CA1170685A - Flexible tee collar - Google Patents
Flexible tee collarInfo
- Publication number
- CA1170685A CA1170685A CA000379526A CA379526A CA1170685A CA 1170685 A CA1170685 A CA 1170685A CA 000379526 A CA000379526 A CA 000379526A CA 379526 A CA379526 A CA 379526A CA 1170685 A CA1170685 A CA 1170685A
- Authority
- CA
- Canada
- Prior art keywords
- conduit
- branch
- material according
- expansion
- collar
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
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- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
Abstract
ABSTRACT
FLEXIBLE COLLAR TEE.
A recoverable sheet material can be provided with a first portion and a second portion having a series of pleats which accommodate an increasing extent of expansion. The sheet A can be wrapped-around to form a branch-off conduit from a main conduit. The pleated region splays out to form an overlap over a hole in the main conduit. The sheet can be provided with a double pleated region to provide a pipe bend.
(Figure 1)
FLEXIBLE COLLAR TEE.
A recoverable sheet material can be provided with a first portion and a second portion having a series of pleats which accommodate an increasing extent of expansion. The sheet A can be wrapped-around to form a branch-off conduit from a main conduit. The pleated region splays out to form an overlap over a hole in the main conduit. The sheet can be provided with a double pleated region to provide a pipe bend.
(Figure 1)
Description
7~ 8S
Flexible Collar Tee This invention relates to recoverable, preferably heat-recoverable, articles. In particular, the invention relates to articles for producing T-shaped branch-offs from conduit 5 .
Recoverable articles are articles the dimensional configuration of which may be made substantially to change on suitable treatment, and heat-recoverable articles are one which change on heat treatment. Usually these articles recover, on heating, towards an original shape from which they have previously been deformed, but the term "heat-recoverable", as used herein, also includes an article which, on heating, adopts a new configuration, even if it has not been previously deformed.
In their most common form, such articles comprise a heat-shrinkable sleeve made from a polymeric material exhibiting the property of elastic or plastic memory as described, for example, in US Patents 2,027,962; 4,086,242 and 3,957,372. As is made clear in, for example, US Patent
Flexible Collar Tee This invention relates to recoverable, preferably heat-recoverable, articles. In particular, the invention relates to articles for producing T-shaped branch-offs from conduit 5 .
Recoverable articles are articles the dimensional configuration of which may be made substantially to change on suitable treatment, and heat-recoverable articles are one which change on heat treatment. Usually these articles recover, on heating, towards an original shape from which they have previously been deformed, but the term "heat-recoverable", as used herein, also includes an article which, on heating, adopts a new configuration, even if it has not been previously deformed.
In their most common form, such articles comprise a heat-shrinkable sleeve made from a polymeric material exhibiting the property of elastic or plastic memory as described, for example, in US Patents 2,027,962; 4,086,242 and 3,957,372. As is made clear in, for example, US Patent
2,027,962, the original dimensionally heat-stable form may be a transient form in a continuous process in which, for example, an extruded tube is expanded, whilst hot, to a dimensionally heat-unstable form but, in other applications, a preformed dimensionally heat stable article is deformed to a dimensionally heat unstable form in a separate stage.
In the production of heat recoverable articles, the polymeric material may be cross-linked at any stage in the production of the article that will enhance the desired dimensional recoverability. One manner of producing a heat-recoverable article comprises shaping the polymeric 1 t. 7(`~
material into the desired heat-stable form, subsequently cross-linking the poly-meric material, heating the article to a temperature above the crystalline melt-ing point or, for amorphous materials the softening point, as the case may be, of the polymer, deforming the article and cooling the article whilst in the deformed state so that the deformed state of the article is retained. In use, sinoe the deformed state of the article is heat-unstable, application of heat will cause the article to assume its original heat-stable shape.
In other articles, as described, for example, in British Patent 1,440,524, an elastomeric member such as an outer tubular member is held in a streched state by a second member, such as an inner tubular member, which, upon heating, weakens and thus allows the elastomeric mem~er to recover.
me use of recoverable articles, for mechanical protection and elec-trical insulation where appropriate, in covering articles, for example pipes and cables, has been disclosed in, for example, US Patent Nos. 2,027,962 to Currie and 3,297,819 to Wetmore. mese articles are designed primarily for covering a single pipe or a butt-junction between tWD pipes. In US Patent No. 3,445,336 to Ellis there is disclosed a heat-shrinkable sleeve which can be wrapped around an article or two butt-joined articles, which is suitable for use, for example, when no free end of the pipe or pipes is available. In the Ellis patent, there is dis-closed a heat-recoverable closure member, usually of sheet form, two opposite edges of which have protuberances along their length which, when the sheet is wrapped around an article to be covered, are in abutting relationship and can be held in such relationship during and after recovery by a fastening means, for example a metal channel. By the use of suitably moulded closure members, and using two or more sets of abutting protuberances, the closure member can be used for covering T or Y junctions on existing pipes and cables. Such mouldings are, however, relatively expensive.
UK Patent 1447048 discloses a heat-recoverable article that is adapted to cover a conduit junction having at least three arms, which comprises a radially heat-shrinkable tubular member or a member in sheet form of which opposing edge regions can be brought and held together to form a radially heat-shrinkable tubular member, the member having at least one heat-shrinkable aperture with an upstanding wall around its periphery, preferably outwardly extending from the member, the wall being such that, on heating, its height and periphery are reduced. A further method of sealing a branch-off to a main conduit is to wrap tapes, generally heat-recoverable tapes, around the crutch region between the main conduit and the branch-off conduit. This is not satisfactory in some instances since it can be difficult to obtain a good seal with certainty, and the wrapping operation is time consuming and craft sensitive.
Branch-offs are often connected after the main conduit has been installed, and therefore the sleeve must be a wraparound. Existing systems have many parts or use tape, which is craft sensitive. It is difficult therefore to get a good seal especially on large diameter pipes. We have now discovered a means of sealing a branch-off conduit to a main conduit which is particularly applicable to ~-shaped branch-offs, but which is also suitable where the branch-off conduit is not perpendicular to the main conduit.
When we use the term "main conduit" we do not indicate that it is necessarily larger that the branch conduit, but merely to differentiate between the conduit which branches off and the conduit from which the branching off occurs.
l.t'7(~35 Thus, the present invention provides a recoverable sheet material for forming a conduit which has been differ-entially expanded, the change in extent of expansion across its surface being accommodated by pleats which increase in depth or number in the direction of increasing expansion.
It is to be understood that the word pleats as used in the specification and claims has a broad meaning including but not limited to folds or creases which are doubled upon themselves, or which have any particular geometric form; the word is intended to encompass any series of corrugations folds, creases or undulations by which a sheet may be compacted into a smaller area than the surface area of its material.
The present invention in particular provides `a recover-able sheet material for providing a sealed branch-off from a main conduit, comprising: a first portion which can define or enclose a branch-off conduit, and a second portion having been expanded differentially and which thus can splay out to form a collar around a hole in the main conduit. Preferably the whole of the sheet is first expanded and the differential expansion of the second portion is superimposed.
The sheet material can be used to join an independent branch-off conduit to a main conduit, or said first portion can itself constitute the branch-off conduit. The invention is particularly useful for larger conduits such as those used for carrying oil or gas.
The invention also provides a method of forming a branch-off, in which the sheet material of the invention is placed on a conduit with the collar around a hole in the conduit, the collar is secured to the conduit, and the ; sheet material recovered. The collar is secured to the conduit by means of an overlying recoverable wrap-around 11'7( }~j~5 sleeve which has a hole through which said first portion can pass, or by two patches or wrap-around or tubular sleeves one either side of the branch-off conduit, where the conduits are large it will generally be necessary to use two patches or sleeves, rather than a single item with a hole.
The sheet material of the invention can be provided as a wrap-around closure member, in which case means will generally be required to secure it in the closed configuration.
Such means can be adhesive or the provision of a rail and channel closure, such as that described in our US Patent 3455336, modifications to this idea are disclosed in UK
Patent 1529351 and in applications 80~8703 and 8005501.
Alternatively the sheet material can be provided as a closed tube. In either case some sort of sealant (such a hot-melt adhesive or mastic) will generally be employed when the branch-off is made. It is preferred, none-the-less, that the sheet material be provided plain, a sealant being added by the craftsman on site where required. The alternative is to provide a coating of sealant on the inner surface of the sheet material; this however makes production of the material more expensive. The sheet material of the invention may be held in the closed configuration, and it may be sealed to the main conduit by a pressure sensitive or heat-activated closure patch, such as that sold by Raychem under the trade mark WPCP.
The method of producing the sheet material in wrap-around form is as follows. A sheet of a suitable plastics material is subjected to the usual cross-linking (by chemical means or by radiation) and heating/cooling operations, but the expansion is a two part process. The sheet is longitudinally expanded as a whole, and the part which is to become the second portion is further expanded. This further expansion increases in extent throughout the width of the second 7~t~35 portion in a direction away from the first portion. The differential expansion of the second portion allows the second portion to splay out to form a collar which can overly a hole in the main conduit. It is to be understood that the expansion of the whole and the further expansion need not be done sequentially, but may be part of the same process. After this expansion, and before the material is closed to form a tube, the second portion preferably will have a generally pleated configuration. The size of such pleats can vary over a wide range, but a typical size could bre regarded as 50mp pitch and 50mp depth.However, the precise configuration will depend on the method employed in the expansion. A continuous in line process can be employed, in which convolutes are produced in the second portion simply simply by pressing.
Where the sheet material is to be in the form of a closed tube, it may be made as above and then welded closed, or it may be moulded as a tube, and then radially expanded in a way corresponding to that described above.
The extent of expansion, and therefore the recovery ratio, is not critical, but for some materials we prefer that the greatest expansion of the second portion is by a factor of 2-3. Any suitable polymeric material having elastic memory imparted thereto can be used in the present invention, for example polyolefins such as polyethylene or polypropylene or copolymers of these polymers with other ethylenically unsaturated monomers, other polymers that are suitable include PVC, polyvinylidene fluoride, polytetra-fluoroethylene and polyvinyl fluoride/hexafluoropropylene.
Additional features can also be provided such as a coating of thermochromic paint to indicate when sufficient heat has been applied for recovery. Other additives of often used in conjunction with polymeric materials in this context include fillers, pigments, antioxidants and flame retardants.
The invention is particularly applicable for use in conjunction with large conduits, for example those having a diameter or from l/2-3m but larger or smaller branch-offs can be made. In general, the branch-off conduit will of course have a smaller diameter than the main conduit, although the relative sizes of the two conduits is not critical. We expect the invention to be particularly applicable to conduits for carrying oil and gas, but it can also be used at joints in conduits carrying supply cables.
The invention can also provide a pipe bend. In this case the sheet material would be provided with a region of differential expansion which increases in extent of expansion and then decreases again across the sheet. The sheet would then be wrapped around to form a closed tube which would naturally form a bend; the region of maximum expansion would become the outer radius and the regions of minimum expansion (now joined) would become the inner radius. The whole of the sheet is preferably expanded uniformly (in one direction), and the region of differential expansion superimposed leaving two edge strips not expanded differentially. These edge strips would be used to form the inner radius of the bend, and could be provided with closure rails, or other closure means. Alternatively, the sheet material could be formed as a tube and then expanded.
The invention will now be further described, by way of example, with reference to the accompanying drawings, in which:
Figure 1 shows a sheet of recoverable material before use;
Figures 2 and 3 show a branch-off formed using the sheet of Figure l; and Figures 4-6 shows how a double region of differential expansion can be used to form a pipe bend.
1~';'(~t~8S
g The sheet of recoverable material A has a first portion 1, which has been expanded to a certain extent, and a second portion 2 which has been expanded to a greater extent. The second portion 2 has a pleated configuration because it has been differentially expanded, the extent of expansion increasing in a direction away from the first portion.
Although the pleats here are regular and produced by sharp folds, when we use the term pleats we intend to cover configurations which are irregular and which are produced by gentler folding or curving.
This differential expansion allows the second portion 2 to splay out to form a collar 5 which can overly a main conduit 3. This is shown in Figures 2a and 2b. In these figures the first portion 1 is used to secure a separate branch-off conduit 4, although the first portion 1 could itself extend a considerable distance thus forming an integral branch-off conduit.
The collar 5 can be secured to the main conduit 3 in many ways, one of which is illustrated in Figure 3. In this figure a recoverable wrap-around sleeve 6 is provided which has a hole 7 through which passes the first portion 1 of the sheet material. The wrap-around 6 is then secured in its closed configuration and then recovered. It is not critical whether the sheet material is recovered before, after or simultaneously with the wrap-around sleeve 6.
The sheet material can be used to cover irregular main conduits. Although the main conduit 3 is of constant cross-section, it may in some cases be stepped at the point where the branch-off occurs, due to the reduced volume that it has to carry after the branch-off.
1.~.'7(~35 --1 o--Figures 4-6m show the production of a pipe bend using a recoverable sheet A having a double region of differential expansion 2a,2b. Firstly, the sheet A is uniformly expanded in the direction shown by the arrow in Figure 4. Then (or simultaneously) further expansion is carried out to produce two regions of pleats 2a and 2b, where the extent of expansion 61, e~ ~", -~ c ~ crec~ J~; e~ ," ~
increases towards the centre. The~ could be reversed'so that ~J maximum expansion occurred a the two edges, but this is not preferred. The sheet is then wrapped-around so that the rails 7 meet. A closure channel 10 or other means is then used to maintain the tubular shape 9. Recovery is then carried out. Preferably the outer regions 11 of the sheet are not subjected to the differential expansion. One of the rails to provide a flap 12 which will underly the rails when the tube 9 is formed. This flap 12 serves to enhance the join and to protect any substrate within the tube.
In the production of heat recoverable articles, the polymeric material may be cross-linked at any stage in the production of the article that will enhance the desired dimensional recoverability. One manner of producing a heat-recoverable article comprises shaping the polymeric 1 t. 7(`~
material into the desired heat-stable form, subsequently cross-linking the poly-meric material, heating the article to a temperature above the crystalline melt-ing point or, for amorphous materials the softening point, as the case may be, of the polymer, deforming the article and cooling the article whilst in the deformed state so that the deformed state of the article is retained. In use, sinoe the deformed state of the article is heat-unstable, application of heat will cause the article to assume its original heat-stable shape.
In other articles, as described, for example, in British Patent 1,440,524, an elastomeric member such as an outer tubular member is held in a streched state by a second member, such as an inner tubular member, which, upon heating, weakens and thus allows the elastomeric mem~er to recover.
me use of recoverable articles, for mechanical protection and elec-trical insulation where appropriate, in covering articles, for example pipes and cables, has been disclosed in, for example, US Patent Nos. 2,027,962 to Currie and 3,297,819 to Wetmore. mese articles are designed primarily for covering a single pipe or a butt-junction between tWD pipes. In US Patent No. 3,445,336 to Ellis there is disclosed a heat-shrinkable sleeve which can be wrapped around an article or two butt-joined articles, which is suitable for use, for example, when no free end of the pipe or pipes is available. In the Ellis patent, there is dis-closed a heat-recoverable closure member, usually of sheet form, two opposite edges of which have protuberances along their length which, when the sheet is wrapped around an article to be covered, are in abutting relationship and can be held in such relationship during and after recovery by a fastening means, for example a metal channel. By the use of suitably moulded closure members, and using two or more sets of abutting protuberances, the closure member can be used for covering T or Y junctions on existing pipes and cables. Such mouldings are, however, relatively expensive.
UK Patent 1447048 discloses a heat-recoverable article that is adapted to cover a conduit junction having at least three arms, which comprises a radially heat-shrinkable tubular member or a member in sheet form of which opposing edge regions can be brought and held together to form a radially heat-shrinkable tubular member, the member having at least one heat-shrinkable aperture with an upstanding wall around its periphery, preferably outwardly extending from the member, the wall being such that, on heating, its height and periphery are reduced. A further method of sealing a branch-off to a main conduit is to wrap tapes, generally heat-recoverable tapes, around the crutch region between the main conduit and the branch-off conduit. This is not satisfactory in some instances since it can be difficult to obtain a good seal with certainty, and the wrapping operation is time consuming and craft sensitive.
Branch-offs are often connected after the main conduit has been installed, and therefore the sleeve must be a wraparound. Existing systems have many parts or use tape, which is craft sensitive. It is difficult therefore to get a good seal especially on large diameter pipes. We have now discovered a means of sealing a branch-off conduit to a main conduit which is particularly applicable to ~-shaped branch-offs, but which is also suitable where the branch-off conduit is not perpendicular to the main conduit.
When we use the term "main conduit" we do not indicate that it is necessarily larger that the branch conduit, but merely to differentiate between the conduit which branches off and the conduit from which the branching off occurs.
l.t'7(~35 Thus, the present invention provides a recoverable sheet material for forming a conduit which has been differ-entially expanded, the change in extent of expansion across its surface being accommodated by pleats which increase in depth or number in the direction of increasing expansion.
It is to be understood that the word pleats as used in the specification and claims has a broad meaning including but not limited to folds or creases which are doubled upon themselves, or which have any particular geometric form; the word is intended to encompass any series of corrugations folds, creases or undulations by which a sheet may be compacted into a smaller area than the surface area of its material.
The present invention in particular provides `a recover-able sheet material for providing a sealed branch-off from a main conduit, comprising: a first portion which can define or enclose a branch-off conduit, and a second portion having been expanded differentially and which thus can splay out to form a collar around a hole in the main conduit. Preferably the whole of the sheet is first expanded and the differential expansion of the second portion is superimposed.
The sheet material can be used to join an independent branch-off conduit to a main conduit, or said first portion can itself constitute the branch-off conduit. The invention is particularly useful for larger conduits such as those used for carrying oil or gas.
The invention also provides a method of forming a branch-off, in which the sheet material of the invention is placed on a conduit with the collar around a hole in the conduit, the collar is secured to the conduit, and the ; sheet material recovered. The collar is secured to the conduit by means of an overlying recoverable wrap-around 11'7( }~j~5 sleeve which has a hole through which said first portion can pass, or by two patches or wrap-around or tubular sleeves one either side of the branch-off conduit, where the conduits are large it will generally be necessary to use two patches or sleeves, rather than a single item with a hole.
The sheet material of the invention can be provided as a wrap-around closure member, in which case means will generally be required to secure it in the closed configuration.
Such means can be adhesive or the provision of a rail and channel closure, such as that described in our US Patent 3455336, modifications to this idea are disclosed in UK
Patent 1529351 and in applications 80~8703 and 8005501.
Alternatively the sheet material can be provided as a closed tube. In either case some sort of sealant (such a hot-melt adhesive or mastic) will generally be employed when the branch-off is made. It is preferred, none-the-less, that the sheet material be provided plain, a sealant being added by the craftsman on site where required. The alternative is to provide a coating of sealant on the inner surface of the sheet material; this however makes production of the material more expensive. The sheet material of the invention may be held in the closed configuration, and it may be sealed to the main conduit by a pressure sensitive or heat-activated closure patch, such as that sold by Raychem under the trade mark WPCP.
The method of producing the sheet material in wrap-around form is as follows. A sheet of a suitable plastics material is subjected to the usual cross-linking (by chemical means or by radiation) and heating/cooling operations, but the expansion is a two part process. The sheet is longitudinally expanded as a whole, and the part which is to become the second portion is further expanded. This further expansion increases in extent throughout the width of the second 7~t~35 portion in a direction away from the first portion. The differential expansion of the second portion allows the second portion to splay out to form a collar which can overly a hole in the main conduit. It is to be understood that the expansion of the whole and the further expansion need not be done sequentially, but may be part of the same process. After this expansion, and before the material is closed to form a tube, the second portion preferably will have a generally pleated configuration. The size of such pleats can vary over a wide range, but a typical size could bre regarded as 50mp pitch and 50mp depth.However, the precise configuration will depend on the method employed in the expansion. A continuous in line process can be employed, in which convolutes are produced in the second portion simply simply by pressing.
Where the sheet material is to be in the form of a closed tube, it may be made as above and then welded closed, or it may be moulded as a tube, and then radially expanded in a way corresponding to that described above.
The extent of expansion, and therefore the recovery ratio, is not critical, but for some materials we prefer that the greatest expansion of the second portion is by a factor of 2-3. Any suitable polymeric material having elastic memory imparted thereto can be used in the present invention, for example polyolefins such as polyethylene or polypropylene or copolymers of these polymers with other ethylenically unsaturated monomers, other polymers that are suitable include PVC, polyvinylidene fluoride, polytetra-fluoroethylene and polyvinyl fluoride/hexafluoropropylene.
Additional features can also be provided such as a coating of thermochromic paint to indicate when sufficient heat has been applied for recovery. Other additives of often used in conjunction with polymeric materials in this context include fillers, pigments, antioxidants and flame retardants.
The invention is particularly applicable for use in conjunction with large conduits, for example those having a diameter or from l/2-3m but larger or smaller branch-offs can be made. In general, the branch-off conduit will of course have a smaller diameter than the main conduit, although the relative sizes of the two conduits is not critical. We expect the invention to be particularly applicable to conduits for carrying oil and gas, but it can also be used at joints in conduits carrying supply cables.
The invention can also provide a pipe bend. In this case the sheet material would be provided with a region of differential expansion which increases in extent of expansion and then decreases again across the sheet. The sheet would then be wrapped around to form a closed tube which would naturally form a bend; the region of maximum expansion would become the outer radius and the regions of minimum expansion (now joined) would become the inner radius. The whole of the sheet is preferably expanded uniformly (in one direction), and the region of differential expansion superimposed leaving two edge strips not expanded differentially. These edge strips would be used to form the inner radius of the bend, and could be provided with closure rails, or other closure means. Alternatively, the sheet material could be formed as a tube and then expanded.
The invention will now be further described, by way of example, with reference to the accompanying drawings, in which:
Figure 1 shows a sheet of recoverable material before use;
Figures 2 and 3 show a branch-off formed using the sheet of Figure l; and Figures 4-6 shows how a double region of differential expansion can be used to form a pipe bend.
1~';'(~t~8S
g The sheet of recoverable material A has a first portion 1, which has been expanded to a certain extent, and a second portion 2 which has been expanded to a greater extent. The second portion 2 has a pleated configuration because it has been differentially expanded, the extent of expansion increasing in a direction away from the first portion.
Although the pleats here are regular and produced by sharp folds, when we use the term pleats we intend to cover configurations which are irregular and which are produced by gentler folding or curving.
This differential expansion allows the second portion 2 to splay out to form a collar 5 which can overly a main conduit 3. This is shown in Figures 2a and 2b. In these figures the first portion 1 is used to secure a separate branch-off conduit 4, although the first portion 1 could itself extend a considerable distance thus forming an integral branch-off conduit.
The collar 5 can be secured to the main conduit 3 in many ways, one of which is illustrated in Figure 3. In this figure a recoverable wrap-around sleeve 6 is provided which has a hole 7 through which passes the first portion 1 of the sheet material. The wrap-around 6 is then secured in its closed configuration and then recovered. It is not critical whether the sheet material is recovered before, after or simultaneously with the wrap-around sleeve 6.
The sheet material can be used to cover irregular main conduits. Although the main conduit 3 is of constant cross-section, it may in some cases be stepped at the point where the branch-off occurs, due to the reduced volume that it has to carry after the branch-off.
1.~.'7(~35 --1 o--Figures 4-6m show the production of a pipe bend using a recoverable sheet A having a double region of differential expansion 2a,2b. Firstly, the sheet A is uniformly expanded in the direction shown by the arrow in Figure 4. Then (or simultaneously) further expansion is carried out to produce two regions of pleats 2a and 2b, where the extent of expansion 61, e~ ~", -~ c ~ crec~ J~; e~ ," ~
increases towards the centre. The~ could be reversed'so that ~J maximum expansion occurred a the two edges, but this is not preferred. The sheet is then wrapped-around so that the rails 7 meet. A closure channel 10 or other means is then used to maintain the tubular shape 9. Recovery is then carried out. Preferably the outer regions 11 of the sheet are not subjected to the differential expansion. One of the rails to provide a flap 12 which will underly the rails when the tube 9 is formed. This flap 12 serves to enhance the join and to protect any substrate within the tube.
Claims (19)
1. A recoverable sheet material for forming a conduit which has been differentially expanded, the change in extent of expansion across its surface being accommodated by pleats which increase in depth or number in the direction of increasing expansion.
2. A recoverable sheet material according to Claim 1, for providing a sealed branch-off from a main conduit, comprising:
a first portion which can define or enclose a branch-off conduit, and a second portion having been expanded differentially and which thus can splay out to form a collar around a hole in the main conduit.
a first portion which can define or enclose a branch-off conduit, and a second portion having been expanded differentially and which thus can splay out to form a collar around a hole in the main conduit.
3. A material according to Claim 1, in the form of a wrap-around closure member.
4. A material according to Claim 1, in the form of a closed tube.
5. A material according to Claim 1, which is heat recoverable.
6. A material according to Claim 2, for sealing a branch-off conduit to a main conduit, in which the first portion can enclose the branch-off conduit.
7. A material according to Claim 2, in which the first portion is or can form a branch-off conduit.
8. A material according to Claim 2, in which the second portion is pleated.
9. A method of producing a material according to Claim 2, in which recoverability is induced into material by a process which includes expanding longitudinally the whole of the material, and further expanding longitudinally the second portion, the extent of the further expansion increasing throughout the width of the second portion in a direction away from the first portion.
10. A method according to Claim 9, in which the further expansion of the second portion is produced by pressing the second portion into a pleated configuration.
11. A method according to Claim 9, which is a continuous in-line method.
12. A method of providing a material according to Claim 4, in which recoverability is induced into the material by a process which includes expanding radially the whole of the tube, and further expanding radially the second portion, the extent of the further expansion increasing throughout the second portion in a direction away from the first poriton.
13. A method of forming a branch-off, in which a material according to Claim 2, is placed on a conduit with the collar around a hole in the conduit, the collar is secured to the conduit and the material is recovered.
14. A method according to Claim 13, which comprises:
securing the collar to the conduit by means of a wrap-around recoverable sleeve having a hole therein, the wrap-around sleeve being wrapped around the conduit with the first portion passing through the hole; securing the sleeve in the wrapped configuration; and recovering the sleeve.
securing the collar to the conduit by means of a wrap-around recoverable sleeve having a hole therein, the wrap-around sleeve being wrapped around the conduit with the first portion passing through the hole; securing the sleeve in the wrapped configuration; and recovering the sleeve.
15. A method according to Claim 13, which comprises: secur-ing the collar to the conduit by means of at least two adhesive patches, one either side of the branch-off conduit.
16. A method according to Claim 13, which comprises: secur-ing the collar to the conduit by means of two recoverable sleeves around the main conduit, one on either side of the branch-off con-duit overlapping the collar; and recovering the two sleeves.
17. A branch-off comprising a main conduit and a branch-off conduit secured by a method according to any of Claims 13, 14 or 15.
18. A recoverable sheet material according to Claim 1, for providing a pipe bend, comprising:
a first portion which has been differentially expanded, the extent of expansion increasing in a first direction; and a second portion adjacent the first portion which has been differentially expanded, the extent of expansion increasing in the opposite direction.
a first portion which has been differentially expanded, the extent of expansion increasing in a first direction; and a second portion adjacent the first portion which has been differentially expanded, the extent of expansion increasing in the opposite direction.
19. A material according to Claim 18, in which the two dire-ctions of increasing expansion are towards one another, and in which a closure rail is provided adjacent each portion, on the side of that portion remote from the other portion.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000379526A CA1170685A (en) | 1981-06-11 | 1981-06-11 | Flexible tee collar |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000379526A CA1170685A (en) | 1981-06-11 | 1981-06-11 | Flexible tee collar |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1170685A true CA1170685A (en) | 1984-07-10 |
Family
ID=4120210
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000379526A Expired CA1170685A (en) | 1981-06-11 | 1981-06-11 | Flexible tee collar |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1170685A (en) |
-
1981
- 1981-06-11 CA CA000379526A patent/CA1170685A/en not_active Expired
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| US4532168A (en) | Heat shrinkable covering | |
| EP0158519B1 (en) | Heat-recoverable article | |
| CA1087824A (en) | Heat recoverable article | |
| US5660660A (en) | Heat-recoverable article | |
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| CA1195265A (en) | Wraparound device | |
| US4436566A (en) | Re-enterable closure | |
| US4366201A (en) | Heat shrinkable wraparound closures | |
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| EP0074280A2 (en) | Recoverable closure | |
| EP0094793B1 (en) | Branch-off | |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |