WO2001092775A1 - Pipe joint - Google Patents
Pipe joint Download PDFInfo
- Publication number
- WO2001092775A1 WO2001092775A1 PCT/GB2001/002376 GB0102376W WO0192775A1 WO 2001092775 A1 WO2001092775 A1 WO 2001092775A1 GB 0102376 W GB0102376 W GB 0102376W WO 0192775 A1 WO0192775 A1 WO 0192775A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pipes
- pipe
- guest
- pipe joint
- metallic
- Prior art date
Links
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
- B29C65/3404—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the type of heated elements which remain in the joint
- B29C65/342—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the type of heated elements which remain in the joint comprising at least a single wire, e.g. in the form of a winding
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/01—General aspects dealing with the joint area or with the area to be joined
- B29C66/05—Particular design of joint configurations
- B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
- B29C66/12—Joint cross-sections combining only two joint-segments; Tongue and groove joints; Tenon and mortise joints; Stepped joint cross-sections
- B29C66/122—Joint cross-sections combining only two joint-segments, i.e. one of the parts to be joined comprising only two joint-segments in the joint cross-section
- B29C66/1222—Joint cross-sections combining only two joint-segments, i.e. one of the parts to be joined comprising only two joint-segments in the joint cross-section comprising at least a lapped joint-segment
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/01—General aspects dealing with the joint area or with the area to be joined
- B29C66/05—Particular design of joint configurations
- B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
- B29C66/12—Joint cross-sections combining only two joint-segments; Tongue and groove joints; Tenon and mortise joints; Stepped joint cross-sections
- B29C66/122—Joint cross-sections combining only two joint-segments, i.e. one of the parts to be joined comprising only two joint-segments in the joint cross-section
- B29C66/1224—Joint cross-sections combining only two joint-segments, i.e. one of the parts to be joined comprising only two joint-segments in the joint cross-section comprising at least a butt joint-segment
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/01—General aspects dealing with the joint area or with the area to be joined
- B29C66/05—Particular design of joint configurations
- B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
- B29C66/12—Joint cross-sections combining only two joint-segments; Tongue and groove joints; Tenon and mortise joints; Stepped joint cross-sections
- B29C66/124—Tongue and groove joints
- B29C66/1244—Tongue and groove joints characterised by the male part, i.e. the part comprising the tongue
- B29C66/12441—Tongue and groove joints characterised by the male part, i.e. the part comprising the tongue being a single wall
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
- B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
- B29C66/52—Joining tubular articles, bars or profiled elements
- B29C66/522—Joining tubular articles
- B29C66/5221—Joining tubular articles for forming coaxial connections, i.e. the tubular articles to be joined forming a zero angle relative to each other
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
- B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
- B29C66/52—Joining tubular articles, bars or profiled elements
- B29C66/522—Joining tubular articles
- B29C66/5229—Joining tubular articles involving the use of a socket
- B29C66/52291—Joining tubular articles involving the use of a socket said socket comprising a stop
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
- B29C66/51—Joining tubular articles, profiled elements or bars; Joining single elements to tubular articles, hollow articles or bars; Joining several hollow-preforms to form hollow or tubular articles
- B29C66/52—Joining tubular articles, bars or profiled elements
- B29C66/522—Joining tubular articles
- B29C66/5229—Joining tubular articles involving the use of a socket
- B29C66/52296—Joining tubular articles involving the use of a socket said socket comprising sealing elements, e.g. gaskets
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/50—General aspects of joining tubular articles; General aspects of joining long products, i.e. bars or profiled elements; General aspects of joining single elements to tubular articles, hollow articles or bars; General aspects of joining several hollow-preforms to form hollow or tubular articles
- B29C66/63—Internally supporting the article during joining
- B29C66/636—Internally supporting the article during joining using a support which remains in the joined object
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C66/00—General aspects of processes or apparatus for joining preformed parts
- B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
- B29C66/72—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined
- B29C66/723—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined being multi-layered
- B29C66/7232—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined being multi-layered comprising a non-plastics layer
- B29C66/72321—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined being multi-layered comprising a non-plastics layer consisting of metals or their alloys
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L25/00—Constructive types of pipe joints not provided for in groups F16L13/00 - F16L23/00 ; Details of pipe joints not otherwise provided for, e.g. electrically conducting or insulating means
- F16L25/01—Constructive types of pipe joints not provided for in groups F16L13/00 - F16L23/00 ; Details of pipe joints not otherwise provided for, e.g. electrically conducting or insulating means specially adapted for realising electrical conduction between the two pipe ends of the joint or between parts thereof
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L47/00—Connecting arrangements or other fittings specially adapted to be made of plastics or to be used with pipes made of plastics
- F16L47/02—Welded joints; Adhesive joints
- F16L47/03—Welded joints with an electrical resistance incorporated in the joint
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
- B29C65/3468—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the means for supplying heat to said heated elements which remain in the join, e.g. special electrical connectors of windings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
- B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
- B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
- B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
- B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
- B29C65/3472—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the composition of the heated elements which remain in the joint
- B29C65/3476—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" characterised by the composition of the heated elements which remain in the joint being metallic
Definitions
- This invention relates to pipe joints.
- metal pipework systems for conveying fuels, water, hazardous gases and fluids, operating at high pressures. This is primarily due to an immunity to permeation through the pipe wall, mechanical strength of metals, and welding jointing techniques.
- Metal pipework systems also offer the advantage of being electrically conductive throughout. Electrical continuity is becoming increasingly important and is specified in many cases because a static charge can build up due to friction generated between the pipe and the medium being transported. If this charge cannot be dissipated then a situation can result where a spark can occur, this could potentially ignite the medium being transported.
- the main disadvantage with metal pipework systems is susceptibility to corrosion and the systems, therefore, require some form of protection.
- Polymer pipework systems offer the advantage of excellent resistance to corrosion.
- the polymer is thermoplastic, they offer the facility to be fully welded.
- Polyethylene for example, is widely used for transporting water and gas and welding techniques of electrofusion and butt fusion are firmly established.
- fuels can permeate through the polymers and into the surrounding area.
- polymer systems cannot offer the same levels of internal pressure resistance as metal pipework systems due to the mechanical characteristics of polymers. Conductivity throughout the polymer pipework system is difficult to achieve due to the electrical insulating properties of polymers.
- permeation can occur from the outside of the pipe through to the inside and can contaminate the medium being transported.
- An example being water supplies piped through contaminated land where leachates are present.
- thermoplastic electrofusion fitting is subjected to the medium being transported and can potentially result in permeation through the wall of the fitting. Also, the fitting is exposed to the internal pressure of the medium being transported and, therefore, places limitations on maximum operating pressures. Metal continuity throughout the pipework system is not achieved therefore there is the possibility of static charge build up.
- British Patent Publication 2,324,132 provides a considerable improvement in relation to the connection of pipes comprising an outer host and an inner guest pipe, it advocating the employment of an outer host pipe, an inner guest pipe, each of a material to provide a particular required attribute, and a pipe insert of a material weld-compatible with the material of the outer host pipe, the pipe insert being inserted in the end of the inner guest pipe and having an outermost flange to overlie the outer edge of the inner guest pipe. Whilst generating a welded joint that is leak free, by way of relatively conventional fusion welding techniques, it does not attend the problem of electrical continuity.
- the object of the present invention is to improve still further the connection between composite pipes.
- a pipe joint for pipes formed by an outer host plastics pipe and an inner guest metallic pipe comprises a hollow metal spigot connector in sealing engagement with the inner wall of the ends of abutting guest metallic pipes and an electrofusion sleeve surrounding the ends of adjacent outer plastics host pipes.
- the spigot has a generally centrally disposed outer flange to lie between and be abutted by the ends of the inner metallic guest pipes
- the electrofusion sleeve has an inner generally centrally disposed flange or central stops to lie between and be abutted by the ends of the outer host plastics pipes.
- the outer surface of the spigot connector can utilise annular projections to each side of its centre and/or metallic attachments such as circlips, spring washers, springs, to bear against the inner wall or edge of the guest metallic pipe to ensure electrical continuity across the joint.
- each end of the spigot has a means of sealing against the inner metallic guest pipes, for example, by means of o-rings, lip-seals, quad-seals, interference fit.
- the metal spigot bridging the guest pipes eliminates any weakness at the joint with respect to resisting the hoop stresses imposed on the joint by the fluid/gases being transported under high pressures.
- the inner bore of the guest pipe may need re-rounding or expanding to a fixed diameter for a specific length to accept the spigot connector.
- the invention therefore allows the provision of an outer plastics host pipe and inner metallic guest pipe system where there is a considerable security against leakage at all connections of pipe to pipe and to bends, tees and elbows and indeed at all polymer/metal transition points.
- Figure 1 is a schematic cross-sectional view of one embodiment of pipe joint in accordance with the invention
- Figure 2 is a side elevation of an alternative spigot to that of Figure 1 ;
- Figure 3 generally corresponds to Figure 1 , but shows a second embodiment of pipe joint.
- Figure 1 is illustrated a joint between adjacent ends of plain pipes 1, each of which are composed of an outer host plastics pipe 2 and an inner guest metallic pipe 3.
- a hollow metal spigot connector 4 is inserted into the adjacent pipe ends, the spigot having a centrally located external flange 5 against which the pipe ends abut and tapered ends 6 to assist in the insertion of the spigot into the pipe ends.
- sealing rings 7 are provided, and the spigot has circumferential ribs 8, to engage with the inner surface of the guest pipe 3.
- an electrofusion coupling member 9 Surrounding the abutting ends of the pipes 1 is an electrofusion coupling member 9 of a compatible plastics material, having an internal centrally located flange 10 against which the pipe ends abut.
- FIG. 2 illustrates an alternate form of spigot, where in place of circumferential ribs, a circular spring 14 is provided to each side of the central flange 5, to provide a mechanical contact as between the spigot and the inner guest pipe, to supplement the sealing action of the sealing rings 7.
- FIG 3 is illustrated the different circumstance of pipes 1 composed of host pipes 2 and guest pipes 3 having a prepared length 15 to receive the spigot 4.
- abutting sockets will be inserted into an electrofusion coupling member as is illustrated in Figure 1.
- the inner bore of the guest pipe may need re- rounding or expanding to a fixed diameter for a specific length to accept the spigot connector.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Rigid Pipes And Flexible Pipes (AREA)
- Joints With Sleeves (AREA)
Abstract
The invention relates to pipe joints for conveying fuels, water, hazardous gases and fluids operating at relatively high pressures. Metal pipes with welded joints have historically been used to provide electrical continuity throughout the system and to eliminate permeation through the pipe wall. However, metal pipes can corrode. Plastics pipes and joints avoid corrosion and can readily be jointed, but there is no electrical continuity and permeation of such as fuels can occur. Composites of plastics host and metal guest pipes are known, that attempt to take advantage of the different properties of each, but electrical continuity continues to be a problem. The objet of the invention is to overcome this difficulty, an objective met by a pipe joint for pipes formed by an outer host plastics pipe (2) and an inner guest metallic pipe (3), comprising a hollow metal spigot connector (4) in sealing engagement with the inner wall of the ends of abutting guest metallic pipes and an electrofusion sleeve (9) surrounding the ends of adjacent outer plastics host pipes.
Description
PIPE JOINT
This invention relates to pipe joints.
The traditional materials used for pipework systems for conveying fuels, water, hazardous gases and fluids, operating at high pressures has been metals. This is primarily due to an immunity to permeation through the pipe wall, mechanical strength of metals, and welding jointing techniques. Metal pipework systems also offer the advantage of being electrically conductive throughout. Electrical continuity is becoming increasingly important and is specified in many cases because a static charge can build up due to friction generated between the pipe and the medium being transported. If this charge cannot be dissipated then a situation can result where a spark can occur, this could potentially ignite the medium being transported. The main disadvantage with metal pipework systems is susceptibility to corrosion and the systems, therefore, require some form of protection.
Polymer pipework systems offer the advantage of excellent resistance to corrosion. When the polymer is thermoplastic, they offer the facility to be fully welded. Polyethylene, for example, is widely used for transporting water and gas and welding techniques of electrofusion and butt fusion are firmly established. However, fuels can permeate through the polymers and into the surrounding area. Also, polymer systems cannot offer the same levels of internal pressure resistance as metal pipework systems due to the mechanical characteristics of polymers. Conductivity throughout the polymer pipework system is difficult to achieve due to the electrical insulating properties of polymers.
There are also applications where permeation can occur from the outside of the pipe through to the inside and can contaminate the medium being transported. An example being water supplies piped through contaminated land where leachates are present.
There are, at present, systems manufactured that utilise combinations of metal and plastic layers to gain the advantages of each material ie. polymer corrosion protection, metallic permeation resistance, metallic resistance to high hoop stresses imposed by high operating pressures, fully welded. None of the above mentioned systems provide jointing
techniques that can offer the same advantages/properties as the pipe. Many of the joints rely solely on the thermoplastic electrofusion fitting. Therefore, the thermoplastic electrofusion fitting is subjected to the medium being transported and can potentially result in permeation through the wall of the fitting. Also, the fitting is exposed to the internal pressure of the medium being transported and, therefore, places limitations on maximum operating pressures. Metal continuity throughout the pipework system is not achieved therefore there is the possibility of static charge build up.
British Patent Publication 2,324,132 provides a considerable improvement in relation to the connection of pipes comprising an outer host and an inner guest pipe, it advocating the employment of an outer host pipe, an inner guest pipe, each of a material to provide a particular required attribute, and a pipe insert of a material weld-compatible with the material of the outer host pipe, the pipe insert being inserted in the end of the inner guest pipe and having an outermost flange to overlie the outer edge of the inner guest pipe. Whilst generating a welded joint that is leak free, by way of relatively conventional fusion welding techniques, it does not attend the problem of electrical continuity.
The object of the present invention is to improve still further the connection between composite pipes.
According to the present invention, a pipe joint for pipes formed by an outer host plastics pipe and an inner guest metallic pipe, comprises a hollow metal spigot connector in sealing engagement with the inner wall of the ends of abutting guest metallic pipes and an electrofusion sleeve surrounding the ends of adjacent outer plastics host pipes. Preferably, the spigot has a generally centrally disposed outer flange to lie between and be abutted by the ends of the inner metallic guest pipes, and the electrofusion sleeve has an inner generally centrally disposed flange or central stops to lie between and be abutted by the ends of the outer host plastics pipes.
Further preferably, the outer surface of the spigot connector can utilise annular projections to each side of its centre and/or metallic attachments such as circlips, spring
washers, springs, to bear against the inner wall or edge of the guest metallic pipe to ensure electrical continuity across the joint. Still further preferable, each end of the spigot has a means of sealing against the inner metallic guest pipes, for example, by means of o-rings, lip-seals, quad-seals, interference fit. By overlaying the ends of the outer plastics host pipes, the electrofusion sleeve allows the creation of an effective seal between the host pipe ends. The weld between the sleeve and outer host plastic pipe also enables the pipework system to resist all loads placed on it due to, for example, expansion, contraction, end loads, ground movement.
By providing a metal spigot bridging the ends of the guest pipes of metal, electrical continuity is provided at the joint between two pipe lengths, and the sealing engagement of the ends of the spigots in the ends of the metal guest pipes ensures that fluid flowing through the guest pipes cannot reach and hence penetrate through the plastic material of the joint. In addition to this, the metal spigot bridging the guest pipes eliminates any weakness at the joint with respect to resisting the hoop stresses imposed on the joint by the fluid/gases being transported under high pressures.
Depending on a host of variables (examples of which could include o-ring compression, o-ring cross section tolerances, spigot connector machining tolerances, inner guest metallic pipe dimensions), the inner bore of the guest pipe may need re-rounding or expanding to a fixed diameter for a specific length to accept the spigot connector. The invention therefore allows the provision of an outer plastics host pipe and inner metallic guest pipe system where there is a considerable security against leakage at all connections of pipe to pipe and to bends, tees and elbows and indeed at all polymer/metal transition points. The provision of the metallic spigot connector ensures the sealing together of metallic guest pipes or inner metallic elements of bends, tees and elbows, with the surety of electrical continuity across a joint and the provision of a considerable ability to withstand high hoop stresses imposed on the pipe system by the pressure in the medium being transported.
Two embodiments of the invention will now be described with reference to the accompanying drawings in which:-
Figure 1 is a schematic cross-sectional view of one embodiment of pipe joint in accordance with the invention; Figure 2 is a side elevation of an alternative spigot to that of Figure 1 ; and
Figure 3 generally corresponds to Figure 1 , but shows a second embodiment of pipe joint.
In Figure 1 is illustrated a joint between adjacent ends of plain pipes 1, each of which are composed of an outer host plastics pipe 2 and an inner guest metallic pipe 3. A hollow metal spigot connector 4 is inserted into the adjacent pipe ends, the spigot having a centrally located external flange 5 against which the pipe ends abut and tapered ends 6 to assist in the insertion of the spigot into the pipe ends. To provide for sealing engagement of the spigot with the pipes, sealing rings 7 are provided, and the spigot has circumferential ribs 8, to engage with the inner surface of the guest pipe 3. Surrounding the abutting ends of the pipes 1 is an electrofusion coupling member 9 of a compatible plastics material, having an internal centrally located flange 10 against which the pipe ends abut. On the inner surface of the coupling member are two wire windings 11 to each side of the centrally located flange 10, the inner ends of the windings being connected together, and the respective outer ends each connected to a terminal 12 in a socket 13 formed on the coupling member.
With the joint assembled as illustrated, and electrical power applied to the winding, the interface as between the plastics coupling member and the plastics host pipe to cause the melting of the interface that on cooling generates a substantially leak free joint between the pipes 1. Figure 2 illustrates an alternate form of spigot, where in place of circumferential ribs, a circular spring 14 is provided to each side of the central flange 5, to provide a mechanical
contact as between the spigot and the inner guest pipe, to supplement the sealing action of the sealing rings 7.
In Figure 3 is illustrated the different circumstance of pipes 1 composed of host pipes 2 and guest pipes 3 having a prepared length 15 to receive the spigot 4. Although not shown, abutting sockets will be inserted into an electrofusion coupling member as is illustrated in Figure 1. Depending on a host of variables (examples of which could include o-ring compression, o-ring cross section tolerances, spigot connector machining tolerances, inner guest metallic pipe dimensions), the inner bore of the guest pipe may need re- rounding or expanding to a fixed diameter for a specific length to accept the spigot connector.
An example of this is detailed in Figure 3 where the pipe bore is increased to provide a prepared diameter X for a length Lp where Lp is greater than the spigot connector insertion length Lsc.
Claims
1. A pipe joint for pipes formed by an outer host plastics pipe and an inner guest metallic pipe characterized by a hollow metal spigot connector in sealing engagement with the inner wall of the ends of abutting guest metallic pipes and an electrofusion sleeve surrounding the ends of adjacent outer plastics host pipes.
2. A pipe joint as in Claim 1 , characterized in that the spigot has a generally centrally disposed outer flange to lie between and be abutted by the ends of the inner metallic guest pipes.
3. A pipe joint as in Claim 1 and Claim 2 characterized in that the electrofusion sleeve has an inner generally centrally disposed flange or central stops to lie between and be abutted by the ends of the outer host plastics pipes.
4. A pipe joint as in any of Claims 1 to 3 characterized in that the outer surface of the spigot connector utilizes annular projections to each side of its centre and/or metallic attachments to ensure electrical continuity across the joint.
5. A pipe joint as in Claim 4 characterized in that the metallic attachments are circlips, spring washers or springs.
6. A pipe joint as in any of Claims 1 to 5 characterized in that each end of the spigot has a means of sealing against the inner metallic guest pipes.
7. A pipe joint as in Claim 6 characterized in that the means of sealing are o-rings, lip-seals, quad seals or an interference fit.
8. A pipe joint as in any of Claims 1 to 7 characterized in that the inner bore of the guest pipe is re-rounded or expanded to a required diameter over a pre-determined length, to accept the spigot connector.
9. A pipe joint substantially as herein before described with reference to Figures 1 , 2 or 3 of the accompanying drawings.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AU58654/01A AU5865401A (en) | 2000-06-01 | 2001-05-30 | Pipe joint |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GBGB0013155.7A GB0013155D0 (en) | 2000-06-01 | 2000-06-01 | Pipe joint |
GB0013155.7 | 2000-06-01 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2001092775A1 true WO2001092775A1 (en) | 2001-12-06 |
Family
ID=9892662
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/GB2001/002376 WO2001092775A1 (en) | 2000-06-01 | 2001-05-30 | Pipe joint |
Country Status (3)
Country | Link |
---|---|
AU (1) | AU5865401A (en) |
GB (1) | GB0013155D0 (en) |
WO (1) | WO2001092775A1 (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1388703A1 (en) * | 2002-08-05 | 2004-02-11 | Uponor Innovation Ab | Fitting for composite pipe |
NL1026142C2 (en) * | 2004-05-07 | 2005-11-08 | Petrus Johannes Bus | Assembly for coupling two tubular elements substantially perme-free. |
WO2005121627A1 (en) | 2004-06-08 | 2005-12-22 | Friatec Aktiengesellschaft | Connecting arrangement, particularly for the non-positive fastening of at least one fiber composite component to another component |
EP1901382A2 (en) * | 2006-08-29 | 2008-03-19 | Yamaha Hatsudoki Kabushiki Kaisha | Fuel cell system with hydrogen supply pipe connecting structure |
EP1511960B2 (en) † | 2002-06-10 | 2010-09-29 | Georg Fischer Rohrleitungssysteme AG | Pipe-connector moulded part for pre-insulated pipe conduits |
WO2013071448A1 (en) | 2011-11-16 | 2013-05-23 | Flexpipe Systems Inc. | Connection for a thermoplastic pipe, assembly and method |
CN107218464A (en) * | 2016-03-22 | 2017-09-29 | 杨明昆 | A kind of electric smelting connecting pipe of steel-plastics composite pipe |
US9857003B2 (en) | 2012-02-17 | 2018-01-02 | Core Linepipe Inc. | Pipe, pipe connection and pipeline system |
NL2021211B1 (en) * | 2018-06-29 | 2020-01-06 | Tse Fuelling Supplies B V | Anti-permeation ring |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0809064A1 (en) * | 1996-05-24 | 1997-11-26 | Nupi S.p.A. | A heat-fusible pipe fitting |
WO1997049540A1 (en) * | 1996-06-25 | 1997-12-31 | Uponor B.V. | Electrofusion fitting |
GB2318543A (en) * | 1996-10-28 | 1998-04-29 | Glynwed Pipe Systems Ltd | Dual wall electrofusion coupler |
GB2324132A (en) | 1996-12-27 | 1998-10-14 | Fusion Group Plc | Outer and inner pipe construction with end insert |
WO1998048207A1 (en) * | 1997-04-21 | 1998-10-29 | Kungsörs Plast AB | A method and an apparatus for discharging static electricity in plastic pipes |
-
2000
- 2000-06-01 GB GBGB0013155.7A patent/GB0013155D0/en not_active Ceased
-
2001
- 2001-05-30 AU AU58654/01A patent/AU5865401A/en not_active Abandoned
- 2001-05-30 WO PCT/GB2001/002376 patent/WO2001092775A1/en active Application Filing
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0809064A1 (en) * | 1996-05-24 | 1997-11-26 | Nupi S.p.A. | A heat-fusible pipe fitting |
WO1997049540A1 (en) * | 1996-06-25 | 1997-12-31 | Uponor B.V. | Electrofusion fitting |
GB2318543A (en) * | 1996-10-28 | 1998-04-29 | Glynwed Pipe Systems Ltd | Dual wall electrofusion coupler |
GB2324132A (en) | 1996-12-27 | 1998-10-14 | Fusion Group Plc | Outer and inner pipe construction with end insert |
WO1998048207A1 (en) * | 1997-04-21 | 1998-10-29 | Kungsörs Plast AB | A method and an apparatus for discharging static electricity in plastic pipes |
Cited By (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1511960B2 (en) † | 2002-06-10 | 2010-09-29 | Georg Fischer Rohrleitungssysteme AG | Pipe-connector moulded part for pre-insulated pipe conduits |
EP1388703A1 (en) * | 2002-08-05 | 2004-02-11 | Uponor Innovation Ab | Fitting for composite pipe |
NL1026142C2 (en) * | 2004-05-07 | 2005-11-08 | Petrus Johannes Bus | Assembly for coupling two tubular elements substantially perme-free. |
WO2005121627A1 (en) | 2004-06-08 | 2005-12-22 | Friatec Aktiengesellschaft | Connecting arrangement, particularly for the non-positive fastening of at least one fiber composite component to another component |
CN1989367B (en) * | 2004-06-08 | 2011-11-30 | 弗利亚特克公司 | Connecting arrangement, particularly for the non-positive fastening of at least one fiber composite component to another component |
EP1901382A2 (en) * | 2006-08-29 | 2008-03-19 | Yamaha Hatsudoki Kabushiki Kaisha | Fuel cell system with hydrogen supply pipe connecting structure |
EP1901382A3 (en) * | 2006-08-29 | 2009-08-05 | Yamaha Hatsudoki Kabushiki Kaisha | Fuel cell system with hydrogen supply pipe connecting structure |
WO2013071448A1 (en) | 2011-11-16 | 2013-05-23 | Flexpipe Systems Inc. | Connection for a thermoplastic pipe, assembly and method |
EP2780619A4 (en) * | 2011-11-16 | 2015-08-12 | Flexpipe Systems Inc | Connection for a thermoplastic pipe, assembly and method |
US9857003B2 (en) | 2012-02-17 | 2018-01-02 | Core Linepipe Inc. | Pipe, pipe connection and pipeline system |
US10544889B2 (en) | 2012-02-17 | 2020-01-28 | Core Linepipe Inc. | Pipe, pipe connection and pipeline system |
CN107218464A (en) * | 2016-03-22 | 2017-09-29 | 杨明昆 | A kind of electric smelting connecting pipe of steel-plastics composite pipe |
NL2021211B1 (en) * | 2018-06-29 | 2020-01-06 | Tse Fuelling Supplies B V | Anti-permeation ring |
Also Published As
Publication number | Publication date |
---|---|
AU5865401A (en) | 2001-12-11 |
GB0013155D0 (en) | 2000-07-19 |
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