GB1565564A

GB1565564A - Packages for sealing pipes or vessels

Info

Publication number: GB1565564A
Application number: GB4532977A
Authority: GB
Original assignee: Readyseal Ltd
Current assignee: Readyseal Ltd
Priority date: 1977-11-01
Filing date: 1977-11-01
Publication date: 1980-04-23

Description

(54) IMPROVEMENTS RELATING TO PACKAGES FOR SEALING PIPES OR VESSELS (71) We, READYSEAL LIMITED, a British Company of 12B, Station Road, Ince, Nr. Chester, Cheshire, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: In our co-pending Application No.

20248/75 (Serial No. 1546073) we have set forth an improved method of repairing leaks in pipes carrying fluent medium under pressure and a means for use in the method.

It is well known that when a leak occurs in a pipe carrying, for example, combustible gaseous medium such as natural or town gas, then a potentially dangerous situation has arisen. Frequently, the leak will be such as not normally to justify replacement of the pipe or pipe section in which the leak exists, but in actual fact in practice this is what happens, as heretofore efficient leak repairing methods have not been available. The most common location in a pipe for a leak to occur, is at a joint, and leaks at joints are even more difficult to repair than when the leak occurs in the pipe between joints.

Furthermore, the problem of repairing the leak in a pipe is increased when the pipe carries a fluent medium which is under pressure, and clearly the greater the pressure, then the greater the difficulty in making an effective repair.

The invention set forth in our co-pending application seeks to overcome the above problem, and provides a method and a means for so doing. The method comprises, as set forth in said copending application, wrapping around the pipe (or pipeline) a flexible wrapping which consists of or includes resin absorbent material and an integral vent member having a vent passage the method including soaking the absorbent material in curable resin before or after application of the wrapping, so that the resin seals the leak to the extent that leaking fluent medium escapes through the vent passage, allowing or effecting curing of the resin after application of the wrapping, and finally sealing said vent passage.

The invention of said co-pending application also comprises a package comprising an envelope containing a flexible wrapping for use in the aforesaid method said wrapping consisting of or including resin absorbent material, and an integral vent member having a vent passage for providing an escape route for medium escaping from a leak in a pipe (or pipeline) around which the wrapping is to be wrapped and wherein the envelope comprises two separate compartments, the wrapping being in one of said two compartments and the other compartment containing curable resin in which the absorbent material is to be soaked, said two compartments being capable of being interconnected so that the resin is free to flow into contact with the wrapping.

The envelope may include a third and separate compartment containing a hardener for the resin, said third compartment being capable of being interconnected with the compartment containing the resin, to intermix with the resin and start it curing before bringing the resin into contact with the wrapping.

The envelope may be in the form of a flexible sachet divided into the compartments by removable clips being in one example complimentary pairs of strip plastics material.

We have found that the package as aforesaid, when it includes a wrapping, otherwise as set forth, but without any vent member, has practical utility, for example in the sealing of pipe or pipeline joints which do not carry fluent medium under pressure, or when the flow of such medium is terminated.

Accordingly the present invention is a modification of the package as aforesaid, wherein there is provided a package adapted for other uses such as the repairing of leaks in pipes in pipelines when they do not carry fluent medium under pressure, said modification residing in that the wrapping has no vent member and therefore the package comprises an envelope containing a flexible wrapping consisting of or including resin absorbent material, but not having an integral vent member, and wherein the envelope comprises two separate compartments, the wrapping being in one of said two compartments and the other compartment containing curable resin in which the absorbent material is to be soaked, said two compartments being capable of being interconnected so that the resin is free to flow into contact with the wrapping.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, where in:- Figure 1 is an elongated section elevation of part of a wrapping of a package according to the embodiment; Figure 2, is a perspective view of the components of a kit, including a wrapping as shown in Fig. 1 for sealing a pipe joint; Figure 3 and 3A respectively are sectional elevations of the package of the kit shown in Fig. 2; and the detail ringed in Fig. 3; and Figs. 4-12 illustrate respectively, and in perspective view, the steps involved in applying the wrapping to a leaking pipe joint.

Referring to the drawings, and firstly to Figure 1, a wrapping is shown in section, and will be seen to comprise a layer of stretchable plastics film 10, in this case a polyurethane film of a thickness of approximately 60 thousandths of an inch. On one side of the film 10 is an absorbent layer 12, this absorbent layer in this example being of polypropylene, needled felt.

Fig. 2 shows a kit which is for use in sealing a pipe joint such as is illustrated generally by the reference numeral X in Fig. 4. The kit comprises a package 20 of which a sectional elevation is illustrated in Fig. 3 and in detail in Fig. 3A, and this package 20 comprises an envelope containing the wrapping described with reference to Fig. 1. The envelope is in fact in the form of a sealed sachet or bag of a three layer material comprising nylon - SURLYN (Registered Trade Mark) -- polythene.

Transversely of the length of the bag the sides are clipped together by means of plastics clips 22 so that in fact the bag is divided into three separate compartments 24, 26 and 28. Compartment 24 contains the wrapping of Fig. 1 whilst compartment 26 contains the resin to be applied to the wrapping and compartment 28 contains a hardener for the resin in compartment 26. The resin system it will be appreciated is a two part system, and in actual fact is a polyurethane resin system. The clips 22 serve to keep the resin parts separate and out of contact with the wrapping in compartment 24 until such times as the wrapping is to be used, when the clips 22 are removed and the two parts of the resin system allowed to intermix and to soak the wrapping as will be explained hereinafter.

The SURLYN of the bag gives the bag a puncture proof property, and the polythene which is the inner layer is inert to the resin catalyst or hardener contained in compartment 28.

For some hardeners, the compartment 28 is lined with a sleeve of metal foil, the ends being sealed closed by clips 22, to stop the ingress of moisture to such an extent as to cause contamination of the hardener.

In addition, the kit contains an abrasive cleaning strip 32 for cleaning the pipe joint prior to application of the wrapping, a wrapping strip 36 of polyurethane film, gloves 40 for the operators use, and a knife 42 for slitting the bag 20 at the appropriate time as will be explained.

Fig. 3 shows a section through the bag 20, the hardener and resin being indicated at 44 and 46. The compartments 24, 26 and 28 are formed by clipping the faces of the bag together by means of the clipping arrangement shown in Fig. 3. This comprises a plastics material strip of U-section 48 and an inner strip 50 which fits in the U-section, trapping the layers of the bag 20 therebetween and effectively sealing the compartments 28, 26 and 24 one from another. In order to interconnect the compartments, it is simply a matter of removing the clipping arrangement 22 either by sliding the strips 48 and 50 one relative to another, or by springing off strip 48.

In order to seal a pipe joint, the joint region is first of all cleaned using the abrasive strip 32 as shown in Fig. 4. It will be noticed in this figure that an excavation around the pipe joint has been shown to enable access thereto by an operator. The pipe joint prior to the sealing of same is shown in Fig. 5.

Fig. 6 illustrates the next stage of the method. The operator removing the clip 22 of the bag 20 separating compartments 28 and 26 to allow the two parts of the polyurethane resin system to mix, and indeed he promotes the mixing by raising and lowering the respective ends of the now enlarged compartment 26 and 28 as illustrated in Fig. 6. This mixing process is continued approximately for 1 minute.

After the completion of the mixing of the two parts of the resin system, the other clip 22 is removed and the mixed resin is allowed to pass into contact with and to soak the wrapping in the compartment 24. The operator at this stage kneads the resin mix into intimate contact with as much of the wrapping as he can. In any case, the needle felt is extremely absorbent and will soak up the resin mix effectively wetting out all of the wrapping.

Upon completion of this step, the operator now uses knife 42 to slit open the bag 20 as illustrated in Fig. 7, whilst the bag lies horizontally on the ground. This exposes the wrapping as shown in Fig. 7 and he unfolds the wrapping at one end and folds it into concertina fashion at the other end so that he can grip the folded end as shown in Fig. 8. He then holds up the wrapping in suspended manner as shown in Fig. 9.

The operator now applies the soaked wrapping to the pipe joint. The wrapping is located so that one of the shorter ends, the end which the operator is shown holding in Fig. 10, will lie on top of the pipe joint.

This end he opens out so that the film 10 is exposed, the layer 12 being folded back. The other end he now places in overlapping relationship with the film 10 thereby to complete the wrapping of the joint, and finally the folded over end of layer 12 is placed into overlapping relationship with said other end to complete the wrapping.

The wrapping strip 36 is now applied over the wrapping as shown in Fig. 12. The wrapping strip is applied initially to the smaller diameter of the pipe joint.

It is to be noted that the wrapping strip is applied to the wrapping whilst the resin is still tacky. and being of a polyurethane film, will firmly anchor and bond to the wrapping in the final joint seal.

The resin is allowed or caused to cure thus forming an effective seal for the pipe joint.

Although it will normally be desirable first of all to clean the outside of the pipe where this is rough and uneven, or pitted, in other cases initial preparation of the pipeline surface may not be necessary.

The method is inexpensive and efficient, and can be carried out very quickly by unskilled labour. The results are extremely encouraging, and it is to be noted that other resins, felt and plastics film material can be used without departing from the scope of the invention as defined in the appended

Claims

claims. Although the embodiment of the invention described has illustrated the repair of a leak in a pipe at a pipe joint, it is to be understood that the package can be used in other applications for example for sealing holes or cracks in vessels such as boilers and water vessels, the resin impregnated wrapping being applied in some cases as a patch. Where the wrapping is applied to seal locations of pipes or vessels which normally carry or contain fluids under pressure, the application of the wrapping should be applied when the paper or vessel is empty. As the wrapping can be used as a patch, it is not necessary in all cases that it should be an elongated rectangular member so as to be wrapped like a bandage; in some cases it may be a square or circular panel, as in effect the absorbent wrapping material is effectively acting as a carrier for the resin, which is the material, when cured, which forms the seal. WHAT WE CLAIM IS:-

1. A modification of the package of claim 12 of the British Patent Application No. 20248/75 (Serial No. 1546073) wherein there is provided a package adapted for other uses such as the repairing of leaks in pipes in pipelines when they do not carry fluent medium under pressure, said modification residing in that the wrapping has no vent member, and therefore the package comprises an envelope containing a flexible wrapping consisting of or including resin absorbent material, but not having an integral vent member, and wherein the envelope comprises two separate compartments, the wrapping being in one of said two compartments and the other compartment containing curable resin in which the absorbent material is to be soaked, said two compartments being capable of being interconnected so that the resin is free to flow into contact with the wrapping.

2. A package according to claim 1, wherein the wrapping comprises a layer of resin absorbent material and a stretchable plastics material film.

3. A package according to claim 2, wherein the film is a polyurethane.

4. A package according to claim 1, 2 or 3, wherein said absorbent material is polypropylene felt.

5. A package according to any of claims 1 to 4, wherein the envelope includes a third and separate compartment containing a hardener for the resin, said third compartment being connectable with the compartment containing the resin, to intermix with the resin and started curing before bringing the resin into contact with the wrapping.

6. A package according to any one of claims 1 to 5, wherein the envelope is in the form of a sealed flexible sachet divided into compartments by one or more removable clips.

7. A package according to any preceding claim and substantially as hereinbefore described with reference to Figs. 2, 3 and 3A of the accompanying drawings.