WO1995025243A1 - Revetement enveloppant - Google Patents

Revetement enveloppant Download PDF

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Publication number
WO1995025243A1
WO1995025243A1 PCT/GB1995/000354 GB9500354W WO9525243A1 WO 1995025243 A1 WO1995025243 A1 WO 1995025243A1 GB 9500354 W GB9500354 W GB 9500354W WO 9525243 A1 WO9525243 A1 WO 9525243A1
Authority
WO
WIPO (PCT)
Prior art keywords
cover
pressure plate
electrical contact
wraparound
contact members
Prior art date
Application number
PCT/GB1995/000354
Other languages
English (en)
Inventor
Johannes Maria Cordia
Marcel Paul Cristens
Dirk Raymond Josef Baert
Original Assignee
N.V. Raychem S A
Raychem Limited
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from GB9405260A external-priority patent/GB9405260D0/en
Priority claimed from GB9408327A external-priority patent/GB9408327D0/en
Application filed by N.V. Raychem S A, Raychem Limited filed Critical N.V. Raychem S A
Publication of WO1995025243A1 publication Critical patent/WO1995025243A1/fr

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Classifications

    • 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
    • B29C65/3408—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 single particles, e.g. fillers or discontinuous fibre-reinforcements
    • B29C65/3412—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 single particles, e.g. fillers or discontinuous fibre-reinforcements comprising fillers
    • 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
    • B29C66/11—Joint cross-sections comprising a single joint-segment, i.e. one of the parts to be joined comprising a single joint-segment in the joint cross-section
    • B29C66/116—Single bevelled joints, i.e. one of the parts to be joined being bevelled in the joint area
    • B29C66/1162—Single bevel to bevel joints, e.g. mitre joints
    • 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
    • B29C66/14—Particular design of joint configurations particular design of the joint cross-sections the joint having the same thickness as the thickness of the parts to be joined
    • 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
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43—Joining a relatively small portion of the surface of said articles
    • B29C66/432—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms
    • B29C66/4322—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms by joining a single sheet to itself
    • 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
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/49—Internally supporting the, e.g. tubular, article during joining
    • 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
    • B29C66/53—Joining single elements to tubular articles, hollow articles or bars
    • B29C66/532—Joining single elements to the wall of tubular articles, hollow articles or bars
    • B29C66/5326—Joining single elements to the wall of tubular articles, hollow articles or bars said single elements being substantially flat
    • 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
    • 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
    • F16L59/00—Thermal insulation in general
    • F16L59/10—Bandages or covers for the protection of the insulation, e.g. against the influence of the environment or against mechanical damage
    • 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
    • F16L59/00—Thermal insulation in general
    • F16L59/14—Arrangements for the insulation of pipes or pipe systems
    • F16L59/16—Arrangements specially adapted to local requirements at flanges, junctions, valves or the like
    • F16L59/18—Arrangements specially adapted to local requirements at flanges, junctions, valves or the like adapted for joints
    • F16L59/20—Arrangements specially adapted to local requirements at flanges, junctions, valves or the like adapted for joints for non-disconnectable joints
    • 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
    • B29C65/3444—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 being a ribbon, band or strip
    • B29C65/3452—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 being a ribbon, band or strip forming a sleeve, e.g. a wrap-around sleeve
    • 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
    • B29C65/3484—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 non-metallic
    • B29C65/3488—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 non-metallic being an electrically conductive polymer
    • 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
    • B29C65/3484—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 non-metallic
    • B29C65/3492—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 non-metallic being carbon
    • 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
    • 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
    • B29C66/526—Joining bars
    • B29C66/5261—Joining bars for forming coaxial connections, i.e. the bars to be joined forming a zero angle relative to each other
    • 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
    • B29C66/71—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 composition of the plastics material of the parts to be joined
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
    • B29K2023/04—Polymers of ethylene
    • B29K2023/06—PE, i.e. polyethylene
    • B29K2023/0658—PE, i.e. polyethylene characterised by its molecular weight
    • B29K2023/0683—UHMWPE, i.e. ultra high molecular weight polyethylene
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2023/00—Tubular articles
    • B29L2023/22—Tubes or pipes, i.e. rigid
    • B29L2023/225—Insulated

Definitions

  • the present invention relates to a wraparound cover that can be positioned around an object such as a pipe or a cable, and that has trinsically heatable fusible overlapping edges, and to a pressure plate that can be used in combination with the cover to effect fusion of the overlapping edges of the cover.
  • Wraparound covers are well known in the field, and are conveniently used to cover pipes or cables, where access to the end of the pipe or cable is restricted so that the use of closed tubular covers is difficult.
  • the present invention provides a wraparound closure system comprising:
  • a wraparound cover having longitudinal edges which can be over lapped in use, and including an electrically heatable fusion heater on at least one of the overlapping edges, and
  • a pressure plate that can be placed, in use, on the overlapping edges of the wraparound cover, and which comprises electrical contact members that contact the electrically heatable fusion heater when the pressure plate is positioned on the wraparound cover, and which can be connected to a source of electrical power to pass electrical current to the fusion heater.
  • District heating pipes typically comprise an inner steel pipe and an outer thick insulation and usually an outer thin insulating cover.
  • a joint is made between two lengths of such pipes, it is necessary to remove the insulation from the end regions of each length of pipe in order that the insulation is not burnt when the pipes are joined, for example by welding.
  • the pipes have been joined it is common to use a canister to bridge the region where the insulation has been removed and to use additional sealing strips to bond the canister to the insulation on either side of the cut back region
  • the wraparound closure of the present invention may be used inter aha in place of the canister common in the prior art.
  • One or both of the overlapping edges of the cover may be bevelled, i.e. tapered.
  • the taper may be in the same or opposite directions at each edge of the cover, but is preferably of approximately the same slope.
  • the pressure plate preferably covers the region of overlap of the edges substantially entirely.
  • a fusion heater is included on one or both of the overlapping edges. Normally a heater would be required at only one edge.
  • the heater is provided on the surface of the overlapping edge facing the other overlapping edge in the wrapped configuration
  • the fusion heater is provided on the inwardly facing surface of the over- flap (Le. of the overlying one of the overlapping edges).
  • electrically heatable fusion heater as used herein we mean an element that is heated by the passage of electrical current therethrough, causing either itself, or an adjacent element, to fuse as a result of the rise in temperature.
  • the electrically heatable fusion heater is in the form of a layer.
  • a particularly preferred fusion heater useful in the present invention is a layer of a conductive polymer comprising a carbon black filler in sintered UHMWPE (Ultra High Molecular Weight Polyethylene)
  • UHMWPE Ultra High Molecular Weight Polyethylene
  • the wraparound cover comprises apertures therethrough through which the electrical contact members of the pressure plate can pass to establish this electrical contact.
  • the cover is provided with two or more (preferably substantially parallel) elongate bus-bars extending along the fusion heater. These bus bars can be contacted by the electrical contact members on the pressure plate, and can cause electrical current to flow across the fusion heater between the parallel bus bars.
  • the fusion heater extends not only along the length of the tapered overlapping edge, but also slightly beyond that tapered overlapping edge.
  • the electrical contact to that fusion heater is also slightly beyond the tapered region of the cover. The effect of this is that not only is there fusion between the overlapping edges of the cover i.e. forming a seam along the longitudinal slit of the wraparound cover, but also some fusion between the inner surface of the cover, and any substrate positioned, in use, within the cover, e.g. a pipe or the like.
  • a power box may conveniently be used in the field to supply the electrical current to the electrically heatable fusion heater.
  • this power box preferably operates at a maximum of about 100V, more preferably a maximum of about 60 Volts.
  • the distance between adjacent electrical contact points on the fusion heater i.e. the distance between the bus-bars if present
  • the distance between adjacent electrical contact points on the fusion heater is at most about 50mm, preferably at most about 35mm.
  • bus-bars along the tapered region of the wraparound cover.
  • these may be electrically connected, via electrical contact members on the pressure plate alternately to the positive, negative, and positive terminals of the power box (or vice versa as would be obvious to the man skilled in the art), thereby creating two heater modules in series with each other.
  • bus -bars could also be used, and their arrangement and relative connection to a power supply to form heater modules would be obvious to the man skilled in the art.
  • a pressure plate is used in combination with the wraparound cover to assist in the formation of the fusion of the overlapping edges of the wraparound cover.
  • the pressure plate is preferably shaped to cover the overlapping edges of the wraparound cover, and is preferably provided with tightening means, e.g. tightening straps to hold the pressure plate firmly against the wrapped cover, during the fusion process.
  • the pressure plate is provided with self contained locating means to ensure its correct positioning relative to the cover. In order to achieve a good fusion bond it is desirable to have heat, appropriately apphed pressure, and time.
  • tightening means on the pressure plate allows positive pressure to be apphed, and use of self contained locating means in the pressure plate ensures that the pressure is appropriately apphed.
  • the self- contained locating means are the same elements as the electrical contact members.
  • the electrical contact members serve a double function, acting both to contact the electrically heatable fusion heater of the wraparound cover (preferably via bus-bars), and also acting to position correctly the pressure plate on the wraparound cover.
  • the cover comprises holes
  • the pressure plate comprises locating lugs (e.g. the contact members). The locating means ensure that the pressure plate is always in the correct position relative to the wraparound cover, i.e. axial or radial misplacement is avoided.
  • the pressure plate comprises a series of rigid blocks that are articulated together.
  • the articulation is substantially parallel to the direction of the overlapping edges of the cover.
  • the electrical contact members used in the pressure plate are resihently biased, e.g. spring loaded.
  • the inner surface of the pressure plate is coated with a release material e.g. Teflon (trade mark) to allow its easy release after fusion of the overlapping edges of the wraparound cover is complete.
  • Teflon is a particularly suitable material because of its thermal resistance.
  • the thermal conductivity of Teflon is relatively low. This is advantageous since it allows fusion to occur in all areas of the overlapping tapered edge regions of the cover, mcluding the tip region, which is very trim. If Teflon is not used, other materials with a low thermal conductivity are preferred because of this advantage. Materials with a high thermal conductivity, e.g. metals, would draw a large amount of heat from the tip region of the overlapping tapered edge regions of the cover, which would inhibit fusion bonding, and are therefore not preferred luding materials for the pressure plate.
  • the pressure plate is provided with a plurality of electrical contact members (or at least means for receiving such electrical contact members), appropriately positioned so that the same pressure plate can be used to contact wraparound covers of different size and/or design, e.g. embodying two, three, four or more bus bars, as described above. For some apphcations, some, but not all of the electrical contact members in the pressure plate will not be required.
  • the inwardly facing surface of the pressure plate which in use will cover the tapered overlap edge regions of the cover is preferably provided with indentations . These become filled with fused material from flow of, or activated by, the fusion heater, and can thereby act as a permanent melt flow indicator to show that effective fusion has taken place. Where one or both of the overlapping edges of the cover are tapered, fusion will generally start at the thinner end of the tapered edge and will then spread across the tapered edge towards the thicker end of the tapered edge. In this case, some or each of the indentations in the inwardly facing surface of the pressure plate preferably extend continuously transversely (ie. generally perpendicular to the axial direction) across a substantial part of the width of the tapered edge.
  • the distance along each transverse indentation along which fusion has taken place is therefore a clear indication of how well fusion has taken place.
  • the fused material that has flowed into the indentations appears, of course, on the outer surface of the final product, as raised ridges, once the installation pressure plate has been removed.
  • the length of the ridges serve as a permanent indicator, that can be inspected at any time during the lif etime of the product, to show whether fusion was sufficient during the installation procedure.
  • the indentations may for example be in the shape of a word or design, e.g. a distinctive name or mark, so that the consequent ridges on the product serve both a practical and a marketing function
  • a wraparound cover having longitudinal edges which can be overlapped in use, and a pressure plate that can be placed, in use, on the overlapping edges of the wraparound cover, wherem one or more of the following applies:
  • the cover and the pressure plate are provided with cooperating elements for secure relative location of the cover relative to the pressure plate, the cover preferably being provided with holes and the plate with cooperating plugs, or vice versa;
  • the cover is provided with holes which can receive electrical contact members provided on the pressure plate;
  • the pressure plate is provided with resihently biased electrical contact members;
  • the cover has tapered overlapping edges, and the cover is provided with a fusion heater that extends over the length of one surface of one tapered edge, and beyond the tapered region of that edge.
  • the present invention also provides a method of covering an elongate object comprising:
  • the steps of the method can be carried out in any order or substantially simultaneously.
  • the fusion heater may be provided as part of the cover as supphed to the installer, or may be supphed as a separate part.
  • the heater causes the heater to heat. This in turn causes fusion of the heater itself, and/or of an additional fusible layer.
  • the material of the fused heater and/or additional layer thereby bonds the overlapping edges of the cover to each other.
  • the present application may be used inter aha in the field of district heating pipes.
  • the cover is wrapped around the joint opening between the bared pipes, across a suitable support so that opposing tapered edges overlap.
  • the pressure plate (which in its preferred articulated configuration is capable of accommodating various radii pipes) is placed over the overlapping edges of the cover which are to be fused together. Electrical power is then supphed via the pressure plate contact members and the bus bars to the fusion heater to cause the overlapping edges to fuse together.
  • the invention is particularly applicable in the district heating market as a repair casing, as a new construction, or as a semi- wraparound Tee, when a branch out is formed in the main body.
  • the invention is not limited to district heating apphcations however, and other general covers for elongate covers such as pipes or cables are envisaged.
  • Figure 1 is a side view of a wraparound cover as used in a wraparound closure system according to the present invention
  • Figure 2 is an enlarged view of the tapered end region of the cover of Figure 1.
  • Figure 3 is a plan view of the wraparound cover of Figures 1 and 2;
  • Figure 4 shows the cover of Figures 1, 2 and 3 in wrapped configuration
  • Figure 5 is a plan view of a pressure plate as used with the cover of Figures 1 - 4 in a closure system according to the present invention
  • Figure 6 is a sectional end view of the pressure plate of Figure 5; and Figure 7 is an end view of the pressure plate of Figures 5 and 6 installed on the wrapped configuration of cover as shown in Figure 4, around a district heating pipe.
  • Figures 8A and 8B show sequential steps in the application of the wraparound cover and pressure plate of Figures 1 to 7 onto a district heating pipe.
  • Figure 1 shows a wraparound cover 2 which comprises polyethylene having tapered ends 4 and 6.
  • end 4 will form the underflap
  • end 6 the overflap.
  • FIG 2 in which the end 6 of the cover 2 is shown in more detail, the cover 2 is covered on the under surface of tapered region 6, and extending slightly beyond the end 8 of the tapered region 6, by a fusion heater 10.
  • the heater 10 is indicated by a solid line in Figure 2.
  • the fusion heater 10 comprises a layer of a conductive polymeric material, preferably carbon-black-containing sintered ultra-high molecular weight polyethylene. Extending in electrical contact with the fusion heater 10, substantially parallel to each other, and approximately uniformly spaced apart, are bus bars 12.
  • the cover 2 also comprises apertures 14 passing through the thickness of the cover, directly above each of the bus bars 12, except the bus bar at the tip end of the tapered region 6 of the cover 2, which tip is, in any case, exposed.
  • the purpose of these apertures 14 is to allow the passage of electrical contact members into electrical contact with the bus bars 12. This is described in detail later.
  • Figure 3 is a plan view of the cover of Figures 1 and 2 and illustrates the features already mentioned. In this Figure the tapered regions are shown shaded, and the bus bars as white rehef against this shading.
  • Figure 4 is a schematic view showing the cover of Figures 1 to 3 in the wrapped configuration, and showing how a fusion bond, or weld can be formed at the overlapping tapered edge regions of the cover.
  • a pressure plate 20 for use with cover 2.
  • the plate 20 comprises a series of rigid blocks 22 which are articulated together along longitudinal lines 24. This provides the pressure plate with longitudinal rigidity, but transverse flexibility allowing the pressure plate 20 to bend to accommodate various radii of pipe or other substrate on to which the wraparound cover is placed.
  • the pressure plate 20 is also provided with tightening straps 26 allowing tightening of the pressure plate 20 around the wraparound cover 2 around a substrate.
  • the pressure plate also comprises five electrical contact members 28 positioned at various places on the articulated pressure plate. These electrical contact members, as is more evident in Figure 6, are resihently biased being provided with spring loading 30.
  • the under surface of the pressure plate 20 is provided with a Teflon layer 32 (see Figure 6). This is indented for permanent indication of fusion (not shown).
  • the cover is wrapped around the substrate in question, so that the tapered edges overlap (as in Figure 4) then the pressure plate is positioned over the overlapped tapered edges, and correctly located relative to the cover by means of the spring loaded contact members 28.
  • These contact members 28 are therefore acting not only as electrical contact members, but also as locating means ensuring that the pressure plate is appropriately positioned over the wraparound cover.
  • the pressure plate is then held in this position by tightening straps 26.
  • electrical power is supphed via the electrical contact members 28, to the bus bars 12 on the fusion heater 10. Electrical current passes through and heats the conductive polymer fusion heater 10. This causes some fusion of the heater 10 resulting in a good bond between the overlapping edge regions 4 and 6 of the wraparound cover 2.
  • An example of this installation is shown in Figure 7.
  • the cover 2 is wrapped around a district heating pipe comprising a central steel pipe 30, a thicker thermal insulating layer 32, and an other polyethylene insulation jacket 34.
  • FIGs 8A and 8B show a particular use of a cover and pressure plate according to the previous figures to bridge the insulation on either side of a district heating pipe joint.
  • the district heating pipe joint is shown prior to application of the cover.
  • Two central steel pipes 30 have been welded at 31, and the insulation 32, and 34 (32 hidden from view) has been cut back on either side of weld 31 to allow the weld to be made.
  • the outer ends of the cut back insulations 34 have been bridged by the wraparound cover 2.
  • the installation pressure plate 20 with electrode contacts 28 is shown in position to close the wraparound cover.
  • bus bars In the embodiments illustrated there have been three bus bars and corresponding electrical contacts, thereby forming two separate heater modules.
  • the bus bars would be connected in positive- negative-positive arrangement or vice versa as would be apparent to the man skilled in the art.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Lining Or Joining Of Plastics Or The Like (AREA)

Abstract

Un revêtement enveloppant polymère (2) destiné à envelopper un objet tel qu'un tuyau ou un câble, notamment une conduite de chauffage urbain (30, 32, 34), possède des bords de chevauchement fusibles, pouvant être chauffés électriquement, et est utilisé en combinaison avec une plaque de pression (20) constituée de contacts électriques (28) qui peuvent être placés en contact électrique avec les bords du revêtement, et connectés à une source de courant électrique afin de chauffer et de fusionner les bords du revêtement. Les bords du revêtement peuvent être chauffés de préférence électriquement au moyen d'une couche d'un polymère conducteur (10), de préférence un polymère conducteur comprenant une charge de noir de carbone dans du polyéthylène fritté de masse moléculaire ultra élevée.
PCT/GB1995/000354 1994-03-17 1995-02-21 Revetement enveloppant WO1995025243A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GB9405260A GB9405260D0 (en) 1994-03-17 1994-03-17 Wraparound cover
GB9405260.2 1994-03-17
GB9408327.6 1994-04-27
GB9408327A GB9408327D0 (en) 1994-04-27 1994-04-27 Wraparound cover

Publications (1)

Publication Number Publication Date
WO1995025243A1 true WO1995025243A1 (fr) 1995-09-21

Family

ID=26304518

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1995/000354 WO1995025243A1 (fr) 1994-03-17 1995-02-21 Revetement enveloppant

Country Status (1)

Country Link
WO (1) WO1995025243A1 (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1074170A1 (fr) * 1998-04-21 2001-02-07 Floatec Corporation Appareil servant a creer des raccords sur des conduits revetus de plastique
US6245174B1 (en) 1995-05-31 2001-06-12 Johannes Maria Cordia Heat recoverable article
EP1201402A2 (fr) * 2000-10-31 2002-05-02 Fusion Group (Holdings) Plc Unités électrofusibles
EP1276583A1 (fr) * 2000-02-04 2003-01-22 Fusionweld Corporation Appareil permettant l'application par fusion d'une piece de gainage sur un tuyau enrobe de plastique
WO2014042613A1 (fr) * 2012-09-11 2014-03-20 Federal-Mogul Powertrain, Inc. Manchon enroulable pourvu d'éléments chauffants et ses procédés d'utilisation et d'élaboration
CN113354897A (zh) * 2021-05-31 2021-09-07 安徽杰蓝特新材料有限公司 一种阻燃抗老化的电力电缆管及其制备方法

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US4096017A (en) * 1977-02-18 1978-06-20 H. C. Price Co. Method and article for forming field joints on pipe coated with thermoplastic material
EP0035750A2 (fr) * 1980-03-10 1981-09-16 Georg Fischer Aktiengesellschaft Soudure de liaison pour tuyaux en matière thermoplastique
EP0157640A2 (fr) * 1984-04-04 1985-10-09 RAYCHEM CORPORATION (a Delaware corporation) Article à reprise thermique en polymères conductrices
FR2594379A1 (fr) * 1986-02-17 1987-08-21 Kabelmetal Electro Gmbh Liaison a manchon pour tuyaux conducteurs isoles thermiquement
DE3712356A1 (de) * 1987-04-11 1988-10-27 Kabelmetal Electro Gmbh Band aus thermoplastischem kunststoff zur abdeckung einer verbindungsstelle von rohren aus kunststoff
EP0302185A2 (fr) * 1987-08-06 1989-02-08 kabelmetal electro GmbH Dispositif pour appliquer une pression pendant la réalisation d'une liaison par soudage entre les extrémités de deux tubes en matière plastique
WO1993019925A1 (fr) * 1992-04-01 1993-10-14 N V Raychem Sa Protection environnementale

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4096017A (en) * 1977-02-18 1978-06-20 H. C. Price Co. Method and article for forming field joints on pipe coated with thermoplastic material
EP0035750A2 (fr) * 1980-03-10 1981-09-16 Georg Fischer Aktiengesellschaft Soudure de liaison pour tuyaux en matière thermoplastique
EP0157640A2 (fr) * 1984-04-04 1985-10-09 RAYCHEM CORPORATION (a Delaware corporation) Article à reprise thermique en polymères conductrices
FR2594379A1 (fr) * 1986-02-17 1987-08-21 Kabelmetal Electro Gmbh Liaison a manchon pour tuyaux conducteurs isoles thermiquement
DE3712356A1 (de) * 1987-04-11 1988-10-27 Kabelmetal Electro Gmbh Band aus thermoplastischem kunststoff zur abdeckung einer verbindungsstelle von rohren aus kunststoff
EP0302185A2 (fr) * 1987-08-06 1989-02-08 kabelmetal electro GmbH Dispositif pour appliquer une pression pendant la réalisation d'une liaison par soudage entre les extrémités de deux tubes en matière plastique
WO1993019925A1 (fr) * 1992-04-01 1993-10-14 N V Raychem Sa Protection environnementale

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6245174B1 (en) 1995-05-31 2001-06-12 Johannes Maria Cordia Heat recoverable article
EP1074170A1 (fr) * 1998-04-21 2001-02-07 Floatec Corporation Appareil servant a creer des raccords sur des conduits revetus de plastique
EP1074170A4 (fr) * 1998-04-21 2002-11-06 Floatec Corp Appareil servant a creer des raccords sur des conduits revetus de plastique
EP1276583A1 (fr) * 2000-02-04 2003-01-22 Fusionweld Corporation Appareil permettant l'application par fusion d'une piece de gainage sur un tuyau enrobe de plastique
EP1276583A4 (fr) * 2000-02-04 2004-05-26 Fusionweld Corp Appareil permettant l'application par fusion d'une piece de gainage sur un tuyau enrobe de plastique
AU2001234836B2 (en) * 2000-02-04 2004-05-27 Fusionweld Corporation Apparatus for forming field joints on plastic coated pipe
EP1201402A2 (fr) * 2000-10-31 2002-05-02 Fusion Group (Holdings) Plc Unités électrofusibles
EP1201402A3 (fr) * 2000-10-31 2002-10-30 Fusion Group (Holdings) Plc Unités électrofusibles
WO2014042613A1 (fr) * 2012-09-11 2014-03-20 Federal-Mogul Powertrain, Inc. Manchon enroulable pourvu d'éléments chauffants et ses procédés d'utilisation et d'élaboration
CN113354897A (zh) * 2021-05-31 2021-09-07 安徽杰蓝特新材料有限公司 一种阻燃抗老化的电力电缆管及其制备方法

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