WO2015139114A1 - Compensateur de dilatation et procédés de fabrication d'un compensateur de dilatation - Google Patents

Compensateur de dilatation et procédés de fabrication d'un compensateur de dilatation Download PDF

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Publication number
WO2015139114A1
WO2015139114A1 PCT/CA2015/000161 CA2015000161W WO2015139114A1 WO 2015139114 A1 WO2015139114 A1 WO 2015139114A1 CA 2015000161 W CA2015000161 W CA 2015000161W WO 2015139114 A1 WO2015139114 A1 WO 2015139114A1
Authority
WO
WIPO (PCT)
Prior art keywords
plastic liner
metal conduit
elongate metal
inner plastic
expansion
Prior art date
Application number
PCT/CA2015/000161
Other languages
English (en)
Inventor
Wayne Ernest Conrad
Original Assignee
Omachron Intellectual Property Inc.
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 CA2846801A external-priority patent/CA2846801C/fr
Priority claimed from CA2846921A external-priority patent/CA2846921C/fr
Priority claimed from CA2847536A external-priority patent/CA2847536C/fr
Priority claimed from CA2847520A external-priority patent/CA2847520C/fr
Application filed by Omachron Intellectual Property Inc. filed Critical Omachron Intellectual Property Inc.
Publication of WO2015139114A1 publication Critical patent/WO2015139114A1/fr

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Classifications

    • 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
    • F16L27/00—Adjustable joints, Joints allowing movement
    • F16L27/10—Adjustable joints, Joints allowing movement comprising a flexible connection only, e.g. for damping vibrations
    • F16L27/107—Adjustable joints, Joints allowing movement comprising a flexible connection only, e.g. for damping vibrations the ends of the pipe being interconnected by a flexible sleeve
    • F16L27/11—Adjustable joints, Joints allowing movement comprising a flexible connection only, e.g. for damping vibrations the ends of the pipe being interconnected by a flexible sleeve the sleeve having the form of a bellows with multiple corrugations
    • 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
    • B29C63/00—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor
    • B29C63/18—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor using tubular layers or sheathings
    • B29C63/20—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor using tubular layers or sheathings using pressure difference, e.g. vacuum
    • 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
    • B29C63/00—Lining or sheathing, i.e. applying preformed layers or sheathings of plastics; Apparatus therefor
    • B29C63/26—Lining or sheathing of internal surfaces
    • B29C63/34—Lining or sheathing of internal surfaces using tubular layers or sheathings
    • 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
    • F16L27/00—Adjustable joints, Joints allowing movement
    • F16L27/10—Adjustable joints, Joints allowing movement comprising a flexible connection only, e.g. for damping vibrations
    • F16L27/107—Adjustable joints, Joints allowing movement comprising a flexible connection only, e.g. for damping vibrations the ends of the pipe being interconnected by a flexible sleeve
    • F16L27/11—Adjustable joints, Joints allowing movement comprising a flexible connection only, e.g. for damping vibrations the ends of the pipe being interconnected by a flexible sleeve the sleeve having the form of a bellows with multiple corrugations
    • F16L27/111—Adjustable joints, Joints allowing movement comprising a flexible connection only, e.g. for damping vibrations the ends of the pipe being interconnected by a flexible sleeve the sleeve having the form of a bellows with multiple corrugations the bellows being reinforced
    • 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
    • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
    • B29C49/24—Lining or labelling
    • B29C2049/2404—Lining or labelling inside the article
    • 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
    • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
    • B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
    • B29C49/04—Extrusion blow-moulding
    • 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
    • B29L2022/00—Hollow articles
    • B29L2022/02—Inflatable articles
    • B29L2022/025—Bladders
    • 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
    • B29L2023/18—Pleated or corrugated hoses

Definitions

  • This disclosure relates generally to expansion compensators for connecting pipes and fittings that are used to convey a fluid, and to methods for manufacturing an expansion compensator for connecting pipes and fittings that are used to convey a fluid.
  • Piping systems are used to convey liquids and/or gasses within, or between, residential, commercial, and/or industrial buildings.
  • most residential buildings have a potable water distribution system for providing cold and/or hot water at one or more locations within the building (e.g. sinks, showers, dish or clothes washing machines).
  • piping systems are made up of a number of components including straight or curved pipe sections, fittings (e.g. elbow fittings), valves, etc. to provide an interior flow path for the liquid being conveyed.
  • a piping system (such as a system comprising thermoplastic pipes), is assembled such that the components are joined in a manner that provides a durable connection that prevents or inhibits the components from separating or cracking due to mechanical, thermal, and/or hydraulic stresses applied to the piping system.
  • Separation of any of the components of the piping system or cracking of any element of the piping system may permit fluid to leak out of the piping system and, e.g., thereby damage the surrounding structure, e.g., the walls of a building which enclose the piping system.
  • Thermoplastic pipes may be subject to thermal expansion and/or contraction after installation.
  • a length of a thermoplastic pipe used for conveying fluid at an elevated temperature e.g. hot water
  • the ends of the pipe may exert an axial force (either compressive or tensile) on the fittings, valves, or other parts of the piping system to which they are connected.
  • hot water usage is intermittent. Therefore, hot water may be conveyed through a pipe for a period of time thereby heating the pipe.
  • thermoplastic pipes e.g., PVC and/or CPVC pipes
  • PVC and/or CPVC pipes can result in a failure of the piping system and result in a leak.
  • plastic pipes that are mounted vertically to transport water between floors are mechanically constrained in their mechanical positions due to their mechanical attachment to transversely mounted pipes that deliver water horizontally to the various rooms or locations on the floors of the building.
  • plastic pipes such as those made of PVC and CPVC are heated by the water that they transport
  • significant forces are created within the walls of the pipe due to the thermal expansion. These forces may exceed the buckling strength of the pipes, especially for pipe diameters under 6 inches, which may cause the plastic pipes to bend and/or buckle. This stress may result in a leak.
  • Once an installation is complete e.g., the interior walls of a building are finished or a piping system is buried under a road
  • accessing the piping system to repair a leak is typically time consuming and expensive.
  • An expansion compensator may expand and/or contract in response to an applied axial force (compressive or tensile) that may arise from expansion and/or contraction of one or more lengths of pipe.
  • an applied axial force compressive or tensile
  • one or more such expansion compensators can be installed between a length of pipe and a fitting so that the axial forces that may be imposed on the pipe and/or the fitting due to thermal expansion and/or contraction of the length of pipe may be reduced.
  • These axial forces may be borne by, or primarily borne by, or substantially borne by the expansion compensator and not by the pipe and/or the fitting.
  • each portion of the piping system that conveys hot water to each floor will be subjected to thermal expansion and contraction cycling. Without the use of an expansion compensator, the total expansion which may occur in the piping system carrying hot water to the top floor will be the aggregate of the expansion occurring for each floor of vertical rise, which may prevent the use of plastic piping.
  • An expansion compensator suitable for use with a plastic piping system may comprise an outer metal conduit and an inner plastic liner that are secured together.
  • Such an expansion compensator may be manufactured by expanding a pre-formed plastic liner inside an elongate metal conduit that already has an expansion/contraction section so as to form an inner plastic liner that has an expansion/contraction section.
  • the pre-formed plastic liner (which may be pre-heated) may be expanded by applying pressure internally in the preformed plastic liner.
  • the pre-formed plastic liner may be preheated and/or may be heated during the deformation process.
  • the pre-formed plastic liner may be deformed using a fluid, preferably a heated fluid under pressure applied on the inside of the pre-formed plastic liner to both soften and displace the pre-formed plastic liner.
  • the process may be characterized as analogous to hydroforming a pre-formed plastic liner against the metal conduit, using the inner surface of the metal conduit as a mold for the pre-formed plastic liner.
  • Such an expansion compensator may alternatively be manufactured by expanding an extruded inner plastic liner into an elongate metal conduit that already has an expansion/contraction section so as to form an inner plastic liner that has an expansion/contraction section.
  • the extruded plastic liner may be inserted into the elongate metal conduit at an elevated temperature.
  • the elevated temperature may be a temperature at which the extruded plastic liner is deformable. If the plastic liner is cooled below its deformation temperature prior to the forming step, then the plastic liner may be reheated to or above its deformation temperature.
  • the extrusion is conducted such that the extruded plastic liner is received in the elongate metal conduit at or near its deformation temperature.
  • the extruded plastic liner may be expanded by introducing a pressurized fluid into the interior of the extruded plastic liner while it is at, or still at, an elevated temperature so as to form an expansion/contraction section in the plastic liner.
  • a member such as a hollow needle
  • the process may be characterized as analogous to blow molding an extruded plastic liner against the metal conduit, using the inner surface of the metal conduit as a mold for the extruded plastic liner.
  • the profile of the expansion/contraction section of the inner plastic liner may be the same as or similar to the profile of the expansion/contraction section of the outer metal conduit.
  • the expansion/contraction section of the inner plastic liner may be aligned with the expansion/contraction section of the outer metal conduit. Accordingly, for example, if the expansion/contraction sections are in the form of a bellows, then each ridge of the bellows section of the inner plastic liner may be nested between two spaced apart opposed walls that define a ridge of the bellows section of the outer metal conduit. Accordingly, when the expansion compensator contracts due to an axial force applied thereto, the bellows section of the inner plastic liner may deform in the same direction, and concurrently with, the bellows section of the outer metal conduit.
  • an expansion compensator suitable for use with a plastic piping system may comprise an outer metal conduit and an inner plastic liner wherein the inner plastic liner is secured to the outer metal conduit such that the outer metal conduit supports the inner plastic liner and absorbs stresses imposed on the inner plastic liner due to thermal cycling of the piping system.
  • At least one, and preferably each end of the outer metal conduit and the inner plastic liner may be provided with a connector that may secure the outer metal conduit and the inner plastic liner together to provide a unitary body (i.e., so that together the outer metal conduit and the inner plastic liner act as a single body).
  • the connector(s) may be provided by being overmolded over the end(s) of the outer metal conduit and the inner plastic liner.
  • an expansion compensator comprising: a) an elongate metal conduit having first and second spaced apart ends, an inner surface, an outer surface, and an expansion/contraction section; b) an inner plastic liner positioned interior of the elongate metal conduit and having first and second spaced apart ends, an inner surface, an outer surface, an expansion/contraction section, and an interior volume extending from the first end to the second end;
  • a first connector provided at the first ends of the elongate metal conduit and the inner plastic liner, the first connector having a first portion secured to the outer surface of the elongate metal conduit, a second portion secured to the inner surface of the inner plastic liner, and an opening in fluid communication with the interior volume of the inner plastic liner; and, d) a second connector provided at the second ends of the elongate metal conduit and the inner plastic liner, the second connector having a first portion secured to the outer surface of the elongate metal conduit, a second portion secured to the inner surface of the inner plastic liner, and an opening in fluid communication with the interior volume of the inner plastic liner.
  • each of the elongate metal conduit and the inner plastic liner have an axial stiffness and the axial stiffness of the elongate metal conduit is greater than the axial stiffness of the inner plastic liner.
  • the expansion compensator may further comprise at least one additional elongate metal conduit and the elongate metal conduits have a combined axial stiffness and the inner plastic liner has an axial stiffness and the combined axial stiffness of the elongate metal conduits is greater than the axial stiffness of the inner plastic liner.
  • an expansion compensator suitable for use with a plastic piping system may comprise an outer metal conduit and an inner plastic liner wherein the outer metal conduit and the inner plastic liner may be secured together and wherein the axial stiffness of the metal conduit is greater than the axial stiffness of the inner plastic liner so that the outer metal conduit absorbs more (optionally a substantial portion or essentially all) of stresses imposed on the expansion compensator due to thermal cycling of the piping system.
  • axial forces imposed by a piping system may be borne by, or primarily borne by, or substantially borne by the expansion compensator, these axial forces may, in turn, be preferentially borne by (e.g., borne by, or primarily borne by, or substantially borne by) the outer metal conduit.
  • an expansion compensator having a longitudinal axis and comprising:
  • an elongate metal conduit having first and second spaced apart ends, an inner surface, an outer surface, a thickness, and an expansion/contraction section;
  • an inner plastic liner positioned interior of the elongate metal conduit and having first and second spaced apart ends, an inner surface, an outer surface, a thickness, an expansion/contraction section, and an interior volume extending from the first end to the second end;
  • each of the elongate metal conduit and the inner plastic liner have a stiffness along the longitudinal axis, and the stiffness of the elongate metal conduit is greater than the stiffness of the inner plastic liner.
  • the stiffness of the elongate metal conduit may be: at least 25% greater; at least 50% greater; from at least 150% greater to about 1 ,000% greater; or from at least 300% greater to about 375% greater than the stiffness of the inner plastic liner.
  • the stiffness of the elongate metal conduit may be sufficiently greater than the stiffness of the inner plastic liner such that the elongate metal conduit will absorb: more than 50%; more than 75%; or about 90% of a compressive force imposed on the expansion compensator by a piping system into which the expansion compensator is positioned.
  • the thickness of the elongate metal conduit and the thickness of the inner plastic liner may each be selected to provide the stiffness of the elongate metal conduit that is greater than the stiffness of the inner plastic liner.
  • the thickness of the elongate metal conduit may be from about 0.005 to about 0.030 inches, or from about 0.012 to about 0.0 6 inches, and the thickness of the inner plastic liner may be from about 0.005 to about 0.250 inches, or from about 0.040 to about 0.090 inches.
  • first spaced apart ends of the elongate metal conduit and the inner plastic liner are secured together by a first connector that is molded over the first spaced apart ends and the second spaced apart ends of the elongate metal conduit and the inner plastic liner are secured together by a second connector that is molded over the second spaced apart ends.
  • the elongate metal conduit may comprise at least an inner and an outer elongate metal conduit, the inner elongate metal conduit is positioned intermediate the outer elongate metal conduit and the inner plastic liner, and each of the inner and outer elongate metal conduits has first and second spaced apart ends, an inner surface, an outer surface, and an expansion/contraction section.
  • each of the inner and outer elongate metal conduit may be from about 0.004 to about 0.025 inches, or from about 0.012 to about 0.016 inches, and the thickness of the inner plastic liner may be from about 0.005 to about 0.250 inches, or from about 0.040 to about 0.090 inches.
  • the elongate metal conduit may comprise at least an inner and an outer elongate metal conduit, the inner elongate metal conduit may be positioned intermediate the outer elongate metal conduit and the inner plastic liner, and each of the inner and outer elongate metal conduits may have first and second spaced apart ends, an inner surface, an outer surface, and an expansion/contraction section.
  • each of the first and second ends of the elongate metal conduit may have a plurality of openings therethrough and each of the first and second connectors may further comprise a connecting portion that extends between the first portion of the respective connector and the outer surface of the inner plastic liner and passes through the plurality of openings.
  • the first and second portions of the connector provided at the first ends of the elongate metal conduit and the inner plastic liner may define a generally U- shaped cavity in which the first ends of the elongate metal conduit and the inner plastic liner are located.
  • the expansion compensator may further comprise a protective layer provided intermediate the inner surface of the elongate metal conduit and the outer surface of the inner plastic liner.
  • the protective layer may be provided on the outer surface of the inner plastic liner.
  • the protective layer may be provided on the inner surface of the elongate metal conduit [0033] In some embodiments,
  • the protective layer may comprise a coating or a film applied to at least one of the inner surface of the elongate metal conduit and the outer surface of the inner plastic liner;
  • the inner plastic liner may comprise a co-extruded body having the protective layer formed as an outer co-extruded layer;
  • the protective layer may comprise a separately formed sleeve positioned between the inner surface of the elongate metal conduit and the outer surface of the inner plastic liner.
  • a lubricant may be provided between the inner and outer elongate metal conduits.
  • the expansion compensator may further comprise a sleeve, the sleeve having a generally longitudinally extending outer surface and the elongate metal layer is provided interior of the sleeve.
  • a lubricant may be provided between the sleeve and the elongate metal layer.
  • the sleeve may further comprise engagement members positioned to maintain the sleeve in a predetermined axial position along the expansion compensator and to permit the expansion/contraction sections to expand to a full design expansion length.
  • the expansion compensator may further comprise a gasket provided on the elongate metal conduit and extending between the outer surface of the elongate metal conduit and an inner surface of the first connector.
  • the expansion compensator may further comprise a longitudinally extending recess provided in the inner wall of the elongate metal conduit.
  • the inner plastic liner may have a generally uniform thickness.
  • the expansion/contraction sections may have a similar profile and may be aligned.
  • the expansion/contraction section of the inner plastic liner may comprise a bellows comprising in sequence a plurality of radially inner valleys and a plurality of radially outer peaks, a portion of the inner plastic liner defining the radial inner valleys having a greater radial thickness then a portion of the inner plastic liner defining the radial outer peaks.
  • the outer metal conduit and the inner plastic liner may be secured together such that fluid flowing in the piping system is not exposed to the outer metal conduit (e.g., the inner plastic liner defines the outer wall of the flow path through the expansion compensator from a pipe or fitting connected at one end of the expansion compensator to a pipe or fitting connected at the other end of the expansion compensator).
  • An advantage of using such expansion compensators is that the fluid in the piping system is exposed only to the inner plastic liner. Accordingly, the outer metal conduit will not be exposed to the fluid, e.g., water, which may cause the metal to corrode over time. At the same time, the inner plastic liner is reinforced or supported by the outer metal conduit thereby reducing the stress imposed on the inner plastic liner and reducing the likelihood of the inner plastic liner cracking thereby resulting in a leak.
  • the expansion/contraction section e.g., a bellows or accordion section
  • the expansion/contraction section may be made of a thinner material which increases the flexibility of the inner plastic liner and reduces the likelihood of the inner plastic liner cracking over time due to expansion and contraction caused by thermal cycling.
  • the inner plastic liner is reinforced or supported by the outer metal conduit, the axial forces imposed on the expansion compensator are preferentially absorbed by the outer metal conduit and the stress imposed on the inner plastic liner is reduced, which reduces the likelihood of the inner plastic liner cracking thereby resulting in a leak.
  • the pipe may be made of a plastic material known in the piping arts.
  • the plastic material may be a thermoplastic material and may be one or more of acrylonitrile butadiene styrene (ABS), PVC, CPVC, ethylene vinyl acetate (EVA), polyethylene (PE), and the like.
  • Preferred materials comprise PVC and/or CPVC.
  • expansion compensators are used in installations requiring a long run of piping, such as in a high rise building.
  • each fitting e.g., a T-junction, may remain essentially static thereby increasing the reliability of the piping system and reducing the likelihood of a leak occurring.
  • Connectors that are compatible with typical thermoplastic piping system components may be provided at each end of the expansion compensator to facilitate its installation.
  • the connectors may be configured to accept typical pipe end dimensions, and for joining and/or sealing using typical means.
  • the expansion compensator may have an inner plastic liner made from the same (or similar) plastic material of the pipes to which it is to be installed, so that a fluid flowing through a pipe and expansion compensator will be in contact with the same (or similar) material through both components.
  • an expansion compensator comprising an outer metal conduit and an inner plastic liner wherein the inner plastic liner is secured to the outer metal conduit such that the outer metal conduit supports the inner plastic liner and absorbs at least some of the stresses imposed on the inner plastic liner due to thermal cycling of the piping system.
  • At least one, and preferably each end of the outer metal conduit and the inner plastic liner is provided with a connector that may secure the outer metal conduit and the inner plastic liner together to provide a unitary body (i.e., so that together the outer metal conduit and the inner plastic liner act as a single body).
  • an inner plastic liner having first and second spaced apart ends, an inner surface, an outer surface, and an interior volume extending from the first end to the second end;
  • the method further comprises heating the inner plastic liner so that the inner plastic liner is at or above the forming temperature during expansion of the inner plastic liner.
  • the expansion/contraction section of the elongate metal conduit may comprise a bellows having radial inner valleys and radial outer peaks
  • the outer surface of the inner plastic liner has thicker bands
  • the method further comprises aligning the thicker bands with the radial outer peaks of the bellows prior to expanding the inner plastic liner, whereby the expansion/contraction section of the inner plastic liner comprises a bellows.
  • the method may further comprise selecting a thickness of the thicker bands such that the bellows of the expanded inner plastic liner has a generally uniform thickness.
  • the inner plastic liner may be formed with the thicker bands.
  • the inner plastic liner may be formed with a wall of generally uniform thickness and the thicker bands are provided after formation of the inner plastic liner.
  • the expansion/contraction section of the elongate metal conduit may comprise a bellows having radial inner valleys and radial outer peaks, and the inner plastic liner has a wall of generally uniform thickness whereby the expanded inner plastic liner has an expansion/contraction section having a non-uniform thickness.
  • radial inner valleys of the expansion/contraction section of the inner plastic liner may have a greater wall thickness than radial outer peaks of the expansion/contraction section of the inner plastic liner.
  • the method may further comprise providing a first connector on the first ends of the inner plastic liner and the elongate metal conduit and providing a second connector on the second ends of the inner plastic liner and the elongate metal conduit.
  • the first and second connectors may be provided by overmolding.
  • the first end of the elongate metal conduit may be provided with a plurality of openings and the method may further comprise overmolding the first connector on the first ends of the inner plastic liner and the elongate metal conduit whereby the first connector comprises a first portion on the outer surface of the elongate metal conduit, a second position on the inner surface of the inner plastic liner and connecting portions that extends through the plurality of openings.
  • the method may further comprise providing a plurality of openings at the first and second ends of the elongate metal conduit and overmolding a first connector on the first ends of the inner plastic liner and the elongate metal conduit and overmolding a second connector on the second ends of the inner plastic liner and the elongate metal conduit.
  • the method may further comprise trimming each of the first and second ends of the inner plastic liner prior to overmolding the first and second connectors on the ends.
  • the method may further comprise providing a gasket on the outer surface of the elongate metal conduit adjacent the first end of the elongate metal conduit prior to providing the first connector over the first ends of the inner plastic liner and the elongate metal conduit whereby the gasket is positioned between the elongate metal conduit and the first connector.
  • the method may further comprise providing a gasket on the outer surface of the elongate metal conduit adjacent the first end of the elongate metal conduit prior to overmolding the first connector over the first ends of the inner plastic liner and the elongate metal conduit whereby the gasket is positioned between the elongate metal conduit and the overmolded first connector.
  • the elongate metal conduit may comprise at least an inner and an outer elongate metal conduit and the method may further comprise providing the inner plastic liner interior of the inner elongate metal conduit.
  • the method may further comprise providing a protective layer intermediate the inner surface of the elongate metal conduit and the outer surface of the inner plastic liner.
  • providing the protective layer comprises at least one of: i) applying a coating or a film to at least one of the inner surface of the elongate metal conduit and the outer surface of the inner plastic liner; ii) co- extruding the inner plastic liner as a co-extruded body with the protective layer formed as an outer co-extruded layer; and iii) providing a separately formed sleeve positioned between the inner surface of the elongate metal conduit and the outer surface of the inner plastic liner.
  • heating the inner plastic liner may comprise providing a heated fluid in the interior volume of the inner plastic liner.
  • applying pressure to the fluid positioned in the interior volume of the inner plastic liner to expand the inner plastic liner may comprise applying pressure to the heated fluid after the inner plastic liner has been heated by the heated fluid.
  • an air gap may be located between the outer surface of the inner plastic liner and the inner surface of the elongate metal conduit prior to expanding the inner plastic liner, and applying pressure to the fluid positioned in the interior volume of the inner plastic liner to expand the inner plastic liner may include withdrawing air from the air gap while expanding the inner plastic liner.
  • an air gap may be located between the outer surface of the inner plastic liner and the protective layer prior to expanding the inner plastic liner, and applying pressure to the fluid positioned in the interior volume of the inner plastic liner to expand the inner plastic liner may include withdrawing air from the air gap while expanding the inner plastic liner.
  • an air gap may be located between the inner surface of the elongate metal conduit and the protective layer prior to expanding the inner plastic liner, and applying pressure to the fluid positioned in the interior volume of the inner plastic liner to expand the inner plastic liner may include withdrawing air from the air gap while expanding the inner plastic liner.
  • the air may be withdrawn by applying a vacuum to the air gap.
  • At least one of the inner surface of the elongate metal conduit and the outer surface of the inner plastic liner may have a longitudinally extending recess, and withdrawing air from the air gap may further comprise drawing air through the longitudinally extending recess while expanding the inner plastic liner.
  • the method may further comprise inserting a thin elongate member in the air gap prior to expanding the inner plastic liner.
  • the method may further comprise providing a lubricant between the inner and outer elongate metal conduits.
  • the method may further comprise providing a sleeve having a generally longitudinally extending outer surface, wherein the elongate metal conduit is provided interior of the sleeve.
  • the method may further comprise providing a lubricant between the sleeve and the elongate metal conduit.
  • providing the inner plastic liner having and positioning the inner plastic liner interior of an elongate metal conduit may comprise extruding the inner plastic liner into the elongate metal conduit.
  • the inner plastic liner may be extruded with open first and second spaced apart ends, and the method may further comprise sealing the open ends of the inner plastic liner prior to expanding the inner plastic liner.
  • applying pressure to a fluid positioned in the interior volume of the inner plastic liner may comprise introducing a pressurized fluid into the interior volume of the inner plastic liner.
  • the apparatus and methods described herein may be used to connect pipes and/or fittings of various materials (e.g. metallic pipes, thermoplastic pipes) to create piping systems for transporting various liquids or gasses.
  • various materials e.g. metallic pipes, thermoplastic pipes
  • the piping system that uses the expansion compensator may be made from different materials (e.g., the pipes may be made of PVC and/or CPVC and the fittings may be made of metal).
  • the piping system components (or at least their inner surfaces through which fluid is conveyed) may be made of the same material.
  • the apparatus and methods may be applied to different sizes of piping, and/or piping systems made of the same or different materials, and therefore may be applicable to piping systems for domestic or commercial uses, such as conveying potable water, non-potable or waste water, or other liquids and/or gasses.
  • Figure 1A is a cross section view of an expansion compensator in accordance with one embodiment
  • Figure 1 B is an enlarged view of the box 1 B in Figure 1A of the expansion compensator of Figure 1A;
  • Figure 2 is a cross section view of an end of the expansion compensator of Figure A joined to a pipe end;
  • Figure 3A is a perspective view of an elongate metal conduit and an inner plastic liner in accordance with the embodiment of Figure 1A;
  • Figure 3B is an enlarged view of the box in Figure 3A;
  • Figure 3C is a perspective view of a two-layer elongate metal conduit and an inner plastic liner in accordance with another embodiment
  • Figure 3D is an enlarged view of the box in Figure 3C;
  • Figure 3E is a perspective view of a two-layer elongate metal conduit, a protective layer, and an inner plastic liner in accordance with another embodiment
  • Figure 3F is an enlarged view of the box in Figure 3E;
  • Figure 3G is a perspective view of a two-layer elongate metal conduit, a protective layer, and a two-layer inner plastic liner in accordance with another embodiment
  • Figure 3H is an enlarged view of the box in Figure 3G;
  • Figure 4A is a perspective view of the expansion compensator of
  • Figure 4B is a perspective view of the expansion compensator of Figure 1A with an alternate sleeve
  • Figure 5 is an exploded view of the expansion compensator of Figure 4B;
  • Figure 6A is a perspective view of the expansion compensator of Figure 4B disposed between two pipe ends;
  • Figure 6B is a perspective view of the expansion compensator and pipe ends of Figure 6A with the pipe ends received in the connectors of the expansion compensator;
  • Figure 7 A is a cross section view of Figure 6B;
  • Figure 7B is an enlarged view of the box 7B in Figure 7A;
  • Figure 7C is a cross section view of an alternate expansion compensator with pipe ends received in the connectors of the expansion compensator;
  • Figure 7D is an enlarged view of the box 7D in Figure 7C;
  • Figure 8A is a perspective view of a forming apparatus, a metal conduit, and a pre-formed plastic liner in accordance with one embodiment
  • Figure 8B is a perspective view of Figure 8A with the pre-formed plastic liner positioned interior of the metal conduit;
  • Figure 8C is a perspective view of Figure 8B with the metal conduit positioned in a cavity of one longitudinally extending body halves of the forming apparatus;
  • Figure 8D is a perspective view of Figure 8C with the longitudinally extending body halves of the forming apparatus in a closed configuration;
  • Figure 8E is a perspective view of Figure 8D with the upper support frame of the forming apparatus partially inserted in the closed body halves;
  • Figure 8F is a perspective view of Figure 8E with the upper and lower support frames of the forming apparatus partially inserted in the closed body halves ;
  • Figure 9A is a cross section along line 9-9 in Figure 8F of the metal conduit and pre-formed plastic liner positioned in the forming apparatus;
  • Figure 9B is an enlarged view of the box 9B in Figure 9A;
  • Figure 0A is a cross section along line 9-9 in Figure 8F with the pre-formed plastic liner partially expanded against the metal conduit;
  • Figure 10B is an enlarged view of the box 10B in Figure 10A;
  • Figure 1 1A is a cross section along line 9-9 in Figure 8F with the pre-formed plastic liner further expanded against the metal conduit;
  • Figure 1 1 B is an enlarged view of the box 1 1 B in Figure 1 1 A;
  • Figure 12A is a perspective view of a pre-formed plastic liner in accordance with one embodiment
  • Figure 12B is a longitudinal cross section view of the pre-formed plastic liner of Figure 12A;
  • Figure 13A is a perspective view of a pre-formed plastic liner in accordance with another embodiment
  • Figure 13B is a longitudinal cross section view of the pre-formed plastic liner of Figure 13A;
  • Figure 14A is a perspective view of a pre-formed plastic liner in accordance with another embodiment
  • Figure 14B is a longitudinal cross section view of the pre-formed plastic liner of Figure 14A
  • Figure 15A is a perspective view of a pre-formed plastic liner in accordance with another embodiment
  • Figure 15B is a longitudinal cross section view of the pre-formed plastic liner of Figure 15A;
  • Figure 16A is a perspective view of a pre-formed plastic liner in accordance with another embodiment
  • Figure 16B is a longitudinal cross section view of the pre-formed plastic liner of Figure 16A;
  • Figure 17 is a cross section view of ends of a two-layer elongate metal conduit and an inner plastic liner inserted into a molding apparatus;
  • Figure 18A is a longitudinal cross section view of a metal conduit, a pre-formed plastic liner, and a thin elongate member disposed therebetween;
  • Figure 18B is a cross section along line 8B-18B in Figure 18A;
  • Figure 19A is a cross section view of an extruding and forming apparatus, and a metal conduit in accordance with one embodiment
  • Figure 19B is the cross section view of Figure 19A with an extruded plastic liner positioned interior of the metal conduit;
  • Figure 19C is the cross section view of Figure 19B with the ends of the extruded plastic liner sealed by the extruding and forming apparatus;
  • Figure 19D is the cross section view of Figure 19C with an optional thin elongate member disposed between the metal conduit and the extruded plastic liner;
  • Figure 19E is a cross section along line 19E-19E in Figure 19D;
  • Figure 20A is a cross section view of the extruded plastic liner being expanded against the metal conduit;
  • Figure 20B is an enlarged view of the box 20B in Figure 20A;
  • Figure 21A is a cross section view with the extruded plastic liner further expanded against the metal conduit;
  • Figure 21 B is an enlarged view of the box 21 B in Figure 21 A;
  • Figure 22A is a cross section view of an extruding and forming apparatus, and a metal conduit in accordance with another embodiment
  • Figure 22B is the cross section view of Figure 22A with an extruded plastic liner positioned interior of the metal conduit;
  • Figure 22C is the cross section view of Figure 22B with the ends of the extruded plastic liner sealed by the extruding and forming apparatus;
  • Figure 22D is the cross section view of Figure 22C with the extruded plastic liner being expanded against the metal conduit;
  • Figure 22E is the cross section view of Figure 22C with the extruded plastic liner being further expanded against the metal conduit;
  • Figure 22F is an enlarged view of the box 22F in Figure 22E;
  • Figure 23 is a cross section view of excess plastic liner being trimmed from metal conduit
  • Figure 24 is a cross section view of an extruding and forming apparatus, a metal conduit, and two extruded plastic liners positioned interior of the metal conduit, in accordance with another embodiment;
  • Figure 25A is a cross section view of an extruding and forming apparatus, a metal conduit, and an extruded plastic liner in accordance with another embodiment;
  • Figure 25B is an enlarged view of the box 25B in Figure 25A;
  • Figure 26A is a cross section view of the extruding and forming apparatus of Figure 25A, a metal conduit with an inner plastic liner, and another extruded plastic liner;
  • Figure 26B is an enlarged view of the box 26B in Figure 26A;
  • Figure 27A is a cross section view of the extruding and forming apparatus of Figure 25A, a metal conduit with two inner plastic liners, and yet another extruded plastic liner; and,
  • Figure 27B is an enlarged view of the box 27B in Figure 27A.
  • Figure 5 is for reference only, and that it may not be possible to assemble and/or disassemble expansion compensator 100 with the components in their illustrated configurations.
  • the apparatuses, methods and compositions may be used with piping systems made of various materials.
  • the pipes and/or fittings to be connected may be made of a plastic material and optionally a thermoplastic material.
  • the thermoplastic material may be one or more of acrylonitrile butadiene styrene (ABS), PVC, CPVC, ethylene vinyl acetate (EVA), polyethylene (PE) or the like.
  • ABS acrylonitrile butadiene styrene
  • PVC polyVC
  • CPVC ethylene vinyl acetate
  • PE polyethylene
  • the thermoplastic material is one or more of PVC and CPVC.
  • the drawings exemplify the use of an expansion compensator to connect sections of pipe together. It will be appreciated that the same expansion compensator may be used to connect any parts of a piping system together. For example, the expansion compensator may be used to connect a pipe with a fitting such as a valve, tees, couplers, elbows, and the like, or to connect one fitting with another fitting.
  • a fitting such as a valve, tees, couplers, elbows, and the like
  • Expansion compensator 100 includes an elongate metal conduit, referred to generally as 1 0, interior to which is positioned an inner plastic liner 120 that provides a fluid flow path through the expansion compensator 100. Also, first and second connectors 130a,b may be provided at opposite ends of the metal conduit and plastic liner. Connectors 130a,b may be used for coupling the expansion compensator to a piping system, as will be discussed further subsequently.
  • each of elongate metal conduit 1 10 and inner plastic liner 120 comprise a single layer, thereby forming a two-layer expansion compensator 100.
  • Expansion compensator 100 comprises a first end 102, a second end 104, and an expansion/contraction section 106.
  • Expansion/contraction section 106 allows for the axial length of expansion compensator 100 to vary in response to an applied axial force (either compressive or tensile). For example, if the position of first end 102 is fixed, and an axial force is applied to second end 104 in a direction towards first end 102, expansion/contraction section 106 may contract in the axial direction, reducing the axial length of expansion compensator 100.
  • expansion/contraction section 106 may expand in the axial direction, increasing the axial length of expansion compensator 100. While expansion/contraction section 106 is illustrated as a bellows section having a series of convolutions, it will be appreciated that other geometric configurations such as sinusoidal or otherwise articulated surface may be used. These constructions permit the expansion compensator to temporarily deform (e.g., elastically deform) axially inwardly and outwardly during thermal expansion and contraction of the piping system, without fracture of the expansion compensator.
  • temporarily deform e.g., elastically deform
  • the main body of expansion compensator 100 comprises elongate metal conduit 110, within which is positioned inner plastic liner 120.
  • inner plastic liner 120 Preferably, the opposite ends of metal conduit 1 10 and inner plastic liner 120 are coupled together to provide a unitary body (i.e., so that the respective ends of the outer metal conduit and the inner plastic liner axial will have the same relative displacement in response to an applied axial force).
  • the elongate metal conduit 110 and the inner plastic liner 120 may be coupled together by providing a connector, which may be formed by overmolding, at one and preferably each end of the expansion compensator.
  • metal conduit 110 (illustrated here as comprising an inner elongate metal conduit 1 16 and an outer elongate metal conduit 1 17) has an outer surface 112 and an inner surface 114. Inner surface 114 is adjacent an outer surface 122 of inner plastic liner 120, while inner surface 124 of inner plastic liner 120 defines the interior volume of expansion compensator 100 between connectors 130a,b.
  • Optional connectors 130a,b may be provided at one or both ends of expansion compensator 100 and may be configured or adapted for coupling expansion compensator 100 to other components of a piping system.
  • connectors 130a,b may comprise exterior and/or interior surface features (e.g.
  • connectors 130a,b in the illustrated embodiments are substantially similar to each other, it will be appreciated that in alternative embodiments different connectors (e.g. for coupling to different sizes and/or types of components) may be provided on opposite ends of the same expansion compensator.
  • the apparatus exemplified uses an insertion fit, i.e., one end of one part of a piping system is inserted into an open end of another part of the piping system.
  • connector 130a,b may be dimensioned to receive first and second pipe ends inserted into first end 102 and second end 104, respectively, of expansion compensator 00.
  • Connector 130 may be configured such that an end of a pipe may be inserted only up to a predetermined distance into connector 130. This may assist in aligning one or more features (e.g. injection passages, grooves) of the connector and/or the pipe end with each other. Therefore, a stop member may be provided inside connector 130.
  • one or both connectors 130a,b may comprise an interior ridge 138 that provides an abutment surface against which a pipe end inserted into the respective connector 130a,b will abut when inserted a predetermined distance, to assist in coupling expansion compensator 100 to a pipe end, as shown in Figure 2.
  • interior ridge 138 may have a height that is similar to or the same as the thickness of the pipe inserted into end 104. Accordingly, the cross sectional area of flow through the pipe and the end of the expansion compensator is generally the same.
  • expansion compensator 100 is shown disposed between and aligned with pipe ends 10a, b.
  • connector 130a is aligned with pipe end 10a
  • connector 30b is aligned with pipe end 10b
  • connectors 130a,b are dimensioned to receive therein, respectively, pipe ends 10a, b.
  • Figure 6B shows expansion compensator 100 once it has been coupled to pipe ends 10a, b. It will be appreciated that the ends of connectors 130a,b may be configured to be connected to a pipe end 10a, b by any means known in the piping arts.
  • Figure 7A shows a cross section view of expansion compensator 100 coupled to pipe ends 10a, b.
  • Expansion/contraction section 106 allows for the axial length of expansion compensator 100 to vary in response to an axial force (either compressive or tensile) applied by pipe end 10a and/or 10b.
  • an axial force either compressive or tensile
  • the pipe ends will exert a compressive force along the longitudinal axis of expansion compensator 100.
  • Such a compressive force may be exerted (or imposed) on expansion compensator 100 by a piping system in response to water having a temperature of from about 55°C to about 85°C flowing through the piping system.
  • expansion/contraction section 106 may contract in the axial direction, reducing the axial length of expansion compensator 100.
  • the amount of contraction of expansion compensator 100 will depend on the amount of the applied compressive force, and the overall axial stiffness of expansion compensator 00. Also, if the axial stiffness of the elongate metal conduit is greater than the stiffness of the inner plastic liner, which is optional, a greater portion of the applied compressive force will be borne (e.g. absorbed) by metal conduit 110 while expansion compensator 100 is compressed, and the stress on plastic liner 120 may accordingly be reduced.
  • expansion/contraction section 106 may expand in the axial direction, increasing the axial length of expansion compensator 100.
  • the amount of expansion of expansion compensator 100 will depend on the amount of the applied tensile force and the axial stiffness of expansion compensator 100.
  • the axial stiffness of the elongate metal conduit is greater than the stiffness of the inner plastic liner, a greater portion of the applied tensile force will be borne by metal conduit 110 while expansion compensator 100 is expanded, and the stress on plastic liner 120 may accordingly be reduced.
  • metal conduit 1 10 may comprise two layers. It will be appreciated that the stiffness of expansion compensator 100 may vary based on the number of metal layers in metal conduit 110, the particular metal or metals used, the thickness of each metal layer, and/or the geometry of metal conduit 110. The stiffness of expansion compensator 100 may also depend on the number of layers in inner plastic liner 120, the particular plastic or plastics used, the thickness of each plastic layer, and/or the geometry of inner plastic liner 120.
  • the overall stiffness of expansion compensator 100 may be selected based on the forces expected to be imposed by a piping system into which it is installed, so as to reduce the stress in the piping system components. For example, an expansion compensator 100 with a relatively lower overall stiffness may compress or expand more easily in response to an applied force than an expansion compensator 100 with a relatively higher overall stiffness. Providing a more pliant expansion compensator 100 may allow greater axial deformation (e.g. expansion or contraction) of piping system components in response to expected thermal changes, which may reduce the internal stress in these components. Methods of manufacturing an expansion compensator using a pre-formed blank
  • Figures 8A to 16B exemplify methods and apparatus for manufacturing expansion compensator 100 using a pre-formed plastic liner in accordance with one aspect of this disclosure. This aspect may be used to manufacture an expansion compensator 100, which may incorporate one or more aspects of an expansion compensator 100 disclosed herein.
  • the method includes positioning a pre-formed plastic liner, referred to generally as 220, interior of elongate metal conduit 110 and using fluid under pressure to expand pre-formed plastic liner 220 outwardly towards inner surface 1 14 of metal conduit 110, whereby the expanded plastic liner forms inner plastic liner 120.
  • the methods may be characterized as being analogous to hydroforming pre-formed plastic liner 220 against metal conduit 1 10, using inner surface 1 14 of metal conduit 110 as a mold for pre-formed plastic liner 220.
  • first and second connectors 130a,b may be provided at one or both ends of the metal conduit and inner plastic liner.
  • Figure 8A illustrates a forming apparatus, referred to generally as 300, which may be used when expanding pre-formed plastic liner 220. It will be appreciated that, in variant embodiments, forming apparatus 300 may comprise more or fewer components. Also, it will be understood by persons skilled in the art that one or more components (e.g. controllers, piping, wiring, etc.) have been omitted for clarity.
  • forming apparatus 300 has first and second body halves 310, 31 1 , each having a complementary recess 318, 319, respectively, for receiving and holding metal conduit 1 10 therebetween. Accordingly, complementary recesses 318, 319 maybe dimensioned to receive metal conduit 1 10 therebetween and to support metal conduit 110 during the forming process.
  • First and second body halves 310, 311 may be configured to reinforce metal conduit during the forming process.
  • complementary recess 318, 319 may be sized and shaped such that the outer surface of metal conduit 110 abuts there against.
  • First and second body halves 310, 31 1 may be selectively securable together and moveable between an open position as exemplified in Figure 8A in which metal conduit 110 may be placed therein and a closed forming position as exemplified by Figure 8F by any means known in the art.
  • the mechanism for moving one of both of first and second body halves 310, 31 1 between the open and forming positions has not been shown. A person skilled in the forming arts will be familiar with such mechanisms and any such mechanism may be used.
  • first body half 310 has one or more upper engagement flanges 312a and one or more lower engagement flanges 312b that may cooperate with one or more upper engagement flanges 313a and one or more lower engagement flanges 313b on second body half 311 , and/or with upper and lower alignment pins 322a, 322b, as will be discussed subsequently.
  • Body halves 310, 31 may each also have one or more upper locking members (314, 315, respectively) and lower locking members (316, 317, respectively), for engagement with upper locking ports 324, 325 on upper support frame 320 and lower locking ports 326, 327 on lower support frame 321 , as will be discussed subsequently. It will be appreciated that other securing means, including pneumatic means may be used and a person skilled in the forming arts will be familiar with such mechanisms and any such mechanism may be used.
  • pre-formed plastic liner 220 Prior to the forming step, pre-formed plastic liner 220 is positioned interior of metal conduit 1 10. As exemplified in Figure 8A, pre-formed plastic liner 220 is inserted into metal conduit 1 10 in the direction indicated by arrow 8 such that pre-formed plastic liner 220 is positioned in metal conduit 110 as exemplified in Figure 8B. Pre-formed plastic liner 220 may be positioned in metal conduit 110 prior to securing metal conduit 1 10 between complementary recesses 318, 319. It will be appreciated that pre-formed plastic liner 220 may alternatively be inserted into metal conduit 1 10 from the other direction, and/or positioned interior of metal conduit 110 during or after the securing first and second body halves 310, 31 1 together.
  • metal conduit 110 is provided as a pre-formed construct (i.e., with the desired profile for the expansion/contraction section 106).
  • Metal conduit 1 10 may be manufactured by any suitable process or processes, such as tube drawing, hydroforming and the like.
  • Metal conduit 1 10 may be made from steel, copper, or other iron alloys, or any other metal used in the piping arts although it will be appreciated that other metallic materials may be suitable.
  • metal conduit 1 10 is made from one or more layers of stainless steel, such as SS316L stainless steel.
  • metal conduit 110 comprises a single layer.
  • the thickness of metal conduit 10 may be from 0.005 to 0.030 inches, preferably from 0.010 to 0.020 inches, and more preferably from 0.012 to 0.0 6 inches.
  • Figures 12A and 12B exemplify a pre-formed plastic liner 220 having a first end 202, a second end 204, an inner surface 224, and an outer surface 222.
  • Pre-formed plastic liner 220 is dimensioned to be receivable (e.g., slidably receivable) in metal conduit 110 and may be retained therein by any means known in the forming arts.
  • first end 202 may be dimensioned such that some or all of first end 202 remains outside of metal conduit 1 10, i.e., axially outwardly of first end 1 1 1 of metal conduit 110.
  • first end 202 may be slightly conical in shape, or may have a stepped profile so as to limit the extent to which pre-formed plastic liner is insertable into metal conduit 110.
  • metal conduit 110 may have engagement members to secure pre-formed plastic liner 220 in a desired position and/or forming apparatus 300 may have a member to secure pre-formed plastic liner 220 in a desired position.
  • all of first end 202 may be received in metal conduit 110.
  • Pre-formed plastic liner 220 may have a length so as to extend to the opposed end of metal conduit and, optionally as shown in Figure 8B, the extend axially past the opposed end of metal conduit 1 0. As exemplified in Figure 8B, pre-formed plastic liner 220 may be dimensioned such that some or all of second end 204 extends past second end 113 of metal conduit 1 10.
  • Pre-formed plastic liner 220 may be manufactured by any suitable process, such as injection molding and the like. As shown in Figures 12A and 12B, pre-formed plastic liner 220 may have a substantially uniform thickness. Alternatively, as will be discussed subsequently, pre-formed plastic liner 220 may be provided with one or more regions of non-uniform wall thickness.
  • inner plastic liner 20 may comprise a single layer.
  • the thickness of inner plastic liner 120 may be from 0.005 to 0.125 inches, preferably from 0.020 to 0.1 inches, and more preferably from 0.040 to 0.090 inches.
  • inner plastic liner 120 may comprise two layers.
  • two pre-formed plastic liners may be nested into metal conduit 10 and the forming process then conducted.
  • an outer pre-formed plastic liner may be individually placed in metal conduit 1 10 and the forming process conducted.
  • an inner pre-formed plastic liner may then be placed in inner formed plastic liner and the forming process conducted again.
  • each plastic layer 126,127 may be from 0.005 to 0.75 inches, preferably from 0.020 to 0.050 inches, and more preferably from 0.03 to 0.045 inches.
  • metal conduit 110 (with pre-formed plastic liner 220 inserted therein) may be positioned in one of the complementary recesses, e.g., recess 318.
  • body halves 310, 31 1 have been brought together so that complementary recesses 318, 319 define a cavity surrounding metal conduit 1 10.
  • upper sockets 302a on upper engagement flanges 312a have received upper projecting members 301 a on upper engagement flanges 313a and these are secured together by any means known in the forming arts.
  • lower sockets 302b on lower engagement flanges 312b have received lower projecting members 301 b on lower engagement flanges 313b and these are secured together by any means known in the forming arts.
  • the respectively coupled engagement members restrain any relative vertical motion of body halves 310, 31 1 , and also cooperatively define upper and lower alignment barrels 304a, 304b.
  • Upper support frame 320 is engaged with first and second body halves 310, 3 1 (see Figure 8E). In doing so, upper alignment pins 322a are received within upper alignment barrels 304a, and upper locking members 314, 315 are received by upper locking ports 324, 325, respectively. Preferably, upper alignment pins 322a are longer than upper locking members 314, 315, so that upper alignment pins 322a engage upper alignment barrels 304a prior to upper locking members 314, 315 engaging upper locking ports 324, 325.
  • the alignment pins and barrels act to constrain the horizontal alignment of upper support frame 320 as it is brought towards first and second body halves 310, 31 1 , which may facilitate the engagement of upper locking members 314, 315 with upper locking ports 324, 325.
  • the engagement of upper support frame 320 with first and second body halves also results in upper plug 328 being received within first end 202 of pre-formed plastic liner 220, which is itself positioned within first end 1 1 of metal conduit 1 10.
  • Lower support frame 321 is engaged with first and second body halves 310, 31 1 (see Figure 8F). In doing so, lower alignment pins 322b is received within lower alignment barrels 304b, and lower locking members 316, 317 is received by lower locking ports 326, 327, respectively.
  • lower alignment pins 322b are longer than lower locking members 316, 317, so that lower alignment pins 322b engage lower alignment barrels 304b prior to lower locking members 316, 317 engaging lower locking ports 326, 327.
  • the alignment pins and barrels act to constrain the horizontal alignment of lower support frame 321 as it is brought towards first and second body halves 310, 311 , which may facilitate the engagement of lower locking members 316, 317 with lower locking ports 326, 327.
  • metal conduit 1 10 and pre-formed plastic liner 220 are positioned in the cavity defined by complementary recesses 318, 319 of first and second body halves 310, 31 1.
  • elongate metal conduit 1 10 may comprise an inner elongate metal conduit 116 and an outer elongate metal conduit 117, together with inner plastic liner 120 forming a three-layer expansion compensator.
  • metal conduit 1 10 comprises more than one metal layer, it will be appreciated that the overall axial stiffness of metal conduit 110 may be approximated as the sum of the axial stiffness for each metal layer.
  • inner elongate metal conduit 1 16 and outer elongate metal conduit 7 may have the same stiffness or they may be different.
  • the thickness of each metal conduit 1 6,117 may be from 0.005 to 0.025 inches, preferably from 0.008 to 0.020 inches, and more preferably from 0.012 to 0.016 inches.
  • metal conduit 110 comprises inner elongate metal conduit 1 6 and outer elongate metal conduit 117
  • expansion/contraction section 115 of metal conduit 1 10 comprises an alternating series of radially outer peaks 160a,b,c and radially inner valleys 162a,b,c.
  • Pre-formed plastic liner 220 is heated and formed.
  • Pre-formed plastic liner 220 may be pre-heated. For example, once metal conduit 1 0 with pre-formed plastic liner 220 is placed in recesses 318,319, pre-formed plastic liner 220 may be heated and formed. It will be appreciated that pre-formed plastic liner 220 may be pre-heated prior to insertion into metal conduit 110 and/or preheated once placed in metal conduit 1 0 but prior to placement of metal conduit 0 into forming apparatus 300. The pre-formed plastic liner 220 may be pre- heated to a temperature above which the plastic becomes formable.
  • pre-formed plastic liner 220 may be conducted and pre-formed plastic liner 220 then formed. Alternatively, the forming and the heating step may occur concurrently. Further, pre-formed plastic liner 220 may not be pre-heated and accordingly, all of the heating may occur once pre-formed plastic liner 220 is positioned in forming apparatus 300.
  • the forming step is conducted by pressurizing the interior of preformed plastic liner 220. Accordingly, once at a forming temperature, the pressure will cause pre-formed plastic liner 220 to deform to produce the desired profile. Accordingly, prior to the forming step, a sealed volume is created that includes the interior of pre-formed plastic liner 220.
  • upper plug 328 and lower plug 329 may provide a sealed volume within pre-formed plastic liner 220, into which a fluid is introduced.
  • conduit 330 may convey fluid into and/or out of the sealed interior volume of preformed plastic liner 220.
  • Conduit 330 may be connected to a pump, compressor, a high pressure fluid line that is available, e.g., high pressure steam or other source of pressurized fluid (not shown) for selectively introducing and/or removing fluid from the sealed interior volume of pre-formed plastic liner 220.
  • Pre-formed plastic liner 220 may be heated in situ by the forming or working fluid.
  • the forming fluid may comprise a heated fluid, preferably a heated liquid, such as water.
  • one or more heat sources such as heating element 332 extending from lower plug 329) may be provided in the sealed interior volume, to heat the fluid contained therein.
  • body halves 310, 31 1 may be provided with heating elements or a heating jacket may be provided.
  • a fluid e.g. water
  • the fluid is introduced at an elevated temperature, so that pre-formed plastic liner 220 is heated (and thus softened) by the fluid.
  • the fluid may be heated after introduction to the sealed interior volume, for example via heating element 332.
  • the forming temperature will depend upon the plastic that is used and the pressure that is applied.
  • the forming temperature may be from 110°C to 150°C, preferably from 120°C to 140°C and more preferably from 125°C to 135°C.
  • lower forming temperatures may be used. Any forming temperature known in the forming arts may be used.
  • the forming fluid may be maintained in the sealed interior volume at a lower temperature for a period of time to partially or fully preheat the preformed plastic liner 220 prior to raising the pressure to a forming pressure. Accordingly, after a sufficient time has elapsed for pre-formed plastic liner 220 to be heated, and thereby softened, which may take from 1 to 30, preferably 2 to 10, more preferably 3 to 5 minutes, the pressure of the fluid in the interior volume may be increased, for example by introducing more fluid into the interior volume (e.g. via conduit 330) or pressurizing the fluid already in the interior.
  • the forming pressure may be from 100 to 800 psi, preferably from 250 to 600 psi and more preferably from 350 to 450 psi. Any forming pressure known in the forming arts may be used. Increasing the pressure within the sealed interior volume will increase the force exerted on the inner surface 224 of preformed plastic liner 220, causing the walls of pre-formed plastic liner 220 to expand towards inner surface 14 of metal conduit 110, as shown in Figures 10A and 10B.
  • the forming fluid may be above the boiling point of the forming fluid, e.g., 120 to130°C so as to reduce the heating time for the plastic to reach, e.g., the forming temperature.
  • forming apparatus 500 is operated so as to prevent the working fluid from boiling.
  • the forming fluid may be an elevated pressure, such as 40 to 70 psi, to prevent the forming fluid from boiling.
  • fluid e.g.
  • vent port 334 may be provided for selectively removing fluid from the annular volume between the outer surface 222 of pre-formed plastic liner 220 and the inner surface 114 of metal conduit 1 10, and/or from the annular volume between the cavity defined by complementary recesses 318, 319 and outer surface 1 12 of metal conduit 110.
  • Vent port 334 may be connected to a pump or other vacuum source.
  • one or more thin elongate members 370 may be provided between inner surface 14 of metal conduit 110 and outer surface 222 of pre-formed plastic liner 220 prior to expanding pre-formed plastic liner 220.
  • Such elongate members may provide a longitudinal airflow path 375 (see e.g. Figure 18B) in the annular volume between the outer surface 222 of pre-formed plastic liner 220 and the inner surface 114 of metal conduit 1 10, facilitating the abutment of outer surface 222 of pre-formed plastic liner 220 and the inner surface 114 of metal conduit 1 10 during expansion of the pre-formed plastic liner 220 by facilitating the escape of air from between metal conduit 10 and pre-formed plastic liner 220.
  • one or more longitudinally extending grooves may be provided on inner surface 1 14 of metal conduit 1 0 and/or the outer surface of the preformed plastic liner 220.
  • Such grooves may provide a longitudinal airflow path in the annular volume between the outer surface 222 of pre-formed plastic liner 220 and the inner surface 1 14 of metal conduit 1 10, facilitating the abutment of outer surface 222 of pre-formed plastic liner 220 and the inner surface 1 14 of metal conduit 1 10 during expansion of the pre-formed plastic liner 220. It will be appreciated that such a recess may be provided on any of all of the metal conduits illustrated herein.
  • pre-formed plastic liner 220 may continue to expand until the outer surface 222 of pre-formed plastic liner 220 abuts the inner surface 1 14 of metal conduit 1 10, as illustrated in Figures 1 1A and 1 1 B and by the dotted lines (denoted 220') in Figure 18B.
  • pre-formed plastic liner 220 is formed so as to develop a profile that conforms to the profile of the inner surface of metal conduit 1 10. As such metal conduit 1 10 may act as a mold.
  • metal conduit 1 10 and inner plastic liner 120 may be abutting as exemplified in Figure 3B.
  • the forming may be conducted, by controlling one or more of the time, pressure and temperature such that such that the profile of plastic liner is similar to that of the interior surface of metal conduit 1 10 but does not completely conform thereto.
  • metal conduit 110 and inner plastic liner 20 may be spaced apart.
  • Expansion/contraction section 106 is generally illustrated as a bellows section having a series of convolutions. While the expansion/contraction sections of metal conduit 110 and inner plastic liner 120 are shown with complementary profiles (e.g. each have a similar profile, and these profiles are aligned), it will be appreciated that that this need not be the case.
  • outer surface 122 of inner plastic liner 120 is illustrated as being in contact with (e.g. abutting) inner surface 1 14 of metal conduit 1 10, it will be appreciated that in some embodiments, an air gap may be present along all or part of the length of expansion compensator 100. This may be achieved by limiting the forming pressure, temperature and/or time.
  • the plastic liner 120 may be cooled. This may occur by one or more of providing a cooling fluid to the interior volume, withdrawing water from the interior volume, applying cooling by the body halves 310, 31 1 , such as by passing a cooling fluid through cooling passages in body halves 310, 3 , applying a cooling fluid to a thermal jacket around forming apparatus 300, withdrawing the formed part from forming apparatus 300 and allowing it to cool by exposing it to the ambient conditions or placing it in a cooling bath, or any other means known in the forming arts.
  • Figures 19A to 27B exemplify alternative methods and apparatus for manufacturing expansion compensator 100 wherein a plastic liner is provided interior of a mold by extruding the plastic liner and positioning the extruded liner when at a desired temperature in the mold in accordance with another aspect of this disclosure.
  • This aspect may be used to manufacture an expansion compensator 100, which may incorporate one or more aspects of an expansion compensator 100 disclosed herein.
  • the method includes positioning an extruded plastic liner, referred to generally as 420, interior of elongate metal conduit 1 10 (e.g., extruding the plastic liner directly into a mold) and introducing a pressurized fluid to expand extruded plastic liner 420 outwardly towards inner surface 1 14 of metal conduit 1 0, whereby the expanded plastic liner forms inner plastic liner 120.
  • the methods may be characterized as being analogous to blow molding extruded plastic liner 420 against metal conduit 110, using inner surface 1 14 of metal conduit 110 as a mold for extruded plastic liner 420.
  • first and second connectors 130a,b may be provided at one or both ends of the metal conduit and inner plastic liner.
  • Figure 19A illustrates an extruding and forming apparatus, referred to generally as 500, which may be used when expanding extruded plastic liner 420. It will be appreciated that, in variant embodiments, forming apparatus 500 may comprise more or fewer components. Also, it will be understood by persons skilled in the art that one or more components (e.g. controllers, piping, wiring, etc.) have been omitted for clarity.
  • forming apparatus 500 may comprise more or fewer components.
  • one or more components e.g. controllers, piping, wiring, etc.
  • extruding and forming apparatus 500 has an extruder 510 for extruding plastic liner 420 and a forming section that holds metal conduit 1 10 in position during the forming step. It will be appreciated that extruder 510 and the forming section may be separate units that may be secured together or may be positioned such that plastic liner 420 extruded from extruder 510 is received directly into the metal conduit 1 10.
  • the forming section may merely hold elongate metal conduit 1 0 in position wherein elongate metal conduit 110 functions as a mold for the plastic liner 420 or the forming section may include sections that have a profile similar to the profile of the outer surface of elongate metal conduit 1 10 such that elongate metal conduit 1 10 is reinforced during the forming step.
  • details of the mechanism for extruding a tubular extruded plastic liner 420 and for securing the metal conduit in position during the forming step have not been shown. A person skilled in the extruding arts will be familiar with such mechanisms and any such mechanisms may be used.
  • the apparatus is shown vertically disposed, it will be appreciated that the apparatus may be oriented in any orientation.
  • extruder 510 may have an extruder outlet that faces downwardly such that extruded plastic liner 420 is extruded downwardly and may be extruded directly into a metal conduit 110 as exemplified in Figure 19B.
  • a non-continuous extrusion process may be utilized.
  • a plunge extruder may be utilized.
  • the plunge extruder may extrude a section of plastic liner into metal conduit 1 10 (preferably downwardly as exemplified in Figure 19B).
  • the plunge extruder may be designed such that the length of plastic conduit that is extruded is sufficient to extend through metal conduit without trimming prior to the forming process.
  • the metal conduit 110 with the extruded length of plastic liner therein may then be removed and replaced by another metal conduit 1 10 and the process repeated. It will be appreciated that the plunge extruder may optionally be moved to be aligned with another metal conduit 1 10.
  • extruded plastic liner 420 may be allowed to cool so that it has sufficient structural integrity to be manipulated prior to being received in a metal conduit 1 10 (the handling temperature).
  • extruded plastic liner 420 may be allowed to cool sufficiently such that sections having a length sufficient for use in the expansion compensator may be cut.
  • Such an embodiment may be used if a continuous extrusion process is used. Accordingly, the plastic liner may be cooled sufficiently to be cut and a cut section may then be inserted into a metal conduit 1 10 or the plastic liner may be extruded into a metal conduit 1 0 and, once cooled sufficiently, extruded plastic liner 420 may be cut.
  • Extruded plastic liner 420 may be extruded and allowed to cool, such as by being exposed to the ambient or by passing through a cooling section such as by being sprayed with a cooling fluid. Extruded plastic liner 420 may be cooled to an elevated temperature at which it has sufficient structural integrity to maintain its shape (e.g., and enable it to be cut into selected lengths) but above ambient. Accordingly the plastic liner may be maintained closer to the forming temperature.
  • Extruded plastic liner 420 may be received in metal conduit 110 once at the handling temperature.
  • extruded plastic liner 420 may be cut to an appropriate length to form the expansion compensator.
  • the metal conduit with extruded plastic liner 420 positioned therein may then be moved and a further metal conduit 1 10 placed in position to receive therein another extruded plastic liner 420.
  • a plurality of metal conduits 10 (at least 2) may be provided on a carousel.
  • One of the metal conduits 1 0 may be aligned with the extruder outlet and a length of plastic that has been extruded is received therein.
  • the plastic may be cut to form extruded plastic liner 420.
  • the metal conduit 1 10 with extruded plastic liner 420 therein may then be removed from the aligned position, e.g., rotated out of position, and a further metal conduit 1 0 may be rotated into position and the process repeated. Accordingly, a continuous extrusion process may be used.
  • extruded plastic liner 420 may be cut from the continuously extruded plastic conduit and then inserted into a metal conduit 0. It will be appreciated that, once extruded plastic liner 420 has been cut from the continuously extruded plastic conduit, forming process may be conducted with the metal conduit 110 and extruded plastic liner 420 in any orientation.
  • extruded plastic liner 420 is ready to be formed, the ends of the conduit are sealed in preparation for the forming step.
  • the sealing step preferably occurs once a length of extruded plastic liner 420 has been positioned in a metal conduit 1 10.
  • extruding and forming apparatus 500 has upper and lower clamping segments 520, 522, which may have complementary recesses 521 , 523, respectively, for sealing an extruded plastic liner 420 therebetween.
  • Each of the upper and lower clamping segments 520, 522 may be selectively securable together and moveable between an open position as exemplified in Figure 19A in which conduit from extruder 510 may pass through and a closed forming position as exemplified by Figure 19C by any means known in the art. Accordingly, for example, after a, e.g., plunge extruder extrudes a length of liner into metal conduit 1 10, the upper and lower ends of the liner may then be sealed. The plunge extruder may then be used to deliver a length of liner into another metal conduit 10.
  • extruded plastic conduit is received in metal conduit 110.
  • upper and lower clamping segments 520, 522 may move the closed position as exemplified in Figure 19C to seal the upper and lower ends of extruded plastic liner 420.
  • upper and lower clamping segments 520, 522 may secure extruded plastic liner 420 in a desired position in metal conduit 110.
  • separate mechanical engagement members may be provided to secure extruded plastic liner 420 in a desired position in metal conduit 1 10.
  • the extruding and forming apparatus may reinforce the outer wall of metal conduit 10 during the forming step.
  • the forming apparatus may comprise first and second body halves that surround the sidewalls of metal conduit 110 and that are configured to reinforce metal conduit during the forming process.
  • forming apparatus 500 may have first and second body halves 510, 51 , each having a complementary recess 518, 519, respectively, for receiving and holding metal conduit 1 10 therebetween.
  • complementary recesses 518, 519 maybe dimensioned to receive metal conduit 1 10 therebetween and to support metal conduit 1 10 during the forming process.
  • First and second body halves 510, 51 may be configured to reinforce metal conduit during the forming process.
  • complementary recess 518, 519 may be sized and shaped such that the outer surface of metal conduit 1 10 abuts there against.
  • First and second body halves 510, 511 may be selectively securable together and moveable between an open position, as exemplified in Figure 8F in which metal conduit 1 10 may be placed therein, and a closed forming position by any means known in the art.
  • the mechanism for moving one of both of first and second body halves 510, 511 between the open and forming positions has not been shown. A person skilled in the forming arts will be familiar with such mechanisms and any such mechanism may be used.
  • first body half 510 has one or more upper engagement flanges 512a and one or more lower engagement flanges 512b that may cooperate with one or more upper engagement flanges 513a and one or more lower engagement flanges 513b on second body half 511.
  • Engagement flanges 512a, 512b are provided with upper and lower sockets 502a, 502b.
  • Engagement flanges 513a, 513b are provided with upper and lower projecting members 501a, 501 b.
  • projecting members 501 a, 501b are received in sockets 502a, 502b and may be secured together by any means known in the forming arts. It will be appreciated that other securing means, including pneumatic means may be used and a person skilled in the forming arts will be familiar with such mechanisms and any such mechanism may be used.
  • metal conduit 110 is provided as a pre-formed construct (i.e., with the desired profile for the expansion/contraction section 106).
  • Metal conduit 1 10 may be manufactured by any suitable process or processes, such as tube drawing, hydroforming and the like.
  • the upper and lower clamping segments 520, 522 may be closed. Accordingly, as exemplified in Figure 19C, upper and lower clamping segments 520, 522 have been brought together so that complementary recesses 521 , 523 each define a cavity for pinching and sealing upper and lower portions, respectively, of extruded plastic liner 420.
  • the respectively coupled clamping members force the inner surface 424 of extruded plastic liner 420 into contact with itself, creating a sealed interior volume 430 within extruded plastic liner 420.
  • one or more thin elongate members 370 may be provided between inner surface 1 14 of metal conduit 1 10 and outer surface 422 of extruded plastic liner 420 prior to expanding extruded plastic liner 420.
  • Such elongate members may provide a longitudinal airflow path 375 (see e.g.
  • Figure 18B in the annular volume between the outer surface 422 of extruded plastic liner 420 and the inner surface 1 14 of metal conduit 1 10, facilitating the abutment of outer surface 422 of extruded plastic liner 420 and the inner surface 114 of metal conduit 1 10 during expansion of the extruded plastic liner 420 by facilitating the escape of air from between metal conduit 1 10 and extruded plastic liner 420.
  • a pressurized fluid is introduced into the interior volume of extruded plastic liner 420 for expanding extruded plastic liner 420 (the forming process or step).
  • a needle 535 of injection member 530 may be used to pierce extruded plastic liner 420 and to convey fluid into and/or out of the sealed interior volume 430 of extruded plastic liner 420.
  • Injection member 530 may be connected to a pump, compressor, a high pressure fluid line that is available, e.g., high pressure steam or other source of pressurized fluid (not shown) for selectively introducing and/or removing fluid from the sealed interior volume of extruded plastic liner 420.
  • a pump, compressor e.g., a high pressure fluid line that is available, e.g., high pressure steam or other source of pressurized fluid (not shown) for selectively introducing and/or removing fluid from the sealed interior volume of extruded plastic liner 420.
  • a high pressure fluid line that is available, e.g., high pressure steam or other source of pressurized fluid (not shown) for selectively introducing and/or removing fluid from the sealed interior volume of extruded plastic liner 420.
  • any means known in the forming art to pressurize the interior volume of an element being formed may be used.
  • one or both of upper and lower clamping segments 520, 522 may be provided with a member
  • the extruding and forming apparatus 500 e.g., the first and second body halves may be adapted to secure two metal conduits in position in the internal recesses.
  • metal conduit 110 comprises inner elongate metal conduit 1 16 and outer elongate metal conduit 117, and expansion/contraction section 115 of metal conduit 110 comprises an alternating series of radially outer peaks 160a,b,c and radially inner valleys 162a, b,c.
  • the extruded plastic liner is subjected to the forming step.
  • Extruded plastic liner 420 is formed while at an elevated temperature.
  • extruded plastic liner 420 is formed while it is still at an elevated temperature from its extrusion. It will be appreciated that the handling temperature of extruded plastic liner 420 may be less than the forming temperature. Accordingly, if the extruded plastic liner cools to below the forming temperature, then the extruded plastic liner 420 may be heated to the forming temperature, preferably once positioned in a metal conduit 0.
  • Extruded plastic liner 420 may be heated in situ by the forming fluid.
  • the forming fluid may comprise a heated fluid, preferably a heated gas (e.g., air) or heated liquid.
  • one or more heating elements may be provided to maintain extruded plastic liner 420 at a formable temperature following its extrusion from extruder 510.
  • heating elements or a heating jacket may be provided to heat metal conduit 1 10, thereby indirectly heating extruded plastic liner 420 during forming (e.g., the heating elements may be provided in or surrounding the first and second body halves is such are provided).
  • the forming step is conducted by introducing a pressurized fluid into the interior of extruded plastic liner 420. Accordingly, while at a forming temperature, the pressure will cause extruded plastic liner 420 to deform to produce the desired profile. Accordingly, prior to the forming step, a sealed volume is created that includes the interior of extruded plastic liner 420.
  • upper and lower clamping segments 520, 522 have sealed extruded plastic liner 420 to create sealed interior volume 430 within extruded plastic liner 420, into which a fluid is introduced.
  • a needle 535 of injection member 530 may be used to pierce extruded plastic liner 420 and to convey fluid into and/or out of the sealed interior volume 430 of extruded plastic liner 420.
  • extruded plastic liner 420 is below the forming temperature at the time of the forming process, it may be heated in situ by any means discussed herein, preferably by a heated fluid may be introduced into the sealed volume and allowed to heat or assist in heating the extruded plastic liner 420 prior to the fluid being pressurized to a forming pressure.
  • the forming temperature will depend upon the plastic that is used and the pressure that is applied. For example, for CPVC, the forming temperature may be from 1 10°C to 150°C, preferably from 120°C to 140°C and more preferably from 125°C to 135°C. For PVC, lower forming temperatures may be used. Any forming temperature known in the forming arts may be used.
  • the forming fluid may be maintained in the sealed interior volume at a lower temperature for a period of time to partially or fully preheat the plastic liner if needed prior to raising the pressure to a forming pressure. Accordingly, after a sufficient time has elapsed for the plastic liner to be heated, and thereby softened, which may take from 1 to 30, preferably 2 to 10, more preferably 3 to 5 minutes, the pressure of the fluid in the interior volume may be increased, for example by introducing more fluid into the interior volume (e.g. via conduit 330) or pressurizing the fluid already in the interior.
  • the forming pressure may be from 00 to 800 psi, preferably from 250 to 600 psi and more preferably from 350 to 450 psi. Any forming pressure known in the forming arts may be used. Increasing the pressure within the sealed interior volume will increase the force exerted on the inner surface 224 of pre-formed plastic liner 220, causing the walls of pre-formed plastic liner 220 to expand towards inner surface 114 of metal conduit 1 10, as shown in Figures 21 A and 21 B.
  • the forming fluid may be above the boiling point of the forming fluid, e.g., 120 to130°C so as to reduce the heating time for the plastic to reach, e.g., the forming temperature.
  • forming apparatus 500 is operated so as to prevent the working fluid from boiling.
  • the forming fluid may be an elevated pressure, such as 40 to 70 psi, to prevent the forming fluid from boiling.
  • fluid e.g. air
  • one or more vacuum sources may be provided for selectively removing fluid from the annular volume between the outer surface 422 of extruded plastic liner 420 and the inner surface 114 of metal conduit 110.
  • one or more thin elongate members 370 may be provided between inner surface 1 14 of metal conduit 110 and outer surface 422 of extruded plastic liner 420 to provide a longitudinal airflow path 375 (see e.g. Figure 18B) in the annular volume between the outer surface 422 of extruded plastic liner 420 and the inner surface 114 of metal conduit 110, facilitating the abutment of outer surface 422 of extruded plastic liner 420 and the inner surface 114 of metal conduit 110 during expansion of the extruded plastic liner 420.
  • one or more longitudinally extending grooves may be provided on inner surface 1 14 of metal conduit 1 10.
  • Such grooves may provide a longitudinal airflow path in the annular volume between the outer surface 422 of extruded plastic liner 420 and the inner surface 1 14 of metal conduit 1 10, facilitating the abutment of outer surface 422 of extruded plastic liner 420 and the inner surface 114 of metal conduit 110 during expansion of extruded plastic liner 420. It will be appreciated that such a recess may be provided on any of all of the metal conduits illustrated herein.
  • extruded plastic liner 420 may continue to expand until the outer surface 422 of extruded plastic liner 420 abuts the inner surface 114 of metal conduit 1 10, as illustrated in Figures 21 A and 21 B and by the dotted lines (denoted 420') in Figure 19E.
  • extruded plastic liner 420 is formed so as to develop a profile that conforms to the profile of the inner surface of metal conduit 110. As such metal conduit 110 may act as a mold.
  • metal conduit 110 and inner plastic liner 120 may be abutting as exemplified in Figure 3B.
  • the forming may be conducted, by controlling one or more of the time, pressure and temperature such that such that the profile of plastic liner is similar to that of the interior surface of metal conduit 1 10 but does not completely conform thereto.
  • metal conduit 110 and inner plastic liner 120 may be spaced apart.
  • Expansion/contraction section 106 is generally illustrated as a bellows section having a series of convolutions. While the expansion/contraction sections of metal conduit 110 and inner plastic liner 120 are shown with complementary profiles (e.g. each have a similar profile, and these profiles are aligned), it will be appreciated that that this need not be the case.
  • outer surface 122 of inner plastic liner 120 is illustrated as being in contact with (e.g. abutting) inner surface 114 of metal conduit 1 10, it will be appreciated that in some embodiments, an air gap may be present along all or part of the length of expansion compensator 100. This may be achieved by limiting the forming pressure, temperature and/or time.
  • the plastic liner 120 may be cooled. This may occur by one or more of providing a cooling fluid to the interior volume, applying a cooling fluid to a thermal jacket around metal conduit 110, withdrawing the formed part from forming apparatus 500 and allowing it to cool by exposing it to the ambient conditions or placing it in a cooling bath, or any other means known in the forming arts.
  • portions 425 of extruded plastic liner 420 that extend from metal conduit 110 may be trimmed or otherwise removed - for example, using a trimming blade 650 as illustrated in Figure 23 - resulting in a two-layer expansion compensator, as exemplified in Figure 3A.
  • the plastic liner is preferably cooled prior to removing the formed expansion compensator from the forming apparatus.
  • the plastic liner may be cooled to a temperature at which the formed plastic liner will maintain its shape. The temperature will vary depending upon the plastic which is used. For example, for CPVC, the plastic liner may be cooled to from 60 to 130°C, preferably below 80°C and most preferably 60 to 70°C before removing the expansion compensator from the apparatus.
  • the plastic liner may be cooled by flowing a cooling fluid through the interior of the plastic liner or filling the interior with a lower temperature fluid, preferably a liquid.
  • Figure 22A illustrates another extruding and forming apparatus, referred to generally as 600, which may be used when expanding extruded plastic liner 420. It will be appreciated that, in variant embodiments, forming apparatus 600 may comprise more or fewer components. Also, it will be understood by persons skilled in the art that one or more components (e.g. controllers, piping, wiring, etc.) have been omitted for clarity.
  • forming apparatus 600 may comprise more or fewer components.
  • one or more components e.g. controllers, piping, wiring, etc.
  • extruding and forming apparatus 600 has an extruder 610 for extruding plastic liner 420.
  • extruder 610 for extruding plastic liner 420.
  • details of the mechanism for extruding a tubular extruded plastic liner 420 have not been shown. A person skilled in the extruding arts will be familiar with such mechanisms and any such mechanism may be used.
  • Extruding and forming apparatus 600 also has upper and lower clamping segments 620, 622, respectively, for securing a metal conduit 10 and for clamping and sealing an extruded plastic liner 420 therebetween. Accordingly, the clamping segments maybe dimensioned to receive metal conduit 110 therebetween and to support metal conduit 110 during the forming process.
  • Upper and lower clamping segments 620, 622 may be configured to reinforce metal conduit 1 10 during the forming process. For example, upper and lower clamping segments 620, 622 may be sized and shaped to abut the outer surface of the upper and lower ends 11 1 , 113 of metal conduit 1 0 during forming.
  • Each of the upper and lower clamping segments 620, 622 may be selectively securable together and moveable between an open position as exemplified in Figure 22A and a closed forming position as exemplified by Figure 22C by any means known in the art.
  • the mechanism for moving one or both of upper and lower clamping segments 620, 622 between the open and forming positions has not been shown. A person skilled in the forming arts will be familiar with such mechanisms and any such mechanism may be used.
  • extruded plastic liner 420 Prior to the forming step, extruded plastic liner 420 is extruded from extruder 610 into the interior of metal conduit 10 as exemplified in Figure 22B. Once extruded plastic liner 420 has been positioned inside metal conduit 0, the upper and lower clamping segments 620, 622 may be closed. Accordingly, as exemplified in Figure 22C, upper and lower clamping segments 620, 622 have been brought together so that upper and lower clamping segments 620, 622 abut the outer surface of the upper and lower ends 111 , 113 of metal conduit 1 10.
  • upper plug 628 Concurrently, prior to, or after engagement of upper clamping segments 620 with first end 1 1 1 of metal conduit 110, upper plug 628 is positioned within first end 402 of extruded plastic liner 420, so that first end 402 of extruded plastic liner 420 is sealed between upper plug 628 and upper clamping segments 620.
  • lower plug 629 is positioned within second end 404 of extruded plastic liner 420, so that second end 404 of extruded plastic liner 420 is sealed between lower plug 629 and lower clamping segments 622.
  • Injection conduit 635 may be connected to a pump, compressor, a high pressure fluid line that is available, e.g., high pressure steam or other source of pressurized fluid (not shown) for selectively introducing and/or removing fluid from the sealed interior volume of extruded plastic liner 420.
  • Extruded plastic liner 420 is formed while at an elevated temperature. The process may be conducted using the same steps as described with reference to extruding and forming apparatus 500 so as to cause the walls of extruded plastic liner 420 to expand towards inner surface 114 of metal conduit 0, as shown in Figure 22D and develop the profile as illustrated in Figures 22E and 22F.
  • fluid e.g. air
  • fluid may be withdrawn - continuously or intermittently - from the annular volume between the outer surface 422 of extruded plastic liner 420 and the inner surface 1 14 of metal conduit 110.
  • one or more vent ports may be provided for selectively removing fluid from the annular volume between the outer surface 422 of extruded plastic liner 420 and the inner surface 114 of metal conduit 110. Vent port 634 may be connected to a pump or other vacuum source.
  • one or more thin elongate members 370 and/or one or more longitudinally extending grooves may be used to provide a longitudinal airflow path 375 (see e.g. Figure 18B) during the forming step.
  • the plastic liner 120 may be cooled. This may occur by one or more of providing a cooling fluid to the interior volume, applying a cooling fluid to a thermal jacket around metal conduit 110, withdrawing the formed part from forming apparatus 600 and allowing it to cool by exposing it to the ambient conditions or placing it in a cooling bath, or any other means known in the forming arts.
  • portions 425 of extruded plastic liner 420 that extend outwardly from metal conduit 1 0 may be trimmed or otherwise removed - for example, using a trimming blade 650 as illustrated in Figure 23 - resulting in a two-layer expansion compensator, as exemplified in Figure 3A.
  • inner plastic liner 120 may comprise a single layer.
  • the thickness of inner plastic liner 120 may be from 0.005 to 0.125 inches, preferably from 0.020 to 0.1 inches, and more preferably from 0.040 to 0.090 inches.
  • inner plastic liner 120 may comprise two or more layers. In such a case, two or more plastic liners may be extruded into metal conduit 1 10 and the forming process then conducted.
  • Figure 24 illustrates another extruding and forming apparatus, which has multiple extruders 610a, 610b for concurrently or sequentially extruding multiple extruded plastic liners 420a, 420b.
  • Extruded plastic liners 420a, b may each be sequentially extruded and formed as discussed above, (e.g., outer extruded plastic liner 420b may be extruded and expanded first, followed by the extrusion and expansion of outer extruded plastic liner 420b) or they may be extruded and formed concurrently.
  • Figures 25A to 27B illustrate the sequential extrusion of multiple extruded plastic liners 420, 420', and 420" using a single extruder 610.
  • Extruded plastic liners 420, 420', and 420" may be sequentially extruded and formed as discussed above to provide an expansion compensator 100 with multiple plastic layers (e.g. as exemplified in Figure 3H).
  • each plastic layer 126,127 may be from 0.005 to 0.75 inches, preferably from 0.020 to 0.050 inches, and more preferably from 0.03 to 0.045 inches.
  • expansion compensator 100 may comprise one or more connectors 130. This aspect may be used by itself or with any one or more other aspects of an expansion compensator 100 disclosed herein.
  • portions of inner plastic liner 120 that extend from metal conduit 110 may be trimmed or otherwise removed, resulting in a two-layer expansion compensator, as exemplified in Figure 3A.
  • expansion compensator may be formed using a pre-formed blank, e.g. as described above with respect to Figures 8A to 16B, using an extruded inner plastic liner, e.g. as discussed above with respect to Figures 19A to 27B, or using any other suitable method.
  • connectors 130a,b may be provided at one or both ends of expansion compensator 100, and may be configured or adapted for coupling expansion compensator 100 to other components of a piping system.
  • each connector 130 is secured to each of metal conduit 110 and inner plastic liner 120 to thereby secure metal conduit 1 10 and inner plastic liner 120 together.
  • connector 30 may have a first portion or arm 132 secured to the outer surface 112 of elongate metal conduit 110, and a second portion or arm 134 secured to the inner surface 124 of inner plastic layer 120.
  • first portion 132 and second portion 134 are connected via an end portion 36, such that connector 130 defines a generally U-shaped cavity between portions 132, 134, and 136.
  • Connectors 130a,b may be provided by various means.
  • connectors 130 a,b are provided by molding a plastic component over the end of metal conduit 110 and plastic liner 120 so as to secure the ends together and essentially form a unitary body.
  • connectors 130 a,b may be formed by overmolding portions 132, 134, and 136 of connector 130 onto the ends of metal conduit 1 10 and inner plastic liner 120.
  • connecting portions 133 by overmolding is that portions 132, 134 of connector 130, connecting portions 133 and inner liner 120 may be formed essentially as a unitary body (e.g., the plastic that is used to overmold will heat inner liner 120 and may melt a sufficient amount of inner liner 120 to be secured thereto).
  • Metal conduit 110 may therefore be embedded therein and securely fixed in position and thereby be adapted to incur axial stresses applied by thermal cycling.
  • connectors 130 may be formed with projections on the inner surface of first portion 132 sized and located to be received in openings 1 18 and act as connecting portions 133 when connector 130 is mounted (e.g. press-fit or snapped on to) an end 102, 104 of metal conduit 110.
  • the connecting portions 133 may be secured to inner plastic liner 120 by, e.g., an adhesive, welding or the like.
  • inner plastic liner 120 may be secured to portions 134 of connector 130 in a similar manner.
  • the ends of metal conduit 110 may be provided with a plurality of openings 18.
  • openings may assist in securing connectors 130a,b to respective ends of expansion compensator 100. Also, engagement of connector 130 and openings 118 in metal conduit 1 10 may allow a greater portion of an axial force applied to connector 130 to be transferred to metal conduit 110, rather than to inner plastic liner 120.
  • openings 1 8 may allow a portion of first portion 132 of connector 130 to project into metal conduit 110, which may provide a more robust connection between metal conduit 1 10 and connector 130.
  • These connecting portions 133 extending through openings 1 18 may be provided by overmolding portions 132, 34, and 136 of connector 130 onto the ends of metal conduit 1 10 and inner plastic liner 120.
  • the ends of metal conduit 10 and inner plastic liner 120 may be inserted into and secured within a mold body 350 that defines an annular cavity 360 into which a liquefied material for forming connector 130 may be injected (e.g. via one or more injection ports 355).
  • a liquefied material for forming connector 130 may be injected (e.g. via one or more injection ports 355).
  • portions 132, 134, and 136, and connecting portions 133 may be molded substantially concurrently.
  • mold body 350 may comprise more or fewer components.
  • one or more components e.g. controllers, piping, wiring, etc.
  • a person skilled in the molding arts will be familiar with such mechanisms and any such mechanism may be used.
  • connecting portions 133 extend at about 90° to the axial forces that are expected to be exerted on expansion compensator 100 by thermal cycling.
  • the axial forces that are applied to expansion compensator 100 may be transferred to metal conduit 110 via connectors 130a,b, and not via inner plastic liner 120.
  • FIGS. 3A and 3C depict, respectively, two- and three-layer expansion compensator bodies.
  • elongate metal conduit 110 comprises inner elongate metal conduit 116 and outer elongate metal conduit 17, then each metal conduit 116, 1 17 may be provided with openings 118. Accordingly, even if two metal conduits 116, 117 are used, connecting portions 133 may extend from portion 132 through both metal conduits 116, 1 17 to be secured to inner plastic liner 120, which itself may be secured to portion 134 of connector 130, such as by heating to form a unitary body, an adhesive or the like.
  • expansion compensator 100 may be constructed to reduce the axial force applied to the expansion compensator that is borne by the plastic liner 120. This aspect may be used by itself or with any one or more other aspects of an expansion compensator 100 disclosed herein.
  • metal conduit 1 10 and inner plastic liner 120 may be characterized as springs acting in parallel.
  • the overall axial stiffness of expansion compensator 100 e.g. k EC
  • the axial stiffness of metal conduit 110 e.g. k MC
  • the axial stiffness of inner plastic liner 120 e.g. ki PL
  • the axial stiffness of the elongate metal conduit may be greater than the stiffness of the inner plastic liner such that a greater portion (preferably a substantial portion, and most preferably substantially all) of an axial force applied to expansion compensator 100 will be borne (e.g. absorbed) by metal conduit 1 10, while inner plastic liner 120 will bear a smaller portion (preferably a significantly smaller portion) of the applied axial force.
  • F EC axial force applied to expansion compensator 100
  • F /PL the magnitude of the force exerted by each of metal conduit 0 (F MC ) and inner plastic liner 120 (F /PL )will be proportional to their respective stiffness:
  • metal conduit 1 10 will provide about 80% of the total force exerted by expansion compensator 100 in response to an applied axial force.
  • inner plastic liner 120 may provide a barrier between the metal conduit and a fluid flowing through expansion compensator 100.
  • inner plastic liner 120 may protect metal conduit 1 10 from corrosive or otherwise reactive fluids, extending the lifespan of metal conduit 1 10 and/or preventing portions of metal conduit 1 10 from leaching into fluids flowing through expansion compensator 100.
  • the expansion compensator has an inner plastic liner made from the same (or similar) thermoplastic material of the pipes to which it is to be installed, so that a fluid flowing through a pipe and expansion compensator will be in contact with the same (or similar) material through both components.
  • the stiffness of expansion compensator 100 may vary based on the number of metal layers in metal conduit 1 10, the particular metal or metals used, the thickness of each metal layer, and/or the geometry of metal conduit 1 10.
  • the stiffness of expansion compensator 100 may also depend on the number of layers in inner plastic liner 120, the particular plastic or plastics used, the thickness of each plastic layer, and/or the geometry of inner plastic liner 120. It will be appreciated that the stiffness of expansion compensator 100 may vary regardless of whether it was formed using a preformed blank, e.g. as described above with respect to Figures 8A to 16B, using an extruded inner plastic liner, e.g. as discussed above with respect to Figures 19A to 27B, or using any other suitable method.
  • inner plastic liner 120 comprises more than one plastic layer
  • the overall axial stiffness of inner plastic liner 20 may be approximated as the sum of the axial stiffness for each plastic layer.
  • each plastic layer may have the same stiffness or they may be different.
  • outer elongate metal conduit 1 17, inner elongate metal conduit 116, protective layer 170, inner plastic layer 126 and outer plastic layer 127 may each be abutting as exemplified in Figure 3H or one or more may be spaced apart.
  • a lubricant may optionally be provided between metal conduit 1 10 and inner plastic liner 120.
  • This aspect may be used by itself or with any one or more other aspects of an expansion compensator 00 disclosed herein.
  • the lubricant may be any lubricant that is compatible with the inner plastic liner and metal conduit and may be talcum powder, powdered Teflon, powdered mica and the like.
  • the lubricant may be provided on the outer surface of pre-formed plastic liner 220 or extruded plastic liner 420 and/or the inner surface of metal conduit 1 10 prior to the insertion of pre-formed plastic liner 220 or extruded plastic liner 420 in metal conduit 110 and/or concurrently therewith and/or subsequent to the insertion step.
  • inner elongate metal conduit 1 16, outer elongate metal conduit 1 17 and inner plastic liner 120 may be abutting as exemplified in Figure 3D or they may be spaced apart.
  • a lubricant may be provided between inner elongate metal conduit 1 16 and inner plastic liner 120.
  • expansion compensator 100 may optionally comprise additional layers. This aspect may be used by itself or with any one or more other aspects of an expansion compensator 00 disclosed herein.
  • These layers may be applied prior to the insertion of pre-formed plastic liner 220 or extruded plastic liner 420 in metal conduit 1 0 and/or concurrently therewith and/or subsequent to the insertion step.
  • a protective layer 170 is disposed between metal conduit 110 (which itself comprises elongate metal conduits 1 6, 1 7) and inner plastic liner 120.
  • Protective layer 170 may serve to reduce the friction between metal conduit 10 and inner plastic liner 120 during expansion and/or contraction of expansion compensator 100.
  • protective layer 170 may provide an additional 'failsafe' layer to prevent leakage of fluid from within expansion compensator 100 (e.g. should one or more cracks develop in inner plastic liner 120 and/or metal conduit 1 10).
  • Protective layer 170 is located between metal conduit 1 10 and inner plastic liner 120 and may abut a surface or may be spaced from the facing surfaces. It will be appreciated that inner elongate metal conduit 116, protective layer 170 and inner plastic liner 120 may be abutting as exemplified in Figures 3E and 3F or they may be spaced apart.
  • Protective layer 170 may be provided: as a coating on outer surface 122 of inner plastic liner 120; as a coating on inner surface 114 of elongate metal conduit 1 10; and/or as a separate layer positioned between metal conduit 1 10 and pre-formed plastic liner 220 or extruded plastic liner 420 prior to expansion.
  • inner plastic liner 120 may comprise a co-extruded body having protective layer 170 formed as an outer co-extruded layer to inner plastic liner 120.
  • outer extruded plastic liner 420b may be a protective layer
  • inner extruded plastic liner 420a may be an inner plastic liner 120.
  • Extruded plastic liners 420a, b may be sequentially extruded and formed as discussed above, or outer extruded plastic liner 420b may be extruded and expanded first, followed by the extrusion and expansion of outer extruded plastic liner 420b.
  • protective layer 170 is made from polytetrafluoroethylene (PTFE) or one or more other suitable fluropolymers, although it will be appreciated that other materials may be used.
  • PTFE polytetrafluoroethylene
  • Figure 3G illustrates an embodiment where protective layer 170 is disposed between metal conduit 1 10 (which itself comprises elongate metal conduits 116, 1 17) and a two-layer inner plastic liner 120 (comprising inner plastic layer 126 and outer plastic layer 127).
  • the ends of metal conduit 1 10 may be provided with one or more surface features (e.g. radial ridges or grooves) to facilitate the installation of a gasket between metal conduit 110 and outer portion 132 of connector 130.
  • This aspect may be used by itself or with any one or more other aspects of an expansion compensator 100 disclosed herein.
  • a radial groove 1 19 may be provided on outer surface 12 of an end of metal conduit 1 10, radial groove 1 19 being configured to receive a gasket such as an O-ring 150.
  • Such a gasket may be provided to minimize the chance of fluid leaking from expansion compensator 100 via, e.g., a gap between inner surface 124 of inner plastic liner 120 and second portion 134 of connector 130, between the ends of metal conduit 110 and inner plastic liner 120 and end portion 136 of connector 130, and between outer surface 112 of metal conduit 1 10 and first portion 132 of connector 130.
  • Radial groove 1 19 may assist in locating and retaining O-ring 150 relative to the end of expansion compensator 100 as connector 130 is mounted and/or molded to an end 102, 104 of metal conduit 110. It will be appreciated that a gasket may be provided in the absence of a groove 119.
  • one or more gaskets may be installed on the ends of metal conduit 110 (e.g. in one or more grooves 1 19) prior to overmolding the connectors.
  • the outer surface 1 12 of metal conduit 110 (and/or the inner surface of inner plastic liner 120) at the ends of expansion compensator 100 may be subject to a surface treatment prior to overmolding, to improve the connection between metal conduit 110 and/or inner plastic liner 120 and connectors 130.
  • expansion compensator 100 may be provided with a sleeve 140. This aspect may be used by itself or with any one or more other aspects of an expansion compensator 100 disclosed herein.
  • Sleeve 140 may overlie some and preferably all or essentially all of expansion/contraction section 106 to protect against damage, restrain deflection of expansion/contraction section 106 in a radial or lateral direction, and/or provide a distinctive aesthetic appearance to expansion compensator 100.
  • expansion/contraction section 106 of expansion compensator 100 may have a corrugated exterior surface. This surface might get caught (which could cause damage to the expansion compensator) as a pipe with the expansion compensator is slid into position.
  • Providing a sleeve 140 over some or all of expansion/contraction section 106 may assist the expansion compensator being placed is position.
  • expansion/contraction section 106 of expansion compensator 100 may tends to deflect laterally instead of compress.
  • Sleeve 140 may overlie some or all of expansion compensator 100 so as to inhibit and, preferably, prevent, lateral deflection under axial loading.
  • the inner diameter of sleeve 140 is preferably proximate that of the outer diameter of expansion/contraction section 106.
  • Sleeve 140 may have one or more tabs 144 or other engagement means to retain it in a preset axial position about expansion compensator 100.
  • the engagement means permit sleeve 140 to be retained in position while still allowing expansion compensator 100 to expand and contract.
  • tabs 144 may be positioned axially outwardly from the axially opposed ends of expansion/contraction section 106 so as to permit expansion/contraction section 106 to expand and contract its entire design distance without restriction. Accordingly, tabs 144 may be spaced sufficiently from the last ridge of expansion/contraction section 106 (i.e. the ridge closes to the connector) such that, when fully expanded the ridge may at most abut tab 144.
  • sleeve 140 may have one or more viewing ports 142 to allow for visual inspection of the outer surface 112 of metal conduit 1 10 in the expansion/contraction section 106.
  • Figure 4B illustrates an example sleeve 140 without viewing ports 142.
  • a sleeve guard 146 that may optionally be disposed between the outer surface 1 12 of metal conduit 1 10 and the inner surface of sleeve 140 such as to reduce friction and/or provide abrasion resistance between these components and/or to reinforce sleeve 140 and/or to provide a sliding fit on expansion/contraction section 106.
  • This aspect may be used by itself or with any one or more other aspects of an expansion compensator 100 disclosed herein.
  • Sleeve 140 (and optionally one or more sleeve guards 146) may be provided after pre-formed plastic liner 220 has been expanded to form inner plastic liner 120, and/or after providing one or more connectors 130.
  • inner plastic liner 120 may have a variable wall thickness. This aspect may be used by itself or with any one or more other aspects of an expansion compensator 100 disclosed herein.
  • inner plastic liner 120 may not have a uniform radial thickness.
  • expansion/contraction section 106 comprises an alternating series of radially outer peaks 160a,b,c and radially inner valleys 162a,b,c
  • the radial thickness T p of inner plastic liner 120 at the radially outer peaks 160a, b,c may be less than the radial thickness T of inner plastic liner 120 at the radially inner valleys 162a,b,c.
  • Such variations in thickness may arise, for example, where a plastic cylinder of substantially uniform thickness is positioned within metal conduit 1 10, heated, and then expanded outwards against inner surface 1 14 of metal conduit 10.
  • inner plastic liner 120 may be expected to experience more erosion or wear at radially inner valleys 162a,b,c as compared with portions of inner plastic liner 120 at radially outer peaks 160a,b,c, as radially inner valleys 162a,b,c may be exposed to higher velocity flows of fluid through expansion compensator 100. Accordingly, providing increased thickness at portions of inner plastic liner 120 that are expected to experience higher erosion or wear may extend the operating lifespan of expansion compensator 00.
  • the ratio of the radial thickness T v to the radial thickness T P may be up to about 2:1 , or up to about 3:1 , or up to about 4:1.
  • the radial thickness T p of inner plastic liner 120 at the radially outer peaks 160a,b,c may be about 0.040 inches
  • the radial thickness T v of inner plastic liner 120 at the radially inner valleys 162a,b,c may be about 0.080 inches (i.e. the ratio of T v to T P is about 2:1 ).
  • the radial thickness T p of inner plastic liner 120 in radially outer peaks 160a,b,c may be substantially equal to the radial thickness T v of inner plastic liner 120 in radially inner valleys 162a,b,c.
  • Such a uniform thickness for inner plastic liner 120 may be achieved, for example, by expanding a plastic cylinder of non-uniform thickness outwardly against inner surface 114 of metal conduit 110 or using the inner surface of metal conduit as an interior mold surface.
  • Providing a generally uniform thickness for inner plastic liner 120 may assist in predicting and/or controlling the axial stiffness of inner plastic liner 120, and thus the overall axial stiffness of expansion compensator 100.
  • the radial thickness T p of inner plastic liner 120 at the radially outer peaks 160a,b,c may be about 0.060 inches
  • the radial thickness T v of inner plastic liner 120 at the radially inner valleys 162a,b,c may be about 0.060 inches (i.e. the ratio of Tv to Tp is about 1 :1 ).
  • pre-formed plastic liner 220 has an expansion/contraction region 215 that comprises one or more annular ribs 230.
  • the radial thickness T p of inner plastic liner 120 in radially outer peaks 160a,b,c may be substantially equal to the radial thickness T v of inner plastic liner 120 in radially inner valleys 162a,b,c. Accordingly, by selecting the thickness of ribs 230 a formed plastic liner 120 having a more or less uniform wall thickness may be obtained.
  • Figures 14A and 14B exemplify another example of a pre-formed plastic liner 220 also has an expansion/contraction region 215 with non-uniform wall thickness, however instead of forming pre-formed plastic liner 220 with a series of ribs 230 (as in Figure 13A), the expansion/contraction region 215 illustrated in Figure 14A comprises one or more annular grooves 240 cut into a pre-formed plastic liner 220 that was initially formed with a uniform wall thickness.
  • FIGS 15A and 15B another example pre-formed plastic liner 220 has an expansion/contraction region 215 that comprises one or more annular ribs 230, and also has a longitudinally extending recess 250 on the outer surface 222.
  • a recess may provide a longitudinal airflow path in the annular volume between the outer surface 222 of pre-formed plastic liner 220 and the inner surface 114 of metal conduit 1 10, facilitating the abutment of outer surface 222 of pre-formed plastic liner 220 and the inner surface 1 14 of metal conduit 110 during expansion of the pre-formed plastic liner 220. It will be appreciated that such a recess may be provided on any of all of the pre-formed plastic liners illustrated herein.
  • Figures 16A and 16B illustrate another example pre-formed plastic liner 220, having a uniform cylindrical profile and wall thickness. In this example, flared or enlarged outer ends are not provided. It will be appreciated that preformed plastic liners with other profiles may be used, depending on the interior profile of metal conduit 1 10 and/or the desired interior profile of inner plastic liner 120.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Rigid Pipes And Flexible Pipes (AREA)

Abstract

L'invention porte sur un compensateur de dilatation qui possède un conduit métallique allongé et un chemisage en matière plastique interne, chacun ayant des première et seconde extrémités espacées les unes des autres et une section de dilatation/contraction, et un volume intérieur s'étendant de la première extrémité à la seconde extrémité. Des raccords peuvent être disposés aux première et seconde extrémités. Le conduit métallique peut avoir une rigidité longitudinale supérieure à la rigidité du chemisage en matière plastique. L'invention porte également sur des procédés de fabrication d'un compensateur de dilatation qui comprennent : l'utilisation d'un chemisage en matière plastique interne; le positionnement du chemisage en matière plastique interne à l'intérieur d'un conduit métallique allongé, le conduit métallique allongé ayant une section de dilatation/contraction; l'application d'une pression à un fluide positionné dans un volume intérieur du chemisage en matière plastique interne pendant que le chemisage en matière plastique interne se trouve à une température de formation, ou au-dessus de celle-ci, de façon à dilater le chemisage en matière plastique interne, ce par quoi le chemisage en matière plastique interne dilaté possède une section de dilatation/contraction; le refroidissement du chemisage en matière plastique interne en dessous de la température de formation.
PCT/CA2015/000161 2014-03-17 2015-03-13 Compensateur de dilatation et procédés de fabrication d'un compensateur de dilatation WO2015139114A1 (fr)

Applications Claiming Priority (8)

Application Number Priority Date Filing Date Title
CA2846801A CA2846801C (fr) 2014-03-17 2014-03-17 Compensateur de dilatation dote de connecteurs
CA2846801 2014-03-17
CA2846921A CA2846921C (fr) 2014-03-18 2014-03-18 Compensateur de dilatation dote de multiples couches ayant une rigidite differente
CA2846921 2014-03-18
CA2847536A CA2847536C (fr) 2014-03-25 2014-03-25 Methodes de fabrication de compensateur d'expansion
CA2847520 2014-03-25
CA2847536 2014-03-25
CA2847520A CA2847520C (fr) 2014-03-25 2014-03-25 Methodes de fabrication de compensateur d'expansion

Publications (1)

Publication Number Publication Date
WO2015139114A1 true WO2015139114A1 (fr) 2015-09-24

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105864554A (zh) * 2016-05-18 2016-08-17 洛阳双瑞特种装备有限公司 一种自带二级充压的管路用膨胀节
CN106641548A (zh) * 2016-11-21 2017-05-10 上海宇航系统工程研究所 一种低温连接器
WO2018091496A1 (fr) * 2016-11-18 2018-05-24 Hilti Aktiengesellschaft Dispositif d'étanchéité à l'air, d'isolation phonique et/ou ignifuge
CN112128498A (zh) * 2020-09-02 2020-12-25 航天科工火箭技术有限公司 一种火箭侧壁管路的补偿装置及方法

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4864711A (en) * 1987-05-29 1989-09-12 Mitsubishi Plastics Industries Limited Method of producing lined Hume pipe
EP1010930A1 (fr) * 1998-12-16 2000-06-21 M.R. Industries Flexible composite pour le transport de fluide et son procédé de fabrication
US6455118B1 (en) * 1997-12-10 2002-09-24 Institut Francais Du Petrole Flexible pipeline having a dual-layer sheath of polymer
US7143788B2 (en) * 2004-09-20 2006-12-05 Thermacor Process, Lp High temperature line expansion installation with bellows
US20090139661A1 (en) * 2007-11-30 2009-06-04 Lubrizol Advanced Materials, Inc. PVC/CPVC Composite Pipe With Metal Interlayer And Process For Making It
US20100244432A1 (en) * 2008-01-04 2010-09-30 Smiths Group Plc Tubes and their manufacture
US20110259040A1 (en) * 2008-11-17 2011-10-27 Industrie Ilpea S.P.A. Refrigeration circuit
CN202171086U (zh) * 2011-08-15 2012-03-21 秦皇岛北方管业有限公司 一种用于强腐蚀介质的工艺管道补偿器
US20120216903A1 (en) * 2011-02-28 2012-08-30 Flo-Link, LLC Multi-layer tubing and method for joining

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4864711A (en) * 1987-05-29 1989-09-12 Mitsubishi Plastics Industries Limited Method of producing lined Hume pipe
US6455118B1 (en) * 1997-12-10 2002-09-24 Institut Francais Du Petrole Flexible pipeline having a dual-layer sheath of polymer
EP1010930A1 (fr) * 1998-12-16 2000-06-21 M.R. Industries Flexible composite pour le transport de fluide et son procédé de fabrication
US7143788B2 (en) * 2004-09-20 2006-12-05 Thermacor Process, Lp High temperature line expansion installation with bellows
US20090139661A1 (en) * 2007-11-30 2009-06-04 Lubrizol Advanced Materials, Inc. PVC/CPVC Composite Pipe With Metal Interlayer And Process For Making It
US20100244432A1 (en) * 2008-01-04 2010-09-30 Smiths Group Plc Tubes and their manufacture
US20110259040A1 (en) * 2008-11-17 2011-10-27 Industrie Ilpea S.P.A. Refrigeration circuit
US20120216903A1 (en) * 2011-02-28 2012-08-30 Flo-Link, LLC Multi-layer tubing and method for joining
CN202171086U (zh) * 2011-08-15 2012-03-21 秦皇岛北方管业有限公司 一种用于强腐蚀介质的工艺管道补偿器

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105864554A (zh) * 2016-05-18 2016-08-17 洛阳双瑞特种装备有限公司 一种自带二级充压的管路用膨胀节
WO2018091496A1 (fr) * 2016-11-18 2018-05-24 Hilti Aktiengesellschaft Dispositif d'étanchéité à l'air, d'isolation phonique et/ou ignifuge
US10145494B2 (en) 2016-11-18 2018-12-04 Hilti Aktiengesellschaft Air, acoustic and/or fire sealing device
CN106641548A (zh) * 2016-11-21 2017-05-10 上海宇航系统工程研究所 一种低温连接器
CN112128498A (zh) * 2020-09-02 2020-12-25 航天科工火箭技术有限公司 一种火箭侧壁管路的补偿装置及方法

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