GB2537883A

GB2537883A - Pipe joint

Info

Publication number: GB2537883A
Application number: GB1507351.3A
Authority: GB
Inventors: Patrick Manning John; Mitchell Henry
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-04-29
Filing date: 2015-04-29
Publication date: 2016-11-02
Also published as: GB201507351D0; GB2540016B; GB201607613D0; GB2540016A

Abstract

A pipe joint 1 for joining a first conduit section 10 to a second conduit section 20, the first conduit section 10 having at least one first connection end comprising a wall 14 defining a receiving recess 12 for receiving a second connection end of the second conduit section 20. The joint 1 comprises: at least one first groove 60 formed in an internal surface of the wall 14 of the first conduit section 10, the first channel 60 being accessible from the outside of the first conduit section 10, e.g. via a channel 70; at least one second groove 62 formed in an external surface of the second conduit section 20; and at least one flexible anchoring element 50 inserted into the first channel 60 so as to be seated between the first 60 and second 62 grooves or channels when they have been brought into alignment. The first and second conduit sections 10, 20 are united so as to be axially substantially immovable relative to each other and thus securely jointed together.

Description

Intellectual Property Office Application No. GII1507351.3 RTM Date:14 October 2015 The following terms are registered trade marks and should be read as such wherever they occur in this document: TEFLON (pages 8 & 12) Intellectual Property Office is an operating name of the Patent Office www.gov.uk/ipo

PIPE JOINT

TECHNICAL FIELD

This invention relates to a joint for pipes and other conduits. More particularly, though not exclusively, the invention relates to a joint for joining together plural lengths of pipe or other conduit, for example in the forming of a fluid transport system.

BACKGROUND AND PRIOR ART

As used herein the term "pipe" is to be construed broadly, and is to be understood as encompassing any form, shape and size of conduit, particularly a tubular conduit. Indeed the terms "pipe" and "conduit" may be used interchangeably herein. Such pipes or conduits to which the invention may be applied may in particular include pipes or conduits having any suitable or desired cross-sectional size (e.g. diameter) and/or longitudinal length.

Fluid transport systems are well-known for conveying flowable materials such as liquids and gases, with common examples including water and fuels, for example gas and oil. Such systems may include oil and gas pipelines for conveying fuel over large distances, even thousands of miles. The tubular conduits commonly used in fluid transport of fuel may be made of various metals, including steel, iron, copper or aluminium, or of various plastics materials. Typically pipelines are made by joining together individual lengths of pipe end-toend using a suitable joint or jointing system.

For small bore plastic pipes a press-or screw-fit joint can often be used, as that form of joint is often sufficient in that context. On the other hand, for small bore copper pipe the use of soft solder is the usual means of joint connection.

For larger diameter pipes, e.g. typically from around 1 to around 1.5 metres (around approximately 40 to 60 inches) in diameter, which is the size of pipe typically used in the transport of fuel via pipelines over large distances, welded joints are commonly used. However, welded joints have a disadvantage of requiring skilled workers to form them, as well as having negative health and safety and environmental implications. For example, the construction of gas or oil conveying pipelines, which are typically made from approximately 12 metre (approximately 40 feet) long lengths of steel pipe with a diameter of around 1 to 1.5 metres (around approximately 40 to 60 inches), conventionally use welded joints. Each joint can typically take a skilled team a whole day to make, taking into consideration the deployment of the necessary equipment at the joint location and the subsequent inspection and/or testing of the completed joint such as by use of X-ray equipment. Also, around 1 in 10 of such welded joints typically may need some repair after such inspection. All this makes oil and gas pipelines particularly expensive and time consuming to construct and maintain.

A further problem with both press-fit and welded joints is that they are difficult to disconnect, for example for repair or maintenance, and once disconnected they are generally not re-useable. Furthermore, disconnection of press-fit or welded joints often results in damage to the pipe lengths themselves.

It is therefore a primary object of this invention to address the above shortcomings of known pipe joints and to provide a novel form of pipe joint which is quick and easy to assemble or deploy, and likewise efficient to disassemble or disconnect whilst maintaining the integrity and re-usability of the pipe lengths.

SUMMARY OF THE INVENTION

Aspects of the present invention provide a pipe joint, a method of joining together at least two lengths of pipe, a kit of parts for use in joining together at least two lengths of pipe, and a pipe or pipeline formed from a plurality of pipe sections in which adjacent sections are joined together using the joint or by the jointing method.

In a first aspect of the present invention there is provided a pipe joint for joining a first conduit section to a second conduit section, the first conduit section having at least one first connection end comprising a wall defining a receiving recess for receiving a second connection end of the second conduit section, wherein the joint comprises: at least one first groove or channel formed in an internal surface of the wall of the receiving recess of the first conduit section, the or each first groove or channel being accessible from the outside of the first conduit section; at least one second groove or channel formed in an external surface of the second connection end of the second conduit section; and at least one flexible anchoring element inserted into at least the or a respective first groove or channel so as to be seated in both that first and the second grooves or channels when they have been brought into register or alignment upon insertion of the second connection end of the second conduit section into the receiving recess of the first conduit section, whereby upon said insertion and seating of the or the respective anchoring element in the said aligned respective first and second grooves or channels the first and second conduit sections are united so as to be axially substantially immovable relative to each other.

In some practical embodiments of the above first aspect the pipe joint may be in an "as (or when) formed" condition, i.e. in which the joint has already been made, wherein the second connection end of the second conduit section has already been inserted into the receiving recess of the first conduit section such as to bring into register or alignment the respective first and the second grooves or channels, and the or the respective flexible anchoring element has been inserted into at least the or the respective first groove or channel so as to be seated in both that first and the second aligned grooves or channels, thereby uniting the first and second conduit sections so as to be axially substantially immovable relative to each other.

However, in other embodiments of the above first aspect the pipe joint may be provided in the form of a kit of parts for, and prior to, forming the said joint. Accordingly, and in accordance with a second aspect of the invention, there is provided a kit of parts for forming a joint between a first conduit section and a second conduit section, wherein the said kit comprises: the said first conduit section and the said second conduit section, wherein the first conduit section has at least one first connection end comprising a wall defining a receiving recess for receiving a second connection end of the second conduit section, and wherein an internal surface of the wall of the receiving recess of the first conduit section has at least one first groove or channel formed therein, the or each first groove or channel being accessible from the outside of the first conduit section, and an external surface of the second connection end of the second conduit section has at least one second groove or channel formed therein; and at least one flexible anchoring element insertable into at least the or a respective first groove or channel so as to be seatable in both that first and the second grooves or channels when they are brought into register or alignment upon insertion of the second connection end of the second conduit section into the receiving recess of the first conduit section, whereby upon said insertion and seating of the or the respective anchoring element in the said aligned respective first and second grooves or channels the first and second conduit sections are united so as to be axially substantially immovable relative to each other.

In embodiments of the pipe joint of the invention any suitable numbers of first and second grooves or channels in, respectively, the internal surface of the wall of the receiving recess of the first conduit section and the external surface of the second connection end of the second conduit section may be provided, for seating therein of a respective one of any suitable number and/or shape and configuration of flexible anchoring elements.

In some embodiments just a single flexible anchoring element may be provided for insertion into and seating in the void created by and between a single pair of first and second grooves or channels in, respectively, the internal surface of the wall of the receiving recess of the first conduit section and the external surface of the second connection end of the second conduit section. However in other embodiments a plurality of flexible anchoring elements may be provided each for insertion into and seating in the respective void created by and between a respective one of a plurality of pairs of first and second grooves or channels in, respectively, the internal surface of the wall of the receiving recess of the first conduit section and the external surface of the second connection end of the second conduit section. In yet other embodiments a single flexible anchoring element may be provided for insertion into and seating in the void created by and between a single one of a first or a second groove or channel in combination with, respectively, a plurality of second or first grooves or channels, as the case may be, wherein the flexible anchoring element is appropriately constructed, shaped and/or configured with a plurality of portions, especially a plurality of axial portions, to permit such seating in those said single first or a second groove or channel, as the case may be, and plurality of second or first, as the case may be, grooves or channels.

In cases of a plurality of either or both of the first or second grooves or channels, those respective first or second grooves or channels of the plurality may be spaced apart from each other in an axially longitudinal direction along the respective conduit section(s).

In cases of such plural, optionally axially spaced apart, first and/or second grooves or channels and plural anchoring elements, it is to be understood that this arrangement may create or contribute to a more structurally secure and stable joint.

In some embodiments the or each pair of first and second grooves or channels may lie or be oriented substantially circumferentially relative to the conduit sections, i.e. they may be oriented so as to lie substantially in a single plane perpendicular or normal to the longitudinal axial direction of the conduit sections. However in other embodiments the or each pair of first and second grooves or channels may lie or be oriented so as to lie substantially in a single plane angled at a non-right angle (e.g. at an angle in the range from about 60 or 70 up to about 85 or 87 or 88 or 89°) to the longitudinal axial direction of the conduit sections.

In yet other embodiments the or each pair of first and second grooves or channels may be spatially arranged so as to lie helically, i.e. to form a helical path around the axis of the conduit sections. Such a helical path may extend by at least one revolution around the axis of the conduits sections, optionally a plurality of revolutions therearound.

In the case of plural pairs of first and second grooves or channels in which each respective pair lies in substantially a single respective plane, the respective planes of different ones of the pairs of first and second grooves or channels may be either substantially parallel to each other or substantially non-parallel, i.e. angled (e.g. at an angle in the range from about 60 or 70 up to about 85 or 87 or 88 or 89°) relative to each other.

In embodiments of the pipe joint the first and second groove(s) or channel(s) in, respectively, the internal surface of the wall of the receiving recess of the first conduit section and the external surface of the second connection end of the second conduit section may be of the same or substantially the same shape or configuration, or they may be of a different or significantly different shape or configuration from one another. In either case the exterior shape or configuration of the or the respective flexible anchoring element may be shaped so as to substantially match the interior shape or configuration of the or the respective pair of first and second grooves or channels when they are brought into register or alignment upon the insertion of the second connection end of the second conduit section into the receiving recess of the first conduit section.

For instance, in one example form the first groove(s) or channel(s) in the internal surface of the wall of the receiving recess of the first conduit section may be of a first shape/configuration and/or depth, for accommodating a correspondingly shaped/configured first radial portion of the or the respective flexible anchoring element, and the second groove(s) or channel(s) in the external surface of the second connection end of the second conduit section may be of a second shape/configuration and/or depth, for accommodating a correspondingly shaped/configured second radial portion of the or the respective flexible anchoring element.

The first shape/configuration may for instance be a substantially rectangular cross-section, in which the radial bed of the or the respective first groove(s) or channel(s) is substantially cylindrical and lies substantially parallel to the longitudinal axis of the first conduit section, optionally with the opposite lateral sides of the or the respective first groove(s) or channel(s) oriented substantially perpendicular to the said longitudinal axial direction. The second shape/configuration may for instance be a substantially non-rectangular cross-section, such as comprising one or a plurality of part-circular-, part-elliptical-, arcuate-, or regularly-or irregularly-cross-sectioned, e.g. part-toroidal or annular, second groove/channel portions, which in the case of plural such second groove/channel portions may optionally be spaced apart from each other in an axially longitudinal direction along the second conduit section within the axial extent of the respective second groove or channel. Of course, the locating of such particularly shaped/configured first and/or second groove(s) or channel(s) in, respectively, the internal surface of the wall of the receiving recess of the first conduit section and the external surface of the second connection end of the second conduit section may be reversed as or if necessary or desired.

Thus, in the above embodiments of differently shaped/configured first and second groove(s) or channel(s), the exterior shape or configuration of the or the respective flexible anchoring element may preferably be shaped or configured into respective first and second radial anchoring portion(s) which substantially match or fit within the respective radial portions of the respective first and second groove(s) or channel(s) into which they are to be seated when the joint is formed.

In practical embodiments of the pipe joint of the invention, such as any of those defined above, the first and second grooves or channels may each be formed by any suitable method or technique for forming grooves or channels in pipe walls or in surfaces of pipe walls adjacent or near connection ends thereof. Such methods or techniques may include any one or more of the following: production moulding (i.e. upon manufacture of the relevant conduit section itself), cutting, machining or grinding. Post-production cutting or machining may be especially useful in many practical example embodiments. Suitable apparatuses or devices for performing such cutting or machining, or even other, groove-or channel-forming techniques, are well-known and widely available in the art and the patent literature.

The or each respective anchoring element may be made of any suitable flexible material, such as a metal or metal alloy, e.g. spring steel, or a plastics material, e.g. made by any suitable moulding or extrusion process. A plastics material may be especially preferred owing to its low cost, ease of manufacture, physical strength and desirable flexible properties. Preferably the material is sufficiently flexible, or possibly even sufficiently resiliently flexible, to enable the or the respective anchoring element to be insertable into the or the respective first groove or channel from the outside of the first conduit section. If desired or necessary the material of the or the respective anchoring element may have a degree of inherent resilience or resilient softness such that it may act as a seal against a surface of the respective first and/or second grooves or channels against which it abuts when in its seated position therein.

Preferably the or each anchoring element may be elongate, e.g. in the form of a wire, cable, rod or strip, preferably with a length at least sufficient for it to be insertable into at least a major proportion of the linear length of the or the respective first groove or channel. That major proportion of the linear length of the or the respective first groove or channel may in some particularly preferred cases be substantially the whole of that linear length of the or the respective first groove or channel, especially in cases where that linear length of the or the respective first groove or channel is a single circumferential length. Such an arrangement may be particularly useful for enhancing the strength of the resulting joint connection.

In some embodiments the or each anchoring element may have a radial dimension at any given axial location therealong which is at least equal to the combined radial dimensions of the aligned respective first and second grooves or channels, into which it is to be seated, at that axial location. In particular, the radial dimension of the or the respective anchoring element may, at any given axial location therealong, be greater than the radial dimension of the respective first groove or channel, whereby the respective anchoring element extends into and preferably fits snugly within the aligned respective second groove or channel when inserted into the respective first groove or channel from the outside of the first conduit section.

If desired or necessary the radial dimension of the respective anchoring element, at any given axial location therealong, may even be slightly greater than the combined radial dimensions of the aligned respective first and second grooves or channels. In this case any such excess radial width of the respective anchoring element may be taken up or accommodated by any inherent resilient softness of the anchoring element material itself, thereby contributing to the sealing effect of the respective anchoring element against the relevant internal surfaces of the respective first and/or second aligned grooves or channels against which it abuts when in its seated position therein.

In certain embodiments of the pipe joint of the invention there may, if desired or necessary, additionally be provided at least one secondary seal element or member between a portion of the receiving recess of the first conduit section and a portion of the second conduit section. Such a secondary seal element or member, which may serve to additionally provide sealing between the respective first and second conduit sections once the joint therebetween has been formed, may be of any conventional type of seal used in the current art, e.g. one or more lip seals, brush seals, leaf seals, finger seals, labyrinth seals, piston rings, split ring seals, carbon seals, or any other suitable type of compliant or resilient contacting seal. Such a secondary seal element or member may optionally be provided or mounted in its own dedicated secondary sealing groove, channel or recess formed in one or other or both of a portion of the inner surface of the receiving recess of the first conduit section and a portion of the outer surface of the second conduit section. Such a secondary sealing groove, channel or recess may be axially spaced from or adjacent the respective first and second grooves or channels which form the pipe joint itself.

In some embodiments, alternatively or additionally to the above at least one secondary seal element or member, the receiving recess of the first conduit section may be provided internally with an end-abutment seating and sealing element, device or arrangement, against which a terminal end of the connection end of the second conduit section may abut and seal once it has been inserted into the recess for forming the joint. Such an arrangement may further enhance the sealing efficacy of the joint between the conduit sections once formed.

In some embodiments the insertion of the or the respective anchoring element into the or the respective first groove or channel may be via an insertion channel or passage which communicates between the first groove or channel and the outside of, especially an exterior surface of, the first conduit section. Such an insertion channel or passage may preferably be oriented non-radially, e.g. tangentially, chordally, or otherwise transversely, relative to the cross-section of the first conduit section. The or the respective insertion channel or passage may preferably be internally shaped and dimensioned to sufficiently accommodate the or the respective anchoring element which is to be inserted therethrough. In some embodiments the or the respective insertion channel or passage may merge smoothly into or with the or the respective first groove or channel so that the or the respective anchoring element can pass smoothly from the former into the latter during its insertion operation.

In some embodiments, for enhancing the ease of insertion of the or the respective anchoring element in the or the respective first groove or channel, the anchoring element may be provided with a terminal end portion comprising a handle, hook or other engagement or manipulation device, so that it may for example be grasped and manipulated manually, or alternatively by use of a tool. Furthermore, if desired or necessary, a lubricant material, e.g. Teflon ®, may be applied to, e.g. as a coating on, the or the respective anchoring element to further facilitate the sliding insertion or extraction thereof into and/or from the or the respective first groove or channel, preferably via the or the respective preferred insertion channel or passage.

In some embodiments the above-mentioned terminal end portion of the or the respective anchoring element may be seatable and/or engageable and/or sealable in a or a respective parking recess, channel or engagement device formed or provided in or on the exterior, especially an exterior surface, of the first conduit section, in order not only to provide a convenient parking site for that terminal end of the inserted anchoring element, but also to prevent or help prevent its unwanted, accidental or unauthorised withdrawal therefrom.

In a third aspect of the invention there is provided a method of joining together at least two conduit sections of a pipe, pipeline or other conduit, wherein the conduit sections comprise a first conduit section having at least one first connection end comprising a wall defining a receiving recess for receiving a second connection end of a second conduit section, there being formed in an internal surface of the wall of the receiving recess of the first conduit section at least one first groove or channel accessible from the outside of the first conduit section, and there being formed in an external surface of the second connection end of the second conduit section at least one second groove or channel, wherein the method comprises: providing at least one flexible anchoring element; inserting the second connection end of the second conduit section into the receiving recess of the first conduit section such as to bring into register or alignment the or a respective first and the second grooves or channels; and inserting the said flexible anchoring element into at least the or the respective first groove or channel so as to be seated in both that first and the second grooves or channels; whereby following said insertion and seating of the or the respective anchoring element in the said respective first and second grooves or channels the first and second conduit sections are united so as to be axially substantially immovable relative to each other.

In some practical embodiments of the above method, the method may comprise the additional steps of actually forming in the internal surface of the wall of the receiving recess of the first conduit section the said at least one first groove or channel accessible from the outside of the first conduit section, and/or actually forming the said at least one second groove or channel in the external surface of the second connection end of the second conduit section. Some embodiments of the method may further additionally comprise the step of forming, e.g. by drilling, the above-mentioned optional yet preferred insertion channel or passage which communicates between the or the respective first groove or channel and the outside of, especially an exterior surface of, the first conduit section, via which insertion channel or passage the or the respective anchoring element is insertable into at least the or the respective first groove or channel.

In embodiments of the above jointing method any of its individual defined features may be the same as or correspond to any of those defined or described above or below in the context of any embodiments of any other aspect of the invention.

In a fourth aspect of the invention there is provided a pipe or pipeline formed from a plurality of conduit sections, wherein adjacent conduit sections are joined together using a joint according to the first or second aspects of the invention or any embodiment of either thereof, or by a jointing method according to the third aspect of the invention or any embodiment thereof.

In embodiments of the above pipe or pipeline any of its individual defined features may be the same as or correspond to any of those defined or described above or below in the context of any embodiments of any other aspect of the invention.

In practical use or deployment of embodiments of pipe joint within the scope of the invention, subsequent to the joint having been formed, it may be disassembled and the first and second conduit sections disconnected by simple reversing the steps by which the joint was formed in the first place. Thus, such a disassembly or disconnection method may include the sequential steps of withdrawing or removing the or the respective anchoring element(s) from its/their respective first groove(s) or channel(s), for example via the (or the respective) exterior-communicating insertion channel or passage through which it was passed to form the joint, thereby allowing the first and second conduit sections to be axially moveable relative to each other once more, following which the first and second conduit sections can be drawn apart and detached from one another. This simple, non-invasive and non-destructive process may thus avoid damage to the first and second conduit sections and also preserve the structural integrity and shape and configuration of the walls defining the first and second connection ends of, respectively, the first and second conduit sections.

Embodiments of the pipe joint of the invention may be applied to a wide variety of pipes or conduits, for conveying a wide variety of materials. Its applicability to the connecting together or jointing of adjacent or sequential conduit sections in the forming of pipelines for various fluid, e.g. gaseous or liquid, products, such as oil, gas or other fuels, may be an especially useful application. Such pipes or conduits may often be substantially circular or cylindrical in cross-section, although other shaped cross-sections may be possible.

Embodiments of the pipe joint of the invention are relatively cheap to make and install, requiring few component parts and little or no specialist machinery, and the jointing operation itself may be carried out wholly from outside the conduit sections to be joined. They are also particularly safe to install and use, as they do not require welding as in many prior art pipe jointing systems Within the scope of this application it is envisaged that the various aspects, embodiments, examples and alternatives, and in particular the individual features thereof, set out in the preceding paragraphs, in the claims and/or in the following description and drawings, may be taken independently or in any combination. For example features described in connection with one particular embodiment are applicable to all embodiments, unless expressly stated otherwise or such features are incompatible.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the invention in its various aspects will now be described, by way of example only, with reference to the accompanying drawings, in which: FIGURE 1 is a longitudinal cross-sectional view of a pipe joint according to one example embodiment of the invention, shown forming a joint between a first (outer) conduit or pipe section and a second (inner) conduit or pipe section; FIGURE 2 is a longitudinal cross-sectional view of the first, i.e. outer, conduit or pipe section alone, showing more clearly the arrangement and configuration of the various internal grooves or channels therein; FIGURE 3 is an enlarged sectional view of the elongate anchoring element which is used to anchor the joint of FIG. 1; and FIGURE 4 is an end-on, part-sectional view of the joint of FIG. 1 along arrows IV-IV therein.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring firstly to FIG. 1, the pipe (or conduit) joint shown generally as 1 is formed between a first, or female, conduit or pipe section 10 and a second, or male, conduit or pipe section 20 of smaller diameter than the first section 10. The walls 14 of a connection end of the first conduit section 10 form and define a receiving recess 12 for receiving therein a connection end of the second conduit section 20. The joint 1 is formed once the connection end of the second conduit section has been inserted into the receiving recess 12 of the connection end of the first conduit section 10. The pipe (or conduit) sections 10, 20 are formed e.g. of plastics material, or alternatively of a metal or metal alloy, depending for example on the practical application of the pipe (or conduit) and, in particular, the material to be conveyed by it.

In a typical example the pipe or conduit sections form part of a pipe or pipeline for conveying liquid or gaseous fluids, such as oil or gas, or even water, sewage or other flowable material. The pipe or pipeline diameter may be of any suitable or desired size, e.g. depending on the industrial application and the material to be conveyed by it. By way of example, a general pipe or pipeline diameter of the order of approximately 1 to 1.5 metres may be typical for e.g. long-distance oil or gas pipelines. The sizing of the components forming the joint 1 may be scaled up or down as appropriate to the size and scale of the pipe or pipeline whose pipe or conduit sections 10, 20 are to be joined.

In FIGS. 1 and 2 the arrangement is illustrated with the first (female) conduit section 10 having two opposite connection ends, with each end being formed with the same arrangement of internal grooves or channels for forming at each such end a respective joint to an adjacent or sequential second conduit section along the pipeline. The first (female) conduit section 10 may of course be of any suitable longitudinal length, although it is shown here in compacted or truncated form for ease of explanation of the construction and configuration of the joint of the embodiment. However, for clarity, the arrangement of internal grooves or channels in the left-hand connection end of the first (female) conduit section 10 into which is shown fitting the connection end of the second (male) conduit section 20 is described by use of reference numerals applied to the corresponding features at the opposite, right-hand connection end of the first (female) conduit section 10 where the same form of joint 1 may be formed with a like second (male) conduit section 20.

The joint 1 is formed by the interaction or cooperation between respective first 60 and second 62 grooves or channels formed, respectively, in the first and second conduit sections 10, 20, and an elongate flexible anchoring element 50 inserted therein from the outside of the conduit sections 10, 20. The flexible anchoring element 50 takes the form of an extruded flattened strip of plastics material, e.g. a polymeric material such as a nylon, polyethylene, polypropylene or other tough yet resiliently flexible material. Optionally the anchoring strip 50 may be coated with a low-friction material or lubricant, e.g. Teflon e. The inherent degree of resilience or resilient softness of the plastics material of the anchoring strip 50 serves to introduce a sealing function to the strip in addition to its primary anchoring and joint-forming functionality.

The first groove or channel 60 is formed in the interior surface of the wall of the receiving recess 12 of the first pipe section 10, such as by a post-production cutting or machining operation using any suitable conventional machine or equipment. The first groove or channel 60 is shown here as being of rectangular cross-section, so as to form a rectangular recessed internal groove extending circumferentially all the way round the internal wall of the first pipe section 10.

To provide access to the first groove or channel 60 from the outside of the first pipe section 10 an access insertion passage or channel 70 is formed generally transversely, e.g. chordally or even tangentially, through the material of the wall 14 of the first pipe section 10 so as to link and provide communication between the first groove or channel 60 and the outside. Where the insertion passage or channel 70 meets the first groove or channel 60 the junction is preferably of the nature of a smooth merging between the two, so as to facilitate the passage of the forward terminal end of the anchoring strip 50 into the latter from the former with a continuous motion or pushing force.

The insertion passage or channel 70 has a cross-sectional shape which substantially matches that of the anchoring strip 50, so it may be readily inserted therein and passed therethrough by simple pushing. The configuration of the insertion passage or channel 70 is shown more clearly in FIG. 4.

The second groove or channel 62 is formed in the exterior surface of the connection end of the second pipe section 20, again by a conventional cutting or machining process. In this example the second groove or channel 62 is configured as the combination of a pair of discrete, axially spaced apart, part-circular-sectioned groove or channel portions extending circumferentially around the second pipe section connection end. The pair of discrete, axially spaced apart, part-circular-sectioned groove or channel portions 62 may or may not themselves be joined by a flat central bridging groove or channel portion, depending for example on the radial thickness of the central portion of the anchoring strip 50 to be accommodated in the void created by and between the combined first and second grooves or channels 60, 62 once they have been brought into register or alignment upon the insertion of the connection end of the second pipe section 20 into the receiving recess 12 of the first pipe section 10.

As shown in FIG. 3, the anchoring strip 50 is formed with an overall shape which substantially matches the shape of the combined first and second grooves or channels 60, 62 once they have been brought into register or alignment upon the insertion of the connection end of the second pipe section 20 into the receiving recess 12 of the first pipe section 10. For this purpose the anchoring strip 50 may comprise a generally rectangular radially outer portion 56, configured for seating within the correspondingly shaped recessed first groove or channel 60, and a pair of axially spaced apart radially inner lobe portions 52, 54, configured for seating within the correspondingly shaped part-circular-sectioned groove or channel portions 62 forming the second groove or channel.

The provision of the pair of axially spaced apart lobe portions 52, 54 of the anchoring strip 50 may thus have a corresponding function to a plurality of discrete, axially spaced apart circumferential anchoring elements which may in alternative embodiments be provided in combination with their own respective discrete, axially spaced apart, circumferential first grooves or channels.

In order to further enhance the sealing between the first and second pipe sections 10, 20 as or once the joint is formed, a secondary seal 80 may be provided, which in this illustrated example is in the form of an elastomeric or resilient lip sealing member or piston-ring-type seal 80 located in its own dedicated secondary sealing groove or channel 82 formed, e.g. again by cutting, in the interior wall of the receiving recess 12 of the first pipe section 10.

In order to form the pipe joint 1, the following sequence of steps are performed: (1) insert the (male) connection end of the second pipe section 20 into the (female) receiving recess 12 of the first pipe section 10; (2) slide the (male) connection end of the second pipe section 20 along and within the (female) receiving recess 12 of the first pipe section 10 far enough to bring into register or alignment the radially outer first groove or channel 60 and the pair of arcuate part-circularsectioned groove or channel portions 62 of the radially inner second groove or channel 62, thereby forming or defining a void by and between the combined aligned radially outer 60 and radially inner 62 grooves or channels; (3) insert the flexible anchoring strip 50 into the transverse insertion passage or channel and from there onward and into the first groove or channel 60 so that it becomes seated and accommodated within the void formed by and between the combined aligned outer and inner grooves or channels 60, 62; (4) in which final configuration -following the insertion and seating of the anchoring strip 50 into the combined aligned outer and inner grooves or channels 60, 62 -the first and second pipe sections 10, 20 are united so as to be axially substantially immovable relative to each other and thus securely joined together.

As or when it may be necessary, e.g. for maintenance or repair of either pipe section 10, 20, or even replacement of any component(s) of the joint 1, or possibly even for dismantling of the joint 1 for re-assembly elsewhere or entire moving of the pipeline, disassembly or disconnection of the joint 1 may be carried out simply and without damage to either pipe section 10, 20 or components of the joint by reversing the above sequence of steps, that is to say: (5) starting from the condition in which the first and second pipe sections 10, 20 are united so as to be axially substantially immovable relative to each other and thus securely joined together following insertion and seating of the anchoring strip 50 into the void formed by and between the combined aligned outer and inner grooves or channels 60, 62: slidably remove or extract -e.g. by simple pulling of its free outer end, either manually or by use of a tool -the flexible anchoring strip 50 from the first groove or channel 60 via the transverse insertion passage or channel 70, and from there completely remove it to the outside of the pipe sections 10, 20; (6) with the pipe sections 10, 20 now no longer fixedly united together in the axial direction and therefore free to slide axially relative to one another: slide the (male) connection end of the second pipe section 20 in the reverse axial direction along and within the (female) receiving recess 12 of the first pipe section 10 far enough to remove the (male) connection end of the second pipe section 20 from the (female) receiving recess 12 of the first pipe section 10, in which final condition the two pipe sections 10, 20 are now detached from one another and can be removed separately for whatever onward treatment, attention or use is required.

Throughout the description and claims of this specification, the words "comprise" and "contain" and linguistic variations of those words, for example "comprising" and "comprises", mean "including but not limited to", and 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.

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.