Abstract: Flexible hose a corrugated wall of which an outer surface comprises a multitude of consecutive protrusions (1) and grooves (2) and of which an inner surface comprises a multitude of internal protrusions (4) and grooves (3), a multitude of barriers for closing off each of the multitude of internal and/or external grooves (2), each of the multitude of barriers comprising a first closing leg (10, 12) of a first profile part and a second closing leg (11, 13) of a second profile part, the second closing leg being directed to the first closing leg, the first and second closing legs having a complementary shape provided to form a substantially smooth inner and/or outer surface.

Abstract: The invention relates to a thermal insulating element. The element comprises a base material comprising one first series of hole configurations, said first series comprising a plurality of elongated interior holes. Each comprises a central hole axis (A) along its elongation, each central hole axis extending substantially mutually in parallel to each other along a first longitudinal direction. Each hole in a plane perpendicular to the first general longitudinal direction comprises a cross sectional hole shape. The elastic modulus E of said base material along said first longitudinal direction is equal to or larger than 1.5 GPa. The thermal insulating element is suitable for varying and high pressure environments. Further, the invention relates to armored unbonded flexible pipes comprising such a thermal insulating element. Further, the invention relates to a method of manufacturing such an element and a method of manufacturing such an armored unbonded flexible pipe.

Abstract: A hose assembly resistant to internal high frequency high pressure fluid impulses including a tubular liner having an inner surface, an outer surface, and a wall therebetween defining a passageway, and at least one extrusion preventing layer operatively connected to said outer surface of said tubular liner. A method for making a hose assembly by extruding a flexible tubular liner, disposing an extrusion preventing layer by disposing an inner wrap of flattened fabric yarn with no interstices between adjacent windings onto an outer surface of the flexible tubular liner, and disposing an outer wrap helically counterwound about the inner wrap, securing the inner and outer wraps of the extrusion preventing layer to each other and to the tubular liner by applying a bond coating, and heating the assembly to dry, fuse, and cure the bond coating. A method of using the hose assembly.

Abstract: A hose having a low permeation rate, in particular a hose for a high temperature coolant, having at least the following layer configuration: a barrier layer in the form of monofilm or multilayer film made of a polymer material; an inner layer that is placed on top of the barrier layer and is made of a polymer material having elastic properties; a reinforcement supported by the inner layer made of threadlike material, and an outer layer made of a polymer material having elastic properties, which protects against external influences. The reinforcement features a spiraled shape, specifically by forming at least two spiraled layers, wherein the area between two spiraled layers is free of an intermediate layer of a polymer material. In addition, the area between two spiraled layers is in particular free of a bonding agent. Further a method for producing such a hose is disclosed.

Abstract: A hose comprising a tubular body of flexible material arranged between an inner and outer helically wound wire. The hose further comprises an elongate member having opposing longitudinal edges, the elongate member being helically wound around the tubular body such that the opposing longitudinal edges of the layer are in an adjacent or overlapping arrangement, wherein each longitudinal edge includes a formation capable of interengaging with a cooperating formation on the opposing longitudinal edge, wherein the elongate member is provided at least one reinforcing member which extends along the longitudinal axis of the elongate member.

Abstract: The present invention relates to a method for manufacturing a flexible piping device for an exhaust gas system of a motor vehicle, said method comprising the steps: a) forming a wound metal hose from at least one profiled metal strip, so that strip edges of adjacent strip windings movably interlock; b) exposing said wound metal hose to heat; and c) assembling the flexible piping device from said wound metal hose and from other components. In order to further reduce or eliminate an ageing function of the flexible piping device to allow the user of the flexible piping device to receive functionality and properties over lifetime at similar condition, the present invention provides that step b) includes subjecting the wound metal hose to quenching.

Abstract: The invention relates to an unbonded flexible pipe for offshore applications comprising an internal sealing sheath and at least one armoring layer comprising at least one helically wound fibre containing elongate armoring element, wherein the fibre containing elongate armoring element comprises polymer material, and at least about 5% by weight of polypropylene fibers.

Abstract: A spoolable pipe is disclosed, the spoolable pipe having an internal pressure barrier formed about a longitudinal axis, a reinforcing layer(s) enclosing the internal pressure barrier, and a weight layer comprising fibers. The pipe can also include an energy conductor(s) integrated with and/or located between the internal pressure barrier and/or the reinforcing layer(s).

Abstract: A spoolable pipe is disclosed, the spoolable pipe having an internal pressure barrier formed about a longitudinal axis, and a reinforcing layer(s) enclosing the internal pressure barrier. In one embodiment, the reinforcing layer(s) can include fibers having at least a partial helical orientation about approximately thirty and about approximately seventy degrees relative to the longitudinal axis, and, the wall can include at least one external layer enclosing the reinforcing layer(s) and having a permeability at least ten times greater than the permeability of the internal pressure barrier. The reinforcing layer(s) can further include a coating. The pipe can also include an energy conductor(s) integrated with and/or located between the internal pressure barrier and/or the reinforcing layer(s).

Abstract: A spoolable composite tube capable of being spooled onto a reel for storage and for use in oil field applications. The spoolable tube exhibits unique anistropic characteristics that provide improved burst and collapse pressures, increased tensile strength, compression strength, and load carrying capacity, while still remaining sufficiently bendable to be spooled onto a reel in an open bore configuration. The spoolable composite tube can include an inner liner, an interface layer, fiber composite layers, a pressure barrier layer, and an outer protective layer. The fiber composite layers can have a unique triaxial braid structure.

Abstract: A method for manufacturing a flexible tubular underwater pipe (10): A leakproof tubular structure (12, 14, 16) is covered with at least one layer (18, 20) of armor wires. At least one continuous longitudinal element made of a deformable material is wound in a helix with short pitch around the layer (18, 20) of armor wires to form a holding layer 24. The at least one longitudinal element is wound under longitudinal tension T0 so as to stretch its deformable material according to a relative elongation corresponding to a tensile stress ?0 less than the elastic limit value ?E of the deformable material, and the elastic limit value ?E corresponds to a tensile stress beyond which the deformation of the material is irreversible.

Abstract: Flexible plastic hose comprising a flexible wall made out of a plurality of laterally connected windings of a helically wound profile, wherein the windings of the profile are attached to each other by means of a weld, wherein the profile comprises a web part with predetermined properties for providing flexibility to the hose, and wherein the profile ends on both sides in an upright part. The weld is located between the upright part of the adjacent windings and together with these upright parts forms a helical reinforcement rib on the flexible wall of the hose with predetermined properties for providing hub strength to the hose.

Abstract: Embodiments disclosed herein relate to one or more embodiments of and methods to make a reinforced flexible pipe. The reinforced flexible pipe includes a pipe structure, a first composite tape member having a T-shaped cross section, and a second composite tape member having a T-shaped cross section, in which the first composite tape member is wrapped on the pipe structure in a first orientation and the second composite tape member is wrapped on the pipe structure in a second orientation. One or more embodiments relate to a method of forming the same.

Abstract: In a flexible tube for fluid transport, a resin layer is on the outer periphery of an interlocked tube for shielding the fluid flowing within the interlocked tube. An internal-pressure-resistant reinforcing layer is on the outer periphery of the resin layer for reinforcing primarily against internal pressure, etc. of the fluid flowing within the interlocked tube. An axial-force reinforcing layer is on the outer periphery of the internal-pressure-resistant reinforcing layer for primarily suppressing the interlocked tube from deforming in the axial direction of the flexible tube. The axial-force reinforcing layer is formed from alternately winding two layers of reinforcing strips with a long pitch. The reinforcing strips are each configured from a metal strip, a resin layer that covers the strip, and the like. The resin layer is resin to which a microparticulate sulfide-trapping material has been added.

Abstract: A method for repairing and strengthening pipes by creating a structural reinforced composite liner within the existing pipe. The liner is created by helically winding a tensile reinforcement material on the inside wall of a pipe and encapsulating it in a hardening matrix material. The reinforcement material is helically wound around the inside wall of the pipe by an installation device. The installation device is configured to relieve and/or prevent the development of torsional stress in the reinforcement material that is created by the act of helically winding it onto the inside wall of a pipe, allowing the reinforcement material to lay flat against the pipe wall without twisting or buckling. The structural reinforced composite can be configured to supplement the strength of the existing pipe or to function as a stand-alone pipe within the existing pipe.

Abstract: An expandable hose is provided which will expand to an extended length from a collapsed length and back again. The hose has a sidewall formed of a spirally wound flexible member which defines an axial passageway surrounding a center axis of said hose. Both side edges of the flexible member in the spirally wound position are engaged to a cap member which provides a skeletal structure to maintain the axial passageway open and to bias the hose back to a collapsed length from the extended length. A fold formed in the spirally wound flexible member allows for increased distance between the two side edges and an increased maximum extended length.

Abstract: A method is presented for making a composite material from strips comprising longitudinal fibers and a binder or resin, which material comprises a number of layer assemblies one on top of the other. Each layer assembly comprises m sets (with m at least 2) of parallel strips each extending in a different direction, Each layer assembly is manufactured by successive steps of depositing groups of parallel strips according to a well defined pattern (without longitudinally interweaving strips with previously deposited strips). Before completing a layer assembly, with the exception of the last layer assembly, by depositing its last group of parallel strips, the first group of parallel strips of the following layer assembly is already deposited. A composite material manufactured with such a method is presented too.

Abstract: A fabric tube with two passages comprises a fabric tube sheet. A first fabric weld strip with right and left flanges extending laterally from a bottom edge of a weld fin is welded to a first surface extending the length of the fabric tube sheet at a distance D1 from the first edge thereof. A second fabric weld strip is welded to an opposite second surface and extends the length of the fabric tube sheet between the first fabric weld strip and the second edge of the fabric tube sheet at a distance D2 from the second edge of the fabric tube sheet. The first edge of the fabric tube sheet is welded to the weld fin of the second fabric weld strip and the second edge of the fabric tube sheet is welded to the weld fin of the first fabric weld strip to form two passages.

Abstract: Devices, apparatus, systems and methods for forming rolled up spiral shaped tubular inserts of interlocking seams of elongated strip material and for inserting the inserts into damaged channels such as damaged culverts, sewer lines, pipes, and the like. The inserts are released to expand outward and unravel until the walls of the unraveling insert abut against interior walls of the damaged channel forming a protective interior wall for the damaged channel. One side of the insert strips can have a hook, and an opposite side of the strips can have a longitudinal groove wherein the hook attaches to and slides within the groove. Slidable surfaces such as bushings, Teflon coatings and O-rings can be used along the interlocking seams to allow for reduced friction as the strip materials are rolled into contracted positions and later expanded out.

Abstract: The helix heated hoses 10 and 12 use two features to increase the flexibility. The first feature is a braided-copper heating element 14, which has increased flexibility over the prior art solid copper heating element. The element is spiral wound around the hose and held in place with a moisture barrier 16. The second feature is the helix twist 18 located just before the point where the hoses 10 and 12 attach to the manifold 20. The helix feature is created with the helix support 22, which initiates the twist around 24 inches back from the point of termination. The helix feature works to reduce the moment of inertia about the neutral axis 26 of the two supply hoses 10 and 12.

Abstract: A flexible, stretchable, crush resistant hose particularly well suited for supplying breathing gases to patients in medical applications and the like has a helix defined by coils of thermoplastic material, and a web of thermoplastic material bonded or welded to adjacent ones of the coils, preferably along inner diameter portions of the surfaces of the coils. The web extends radially outwardly from between the adjacent coils to define a helical reverse-direction crease at a maximum outer diameter of the hose when the hose is in a normal minimal-length condition wherein the coils are situated side-by-side sandwiching portions of the web therebetween. The thermoplastic material of hose is stress relieved by an annealing process after the hose is formed, to enhance the flexibility of the hose and the ease with which the hose can be extended.

Abstract: A flexible pipe includes: an inner liner formed as a tube and having an outer surface and an inner surface defining an inner diameter; a reinforcement layer bonded to the inner liner and including at least a first ply of reinforcing tape helically wrapped in a first helical direction about the inner liner and a second ply of reinforcing tape helically wrapped about the first ply of reinforcing tape, the second ply of reinforcing tape helically wrapped in a second helical direction opposite to the first helical direction; and an outer jacket applied over and bonded to the reinforcement layer, the outer jacket including a thermoplastic.

Abstract: A hose comprising an inner tubular structure, an outer tube and an insulation layer, wherein the inner tubular structure comprises a tubular body disposed between inner and outer gripping members, the tubular body including a sealing layer, and being formed of a material capable of withstanding cryogenic temperatures, wherein the outer tube comprises a rubber layer and a reinforcing layer disposed around the rubber layer, wherein the insulation layer is either incorporated in the inner tubular structure and/or is disposed between the inner tubular structure and the outer tube.

Abstract: Helically reinforced, flexible tubing or hose is formed from continuously extruded thermoplastic material helically circumferentially wound at a wrapping station around an array of bearing-supported rods that are concurrently but individually turned and are canted relative to an imaginary center axis. The tubing or hose being formed has a continuous reinforcing rib helically wound therearound and continuously integrally connected thereto. The positions of the rods are progressively altered during formation of at least a contiguous portion of the length of tubing or hose, causing the resulting tubing or hose portion to exhibit a progressive continuous change in diametrical size. The resulting tubing or hose may be transversely severed at intervals along its length, and may be flattened to form cuffs near where severed.

Abstract: A seamless convoluted hose assembly. The assembly includes: a tubular inner liner having an outer surface, an inner surface, and an inner liner wall therebetween which defines a passageway. The assembly further includes a helical coil or a plurality of annular loops which produce convolutions in the outer surface of the tubular liner when the tubular inner liner is forced through the helical coil or plurality of loops under heat and pressure.

Abstract: A flexible stretch hose with a wall which comprises a spirally wound profile (1; 11; 21) in a plastic material. Consecutive windings of the profile are secured to each other by means of a weld. The profile comprises, in cross-section, at least one bottom section (2; 12) and at least one rib section (4; 14; 24), wherein the rib section of the profile, relative to the bottom section, also forms a protrusion of the wall of the hose which gives the hose a predetermined hub strength. The profile comprises an unfoldable section (5; 15; 25) provided in order to be unfolded under the influence of a tensile; force in the axial direction of the hose, thereby allowing an extension of the hose, wherein the unfoldable section comprises at least two profile sections lying loosely against each other, which sections are interconnected at one end.

Abstract: A flexible muffler for use in an aircraft environmental system includes a flexible body having a porous inner layer and an air impervious outer layer both supported by a helically wound adhesively attached reinforcing cord. The flexible body includes a pair of connecting end caps at opposed ends thereof which are joined to the flexible body in an air tight attachment. The resulting muffler provides acoustic energy absorptive and is readily flexed and bent to accommodate space restrictions within the environmental control system of the aircraft.

Abstract: A subsea flexible pipe, including an internal sealing sheath (18), at least one tensile pressure armor layer (14, 16) wound around the internal sealing sheath, a retaining layer (12) having at least one reinforcing strip (34), the reinforcing strip having filamentary strands (36) directed substantially longitudinally. The filamentary strands (36) having polymer fibers (38). The polymer fibers have, at room temperature, an elastic modulus in excess of 55 GPa so that the reinforcing strip is able to prevent radial expansion of the armor layer, when the armor layer experiences radial force; and the polymer fibers furthermore have an elongation at break in excess of 4% such that the reinforcing strip is able to undergo deformation without breaking.

Abstract: A composite pipe including an internal liner and at least one external layer made of a fiber reinforced consolidated thermoplastic material. A heat-resistant material mechanically separates the liner from the at least one external thermoplastic layer. The heat-resistant material forms a non-bonding barrier that is non-bonded to at least one of liner and the adjacent at least one thermoplastic layer. A method and an assembly for producing the composite pipe.

Abstract: An expandable hose is provided which will expand to an extended length from a collapsed length and back again. The hose has a sidewall formed of a spirally wound flexible member which defines an axial passageway surrounding a center axis of said hose. Both side edges of the flexible member in the spirally wound position are engaged to a cap member which provides a skeletal structure to maintain the axial passageway open and to bias the hose back to a collapsed length from the extended length. A fold formed in the spirally wound flexible member allows for increased distance between the two side edges and an increased maximum extended length.

Abstract: A fastenable air delivery conduit includes a body portion having a supply end and a delivery end and a fastener that substantially extends from the supply end to the delivery end. The fastener, when engaged, forms the body portion into a fastened configuration, and when disengaged, forms the body portion into an unfastened configuration. The body portion defines a longitudinal axis when in the fastened configuration, and the fastener extends from the source end to the delivery end of the body portion at an angle that is non-parallel with the longitudinal axis of the conduit.

Abstract: A flexible pipe which can be heated efficiently, and may therefore be used for conveying oil in cold regions, is provided. The pipe comprises in order from inside to outside: an interior lining; a wound tape; and at least one reinforcement layer. The wound tape contains a first exterior layer of a plastics molding composition that is not electrically conductive; an intermediate layer of an electrically conductive plastics molding composition; and a second exterior layer of a plastics molding composition that is not electrically conductive. A volume resistivity to IEC 60093 of the intermediate layer is in the range from 10?3 to 1010 ?m, and the intermediate layer comprises at least two metallic conductors embedded into the plastic molding composition along an entire length of the tape in such a way that, the two conductors do not touch one another.

Abstract: A flexible pipe comprising a flexible cylindrical tubular pipe body connected at each of its ends to a rigid connector end fitting in the form of a sleeve. The wall of the pipe body is mechanically reinforced by at least one traction layer of filaments of small thickness, presenting high traction strength, that are wound helically about the longitudinal axis of the pipe. The traction layer is composed of an array of uninterrupted filaments interconnecting the two end fittings alternately in one direction and then in the other direction, while being fastened on the end fittings.

Abstract: Methods of providing flexible duct are provided. The methods include the steps of providing an inner core, the inner core having a cylindrical shape and an outer surface, providing a layer of insulation having a constant uncompressed thickness, fiber diameter and density, wrapping the layer of insulation around the outer surface of the inner core thereby forming a layered assembly, selecting an outer jacket from a set of outer jackets of different diameters, the selected outer jacket configured to compress the layer of insulation to a desired thickness and inserting the layered assembly into the selected outer jacket thereby forming flexible duct. The thickness of the compressed layer of insulation provides a desired insulative value. The outer jackets included in the set of outer jackets are configured to compress the layer of insulation into a plurality of flexible duct having different insulative values from each other.

Abstract: There is disclosed an animal-resistant tubing system. The animal resistant tubing system may include a flexible tube disposed within a coil shield, the coil shield having an uncompressed length longer than a length of the flexible tube. The coil shield may have an inside diameter larger than an outside diameter of the flexible tube. The entire length of the coil shield may be free to move radially, axially and rotationally about the flexible tube except that the first and second fittings may prevent the coil shield from moving axially beyond the ends of the flexible tube, such that the length of the coil shield is compressed between the first fitting and the second fitting.

Abstract: Embodiments disclosed herein relate to one or more embodiments of and methods to make a reinforced flexible pipe. The reinforced flexible pipe includes a pipe structure, a first composite tape member having a T-shaped cross section, and a second composite tape member having a T-shaped cross section, in which the first composite tape member is wrapped on the pipe structure in a first orientation and the second composite tape member is wrapped on the pipe structure in a second orientation. One or more embodiments relate to a method of forming the same.

Abstract: A siphon tube having a polymeric material into which at least one continuous reinforcing agent is embedded, and wherein the at least one reinforcing agent runs substantially the length of the siphon tube. The polymer material can be one or more polymers selected from one or more high density polyethylenes, one or more polyamides, and one or more fluoropolymers.

Abstract: A composite hose for transfer of cryogenic fluids, includes two end flanges, a helical wound inner wire several layers of protective fabric layers, at least one gas-tight sealing layer sandwiched between one or more protective layers and an outer helical wound wire which is placed on top of the protective layers between the pitch of the inner wire, characterized in that the inner wire is connected to a flexible inner liner that follow any axial and/or radial displacement of the inner wire and that covers the inner corrugations of the composite hose so to create a smooth inner bore of the composite hose.

Abstract: An apparatus (10) for remotely running a subsea production tree (12) and desuspending a well is described. The apparatus comprises a tree running tool (16) adapted to be connected to a production tree, at least one downhole tool, at least one of the tools being a plug retrieval tool (22) and a tool deployment device (18) in hydraulic communication with at least the plug retrieval tool to hydraulically operate the plug retrieval tool.

Abstract: A core having enhanced ID stiffness is provided. The core includes inner, intermediate, and outer wall zones. The intermediate zone is spring-like in that it minimizes deformation of the inner zone from a radial deflection of the outer zone by absorbing at least some of the deformation. Similarly, the intermediate zone minimizes deformation of the outer zone from a radial deflection of the inner zone by absorbing at least some of the deformation. The intermediate zone includes at least first and second intermediate layers and one or more intermediate support layers. The first and second layers include a number of plies and gaps that are offset from each other, i.e. the plies of the first layer are radially aligned with the gaps of the second layer. The intermediate support layers are between the first and second layers and extend radially across the gaps of the first and second layers.

Abstract: A flexible conduit assembly that includes a central fluid transfer conduit and at least two thermal fluid transfer conduits in overlying relationship to the central fluid transfer conduit at an orientation other than linear relative to the center axis of the central fluid transfer conduit. The flexible conduit assembly may also include an outer jacket concentrically disposed relative to the central fluid transfer conduit with the fluid transfer conduit interposed between the central fluid conveying conduit and the outer jacket.

Abstract: The flexible hose of the present invention is crush resistant, burst resistant, and virtually impossible to kink in normal use and is applicable to hoses that are designed for delivering virtually any kind of fluid including water, organic liquids, aqueous based herbicides, aqueous based insecticides, industrial chemicals, beverages, air, industrial gases, vacuum, and the like. The hose design of the present invention is particularly applicable to garden hoses for the delivery of water. In fact, garden hoses having the construction of the present invention are highly resistant to kinking and almost never kink when being used in conventional lawn, garden, and cleaning applications.

Abstract: Compact flexible reinforce rubber hose adapted for conveying fluids under high pressure. The hose includes a thin inner tube formed of a vulcanized rubber.

Abstract: A spoolable composite tube capable of being spooled onto a reel for storage and for use in oil field applications. The spoolable tube exhibits unique anistropic characteristics that provide improved burst and collapse pressures, increased tensile strength, compression strength, and load carrying capacity, while still remaining sufficiently bendable to be spooled onto a reel in an open bore configuration. The spoolable composite tube can include an inner liner, an interface layer, fiber composite layers, a pressure barrier layer, and an outer protective layer. The fiber composite layers can have a unique triaxial braid structure.

Abstract: A high-temperature composite hose (100) allows for the carrying out of high temperature air, gases and liquids in a range of 600 to 2000° F. The hose remains flexible at such elevated temperatures and may be used in situations where solid or flexible metal hose was previously used. The hose construction preferably includes a spirally wound inner wire element (10) over which is applied multiple layers (21, 23, 17) preferably beginning with a layer of heat resistant textile or fabric (21) and ending with a cover layer (17) which serves to provide abrasion and other resistance to the composite hose. A 2nd outer wire element (16) is preferably applied which, in connection with the inner wire element 10, serves to sandwich or compress and hold the heat resistant and other hose layers (21, 23, 17) together.

Abstract: Apparatus and methods described herein provide for the management of noise associated with a duct. A sound-dampening apparatus is provided consisting of a duct through which a fluid flows, such as an air duct. A flexuous cord is helically wound around the inner or outer surface of the duct at a pitch corresponding to a selected acoustical frequency range associated with the fluid flow through the duct.

Abstract: An elongate metallic or polymeric or composite tape is disclosed along with a method of manufacturing such tape. The tape is of a type suitable for forming at least one helically wound layer of interlocked windings in a flexible pipe body for transporting production fluids. The tape is configured for interlocking of adjacent windings in the layer of tape by nesting a hooked region of a winding in a valley region of an adjacent winding. The tape comprises first and second elongate tape elements arranged in contacting relation.

Abstract: A flexible hose (100) having a grooved liner (102) forming a part of the side walls of the hose to define an internal bore (101). Helically formed grooves (108) are formed at an external facing side of liner (102) with an innermost side (104) comprising a substantially smooth, non-profiled surface. A coiled wire retainer (107) is housed within each groove (108) to provide a hose (100) resistant to crushing and collapse of the internal bore (101) due to kinking when the hose (100) is flexed.

Abstract: In one aspect, the present disclosure relates to a tubular assembly with gap control. Embodiments disclosed herein relate to one or more embodiments of and methods for controlling gaps between helically wrapped layers in a pipe structure. A tubular assembly includes a fluid barrier, a first layer, and a second layer comprising a plurality of non-interlocking helical wraps and disposed on an outer surface of the first layer, in which the first layer is disposed between the fluid barrier and the second layer and configured to at least partially displace into a space created between adjacent non-interlocking helical wraps of the second layer.

Abstract: There is disclosed an insert (2) for a conduit (4) adapted to effect helical flow in the conduit (4) comprising a longitudinally extending member having a helical formation.