Abstract: A flexible conduit for conveying cryogenic fluids has a metal inner tube and a metal outer tube. A strip-shaped spacer member is made of a material of low thermal conductivity, which is spirally wound on the inner tube such that it contacts both the inner and outer tubes. The strip-shaped spacer member is twisted about its own axis and includes a metal that is stable with respect to high-energy radiation and has a thermal conductivity of less than 25 W/m·K and a tensile strength of more than 240 MPa.

Abstract: A tubing assembly including conductive corrugated tubing including convolutions of peaks and valleys and a conductive polymer jacket disposed in said valleys along a length of said corrugated tubing.

Abstract: A collapsible handle for use with a shower head includes a hollow tubular handle provided with a pair of oppositely formed tracks formed on an inner face of the tubular handle. An inner tube is selectively and slidably received in the tubular handle so that the inner tube is able to extend out of the tubular handle. The inner tube has a pair of oppositely formed ribs on an outer face of the inner tube to correspond to the pair of tracks such that after the ribs are received in the corresponding tracks, the inner tube is able to slide in and extend out of the tubular handle. A retaining device is movably mounted on the tubular handle, so that relative position between the inner tube and the tubular handle is determined by the retaining device and overall length of a handle is adjustable.

Abstract: A canal or pipe system and process for rehabilitation of a canal or pipe system and for installation of a cable or empty tube into a canal or pipe system as well as device for installation of a cable or empty tube. For rehabilitation of a canal or pipe system (AR) an outer casing (AL1) is inserted. Subsequently, an inner casing (IL1) with help by distancing elements (AH) is inserted, so that a ring gap (RS) between the inner and outer casings (IL1, AL1) is created. A cable (OC1) or empty tube (LR) to be installed is inserted together with the inner casing (IL1) in such a way, that the cable (OC1) or empty tube (LR) comes to rest in the ring gap (RS). For rehabilitation of the canal or pipe system, where a cable (OC1) or empty tube (LR) is already installed at an inner wall (IW), only the inner casing (IL1) will be inserted into the canal or pipe system (AR), so that the ring gap (RS) is created between the inner wall (IW) and the casing (IL1).

Abstract: A fluid transport system including a fluid transfer assembly, an air dryer and a tube. The fluid transfer assembly includes a pipe for transporting a cold fluid and a vapor barrier surrounding the pipe. The air dryer removes moisture in the air. The tube is connected to the air dryer and the fluid transfer assembly. The tube transfers air from the air dryer to the fluid transfer assembly at a plurality of points along a length of the fluid transfer assembly.

Abstract: A leak-free flexible conduit and method of making the same is described. By attaching a flexible outer hose to a flexible inner hose without directly clamping the outer hose to the inner hose, the life of the inner hose is increased. Furthermore, the outer flexible hose creates a heat-resistant, airtight seal that prevents exhaust leaks from the inner flexible hose from escaping, substantially reduces the heat lost to the atmosphere, decreases the amount of vibration, reduces noise, and protects the inner flexible hose from corrosive elements and contaminants, thereby also extending the life of the inner flexible hose.

Abstract: The present invention provides a transitional telescoping plenum apparatus that is intended to facilitate the interconnection of HVAC equipment to duct systems. The unit expands in length, width and height directions, and is composed of modular tier sections. Each modular tier includes at least four corner sections, with each corner section being interleaved with two adjacent corner sections to complete a single modular tier. Each modular tier includes a tier-connecting flange that communicates with a tier-connecting flange on another modular tier, such that the modular tiers can be interconnected to form a finished transitional telescoping plenum apparatus. Clips are also taught for connecting modular tiers to each other.

Abstract: A flexible hose for use as a refrigerant passageway in a vehicular refrigerating cycle has an inner hose and an outer hose. The outer hose covers the inner hose with a space formed in a given distance. The outer hose and the inner hose are formed of resin having flexibility.

Abstract: A pipe, piping system, kit, and radiant heating system that include lengths of cross-linked polyethylene pipe, which form connections between flow components. Some embodiments utilize a sheath disposed about the outside of the cross-linked polyethylene pipe to enhance rigidity.

Abstract: A collapse tolerant flexible pipe and method of manufacturing same according to which an inner tubular layer is provided within an outer tubular layer in a coaxial relationship thereto. The inner layer maintains the maximum allowable strain on the outer layer below a value that will cause damage to the outer layer when the pipe collapses.

Abstract: In order to provide a line arrangement for transmitting volume flows of fluids with a port which is assigned to a pump, a port which is assigned to an actuator and a connecting line which connects the pump to the actuator, which has an amplified damping effect of pulsations occurring in the line arrangement, it is proposed that at least one line through which there is not a flow and which is composed at least partially of an elastic hose should branch off from the connecting line. The same result is achieved if at least one line which runs in parallel with the connecting line and which is composed at least partially of an elastic hose is provided.

Abstract: The invention concerns a double-sheath rigid pipe for transporting hydrocarbons consisting of two respectively inner (2) and outer (3) coaxial tubes separated by an annular gap (5), said pipe being adapted to be wound and comprising a device limiting the propagation of a deformation occurring on the outer tube, wherein a radial stop device (10) linked to the inner tube (2) but not linked to the outer tube (3) allows a localised collapse of value G of the outer tube, G being selected to stop the propagation of a deformation of the outer tube (3).

Abstract: A rotary holder for a corrugated tube is formed such that an inner rotary body containing a corrugated tube is received in an inner portion of an outer fixing body, and an outer peripheral sliding surface of the inner rotary body may rotate relative to the outer fixing body. The inner rotary body is formed by assembling two divided rotary members, each having a round arch surface on an outer periphery thereof. The outer peripheral sliding surface is formed by abutting a surface of each divided rotary member against each other. Further, a cut surface retracting inside from a rotation locus of the round arch surface in each divided rotary member is formed in each end portion of the round arch surface.

Abstract: A heat shield for an internal combustion engine exhaust system for supporting a first heat shield plate and a second heat shield plate on a U-shaped exhaust pipe extending from an exhaust port of an engine, via a support member such as band members, and heat shield plate attachment fixtures. The first heat shield plate covers all around a curved section of the U-shaped exhaust pipe in the vicinity of the exhaust port. The second heat shield plate covers an upper part of a straight section of the U-shaped exhaust pipe and extends rearwardly from the curved section. Further, since the exhaust pipe is formed as one piece, the first heat shield plate may be formed as a simple two-part structure using the band members. With this configuration, an effective heat shielding effect can be exhibited, and cost can be reduced.

Abstract: A catalyst container of a catalytic converter is of a double-pipe structure wherein an outer periphery of an inner pipe and an inner periphery of an outer pipe are fittingly superposed on each other. The catalyst container has a catalyst installing portion, tapered cone portions extending from the catalyst installing portion with a gradually decreasing diameter, and straight connecting portions extending from smallest-diameter regions of the cone portions to the ends to be connected with connecting pipes upstream and downstream of the catalytic converter. Holes maybe formed in the cone portions of one of the inner or outer pipes to permit fluids to be displaced from the space therebetween. Such a catalyst container has sufficient rigidity and radiated noise suppression properties and thus can be reduced in weight by being thinned.

Abstract: The present invention relates to apparatus for use in venting pipelines that have a plastic lining such as these used for transporting hydrocarbon fluids. A pipeline assembly comprises a pipeline (2), a corrosion resistance liner (3), and a micro-annulus (4) located between said pipeline and liner. The pipeline assembly also comprises a venting means (5) adapted for fitment in or through the corrosion resistance liner (3), wherein the venting means (5) allows gas to flow from the micro-annulus into the centre of the pipeline assembly but not in the opposing direction.

Abstract: A heat exchange system utilizing flow reducers at 180 degree bends in the tubes includes a first set of media tubes in which heating/cooling media flows, and a set of product tubes positioned concentrically within the media tubes and in which liquid product flows in a counter direction to the heating/cooling media. The tubes are arranged in a serpentine, back and forth manner, and U-shaped tubes interconnect successive pairs of product tubes to achieve the 180-degree change in flow direction. The U-shaped tubes are of a cross-sectional diameter greater than the product pipes. Tapering flow reducers extend between the opposing ends of the U-shaped tubes and the product tubes. The exit flow reducer is eccentrically formed to facilitate a smooth transition of the product from the U-shaped bend to the product tube and prevent liquid product from becoming entrapped along the bottom of the flow reducer.

Abstract: An instrument support member with an integrated air conducting unit to be mounted between the A-columns of a motor vehicle is composed of at least two metal shells which are connected to each other by plasma jet welding with an effective focus remote from the nozzle, and a plastic tube surrounded by the shells. The plastic tube is mounted at a radial distance from the shells.

Abstract: A method and device is provided for repairing a plumbing waste pipe without having to remove a failed portion of the waste pipe. A flexible sleeve with a flange is fit inside the failed waste pipe such that the outer circumference of the sleeve is in radial contact with the inner circumference of the failed pipe and the body of the sleeve extends through the failed waste pipe beyond the point of failure. The flange can be fastened between the plumbing fixture and the failed waste pipe to securely maintain the flexible sleeve within the failed pipe. Water and waste material will enter the sleeve through the flange and pass through the interior of the sleeve beyond the point of failure in the waste pipe. The water and waste can then be discharged into the waste pipe to be carried along its normal route.

Abstract: A device for arresting the propagation of a buckle appearing on an outer tube of a double-walled rigid pipe intended to transport hydrocarbons and consisting of two coaxial tubes. The double-walled pipe is of the reelable type and intended for very great depths and consists of a thick and rigid annular transverse partition fastened to the inner tube and to the outer tube. The partition is joined to the outer tube and to the inner tube by way of an outer and inner sleeve having the same diameter as the outer and inner tubes and fastened to the latter.

Abstract: The invention relates to a protective corrugated plastic tube or pipe, a corrugated piping, wherein according to the invention at least some of the flanks of corrugations of the tube or pipe have extensions (16), which go from one corrugation (11a) towards a neighboring corrugation (11b) and extend in the axial direction of the protective corrugated plastic pipe.

Abstract: A method of transferring a cryogenic fluid comprises passing a cryogenic fluid through a flexible conduit having a wall formed of a first layer of a porous polymeric (12) material and a second layer formed of an impermeable material (14).

Abstract: A cryogenic fluid system having a flexible conduit for conducting cryogenic materials and a method for fabricating such a flexible conduit is herein disclosed. The flexible conduit of the cryogenic fluid system generally includes a first tube and a second tube disposed about the first tube. The first and second tubes can be made from the same or different materials (including composites) as long as the material which makes up at least one of the first and second tubes is silicone rubber-impregnated glass cloth. The flexible conduit also generally includes a fluorocarbon polymer liner disposed against a first inner wall of the first tube, so that the first tube is positioned between the second tube and the fluorocarbon polymer liner. Some variations of the flexible conduit have an annulus between the first and second tubes which optionally is occupied, at least in part, by insulation.

Abstract: The pipes associated with an in-ground swimming pool can be supported by a support that includes a base and two telescopingly engaged tubular sections. A U-shaped element is located on one end of the tubular sections and has a pad on which the pipe rests. A lock connects the two tubular sections together once the height of the support is selected.

Abstract: The invention relates to an arrangement (2; 2.2; 2.6; 2.7) to increase the thermal fatigue resistance of glass tubes (1; 1.2; 1.6; 1.7) flown through by fluid and pressure-loaded. This arrangement comprises a glass tube (1; 1.2; 1.6; 1.7), into which an interior component (3; 3.2; 3.6; 3.7) is inserted. The interior component (3; 3.2; 3.6; 3.7) can be designed as thin-walled tube (19; 19.2) or tubular component. In accordance with a first design example the cavity enclosed by the interior component (3; 3.2) is hydraulically connected with the interior (10) of the glass tube (1; 1.2). The wall thickness (s3) of the interior component (3; 3.2) is smaller than the wall thickness of the glass tube (1; 1.2) and the interior component (3; 3.2) is in the condition of being flown through by fluid at least partially free from a direct heat connection with the glass tube (1; 1.2). In accordance with a second design example the interior component (3.6; 3.7) increases the wall thickness of the glass tube (1.6; 1.7).

Abstract: A fluid line assembly is disclosed that includes an outer fluid line and an inner fluid line disposed substantially within the outer fluid line. The inner and outer fluid lines each include a slip joint. In an embodiment of the invention, at least one of the slip joints includes a reservoir in communication with the interior of the corresponding fluid line. Among other things, the reservoir is suitable for receiving fluid from the corresponding fluid line as the fluid line assembly is contracted and expelling fluid into the corresponding fluid line as the fluid line assembly is extended. In another embodiment of the invention, the inner and outer fluid lines include a ball joint assembly.

Abstract: A conduit for the transport of cryogenic media, in particular a superconducting cable, includes at least two metal pipes arranged concentrically and spaced apart from one another, an insulation layer being situated in the annular gap between the metal pipes and the annular gap being evacuated. The exterior of the metal pipe (4) is separated at predetermined intervals and above each opening a pump connector (10) is welded vacuum-tight to the outer metal pipe (4).

Abstract: A device for eliminating propagation of a buckle in the outer wall of a double-walled tube, where the double-walled tube comprises an outer pipe, an inner pipe and an annular space between them in which the deformable element is disposed with the external surface of the deformable element in contact with the internal wall of the outer pipe and the interior of the deformable element being spaced outward from the inner pipe and having a sheath on the interior of the deformable element. The deformable element may be a wound wire, a profiled wire, an interlocked wire with interlocked turns, a non-interlocked wire, a spring with turns urged outwardly or reinforcement with turns urged outwardly and bearing blocks in the annular space on the inner pipe for at least one end of the reinforcement.

Abstract: A fluid transport system including a fluid transfer assembly, a supply of dry gas and a tube. The fluid transfer assembly includes a pipe for transporting a cold fluid and a vapor barrier surrounding the pipe. The tube is connected to the the supply of dry gas and the fluid transfer assembly, and located at least partially within the fluid transfer assembly. The tube transfers gas from the supply of dry gas to the fluid transfer assembly throughout at least a segment of the tube within the fluid transfer assembly.

Abstract: A process for manufacturing a safety hose system. In one embodiment, the process of the present invention comprises the steps of positioning the inside hose with the outside hose; inserting first and second pre-mold inserts about the first and second end portions of the inside hose; attaching the first and second connectors to the first and second end portions of the inside hose to form first and second crimped portions, respectively; applying an adhesive to the first and second crimped portions; inserting the first and second crimped portions into the connector inlet portions of the first and second pre-mold inserts, respectively; inserting the drain hose into the drain hose inlet portion of the first pre-mold insert; molding a first end-cap member to the first end portion of the outside hose, the first pre-mold insert, and the drain hose; and molding a second end-cap member to the second end portion of the outside hose and the second pre-mold insert.

Abstract: A method and system for treating crude oil to improve its flowability includes operating an internal combustion engine to produce exhaust gas, reducing the temperature of the exhaust gas, injecting cooled exhaust gas into a separator in which water is extracted to provide dry exhaust gas, pumping crude oil at an elevated pressure into a treatment vessel, compressing the dry exhaust gas to provide pressurized exhaust gas that is introduced into the treatment vessel and intimately mixing the crude oil and the pressurized exhaust gas in the treatment vessel to provide treated crude oil having a substantial portion of the exhaust gas absorbed therein to thereby provide crude oil having improved flowability.

Abstract: A casing spacer comprised of a pair of bands formed in a semi-circular configuration of a desired radius. Each band has a plurality of threaded studs that extend radially outward from the outside radial surface of each of the bands. The bands have a plurality of selected interchangeable risers, each of the interchangeable risers is configured to extend a desired distance from the outside radial surface of each of the band. The risers have a plurality of bore holes that are adapted to receive one of the threaded studs. The risers are detachably mounted to the bands by means of the threaded studs. The bands are fastened together around a carrier pipe to support the carrier pipe on the selected risers at a desired position when the carrier pipe is inserted into a casing pipe.

Abstract: A lined tubular system and method provides for the manipulation and control of annular fluids in channels (18) between the tubular (10) and the liner (17). This structure allows for profiling of the exterior wall of a liner such that one or more continuous channels are provided along the length of the lined tubular system. The system may also include one or more non-crushable members or tubes between the liner's exterior surface and host tubular's interior surface. Rounded, granular particles or spacers in the annulus between the liner and host may provide an alternative path for fluid flow. The particles or spacers may be uniformly or randomly distributed in the annulus.

Abstract: The invention concerns a flexible pipe element, in particular for exhaust pipes of combustion engines of motor vehicles, with a helically threaded or ring-corrugated bellows, at least one strip wound hose which is coaxially adjacent to the bellows and which is helically wound or comprises several annular segments, at least one spacer which is disposed locally between the bellows and the strip wound hose and a knitted tube disposed on the outside, wherein the pipe element has an overall maximum rigidity of 5 N/mm.

Abstract: Improved thermoplastic liner containing metal pipelines in which the liners consist essentially of polyamide 11 or polyamide 12 as well as methods for their preparation and use are disclosed.

Abstract: A method of treating fluids in an annulus (18), comprising the steps of: providing a fluid-circulation annulus (18) between a host tubular (10) and a liner (17) therein; and manipulating fluids in the annulus (18) so that the relative proportions of fluid components in the annular fluid correspond to the relative permeation rates of the fluid components from the bore to the annulus (18). The method may further comprise the steps of: detecting an undesired fluid in the annulus (18); and manipulating the annular fluids in response to the undesired fluid, so that the relative proportions of fluid components in the annular fluid, including the undesired fluid, correspond to the relative permeation rates of the fluid components from the bore to the annulus (18). In a case where the undesired fluid has potential for harm to the host tubular (10), the manipulating step may reduce the potential for harm.

Abstract: The flexible pipe comprises a plastic sealing sheath and, an inner plastic sheath which define an annular space in which structural elements are placed, the said structural elements comprising at least one armour ply consisting of metal wires wound helically with a long pitch, a end fitting (12, 13) being fitted at each end of the said flexible pipe (1), the device (14) comprising at least one external anode electrically connected by connection means to the said armour ply, and it is characterized in that the anode is placed in an intermediate region (40) of the flexible pipe (1) distal from the said end fittings, the connection means connecting the anode to at least one of the metal wires in the said intermediate region.

Abstract: An energy attenuation restrictor device for use in an energy attenuation apparatus for a conduit adapted to convey a liquid under pressure, particularly, in the power steering system of a vehicle wherein said energy attenuation restrictor device includes a tuning cable composed of a first organic polymer and a fitting member composed of a second organic polymer, and a method for molding the energy attenuation restrictor device are described.

Abstract: An insulated pipeline comprises an inner pipe, and an outer poly sleeve co-axial with the inner pipe. The inner pipe and the outer poly sleeve are in spaced relationship to define an annulus. An insulating core within the annulus encases lengthwise the inner pipe, and comprises a plurality of pre-cured syntactic elements. A first binder fills interstices in the annulus. The pre-cured syntactic elements include microspheres and a second binder. Each of the pre-cured syntactic elements may also include macrospheres. The pre-cured syntactic elements are preferably extruded and cylindrically shaped. In addition, in one embodiment, the second binder is preferably more rigid than the first binder.

Abstract: The present invention provides a transitional telescoping plenum apparatus that is intended to facilitate the interconnection of HVAC equipment to duct systems. The unit expands in length, width and height directions, and is composed of modular tier sections. Each modular tier includes at least four corner sections, with each corner section being interleaved with two adjacent corner sections to complete a single modular tier. Each modular tier includes a tier-connecting flange that communicates with a tier-connecting flange on another modular tier, such that the modular tiers can be interconnected to form a finished transitional telescoping plenum apparatus. Clips are also taught for connecting modular tiers to each other.

Abstract: The present invention is an improved tube for the effective transfer of cryogenic fluids and the like. The transfer tube (22) comprises at least two tubes, an inner tube (30) coaxially housed within an outer tube (44) with a defined gap therebetween. The inner tube is sufficiently permeable to gaseous cryogenic fluid that it allows release of limited amounts of gaseous fluid into the defined gap. The outer tube is essentially impermeable so as to contain the gaseous fluid within the gap. Preferably both tubes are constructed from flexible and cold temperature resistant polymer materials, such as fluoropolymer materials and especially expanded polytetrafluoroethylene (PTFE) and/or fluorinated ethylene propylene (FEP). The transfer tube of the present invention is highly effective at cryogenic fluid transfer while being lighter, more flexible, and more efficient than currently available transfer tubes.

Abstract: A casing spacer disposed between and engaging an inner carrier pipe and an outer casing maintains separation between and alignment of the carrier pipe and the casing. The casing spacer includes plural connected shell members, or segments, disposed about and engaging an outer surface of a carrier pipe and an inner surface of the casing. Each shell member includes one or more non-slip members engaging the carrier pipe to prevent movement of the casing spacer along the carrier pipe/casing combination. Each shell member is comprised of a high-strength, pliable material permitting shell members of different sizes to be connected together in a single casing spacer to accommodate a wide range of carrier pipe circumferences. The shell members are connected by plural nut and bolt couplers, with each shell member further including tapered coupling apertures and plural connector flanges to facilitate assembly and installation.

Abstract: A pipeline for moving effluents at seabed level, including an inner shell and at least one outer shell having an outer surface separated from the inner shell by an annular space for receiving an insulating layer, wherein the outer shell includes a set of mutually spaced flutings arrayed along at least a portion of the outer surface and each fluting has a bottom resting on a spacer element located around the inner shell.

Abstract: A leak-free flexible conduit and method of making the same is described. By attaching a flexible outer hose to a flexible inner hose without directly clamping the outer hose to the inner hose, the life of the inner hose is increased. Furthermore, the outer flexible hose creates a heat-resistant, airtight seal that prevents exhaust leaks from the inner flexible hose from escaping, substantially reduces the heat lost to the atmosphere, decreases the amount of vibration, reduces noise, and protects the inner flexible hose from corrosive elements and contaminants, thereby also extending the life of the inner flexible hose.

Abstract: A fluid transport system including a fluid transfer assembly, a supply of dry gas and a tube. The fluid transfer assembly includes a pipe for transporting a cold fluid and a vapor barrier surrounding the pipe. The tube is connected to the the supply of dry gas and the fluid transfer assembly, and located at least partially within the fluid transfer assembly. The tube transfers gas from the supply of dry gas to the fluid transfer assembly throughout at least a segment of the tube within the fluid transfer assembly.

Abstract: An insulated pipework system comprises an outer sleeve, an inner flow pipe and one or more evacuated volumes in the space therebetween defined by annular plugs of a setting polymeric composition such as epoxy resin or a syntactic foam, typically at regular intervals along the length of the pipeline. The epoxy resins (for example) are ideally of sufficient rigidity to allow effective transfer of longitudinal forces between the inner and outer pipes. Thus, the evacuated volumes will themselves be annular. Other plugs of different orientation (for example longitudinal) could be included to subdivide the evacuated volumes further. The plugs allow the space between the pipes to be partitioned so that air can be evacuated from the sections so formed to provide the vacuum that acts as the insulating layer. Also, the plugs replace the need for bulkheads in that the partitioning of the inter-pipe space provides the desired water-stopping means.

Abstract: A safety hose apparatus delivers water from a standard threaded hose bib to an appliance or plumbing fixture. The apparatus includes an outer hose and an inner hose that extends through the outer hose. A first threaded connector is rotatably attached to the outer hose and is in communication with the inner hose. The first threaded connector is threadably engagable with the spout to communicably connect the inner hose to the hose bib. A second threaded connector is rotatably attached to the outer hose and is in communication with the second end of the inner hose. The second threaded connector is threadably engagable with the inlet to communicably connect the inner hose to the inlet. A first closure is engaged with the first end of the outer hose and a second closure is engaged with a second end of the outer hose for sealing the space between the inner and outer hoses and retaining within the space water leaking through a rupture in the inner hose.

Abstract: A device for arresting the propagation of a buckle appearing on an outer tube of a double-walled rigid pipe intended to transport hydrocarbons and consisting of two coaxial tubes. The double-walled pipe is of the reelable type and intended for very great depths and consists of a thick and rigid annular transverse partition fastened to the inner tube and to the outer tube. The partition is joined to the outer tube and to the inner tube by means of an outer and inner sleeve having the same diameter as the outer and inner tubes and fastened to the latter.

Abstract: A flow-dampening degassing apparatus for transport of liquid chromatography fluids therethrough includes a substantially burdoin-shaped flexible tube disposed in a reduced-pressure chamber, the tube being sufficiently flexible to expand in a cross-sectional direction upon incursion of a fluid pulsation to thereby increase an inner volume of the tube and correspondingly reduce fluid pressure therein. In a particular embodiment, the tube is fabricated from a gas-permeable and liquid-impermeable material for degassing transported fluids in the reduced-pressure chamber.

Abstract: A device for arresting the propagation of a buckle appearing on an outer tube of a double-walled rigid pipe intended to transport hydrocarbons and consisting of two coaxial tubes. The double-walled pipe is of the reelable type and intended for very great depths and consists of a thick and rigid annular transverse partition fastened to the inner tube and to the outer tube. The partition is joined to the outer tube and to the inner tube by way of an outer and inner sleeve having the same diameter as the outer and inner tubes and fastened to the latter.