Abstract: Various embodiments of an umbilical are provided. In one aspect, an umbilical is provided that includes a first tube, a second tube positioned in the first tube and a plurality of third tubes positioned in the first tube. Each of the plurality of third tubes has an inner polymer sleeve and an outer sleeve of carbon fibers in an epoxy matrix positioned around the polymer sleeve. The composite tubes yield a lighter umbilical that is easier to handle than a comparably sized conventional umbilical incorporating steel inner tubing and is more tolerant of dynamic bending and hydrostatic pressure loading.

Abstract: The present invention describes a multi-lumen tube arrangement for use in a centrifuge free of a sliding seal having at least two individual tubes, which are rotated around one another around their longitudinal axes and/or their parallel axes. The rotation of the tubes takes place in this connection in opposite directions starting from a support position disposed approximately centrally in order to compensate the torques applied to the tube arrangement. Furthermore, a method for manufacturing a tube arrangement in accordance with the invention is described.

Abstract: In an umbilical, one or more steel rods, which provide strength and ballast, are wound helically within the umbilical along with the steel tubes and/or elongated active umbilical elements. These steel rods replace some or all of the thermoplastic filler elements that would otherwise be included within the umbilical. An umbilical according to an embodiment of the invention may include a plurality of steel tubes helically wound around a core, and at least one substantially solid steel rod helically wound around the core, the steel rod being arranged in a void between the steel tubes. Thus, the invention avoids the need to apply additional armoring layers to the outside of the umbilical for strength and ballast.

Abstract: A flexible innerduct structure is configured to contain a cable within a conduit. The innerduct structure includes a pair of adjacent strip-shaped layers of flexible material that are joined along their longitudinal edges to define a channel through which the cable can extend longitudinally through the innerduct structure between the layers. The adjacent layers have differing widths between their longitudinal edges, whereby the wider layer bulges away from the narrower layer to impart an open configuration to the channel. Other features of the innerduct structure relate to the material of which it is formed. Such features includes the structure of the material, such as a woven structure, and further include properties such as melting point, tensile strength, elongation, coefficient of friction, crimp resistance and compression recovery.

Abstract: A retention device for the installation of cabling includes a bottom surface for connecting the retention device to a support structure, and a top surface which is integrally connected to the bottom surface at a distance therefrom by an aft surface. The top surface includes at least two cable gripping members which define a passage for selectively housing the cable clusters. The gripping member is defined by a distal edge, a proximal edge and a structural area connecting them. The passage is defined by the distal edge and proximal edge of the adjacent gripping members and an aft edge of the aft surface. The aft edge engages the top surface in an off-set manner sufficiently large to generate clearance for, and reduce bending tension of, cable clusters which engage the retention device during installation. The gripping member further includes a forward end extension, integrally connected to the structural area of the gripping members.

Abstract: A mounting assembly, particularly suitable for mounting a buoy incorporating an analysis device is disclosed, which conveniently allows a device to be deployed at a remote location from a mounting point and suspended adjacent the mounting point for maintenance.

Abstract: In a super-insulation support system disposed in an annular space between concentric inner and outer corrugated tubes, a number of axially spaced rings is provided, which are interconnected by axially extending rods mounted in circumferentially spaced relationship alternately to the inside and the outside of the axially spaced rings thereby forming a cylindrical frame structure, which is disposed adjacent the inner corrugated tube and super-insulation is disposed on the cylindrical frame structure and supported thereby at a distance from the corrugated inner tube.

Abstract: The invention concerns a method for the manufacture of individual pipe sections of a pipe formed by a product pipe [(1) and by] having at least one channel [(5)] running along the product pipe. The channel is formed by filling a pipe jacket with an insulating mass which exhibits a flowability only in the processing condition. The pipe jacket contains the product pipe and a core which is disposed on the product pipe and which defines the contour of the channel. [(1), in which case the product pipe (1) and the channel (5) are fitted with the insulation (3) enclosed by the jacket pipe (2). A method consisting of the following process steps is proposed to provide a simple and cost-effective manufacture of almost any type of channel along the product pipe (1).

Abstract: A flexible innerduct structure is configured to contain a cable within a conduit. The innerduct structure includes a pair of adjacent strip-shaped layers of flexible material that are joined along their longitudinal edges to define a channel through which the cable can extend longitudinally through the innerduct structure between the layers. The adjacent layers have differing widths between their longitudinal edges, whereby the wider layer bulges away from the narrower layer to impart an open configuration to the channel. Other features of the innerduct structure relate to the material of which it is formed. Such features includes the structure of the material, such as a woven structure, and further include properties such as melting point, tensile strength, elongation, coefficient of friction, crimp resistance and compression recovery.

Abstract: A deformed pipe having a deformed cross-sectional shape is press-fitted in a round hollow pipe having a circular cross-sectional shape. The deformed pipe has a plurality of radially outwardly projecting ridges having respective outermost vertexes held in contact with an inner circumferential surface of the round hollow pipe. The round hollow pipe and the deformed pipe are arc-welded to each other at axially spaced locations.

Abstract: In a device for placing a structural element in a cable installation conduit in order to sub-divide it, the structural element has a width close to the size of the internal perimeter of the conduit and comprises a plate surmounted by ribs. The device comprises a hot air inlet designed to soften the plate of the structural element; an external cylinder whose diameter is identical to that of the conduit, the cylinder comprising a shaping cone at one end in order to enable the softened structural element in order to gradually take a cylindrical shape; and an internal core fixedly held at a position located in the shaping cone of the external cylinder and positioned inside the softened structural element in order to give it a constant internal diameter when it is being shaped.

Abstract: A multichannel capillary column having an interior wall defining a single internal bore, wherein the interior wall defines a plurality of n channels and n ridges, wherein adjacent channels are partially separated by a respectively interposed ridge, and wherein a central, coaxial portion of the internal bore allows cross-channel fluid communication between all of the n channels.

Abstract: Each raceway stretch includes a base section, external walls; one or more compartment walls providing for the existence of sub-raceways, folds capping the walls and forming longitudinal slots and a cover section for each sub-raceway. The internal bottom surfaces of each base section are coplanar and have juxtaposable end cuts over the whole extension thereof. The elbow includes for each sub-raceway, an angled closing member having skirts engageable simultaneously in longitudinal slots of both raceway stretches, closing portions of a sub-raceway of each stretch; and a covering member which, in said active position, covers said angled closing members from above and is provided with means for engagement with said base sections.

Abstract: Hydraulic hoses coupled between the tractor and trailer units of an articulated vehicle are connected to each of the units by a swivel joint to permit the hydraulic hoses to swivel at the point of connection to the respective tractor and trailer units. The hydraulic hoses are individually positioned within separators to separate the hydraulic hoses and position them in a predetermined manner relative to forming a hose bundle. Each of the hydraulic hose supporting separators is positioned on a steel spring bow to control the shape of the hose bundle, with each end of the spring bow terminating in a coil spring at the point of connection with the tractor and trailer units. A support frame, preferably joined to the trailer unit, retains the hose bundle in a predetermined position to provide vertical stability and a spiral plastic or rubber outer wrap encircles the hose bundle to protect and keep the bundle together.

Abstract: The invention relates to a conduit and coiled tubing system for deployment in a well, in which the conduit is arranged internally of the coiled tubing, and one end of the coiled tubing is attached to a powered device such as a motor or a drill which is to be installed in the well, and wherein the conduit is connected at one end to a power supply at the surface and connected at the opposite end to the powered device and wherein, in a locked state, the coiled tube comprises at least one protrusion extending inwardly from its internal wall and acts against the conduit or an anchoring surface provided thereon, to prevent axial movement of the conduit with respect to the coiled tubing at least on one direction. An anchoring collar may be provided on the tube against which the protrusions engage to secure the conduit in position inside the tube.

Abstract: A telescopic conduit passage assembly for extending conduit, such as electrical wiring, through a hole in an exterior wall of a structure. The telescopic conduit passage assembly includes a main tube and an extension tube each having a pair of opposite open ends. A first of the ends of the extension tube is slidably inserted into a first of the ends of the main tube. The main tube and the extension tube each have an outwardly radiating end flange adjacent a second of the ends of the respective tube.

Abstract: A subsea control cable includes an outer sheath and cables, conduits etc. arranged inside the sheath, and also at least one weight element. The weight element includes at least one strength member extending continuously along the entire length of the control cable, to which strength member there is attached a weight element or elements. The weight of the weight element in relation to the diameter of the control cable varies along the length of the control cable, e.g., from a predetermined minimum weight/diameter ratio, where the weight element consists only of the strength element, to a predetermined maximum weight/diameter ratio, where the cross-section of the control cable is filled to the maximum with the weight member.

Abstract: The invention relates to a machine frame for the meat processing industry, which can be assembled at least partly from tube profile parts, which tube profile parts can be loaded and the outside of which comprises at least one guide surface for guiding machine parts.The invention also relates to a tube profile for assembling such a machine frame. Using the machine frame and the tube profile according to the invention it is possible to assemble constructions which can be cleaned very easily.

Abstract: An articulated bend limiter (10) is provided for connection to an elongate flexible member such as a steel cable (14). In a preferred embodiment, the apparatus includes of a plurality of interconnected segments (12), each of which includes a modified ball and socket joint capable of limited angular movement. The ball (36) contained within each socket is modified in that it comprises two generally hemispherical sections (36A,36B) that form a split ball and that move relative to one another within a limited range. Each hemispherical section (36A,36B) is formed of two half-portions which may be bolted together about a mid span region of a cable (14). The socket is defined by a curved inner surface (34) of an outer sleeve (30) that, itself, includes two half-portions (30A,30B) which are bolted around the ball assembly (36). The range of movement of each of the hemispherical sections (36A,36B) within the socket is defined by a coacting stop surfaces (42A,42B) respectively provided on the sections (36A,36B).

Abstract: A flexible solar absorbing means, which can be one or more extruded or molded plastic or rubber oval tubes which may or may not be connected to each other at the edges by a small webbing; communicating with a rounding connection adapter means communicating with a distribution and collecting header means which can be connected as separate parts or molded as a unit; communicating with the remainder of the solar systems, mounting, piping, pumping, control and storage means as well as frame and glazing means where appropriate.

Abstract: A submarine cable protecting device in which a plurality of pairs of half members are connected in series, includes a cylindrical portion which encloses a submarine cable. An outside spherical surface extending from one end of the cylindrical portion is provided at one end of each of the half members. An inside spherical surface extending from the other end of the cylindrical portion is provided at the other end of each of the half members, the inside spherical surface being shaped such that the inside spherical surface of one of the half members encompasses the outside spherical surface of another of the half members and the outside spherical surface cannot be detached from the inside spherical surface when the two half members are connected in series. The outside spherical surfaces of one pair of the half members has a reduced outside diameter when the outside spherical surfaces are contacted and the inside spherical surfaces are separated.

Abstract: The present invention provides a channel housing comprising curving channels whereby complex and varied channels can be compactly contained.Plural curving channels that must be connected to plural valves, for example, are formed by partitioning walls forming curving channels inside a pair of symmetrical housing halves, which are then bonded together to form the complex channel system.The housing halves may be joined by welding or adhesive bonding. To improve the bonding strength, a pair of opposing channel members is provided along the length of the contacting members that are welded or bonded. The cavity formed by the opposing channel members D, D is then filled with an adhesive resin M to integrate the two halves.

Abstract: A wall feedthrough fitting for a conduit has a guide tube centered on an axis, adapted to be mounted in a wall with the conduit passing axially through the tube, and having an outer end of a predetermined inside diameter. A flexible and shrinkable sleeve generally centered on the axis has an inner portion secured to an outer surface of the guide-tube outer end and a shrinkable outer portion projecting axially outward past the outer end. A support tube of generally the same inside diameter as the guide tube is releasably coaxially fitted with the guide-tube outer end, and is fitted in, lines and supports the outer portion of the sleeve.

Abstract: A fluid coupling 10 for connecting the output of an upper 102 and a lower 101 submersible pump in a well casing 100 to the well supply pipe 105. The fluid coupler 10 includes an upper coupling unit 11 connected to the upper pump 102, a lower coupling unit 12 connected to the lower pump 101, and a manifold unit 13 operatively connecting the upper 11 and lower 12 units together to form a framework which surrounds and suspends the upper pump 102.

Abstract: The invention relates to a machine frame for the meat processing industry, which can be assembled at least partly from tube profile parts, which tube profile parts can be loaded and the outside of which comprises at least one guide surface for guiding machine parts.The invention also relates to a tube profile for assembling such a machine frame. Using the machine frame and the tube profile according to the invention it is possible to assemble constructions which can be cleaned very easily.

Abstract: A fuel feeding arrangement for a motor vehicle has at least one fuel feeding component having a pipe provided with at least one outwardly projecting collar, at least one fuel conduit mountable on the pipe and formed as a tube, the tube having an end mountable at least directly on the pipe, a mounting element fixed on the end of the tube and displaceable on the pipe and having a springy locking element which is engageable on the at least one collar.

Abstract: The present invention provides a channel housing comprising curving channels whereby complex and varied channels can be compactly contained.Plural curving channels that must be connected to plural valves, for example, are formed by partitioning walls forming curving channels inside a pair of symmetrical housing halves, which are then bonded together to form the complex channel system.The housing halves may be joined by welding or adhesive bonding. To improve the bonding strength, a pair of opposing channel members is provided along the length of the contacting members that are welded or bonded. The cavity formed by the opposing channel members D, D is then filled with an adhesive resin M to integrate the two halves.

Abstract: A dual containment pipe system suitable for installation into an existing conduit includes an impervious containment pipe adapted to be installed as a primary containment pipe and a crush-resistant and flexible spacer element disposed about the entire external circumference of the primary containment pipe. The annular spacer is formed of a plurality of spaced apart and parallel substantially crush-resistant longitudinal members with a plurality of spaced apart parallel flexible connecting ribs bonded thereto. The longitudinal members form a uniform space when the containment pipe suitable for installation of leak detection systems including cables or based on measuring pressure differentials. The new impervious primary containment pipe may be cured in place, folded and formed, diameter reduced pipe, or any other pipe suitable for pipeline rehabilitation.

Abstract: A flexible plastic water tube which can be stored on a roll has a flexible but substantially inextensible line member attached to it and can include a number of pre-attached drippers. The tube can be stretched between spaced apart supports with the line member preventing undesirable sagging. The tube can therefor be made from inexpensive thin walled plastic.

Abstract: A dual containment pipe system suitable for installation into an existing conduit includes an impervious containment pipe adapted to be installed as a primary containment pipe and a crush-resistant and flexible spacer element disposed about the entire external circumference of the primary containment pipe. The spacer is formed of a plurality of spaced apart and parallel substantially crush-resistant longitudinal members with a plurality of spaced apart parallel flexible connecting ribs bonded thereto. The longitudinal members form a uniform space when the containment pipe suitable for installation of leak detection systems including cables or based on measuring pressure differentials. The new impervious primary containment pipe may be cured in place, folded and formed, diameter reduced pipe, or any other pipe suitable for pipeline rehabilitation.

Abstract: An improved trunk-line structure comprising a plurality of elongate beer lines and glycol lines made of flexible plastic tubing in parallel juxtaposition; an elongate sheath of high tensile strength, tear resistant, flexible plastic material is tightly engaged about and extending longitudinally of the assembly of beer and glycol lines and holds the lines in set position relative to each other; an elongate tube of soft, flexible, resilient, thermal insulating foam plastic material is engaged about and extending longitudinally of the sheath; and, a skin of inhervious, soft, flexible and resilient plastic material is positioned about and extending longitudinally of the tube, the plastic materials of which the parts of the trunk-line structure are made have low indexes of heat conductivity.

Abstract: The tubular member for telescopic propeller shafts has a cross-sectional profile with four projections 1, 1 and 3, 3 and respective longitudinal channels 5, 5 and 7, 7; each of the projections has symmetrical outwardly converging walls; and the plane of symmetry X--X of two opposing projections 1, 1 forms an angle of 85.degree. and an angle of 95.degree. with the plane of symmetry Y--Y of the other two opposing projections 3, 3.

Abstract: Method and apparatus for reduction of fluid borne noise in a hydraulic system are disclosed. An improved isolating hose assembly comprising first, second and third volumetrically compliant members with first and second inductive flow members providing fluidic coupling therebetween is disclosed. The improved isolating hose assembly acts similarly to an electronic low pass filter network in deterring fluid borne noise from entering portions of the hydraulic system located therebeyond. A modified isolating hose assembly comprising a resistive member introduced within the second volumetrically compliant member in order to eliminate the possibility of a deleterious resonance in the assembly is disclosed. In addition, apparatus for additionally reducing structure borne noise in hydraulic systems comprising direct hydraulic coupling of the first volumetrically compliant member to internal output ports of the hydraulic system's pump is disclosed.

Abstract: An aerial duct having a first duct in which a support strand is contained for aerially mounting the aerial duct, and a second duct in which an inner duct or liner is contained through which a transmission or other cable is strung. A multiplicity of support strands or several braided support strands could be contained in the first duct. The first duct and second duct are joined by an intervening web so that the first and second duct have substantially parallel longitudinal axes. The inner duct has spaced apart ribs formed within its inner surface. Valleys are formed between the spaced apart ribs and adapted to retain lubricant placed therein for facilitating the passage of a transmission or other cable through the inner duct. The ribs can be either longitudinal, corrugated or spiral. If desired, the aerial duct and support strand could be made of an all-dielectric material.

Abstract: A generally tubular textile braid is divided into two axially extending portions by stitching or otherwise securing opposed wall portions of said braid together, one of said portions being adapted to receive a wiring harness and the other containing an axially extending reinforcement constituted by a second tubular braid of the same or a different textile material, the two braids being formed with the same or very similar braiding angles, so that on radial expansion of the first portion to install it over a substrate such as a wiring harness assembly, both axially extending portions and the reinforcement contract by substantially the same amount in an axial direction.

Abstract: A conduit for use in a geothermal heating and cooling system which includes an elongated tubular member having first and second ends, the member having an outer surface. A longitudinally extending divider wall is disposed within the tubular member. The divider wall divides the interior of the tubular member into first and second fluid flow passageways extending longitudinally within the tubular member. The apparatus further includes a cup shaped member disposed on the second end of the elongated tubular member. The cup shaped member directs all fluid flow in the first fluid flow passageway from the first end to the second end into the second end of the second fluid flow passageway. Other forms of the invention have first and second elongated tubular members that have first and second ends and each of the tubular members has an outer surface.

Abstract: A coaxial piping system connected between an underground pump and an above-ground liquid dispenser is used to provide containment of the pumped liquid from the underground piping system, preventing unintended release into the environment. A pair of coaxial pipes are removably connected to the underground pump at one end and to the dispenser at the other end using quick-disconnect fittings to allow for the replacement of the piping. A primary pipe for conveying gasoline or the like is surrounded by a secondary pipe, which provides containment in the event of leakage from the primary pipe. The piping system can be tested for leaks or replaced from grade without excavating at the installed tank site. A sensor in the annular space between the primary and secondary pipes may be used to detect leakage. A path may be provided for the gravity drainage of such leaks from the secondary pipe into a containment chamber, where the liquid may be detected and removed.

Abstract: An assembly and method for supporting a plurality of individually insulated pipes or conduits inside a vacuum jacket where the insulated pipes are positioned or fixed relative to one another and the inside surface of the vacuum jacket.

Abstract: A system for conveying a fluid through an under-the-ground location and method of making the same are provided, the system comprising a primary flexible conduit for conveying the fluid therethrough and having an outer peripheral surface and an inner peripheral surface, and an outer secondary conduit having at least a portion of the primary conduit removably disposed therein and having an inner peripheral surface and an outer peripheral surface that engages the ground in the under-the-ground location thereof, the secondary conduit having the inner peripheral surface thereof comprising a helically disposed and inwardly directed projection thereof that engages the outer peripheral surface of the primary conduit in a spiral manner and cooperates therewith to define a helically disposed passage that extends therebetween throughout substantially the entire engagement area thereof.

Abstract: A dual containment pipe system suitable for installation into an existing conduit includes an impervious containment pipe adapted to be installed as a primary containment pipe and a crush-resistant and flexible spacer element disposed about the entire external circumference of the primary containment pipe. The spacer is formed of a plurality of spaced apart and parallel substantially crush-resistant longitudinal members with a plurality of spaced apart parallel flexible connecting ribs bonded thereto. The longitudinal members form a uniform space when the containment pipe suitable for installation of leak detection systems including cables or based on measuring pressure differentials. The new impervious primary containment pipe may be cured in place, folded and formed, diameter reduced pipe, or any other pipe suitable for pipeline rehabilitation.

Abstract: An umbilicus conveys fluid between a stationary body and a rotating body in a small, compact operating environment. The umbilicus comprises an elongated body including a proximal end, a distal end, and a middle region between the proximal and distal ends. A first support block is attached to the proximal end. A second support block is attached to the distal end. The first support block includes a strain relief sleeve. The umbilicus is otherwise free of any other strain relief sleeve. A thrust bearing member in the middle region spaced apart from the strain relief sleeve and the distal end. The umbilicus is otherwise free of any other thrust bearing member. The thrust bearing member has an inner annular body, an outer annular body about the inner annular body, and an array of ball bearings between the inner and outer annular bodies. The ball bearings support the inner annular body for rotation relative to the outer annular body.

Abstract: A length of elongate material such as rubber hose is supported and guided while being fed along a desired path of travel that extends through the hollow interior of a tubular structure. The tubular structure mounts an array of relatively closely spaced rollers that project into the hollow interior to guide and support the moving length of material. The tubular structure is formed as a "tube within a tube" assembly of "inner" and "outer" tubular members that closely interfit, and that sandwich roller support pins between overlying portions of the inner and outer tubular members. The roller support pins bridge roller positioning holes that are formed through the inner tubular member at an array of spaced locations.

Abstract: The present invention relates to a multiple-duct tube for centrifugal separators for blood in particular, suitable for connecting a rotating connector to a stationary connector. The multiple-duct tube comprises, in a monolithic structure, a plurality of ducts which have parallel axes. The outer surface of the tube is defined by blended portions of walls of the peripheral ducts, so as to assume a lobate shape in a transverse cross-section.

Abstract: A tuner hose assembly for a motor vehicle power steering system including a flexible hose, a first flexible tuner tube inside the flexible hose having an upstream end connected to a pump, and a second flexible tuner tube inside the flexible hose having a downstream end connected to a power steering gear. A downstream end of the first flexible tuner tube is longitudinally separated from an upstream end of the second flexible tuner tube by a wave interference gap which terminates where an inner wall of the flexible hose is clamped against the upstream end of the second flexible tuner tube. The length of the second flexible tuner tube is selected, i.e. "tuned", to attenuate higher order pump fluid-borne noise and simulates a rigid metal tube of a prior tuner hose assembly having greater overall length.

Abstract: A system is herein disclosed for use in the delivery of fluid from a reservoir to a relatively reciprocating fluid discharge mechanism via an arrangement of coiled tubes which may be expanded or retracted with reciprocation of the discharge mechanism. The system is preferably arranged with a series of concentrically coiled tubes, each tube carrying a different fluid to the discharge mechanism. Adjacent coils are wrapped in opposing rotational directions so as to create a web-like matrix which supports the coils in their extended form.

Abstract: A double-containment piping assembly has two anchor supports, and at least one elbow fitting with an outer elbow section and an inner elbow section received within the inner elbow section. A first leg having a first inner pipe received within a first outer pipe is coupled between an anchor support and the elbow fitting. A second leg having a second inner pipe received within a second outer pipe is coupled between the other anchor support and the other side of the elbow fitting. First flexibility supports are mounted on either side of the elbow fitting, and permit axial and lateral movement of the inner pipe relative to the outer pipe in the areas of the elbow. First axial-guiding supports, which permit axial movement of the inner pipe relative to the outer pipe, but prevent lateral movement of the inner pipe, are each mounted a minimum distance from the elbow fitting between the inner and outer pipes.

Abstract: A system for conveying a fluid through an under-the-ground location and method of making the same are provided, the system comprising a primary flexible conduit for conveying the fluid therethrough and having an outer peripheral surface and an inner peripheral surface, and an outer secondary conduit having at least a portion of the primary conduit removably disposed therein and having an inner peripheral surface and an outer peripheral surface that engages the ground in the under-the-ground location thereof, the secondary conduit having the inner peripheral surface thereof comprising a helically disposed and inwardly directed projection thereof that engages the outer peripheral surface of the primary conduit in a spiral manner and cooperates therewith to define a helically disposed passage that extends therebetween throughout substantially the entire engagement area thereof.

Abstract: An improved flexible multi-duct conduit system for housing and protecting subterranean fiber-optic cable comprises matable sections each having an outer casing and a plurality of inner ducts for carrying the cable. An rubberized inner duct coupler is provided at one end of each section for aligning and sealing the inner ducts of adjacent sections when the sections are joined together end-to-end. An outer casing coupler for coupling and sealing the outer casings of adjacent joined sections comprises a cylindrical collar that extends around the ends of two adjacent sections. Sealing gaskets disposed between the outer casing ends and the collar insure against ingress of moisture and other corrosive subterranean elements into the outer casings. The inner ducts are bendable and the outer casings are formed with corrugated exterior surfaces so that the entire system, when assembled in the field, can be bent about an arc to accommodate turns and the like.

Abstract: A structure formed by one or more double tube assemblies characterized by a cross-sectional configuration including two circular walls interjoined by two planar walls interconnected with the circular walls substantially at diametrically opposed circumferential locations in the circular walls.

Abstract: Hose arrangement for a seal-less centrifuge having a soft inner layer and a hard outer layer and is formed by means of coextrusion.