GB2423559A

GB2423559A - Slip coupler with flexible seals and injection holes for adhesive

Info

Publication number: GB2423559A
Application number: GB0503687A
Authority: GB
Inventors: Richard Statham; John Burrowson Kurn; Michael Bull
Original assignee: Glynwed Pipe Systems Ltd
Current assignee: Glynwed Pipe Systems Ltd
Priority date: 2005-02-23
Filing date: 2005-02-23
Publication date: 2006-08-30
Also published as: GB0503687D0

Abstract

A slip coupler 1 for joining pipe ends 17, 19 has a one-piece body and comprises pairs of flexible seals 5a, 5b at each end of the coupler. The seals fit into grooves on the inside of the coupler, and an injection hole 13 and a bleed hole 15 is provided between the two seals of each pair. A solvent cement or adhesive can be injected into the space 21 between the seals 5a, 5b, to form a permanent coupling between the pipes and the coupler. The solvent cement or adhesive may be injected using a syringe applicator or a cartridge type applicator. The coupler 1 can slide along the pipes 17, 19 before the cement or adhesive is applied, and a lubricant may be used to assist sliding. The injection hole may be closer to the outer seal 5a in each pair. The flexible seal 5 may have an annular recess 7, may have a reinforcing ring 11, and may have blade members 9.

Description

A SliD CouDler The present invention relates to a slip coupler. Couplers

are used to connect two or more lengths of pipes or a pipe to a fitting.

Existing couplers are assembled with the application of cement to both the inside of the coupler and the exterior of a pipe end. The pipe is then pushed inside the coupler to meet a pipe stop within the coupler. Cement sits between the exterior of the pipe and the inside of the coupler. When the cement cures, the pipe and coupler are fused together.

The need to apply cement to both the coupler and the pipe for assembly is not practical, particularly when modules of pipework or prefabricated Tpods" of pipework are assembled off-site prior to final installation on site.

Connection of two or more pods is difficult because the pipe to be S..

connected and the coupler cannot be flexed or moved for adjustment during on-site installation. There are often space constraints at the installation site and the rigidity of the pipes and the couplers make it very S...

difficult to connect two or more modules of pipework.

Alternatively, "dry" on-site assembly of a pipe and a coupling is possible.

Cement is injected into the gap between the pipe and coupling after on site installation when two or more modules of pipe work are aligned and connected using a coupler. The cement may be injected through openings in the coupler. Many existing dry assembly systems make use of a central pipe stop, which is met by the two pipes to be joined, when they are inserted into the coupler. A pipe stop is necessary to ensure that the pipes are fitted at a sufficient distance inside the coupler. However, a central pipe stop prevents movement or adjustment of pipes during on-site installation and, again, makes connection of pipework difficult.

The use of cement requires the coupler and pipe/s to be sized such that there is an optimum gap between the coupler and the pipe. The gap must be wide enough to hold the applied cement in place but narrow enough to prevent escape of the cement. Existing systems prevent escape of the cement by preventing movement between the pipe and coupler when they are fitted together.

For example, US 5022685 discloses a dry assembly pipe system wherein a joint is clamped to the pipes to be joined. The clamping means must be positioned and left in place at least until the cement sets. The positioning of clamping means is difficult at cramped installation sites. Other systems make use of a socket with a taper. These sockets have a greater diameter at the socket opening or "mouth" than at the socket "root", to prevent movement of the pipes to be joined. The pipes and couplings of such existing systems cannot be flexed or moved for alignment during assembly. Once a module of pre-assembled pipe work is brought to the site of installation the pipes making up the modules and the couplers by S..

which the modules are fitted together, cannot be further adjusted. It may be possible to connect a coupler to one module of pipe work but the rigidity of the modules of pipe work and the limited space for manoeuvre S...

makes it very difficult to connect the coupler to another module. This makes the installation of pre-assembled modules of pipework both difficult and time consuming.

The object of the present invention is to provide a coupler which is both quick and easy to use even at a cramped installation site.

In one aspect, the invention provides a slip coupler for joining or capping at least one pipe comprising; a hollow body of unitary configuration with two open ends, at least one pair of flexible seals at each end of the coupler, each seal fitted into a groove around the inner circumference of the hollow body, and at least one injection hole at each end of the hollow body positioned between the pair of flexible seals, the arrangement being such that the slip coupler can slide along a pipe.

The present invention of a "slip" coupler allows the coupler to slide freely over a pipe for convenient and accurate positioning during on-site assembly. The use of a slip coupler allows for pre-assembled modules to be brought to the installation site and be connected with further modules, even when the modules of pipe work are rigid and there is limited space at the installation site. The interference between the flexible seals and grooves of the present invention alleviates the problems previously described. The slip coupler allows for adjustment of the pipe/s within the dry coupler but when cement is applied, the flexible seals prevent escape of the cement from within the coupling.

Preferably, the at least one injection hole is closer to the seal closest to the open end of the hollow body.

Preferably, the flexible seal comprises an annular recess such that the seal is U-shaped.

Preferably, the flexible seal comprises at least one blade-shaped member.

The flexible seal is shaped to allow ease of movement of the coupler over the pipe/s to be joined whilst providing effective sealing when the cement is injected.

Preferably, a reinforcing ring sits in the annular recess of the flexible seal.

A reinforcing ring prevents the seal/s escaping from their respective grooves when the coupler is moved over the pipe/s to be joined.

Preferably, the coupler is produced from a plastic material.

Preferably, the flexible seal is produced from rubber.

Preferably the reinforcing ring is produced from a plastic material.

Preferably, the compression of the flexible seal against the external diameter of the pipe is from 0 to 90%.

More preferably, the compression of the flexible seal against the external diameter of the pipe is from 0 to 30%.

Preferably the distance between the pair of rubber seals is from 14 mm to 168 mm. * * * * a.

Preferably, for a 9.525 mm (3/8") diameter pipe the distance between the:" pair of rubber seals is 14.5 mm. * a *

Preferably, for a 16 mm diameter pipe the distance between the pair of rubber seals is 14 mm. * a.. * a a

Preferably for a 315 mm diameter pipe the distance between the pair of rubber seals is 163.5 mm.

Preferably for a 304.8 mm (12") diameter pipe the distance between the pair of rubber seals is 168 mm.

The distance between the two rubber seals is similar to that of a conventional pipe coupling such that each end of the coupling provides a similar integrity of joint as a conventional pipe coupler.

Preferably, solvent cement or an adhesive is injected through the injection holes to fuse the coupler to the pipe/s.

Preferably the solvent cement or adhesive is injected using a syringe applicator.

Alternatively, the solvent cement or adhesive is injected using a cartridge- type applicator.

Preferably, the solvent cement or adhesive is a different colour to that of the coupler and pipes.

By using solvent cement or adhesive of a different colour a user is able to observe any cement or adhesive that escapes from the bleed holes.

Preferably, the solvent cement comprises a solution of the type of polymer from which the pipe and/or fitting is made. :...:.

More preferably, the solvent cement comprises ABS polymer dissolved in methyl ethyl ketone (MEK).

* * *, Alternatively, the solvent cement is PVC polymer dissolved in Tetra Hydro Furan (THF).

Alternatively, the adhesive is a cyanoacrylate.

Preferably the viscosity of the solvent cement is in the range 50 to 2000 m Pa.

Preferably the thickness of the slip coupler is from 1 mm to 100 mm.

Preferably, for a 16 mm or 9.525 mm (3/8") diameter pipe the thickness of the slip coupler is at least 1.5 mm.

Preferably for a 315 mm or 304.8 mm (12") diameter pipe the thickness of the slip coupler is no more than 35 mm.

The thickness of the slip coupler may be greater than that of a conventional pipe coupling to compensate for attack of the pipe by the solvent due to a reduced rate of solvent evaporation.

Preferably, for a 16 mm or 9.525 mm (3/8") diameter pipe the length of the slip coupler is no more than 30 mm.

Preferably for a 315 mm or 304.8 mm (1211) diameter pipe the length of the slip coupler is no more than 700 mm.

The length of the slip coupler may be greater than that of a conventional pipe coupling to ensure that the mouth of a pipe/s inserted into the:. a coupling is inserted past both seals of the pair of flexible seals. a

Preferably, the slip coupler further comprises at least two bleed holes. * S * * S ** *.

Bleed holes allow air and/or excess cement to escape from the coupling after cement is injected. :; Preferably, a lubricant is applied to assist the slip coupler to slide along a pipe/s.

The lubricant applied to the slip coupler allows for easier adjustment of the pipe/s within the dry coupler but when cement is applied and the coupler is fixed the lubricant is not detrimental to the integrity of the joint.

The invention will now be described by way of example with reference to the accompanying diagrammatic drawings, in which:- Figure 1 is a longitudinal cross-sectional view of the internal surface of a slip coupler constructed in accordance with the present invention; Figure 2 is a cross-sectional view of an annular seal in accordance with the present invention; Figure 3 is a longitudinal view of the slip coupler of Figure 1 shown in use in accordance with the present invention.

As can be seen from figure 1, the slip coupler 1 comprises a hollow cylindrical body into the internal surface of which are machined a series of grooves 3. A pair of grooves 3 is positioned at each end of the hollow body. Each groove 3 is fitted with a flexible rubber seal 5. One rubber seal of the pair 5a is closer to the "mouth" of the coupler and the other rubber seal 5b is closer to the "root" of the coupler. * . . * I*

As shown in Figure 2, the rubber seal 5 is a U-shaped ring with an annular recess 7 running centrally between two blade-shaped members 9. A reinforcing ring 11 sits in the annular recess between the two bladeshaped members. * *

Referring to Figure 1, two injection holes 13 and two corresponding bleed holes 15 are drilled through or moulded in each end of the coupler 1. Each injection hole 13 and bleed hole 15 sits in between a pair of rubber seals 5. The injection hole 13 and bleed hole 15 are positioned closer to the rubber seal 5a, which is closer to the mouth of the coupler than to the rubber seal 5b, which is closer to the root of the coupler.

With reference to Figure 3, in use, the coupler 1 is slid over one end of a first pipe 17. The first pipe 17 may be part of a first module of preassembled pipe work. The first pipe 17 and coupler 1 are then moved into position close to a second module of pipework including a second pipe 19 to which the pipe 17 and coupler 1 are to be fitted. The interference between the rubber seals 5 and the external diameter of the pipes 17 and 19 is such that the slip coupler 1 can slide over the second pipe 19 and be adjusted such that the coupler 1 sits equidistant across the two pipe ends 17, 19. Each pipe 17, 19 is inserted through the "mouth" seal 5a and through the "root" seal Sb.

Solvent cement is injected through the injection holes 13 into the gap 21 between the pair of seals and between the internal diameter of the coupler 1 and the external diameters of the pipes 17, 19.

The solvent cement is injected using a syringe applicator. The size of the syringe applicator is specific to the size of the pipes 17, 19 and the coupler 1. The volume of cement contained within the syringe applicator is sufficient to completely fill the gap 21 between the outside diameter of the pipe 17, 19 and the inside diameter of the coupler 1. Typically the volume of cement required to fill the gap 21 is in the range of 0.03 ml to 500m1. * *

S.....

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As the cement is injected, it flows between the pair of seals 5a and Sb, S..

around the entire internal circumference of the coupler 1 and external circumference of the pipes 15, 17 to fill the gap 21. The rubber seals 5 prevent the escape of cement from the gap 21. The cement cannot escape out of the mouth of the coupling 1 or through the root of the coupling into the pipes 17, 19. Any excess air escapes through the bleed holes 15.

When the gap 21 is full, any excess cement escapes from the coupler 1 through the bleed holes 15. The cement is a different colour to that of the coupler 1 and pipes 17, 19 and allows a user to observe any cement that escapes from the bleed holes 15.

The cement between the pair of seals 5 and between the internal diameter of the coupler 1 and the external diameters of the pipes 17, 19, is left to cure. When the cement is cured the pipes 17, 19 are permanently joined together inside the slip coupler 1.

The above described embodiment has been given by way of example only, and the skilled reader will naturally appreciate that many variations could be made thereto without departing from the scope of the present invention. For example, the previously described method can be used for coupling pipes to fitting such as T-fittings and elbow fittings. * . * ** * S

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Claims

Claims 1. A slip coupler for joining or capping at least one pipe

comprising; a hollow body of unitary configuration with two open ends, at least one pair of flexible seals at each end of the coupler, each seal fitted into a groove around the inner circumference of the hollow body, at least one injection hole at each end of the hollow body positioned between the pair/s of flexible seals, the arrangement being such that the slip coupler can slide along a pipe/s.
2. A slip coupler according to claim 1 wherein the at least one injection hole is closer to the seal closest to the open end of the hollow body.
3. A slip coupler according to claim 1 or claim 2 wherein the flexible seal comprises an annular recess.
4. A slip coupler as claimed in claim 3 wherein a reinforcing ring sits in the annular recess of the flexible seal.
5. A slip coupler as claimed in any preceding claim wherein the flexible seal comprises at least one blade-shaped member.
6. A slip coupler as claimed in any preceding claim wherein the coupler is produced from a plastic material.
7. A slip coupler as claimed in any preceding claim wherein the at least one flexible seal/s is rubber.
8. A slip coupler as claimed in any preceding claim wherein the reinforcing member is produced from a plastic material.
9. A slip coupler as claimed in any preceding claim wherein the compression of the flexible seal against the external diameter of the pipe is from U to 90 %.
10. A slip coupler as claimed in any of claims 1 to 8 wherein the compression of the flexible seal against the external diameter of the pipe is from U to 30 %
11. A slip coupler as claimed in any preceding claim wherein the distance between the pair of rubber seals is from 14 mm to 168 mm.
12. A slip coupler as claimed in any preceding claim wherein for a 16 mm diameter pipe the distance between the pair of rubber seals is 14.0 mm.

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13. A slip coupler as claimed in any of claims 1 to 11 wherein for a 1SI 9.525 mm (3/8") diameter pipe the distance between the pair of rubber seals is 14.5 mm. * 0*S S * S S. *
14. A slip coupler according to any of claims 1 to 11 wherein for a 315 mm diameter pipe the distance between the pair of rubber seals is 163.5 mm.
15. A slip coupler according to any of claims 1 to 11 wherein for a 304.8 mm (12") diameter pipe the distance between the pair of rubber seals is 168 mm.
16. A slip coupler as claimed in any preceding claim wherein solvent cement or an adhesive is injected through the injection holes to fuse the coupler and the pipe/s and/or fittings together.
17. A slip coupler as claimed in claim 16 wherein the volume of solvent cement or adhesive is from 0.03 to 500 ml.
18. A slip coupler as claimed in any of claims 16 or 17 wherein the solvent cement or adhesive is injected using a syringe applicator.
19. A slip coupler as claimed in any of claims 16 or 17 wherein the solvent cement or adhesive is injected using a cartridge-type applicator.
20. A slip coupler as claimed in any of claims 16 to 19 wherein the solvent cement comprises a solution of the type of polymer from which the pipe and/or fitting is made. *

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21. A slip coupler as claimed in any of claims 16 to 20 wherein the solvent cement comprises ABS polymer dissolved in methyl ethyl ketone (MEK). *.** * S ****
22. A slip coupler as claimed in any of claims 16 to 21 wherein the solvent cement is PVC polymer dissolved in Tetra Hydro Furan (THF).
23. A slip coupler as claimed in any of claims 16 to 19 wherein the adhesive is a cyanoacrylate.
24. A slip coupler as claimed in any of claims 16 to 22 wherein the viscosity of the solvent cement is in the range 50 to 2000 mPa.
25. A slip coupler as claimed in any preceding claim wherein the thickness of the slip coupler is from 1 mm to 100 mm.
26. A slip coupler as claimed in any of claims 1 to 13 and 16 to 25 wherein for a 16 mm or 9.525 mm (3/8") diameter pipe the thickness of the slip coupler is at least 1.5 mm.
27. A slip coupler as claimed in any of claims claim 1 to 11 and 14 to 25 wherein for a 315 mm or 304.8 mm (12") diameter pipe the thickness of the slip coupler is no more than 35 mm.
28. A slip coupler as claimed in any preceding claim wherein the length of the slip coupler is from 10 mm to 1000 mm.
29. A slip coupler as claimed in any of claims 1 to 13, 16 to 26 and 28 wherein for a 16 mm or 9.525 mm (3/8") diameter pipe the length of the slip coupler is at least 30 mm.
30. A slip coupler as claimed in any of claims 1 to 11, 14 to 25, 27 and..

28 wherein for a 315 mm or 304.8 mm (12") diameter pipe the length of the slip coupler is no more than 700 mm.
31. A slip coupler as claimed in any preceding claim wherein the slip coupler further comprises at least two bleed holes.
32. A slip coupler as claimed in any preceding claim wherein the bleed holes allow air and/or excess cement or adhesive to escape from the coupling after cement or adhesive is injected.
33. A slip coupler as claimed in any preceding claim wherein a lubricant is applied to assist the slip coupler to slide along a pipe/s.
34. A slip coupler substantially as described herein and with reference to Figures 1, 2 or 3.