403 Internal formations

404 External formations

900 Longitudinal axis [0098] All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

[0099] Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

[00100] The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. The claims should not be construed to cover merely the foregoing embodiments, but also any embodiments which fall within the scope of the claims.

[00101] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

[00102] Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

[00103] The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

Claims

1. A service head adaptor assembly adapted to be fitted onto a service pipe, where the service pipe comprises a metallic host pipe that is lined with an interior lining pipe, the adaptor assembly comprising: a. a body that is adapted to form a fluid-tight seal with the host pipe, the body having an interior surface and a bore therethrough, the bore having a first diameter portion capable of accommodating an end of said lining pipe and a second, larger, diameter portion capable of accommodating an end of said host pipe; b. a clip having an inner surface adapted to be attached onto an outer surface of the lining pipe in order to substantially prevent axial movement of the lining pipe with respect to the host pipe, in use; and c. a tapered plug insertable into said end of said lining pipe so as to apply a force to radially expand at least a part of said lining pipe to bear against said interior surface of said body. 2. The adaptor assembly of claim 1 wherein the tapered plug has a non-circular cross section. 3. The adaptor assembly of claim 1 or claim 2 wherein the tapered plug has an oval or elliptical cross section. 4. The adaptor assembly of any of the preceding claims wherein the tapered plug has one of more radially-extending formations on an exterior surface thereof. 5. The adaptor assembly of any of the preceding claims wherein the tapered plug has a radially-extending flange at one end thereof. 6. The adaptor assembly of any of the preceding claims wherein the tapered plug comprises one or more elastomeric seals on an exterior surface thereof, the elastomeric seal or seals being capable of forming a fluid-tight seal against said body and/or against said lining pipe. 7. The adaptor assembly of any of the preceding claims wherein the taper of said tapered plug comprises a tapered leading edge. 8. The adaptor assembly of any of claims 1-6 wherein the taper of said tapered plug comprises a taper extending along the longitudinal axis of the plug. 9. The adaptor assembly of any of the preceding claims wherein the tapered plug is made from a thermoplastic material, for example polyoxymethylene (acetal). 10. The adaptor assembly of any of the preceding claims wherein the clip is generally C shaped. 11. The adaptor assembly of any of the preceding claims wherein the clip is attachable to the outer surface of the lining pipe by a snap fit. 12. The adaptor assembly of any of the preceding claims wherein, in use, the clip abuts a formation on said interior surface of said body and/or an end of the host pipe in order to substantially prevent axial movement of the lining pipe with respect to the host pipe. 13. The adaptor assembly of any of the preceding claims wherein the clip comprises an interior surface having a recess therein capable of receiving a correspondingly-shaped formation on the exterior surface of the lining pipe. 14. The adaptor assembly of any of the preceding claims wherein the clip comprises an exterior surface having a formation thereon capable of engaging with said formation on said interior surface of said body. 15. The adaptor assembly of claim 14 wherein the formation on the exterior surface of the clip defines a flow channel to permit axial fluid flow past the clip, in use. 16. The adaptor assembly of any of the preceding claims wherein the interior surface of the body comprises a recess into which the exterior surface of the lining pipe can be radially expanded and/or compressed thereinto by said tapered plug. 17. The adaptor assembly of any of the preceding claims wherein at least part of the second diameter portion of the body is internally threaded. 18. The adaptor assembly of any of the preceding claims wherein at least part of the first diameter portion of the body is externally threaded. 19. The adaptor assembly of any of the preceding claims wherein the body has a unitary construction. 20. The adaptor assembly of any of the preceding claims wherein the body includes one or more ports through which filler or sealant material can be introduced. 21. A method of attaching the adaptor assembly of any of the preceding claims to a service pipe, the method including the steps of: a) cutting the lining pipe so that a length of lining pipe protrudes from the host Pipe; b) attaching said clip to the outer surface of the lining pipe in order to substantially prevent axial movement of the lining pipe with respect to the host pipe; c) attaching and sealing the body to the host pipe such that the end of the lining pipe extends into the bore of the body; d) inserting the tapered plug into the body and into said end of said lining pipe so as to apply a force to radially expand at least a part of said lining pipe to bear against said interior surface of said body. 22. The method of claim 21 wherein the body is attached to the host pipe via the thread on the second diameter portion of the body. 23. The method of claim 21 or claim 22 further comprising the step of applying a filler or sealant material between the exterior surface of the lining pipe and an interior surface of the host pipe. 24. The method of any of claims 21 to 23 further comprising the step of inserting the plug using a tool which does not impart a rotational force to the assembly, for example a screwjack, mallet or hammer. 25. The method of any of claims 21 to 24 wherein the radial expansion of at least a part of said lining pipe is an expansion of the internal diameter thereof by 2% to 4%. 26. The method of any of claims 21 to 25 wherein said application of force expands said exterior surface of said lining pipe into recesses in the interior surface of said body. 27. The method of any of claims 21 to 26 wherein said application of force compresses the material of said lining pipe. 28. The method of any of claims 21 to 27 further comprising the step of forming a fluid tight seal between the lower portion of the plug and said lining pipe. 29. The method of any of claims 21 to 28 further comprising the step of forming a fluid tight seal between the upper portion of the plug and said body. 30. The method of any of claims 21 to 29 wherein, at least upon initial insertion of the tapered plug, during application of said radially-expanding force the lining pipe is ovalized, and one or more foci of the ovalized lining pipe abut recesses in the interior surface of said body substantially preventing axial displacement of said lining pipe with respect to said body. 31. The method of any of claims 21 to 30 wherein, after insertion of the tapered plug into the body, the tapered plug is flush with and does not substantially protrude from the body. Amendments to the Claims have been filed as follows:CLAIMS

1. A service head adaptor assembly adapted to be fitted onto a service pipe, where the service pipe comprises a metallic host pipe that is lined with an interior lining pipe, the adaptor assembly comprising:

a. a body that is adapted to form a fluid-tight seal with the host pipe, the body having an interior surface and a bore therethrough, the bore having a first diameter portion capable of accommodating an end of said lining pipe and a second, larger, diameter portion capable of accommodating an end of said host pipe;

b. a clip having an inner surface adapted to be attached onto an outer surface of the lining pipe in order to substantially prevent axial movement of the lining pipe with respect to the host pipe, in use; and

c. a tapered plug insertable into said end of said lining pipe so as to apply a force to radially expand at least a part of said lining pipe to bear against said interior surface of said body.

2. The adaptor assembly of claim 1 wherein the tapered plug has a non-circular cross section.

3. The adaptor assembly of claim 1 or claim 2 wherein the tapered plug has an oval or elliptical cross section.

4. The adaptor assembly of any of the preceding claims wherein the tapered plug has one of more radially-extending formations on an exterior surface thereof.

5. The adaptor assembly of any of the preceding claims wherein the tapered plug has a radially-extending flange at one end thereof.

6. The adaptor assembly of any of the preceding claims wherein the tapered plug comprises one or more elastomeric seals on an exterior surface thereof, the elastomeric seal or seals being capable of forming a fluid-tight seal against said body and/or against said lining pipe.

7. The adaptor assembly of any of the preceding claims wherein the taper of said tapered plug comprises a tapered leading edge.

8. The adaptor assembly of any of claims 1-6 wherein the taper of said tapered plug comprises a taper extending along the longitudinal axis of the plug.

9. The adaptor assembly of any of the preceding claims wherein the tapered plug is made from a thermoplastic material.

10. The adaptor assembly of claim 9 wherein the thermoplastic material is polyoxymethylene (acetal).

11. The adaptor assembly of any of the preceding claims wherein the clip is generally C shaped.

12. The adaptor assembly of any of the preceding claims wherein the clip is attachable to the outer surface of the lining pipe by a snap fit.

13. The adaptor assembly of any of the preceding claims wherein, in use, the clip abuts a formation on said interior surface of said body and/or an end of the host pipe in order to substantially prevent axial movement of the lining pipe with respect to the host pipe.

14. The adaptor assembly of any of the preceding claims wherein the clip comprises an interior surface having a recess therein capable of receiving a correspondingly-shaped formation on the exterior surface of the lining pipe.

15. The adaptor assembly of any of the preceding claims wherein the clip comprises an exterior surface having a formation thereon capable of engaging with said formation on said interior surface of said body.

16. The adaptor assembly of claim 15 wherein the formation on the exterior surface of the clip defines a flow channel to permit axial fluid flow past the clip, in use.

17. The adaptor assembly of any of the preceding claims wherein the interior surface of the body comprises a recess into which the exterior surface of the lining pipe can be radially expanded and/or compressed thereinto by said tapered plug.

18. The adaptor assembly of any of the preceding claims wherein at least part of the second diameter portion of the body is internally threaded.

19. The adaptor assembly of any of the preceding claims wherein at least part of the first diameter portion of the body is externally threaded.

20. The adaptor assembly of any of the preceding claims wherein the body has a unitary construction.

21. The adaptor assembly of any of the preceding claims wherein the body includes one or more ports through which filler or sealant material can be introduced.

22. A method of attaching the adaptor assembly of any of the preceding claims to a service pipe, the method including the steps of:

23. The method of claim 22 wherein the body is attached to the host pipe via a thread on the second diameter portion of the body.

24. The method of claim 22 or claim 23 further comprising the step of applying a filler or sealant material between the exterior surface of the lining pipe and an interior surface of the host pipe.

25. The method of any of claims 22 to 24 further comprising the step of inserting the plug using a tool which does not impart a rotational force to the assembly.

26. The method of any of claims 22 to 25 wherein the radial expansion of at least a part of said lining pipe is an expansion of the internal diameter thereof by 2% to 4%.

27. The method of any of claims 22 to 26 wherein said application of force expands said exterior surface of said lining pipe into recesses in the interior surface of said body.

28. The method of any of claims 22 to 27 wherein said application of force compresses the material of said lining pipe.

29. The method of any of claims 22 to 28 further comprising the step of forming a fluid tight seal between a lower portion of the plug and said lining pipe.

30. The method of any of claims 22 to 29 further comprising the step of forming a fluid tight seal between an upper portion of the plug and said body.

31. The method of any of claims 22 to 30 wherein, at least upon initial insertion of the tapered plug, during application of said radially-expanding force the lining pipe is ovalized, and one or more foci of the ovalized lining pipe abut recesses in the interior surface of said body substantially preventing axial displacement of said lining pipe with respect to said body.

32. The method of any of claims 22 to 31 wherein, after insertion of the tapered plug into the body, the tapered plug is flush with and does not substantially protrude from the body.