GB2560372A

GB2560372A - Pipe joining means

Info

Publication number: GB2560372A
Application number: GB1703849.8A
Authority: GB
Inventors: Virgil Webb Darren
Original assignee: Polypipe Ltd
Current assignee: Polypipe Ltd
Priority date: 2017-03-10
Filing date: 2017-03-10
Publication date: 2018-09-12
Anticipated expiration: 2037-03-10
Also published as: GB201703849D0; GB2560372B

Abstract

A locking means 1 constrains axial movement of a first pipe 2 relative to a second pipe (3, Fig. 1) when an end portion of the first pipe is located in a socket 4 of the second pipe with the socket having a radially outward projecting portion 5. The locking means comprises an anchoring means 6 affixed to the exterior surface 7 of the first pipe at a position proximate but external from the socket when the first pipe is in the socket. The locking means further comprises a connecting member 8 arranged to engage with the anchoring means and the radially outward projecting portion of the socket, thereby constraining axial movement of the first pipe relative to the second pipe. A kit comprises the locking means, first and second sections of pipe and a socket for coupling the two sections of pipe. The allowed amount of axial displacement can be pre-defined in order to limit expansion movement. The connecting member can comprise a pair of semi-circular arcuate collar sections each having axially spaced apart shoulders 10a, 10b and radially outward tabs for securing the collar sections together. A method of constraining axial movement uses the apparatus previously described.

Description

(54) Title of the Invention: Pipe joining means

Abstract Title: Expansion constraining coupling locking means (57) A locking means 1 constrains axial movement of a first pipe 2 relative to a second pipe (3, Fig. 1) when an end portion of the first pipe is located in a socket 4 of the second pipe with the socket having a radially outward projecting portion 5. The locking means comprises an anchoring means 6 affixed to the exterior surface 7 of the first pipe at a position proximate but external from the socket when the first pipe is in the socket. The locking means further comprises a connecting member 8 arranged to engage with the anchoring means and the radially outward projecting portion of the socket, thereby constraining axial movement of the first pipe relative to the second pipe. A kit comprises the locking means, first and second sections of pipe and a socket for coupling the two sections of pipe. The allowed amount of axial displacement can be pre-defined in order to limit expansion movement. The connecting member can comprise a pair of semi-circular arcuate collar sections each having axially spaced apart shoulders 10a, 10b and radially outward tabs for securing the collar sections together. A method of constraining axial movement uses the apparatus previously described.

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Pipe joining means

Technical Field

The present invention relates to joints/couplings in pipe installations, and more specifically to arrangements for joining and locking two pipes together whilst both allowing for and controlling the extent of expansion at and about the joint.

Background

Relevant pipe coupling assemblies known in the art are described, for example, in US 2012/0217743 A1 and GB 2349189 A.

Such arrangements employ a pipe collar of some form which engages with circumferential grooves or shoulders formed at the ends of the two pipes to be joined. A rubber gasket is typically contained within the collar which provides a fluid seal at the joint between the two pipes. The collar, by engaging the grooves or shoulders, substantially prevents the two pipes from moving axially relative to each other thereby locking them together with little or no built-in expansion tolerance.

The present inventors have appreciated that such arrangements can only operate with pipes having appropriately matching pre-formed grooves or shoulders which can engage with the pipe collar to form a tight coupling of the two pipes. Furthermore, these assemblies can accommodate little, if no, expansion at the joint and consequently the inclusion of a separate expansion mechanism at a different location, such as rubber bellows, may be required if expansion is foreseen. If expansion is not adequately accommodated, a large amount of strain may be placed on the pipe coupling when in use (e.g. when a hot fluid is flowing through the pipe) which may ultimately lead to the failure of the pipe coupling/joint.

Accordingly, an alternative means for joining and locking two pipes together is sought, which enables control of the expansion whilst being applicable to standard pipes and sockets, without requiring them to be fabricated with specifically tailored grooves or shoulders.

Summary

According to a first aspect of the invention there is provided a locking means for constraining axial movement of a first pipe relative to a second pipe when an end portion of the first pipe is located in a socket of the second pipe, the socket having a radially outward projecting portion, the locking means comprising: an anchoring means for affixing to the exterior surface of the first pipe at an axial position proximate but external from the socket when the first pipe is located in the socket; and a connecting member arranged to engage and cooperate with both the anchoring means and the radially outward projecting portion of the socket, thereby constraining axial movement of the first pipe relative to the second pipe.

The locking means may be configured so as to allow a pre-defined maximum amount of axial displacement of the first pipe relative to the socket of the second pipe, in order to limit expansion movement of the first pipe and/or the second pipe.

The connecting member may comprise a pair of substantially semi-circular arcuate collar sections, each collar section having axially spaced-apart inward first and second shoulders and radially outward tabs at end portions thereof for securing the pair of collar sections together to form a collar around the first and second pipes. The collar sections may be arranged to be screwed or glued together at the tabs thereof.

The anchoring means may be formed of a ring having a radially outward projection around the circumference thereof, and wherein the diameter of the ring is configured to accommodate the first pipe. The ring may have a plurality of axially spaced apart radially outward projections around the circumference thereof, in order to provide different tolerances for the amount of axial movement of the first pipe relative to the second pipe.

The first shoulders of the collar may be arranged to engage and cooperate with the radially outward projection of the anchoring means and the second projections of the collar may be arranged to engage and cooperate with the radially outward projecting portion of the socket.

The first pipe may be made of polyvinyl chloride (PVC), high-density polyethylene (HDPE) or another thermoplastic, and the second pipe may be made of polyvinyl chloride (PVC), high-density polyethylene (HDPE) or another thermoplastic. The connecting member and anchoring means may each be made of PVC, HDPE or another thermoplastic. The anchoring means may be solvent welded or butt welded to the first pipe.

The radially outward projecting portion of the socket may contain a rubber seal for sealably engaging the first pipe, i.e. the socket may be a ring seal socket.

According to a second aspect of the invention, a kit is provided, the kit comprising: the locking means according to the first aspect of the invention, first and second sections of pipe, and a socket for coupling the first section of pipe to the second section of pipe.

According to a third aspect of the invention, a pipe installation is provided, the pipe installation comprising: a first section of pipe installed within a socket of a second section pipe, and the locking means according to the first aspect of the invention.

According to a fourth aspect of the invention, a method is provided of constraining axial movement of a first pipe relative to a second pipe when an end portion of the first pipe is located in a socket of the second pipe, the socket having a radially outward projecting portion, the method comprising: affixing an anchoring means to the exterior surface of the first pipe at an axial position proximate but external from the socket when the first pipe is located in the socket; and providing a connecting member which engages and cooperates with both the anchoring means and the radially outward projecting portion of the socket, thereby constraining axial movement of the first pipe relative to the second pipe.

The locking means according to the present invention can be used in conjunction with a conventional ring seal socket and pipe sections, and does not require the pipes to have pre-formed grooves or shoulders for engagement with a collar, as is the case in the prior art. Furthermore, the present invention provides for a controlled amount of expansion at the pipe joint which can be set during pipe installation. The present invention therefore provides a means for creating a permanent joint in a pipe installation without the risk of the two pipes becoming separated due to excessive expansion or poor installation. The locking means according to the present invention is also more versatile in that it can be used with pipes made of different materials and sizes. The locking means can be provided as a kit, included with existing pipes and sockets.

Brief Description of the Drawings

Some embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Figure 1 illustrates a perspective view of a first pipe inserted in a socket of a second pipe, wherein a locking means according to the invention is installed around the joint; Figure 2 illustrates a cross section view of the arrangement of Figure 1;

Figure 3 illustrates in detail the encircled portion of Figure 2, and is a detailed cross section the locking means when installed around the joint; and

Figure 4 illustrates in cross section the collar portion of the locking means.

Detailed Description

According to an embodiment of the invention, and with reference to Figures 1 to 3, a locking means 1 is provided for constraining axial movement of a first pipe 2 relative to a second pipe 3 when an end portion of the first pipe 2 is located in a socket 4 of the second pipe 3, the socket 4 having a radially outward projecting portion 5, the locking means 1 comprising: an anchoring means 6 for affixing to the exterior surface 7 of the first pipe 2 at an axial position proximate but external from the socket 4 when the first pipe 2 is located in the socket 4; and a connecting member 8 arranged to engage and cooperate with both the anchoring means 6 and the radially outward projecting portion 5 of the socket 4, thereby constraining axial movement of the first pipe 2 relative to the second pipe 3.

According to an embodiment, the anchoring means 6 is a short tubular section, i.e. a ring, formed of e.g. plastic, where the ring has a diameter chosen to receive and fit around the first pipe 2. The tubular section/ring of the anchoring means has two radially outwardly projecting shoulders 9a and 9b. Alternatively, the tubular section could have only one outwardly projecting shoulder and still perform its intended function. In a pipe installation where the first pipe 2 is to be connected to a second pipe 3 by means of a socket 4 provided on the second pipe 3, the anchoring means 6 is affixed around the external surface 7 of the first pipe at an axial position proximate but external from the socket 4 when the first pipe 2 is inserted in the socket 4 (e.g. a ring seal socket) in the usual manner, i.e. the normal extent of insertion of the first pipe 2 into the socket 4 such that the first pipe 2 sealably engages with the socket 4. In other words, the anchoring means 6 is mounted around the first pipe 2, at a distance from its end sufficient to allow a socket 4 of a second pipe 3 to be placed over the end of the first pipe 2 without the anchoring means 6 interfering with the fit and function of the socket 4. The anchoring means 6 may be affixed by solvent welding or butt welding it to the outer surface 7 of the first pipe, for example. Alternatively, the first pipe 2 may be manufactured in such a way as to already include the anchoring means 6 at an appropriate position.

According to an embodiment, the connecting member 8 is formed of a pair of arcuate collar sections 8a and 8b. Each collar section 8a, 8b has axially spaced-apart radially inwardly extending first and second shoulders 10a and 10b, in addition to tabs 13 for securing the pair of collar sections 8a and 8b together to form a collar 8 around the joint of the first pipe 2 with the socket 4 of the second pipe 3. The collar sections 8a and 8b may be secured together by means of screws placed in tapped holes provided on the tabs 13, or by gluing the collar sections 8a and 8b together at the tabs 13. Thus when viewed in cross section in a plane parallel to the collar/pipe axis, each collar section 8a, 8b is shaped approximately like an elongated ‘IT, owing to the shoulders 10a and 10b, as illustrated in Figure 3. When viewed in cross section in a plane perpendicular to the collar/pipe axis the collar sections 8a, 8b are substantially semicircular in cross section with the tabs 13 extending radially outwards from each end of the collar sections, as illustrated in Figure 4.

In a pipe installation, the first pipe 2 - which may be made from polyvinyl chloride (PVC) - has the anchoring means 6 as described above affixed near an open end of the first pipe. The first pipe is then inserted in the socket 4 of the second pipe 3 - which may be made from high-density polyethylene HDPE - whereby the rubber seal 11 within the socket 4 sealably engages the first pipe 2. Prior to affixing the anchoring means to the first pipe, e.g. by solvent welding or butt welding it to the first pipe, the first pipe may first be temporarily inserted in the socket by the desired extent such that a preferred position of the anchoring means relative to the axis of the first pipe can be determined and marked-off. The location of the anchoring means will determine the amount of expansion which can occur within the collar, since this is a function of both the axial extent of the collar (i.e. the distance between collar shoulders 10a and 10b), and the nominal separation of the anchoring means shoulders 9a or 9b relative to the outward projecting portion 5 of the socket 4 which houses the rubber seal 11. Forming the ring 6 in two parts (e.g. two semi-circular halves) allows it to be affixed to the first pipe 2 after the first pipe 2 has been inserted in the socket 4 of the second pipe 3.

Once the first pipe (with the anchoring means affixed) has been inserted in the socket, the collar sections 8a and 8b are positioned around the joint of the first pipe and socket and secured together at the tabs 13, e.g. with screws or glue. The collar is positioned such that the shoulder 10a of the collar is nominally positioned axially outward of the shoulder 9a or 9b of the anchoring means, and the shoulder 10b is nominally positioned axially outward of the outward projecting portion 5 of the socket which houses the rubber seal 11. In this manner, when temperature change, or other factors, cause the first pipe 2 to move axially relative to the socket 4 of the second pipe 3 due to expansion, it will move within the collar 8. The shoulders 10a and 10b of the collar cooperate and engage with one of the shoulders 9a or 9b of the anchoring means and the outward projecting portion 5 of the socket 4 to constrain the maximum amount of axial movement/displacement of the first pipe 2 relative to the socket 4 and hence relative to the second pipe 3. Thus, thermal expansion can be allowed for, while ensuring that the joint remains intact.

For example, as shown in Figure 3 there is a gap 12 between shoulder 10a of the collar section 8a and shoulder 9a of the anchoring means 6. If expansion causes the first pipe 2 to move axially away from the socket 4 then the limit of this movement will be set by the gap 12, such that when this gap is closed, i.e. when shoulder 10a of the collar is abutting/engaging shoulder 9a of the anchoring means 6 and shoulder 10b of the collar is abutting/engaging the outward projecting portion 5 of the socket, no further expansion movement in the axially outward direction is possible. This prevents uncontrolled movement/displacement of the first pipe 2 relative to the socket 4 of the second pipe 3 and therefore prevents disengagement of, for example, the first pipe with the rubber seal 11 and hence failure of the joint - thereby preventing leakage of potentially hazardous waste or chemicals.

If shoulder 10a of the collar is inserted in the gap between shoulders 9a and 9b of the anchoring means 6, motion of the collar 8 with respect to the anchoring means 6 is substantially prevented, but the first pipe 2 can still move axially with respect to the socket 4 by an extent governed by the maximum possible separation between collar shoulder 10b and the outward projecting portion 5 of the socket. Such an arrangement may be used where it is desirable to limit relative motion of the collar and anchoring means. For such an arrangement the spacing between the shoulders 9a and 9b of the anchoring means 6 is sized to substantially match the width of the shoulder 10a of the collar. This enables the collar shoulder 10a to lock into the groove formed by shoulders 9a and 9b of the anchoring means 6.

In a typical installation comprising many such joints between two pipes, each joint could be equipped with a locking means 1 consisting of an anchoring means 6 and collar 8 to control expansion at each joint. If one joint reaches the maximum limit of its expansion then further expansion can be accommodated at the next joint and so forth.

Since the limit of expansion at each joint is defined by the cooperation of the anchoring means with the collar, this creates a fixed calculated expansion point for each floor on a multi-storey building, for example. It should further be noted that the present invention also prevents failure of a joint due to poor installation, since the collar 8 in cooperation with the anchoring means 6 and the outward projecting portion 5 prevents the two pipes from becoming disconnected.

The first pipe 2 may be formed of polyvinyl chloride (PVC), high-density polyethylene (HDPE), or any other thermoplastic. Similarly, the socket 4 of the second pipe 3 and the second pipe 3 itself may be formed of polyvinyl chloride (PVC), high-density polyethylene (HDPE), or any other thermoplastic. The connecting member 8 and anchoring means 6 may each be made of polyvinyl chloride (PVC), high-density polyethylene (HDPE) or any other thermoplastic.

Although the above described embodiment of the locking means employs an anchoring means and connecting member which both wrap around substantially the whole circumference of the joint, it is also contemplated that the invention could be realized by way of an anchoring ‘point’ provided on the exterior surface of the first pipe and a corresponding point provided on the socket, which may be brought into rotational alignment during installation of the first pipe in the socket of the second pipe, and connected by an elongate connecting member to achieve the result of preventing disconnection of the first pipe from the socket of the second pipe whilst allowing for a controlled amount of expansion about the joint.

It will be appreciated by the person of skill in the art that various modifications may be made to the above described embodiments without departing from the scope of the present invention.

Claims

CLAIMS:

1. A locking means for constraining axial movement of a first pipe relative to a second pipe when an end portion of the first pipe is located in a socket of the second pipe, the socket having a radially outward projecting portion, the locking means comprising:

an anchoring means for affixing to the exterior surface of the first pipe at an axial position proximate but external from the socket when the first pipe is located in the socket; and a connecting member arranged to engage and cooperate with both the anchoring means and the radially outward projecting portion of the socket, thereby constraining axial movement of the first pipe relative to the second pipe.

2. The locking means according to claim 1, configured so as to allow a pre-defined maximum amount of axial displacement of the first pipe relative to the socket of the second pipe, in order to limit expansion movement of the first pipe and/or the second pipe.

3. The locking means according to claim 1 or 2, wherein the connecting member comprises a pair of substantially semi-circular arcuate collar sections, each collar section having axially spaced-apart inward first and second shoulders and radially outward tabs at end portions thereof for securing the pair of collar sections together to form a collar around the first and second pipes.

4. The locking means according to claim 3, wherein the collar sections are arranged to be screwed or glued together at the tabs thereof.

5. The locking means according to claim 3 or 4, wherein the anchoring means is formed of a ring having a radially outward projection around the circumference thereof, and wherein the diameter of the ring is configured to accommodate the first pipe.

6. The locking means according to claim 5, wherein the ring has a plurality of axially spaced apart radially outward projections around the circumference thereof, in order to provide different tolerances for the amount of axial movement of the first pipe relative to the second pipe.

7. The locking means according to claim 5 or 6, wherein the first shoulders of the collar are arranged to engage and cooperate with the radially outward projection of the anchoring means and the second projections of the collar are arranged to engage and cooperate with the radially outward projecting portion of the socket.

8. The locking means according to any preceding claim, wherein the first pipe is made of polyvinyl chloride (PVC), high-density polyethylene (HDPE) or another thermoplastic and the second pipe is made of polyvinyl chloride (PVC), high-density polyethylene (HDPE) or another thermoplastic.

9. The locking means according to any preceding claim, wherein the connecting member and anchoring means are each made of polyvinyl chloride (PVC), high-density polyethylene (HDPE) or another thermoplastic.

10. The locking means according to any preceding claim, wherein the anchoring means is arranged to be solvent welded or butt welded to the first pipe.

11. The locking means according to any preceding claim, wherein the radially outward projecting portion of the socket contains a rubber seal for sealably engaging the first pipe.

12. The locking means according to any preceding claim, wherein the socket is a ring seal socket.

13. A kit comprising: the locking means according to any preceding claim, first and second sections of pipe, and a socket for coupling the first section of pipe to the second section of pipe.

14. A pipe installation comprising: a first section of pipe installed within a socket of a second section pipe, and the locking means according to any one of claims 1-12.

15. A method of constraining axial movement of a first pipe relative to a second pipe when an end portion of the first pipe is located in a socket of the second pipe, the socket having a radially outward projecting portion, the method comprising:

affixing an anchoring means to the exterior surface of the first pipe at an axial position proximate but external from the socket when the first pipe is located in the socket; and providing a connecting member which engages and cooperates with both the anchoring means and the radially outward projecting portion of the socket, thereby constraining axial movement of the first pipe relative to the second pipe.

Intellectual

Property

Office

Application No: Claims searched:

GB 1703 849.8 1-15