Abstract: A laminated fuel line has an inner layer of a synthetic material such as Nylon, an intermediate vapor barrier layer that contains a polyethylene terephathalate material (such as MYLAR), and an outer layer preferably of a high temperature resistant thermoplastic material such as a polyamide or VICHEM olefinic/PVC. A channeled fuel tube has an inner fuel jacket concentrically formed within and spaced from a relatively larger outer jacket, each of which can be formed with the laminated structure above. A connector for the channeled fuel line has a tubular end connecting element for connecting between the inner and outer fuel lines, a tubular inner connecting element for connecting to the inner line through the end connecting element, and a tubular outer connecting element connecting over both the end connecting element and the inner connecting element. The outer connecting element has a first passageway for communicating with the inner line and a second passageway for communicating with the outer line.

Abstract: The present invention discloses a glide tube ring for tube-in-tube systems, pipe conduits and the like. The glide ring tube according to the invention is provided with axially spaced glides running parallel to each other whose material has the lowest possible friction coefficient, especially a plastic, preferably a fiberglass-reinforced polyethylene, polyamide or the like, in which the glide tube ring is attached to the central tube forming a closed ring that centers this tube in the protecting tube, pipe conduit or the like.

Abstract: Forming a novel double containment polymeric piping assembly by interfitting slidably interfittable polymeric inner pipe components, including a first induction responsive layer therebetween, and slidably interfittable polymeric outer pipe components, preferably including a second induction responsive layer therebetween, to form an inner connection and an outer connection, while causing the inner connection to be axially offset from the outer connection, applying an electrical induction force around the periphery of the outer pipe components, axially aligned with the inner connection but not with said outer connection, and thereby fusing the inner pipe components and the first polymeric layer together, and moving the components relative to said electrical induction force, axially away from the inner connection, and axially aligned with the outer connection, applying an inductive force around the periphery of the outer pipe components, and thereby fusing the outer pipe components and the second polymeric layer

Abstract: The section of a main pipe wall made of synthetic resin material is formed to be substantially triangular and one inclined wall approaches the other inclined wall while the inclined wall goes over a center line passing through a top of both the inclined walls forming the main pipe wall and the approaching posture is capable of being maintained by itself. A second pipe wall, the wall thickness of which is smaller than that of the main pipe wall, is integrally connected with the inside of the pipe main wall, the section of the second pipe wall is substantially triangular, a bottom of the second pipe wall and predetermined portions of both the inclined walls at the bottom side adhere to a bottom of the main pipe wall and both the inclined walls, and a small space is formed between a top of the second pipe wall and the top of the main pipe wall.

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: Coaxial tubing systems incorporate bending sleeves of insoluble, compression resistant material with cold flow characteristics. Bending sleeves of length coextensive with a bend are dimensioned to substantially fill the annular space between inner and outer coaxial tubes, while also providing longitudinal fluid passageways between the tubes. Such bending sleeves are effective to enable bending of coaxial tubing systems by (a) transmitting bending forces to, from and between inner and outer tubes during bending, (b) restricting tube collapse, wrinkling and deformation during bending, and (c) maintaining spacing between inner and outer tubes after bending and limiting inner tube vibration, while (d) providing fluid passageways between the tubes for leak containment, leak detection, heating, heat dissipation and other auxiliary fluid flow purposes. Conductive spacers are provided for maintaining annular tube spacing, particularly at tube ends, and for enabling electrical grounding of the inner tube.

Abstract: An acoustically improved, air gap engine exhaust conduit having a dual wall, air gap, metal exhaust conduit of an outer jacket and a thin inner liner, the jacket having at least one exhaust gas inlet and an exhaust gas outlet, the liner having at least one inlet and an outlet, the jacket inlet and the liner inlet being adjacent each other, the liner being secured to the jacket adjacent the jacket inlet and the liner inlet, the liner outlet being optionally in engagement with the jacket, and the liner otherwise being spaced from the jacket over its length to form a continuous air gap from the liner inlet to the liner outlet, a pattern of indentation ribs protruding into or out of the jacket over substantially all of said jacket, each indentation rib protruding toward or away from the liner, and terminating short of the liner to be spaced from and not in engagement with the liner, to maintain the continuous air gap.

Abstract: A spacer clip for maintaining the coaxial spacing of the walls in a multiple wall chimney. A plurality of spacer clips are circumferentially positioned within the annulus between the walls. The clip attaches to the outer wall and includes a biasing arm which engages the inner wall to maintain the spacing between the walls. The biasing arm of the clips may be retracted to facilitate insertion or removal of the inner wall from within the outer wall.

Abstract: A flexible hose construction and method of making the same are provided, the flexible hose construction comprising an inner tube made of polymeric material, an outer sleeve of reinforcing material disposed in telescoping relation on the inner tube from one end thereof to the other end thereof, rib structure disposed between the sleeve of reinforcing material and the inner tube, the rib structure being disposed on the inner tube so as to define alternating coil structure of rib structure and coil structure of non-rib structure serially along the longitudinal axis of the inner tube in a like repeating pattern thereof, the coil structure of non-rib structure comprise coil structure of void space, and an outer tube of polymeric material disposed between the rib structure and the sleeve of reinforcing material so as to extend in a generally straight-line manner from coil structure of the rib structure to coil structure of the rib structure so as to tend to prevent the sleeve of reinforcing material from entering i

Abstract: A method for installing plastic liners in pipes includes the steps of providing a plurality of cylindrical tubular liners of plastic material of predetermined diameters. Ribs extend radially between the liners. The liners are deformed or collapsed to reduced overall diameters. The liners are introduced into the pipe. The cylindrical shapes of the liners in the pipe are then restored with the ribs spacing the liners one from the other.

Abstract: A double wall vent pipe is provided which comprises a first tubular wall that is helically corrugated to form radially outermost ridges spiraled around the outside of the first tubular wall and corresponding first recesses spiraled between the outermost ridges. The vent pipe also comprises a second tubular wall slidably disposed in a concentric relationship with the first tubular wall. The second tubular wall is helically corrugated to form radially innermost ridges which spiral around the inside of the second tubular wall and corresponding second recesses spiral between the innermost ridges. The radially innermost ridges are oriented in a direction oblique to the orientation of the radially outermost ridges such that a space between the first wall and the second wall will be maintained within the first recesses and the second recesses regardless of any bending of the vent pipe.

Abstract: A method of forming a dual tube conduit having a predetermined outer tube dimension, a predetermined inner tube dimension, and a predetermined gap between the tubes. A dual tube workpiece may be initially bent in one or more zones to a desired nonlinear configuration, the inner and outer tubes are hydroform expanded simultaneously to obtain the selected inner tube dimension, and the outer tube is then hydroform expanded to the desired outer tube dimension and to the desired gap therebetween, while the inner tube is held constant.

Abstract: A fire resistant plastic structure comprises a pair of parallel walls, wherein the spacing between the walls is filled with an array of mutually spaced strut elements, thereby providing a flow path for a cooling fluid throughout the spacing.

Abstract: A duplex metal pipe for damping wherein an inner pipe is inserted into an outer pipe with a clearance of 10 .mu.m to 150 .mu.m provided between an inner surface of the outer pipe and an outer surface of the inner pipe. The outer pipe and said inner pipe are formed of a steel pipe.

Abstract: A method of forming a tubular, double wall, air gap, exhaust duct component for an internal combustion engine, the resulting exhaust duct component, and the blank for such, involving providing an inner membrane duct element, with orifices therethrough spaced along its length, providing an outer structural duct element in 360 degree engagement with the inner duct element in the areas where forming and bending operations are to be performed, conducting such forming and bending operations, securing the resulting blank in a hydroforming die cavity, sealing the ends of the inner element to the ends of the outer element, plugging the ends of the inner element, injecting a liquid, preferably water, into the inner duct element and increasing the pressure on the liquid to expand the outer element away from the inner element and ultimately into conformity with the die cavity while the inner element floats in place, in a manner to create an air gap substantially over the full length of the duct component, i.e.

Abstract: A hose assembly and method of making the same are provided, the hose assembly having fluid passages therein for respectively conveying a volatile liquid in one direction from the container, the assembly comprising a flexible inner hose having an outer peripheral surface and defining an inner one of the passages, a flexible outer hose having an inner peripheral surface and being disposed around the inner hose, the inner peripheral surface of the outer hose and the outer peripheral surface of the inner hose defining an outer one of the passages, a coupling fixed to an end portion of the outer hose, a tubular fitting fixed to an end portion of the inner hose, and a holding unit holding the fitting and the end portion of the inner hose substantially concentrically within the coupling and the outer hose to define a continuation of the outer passage, the holding unit comprising a spider-like member having a ring telescopically disposed on the fitting and a plurality of substantially straight arms radiating outwardl

Abstract: A system for use with assisted human breathing systems which includes an enclosure adapted to receive a granular material for absorption of carbon dioxide from the air exhausted from a patient using the system. An exhausted air inlet is provided to the device, and a return air outlet is provided from the device to the user. The exhausted air inlet and the return air outlet are in communicative relation through the granular material contained within the apparatus. The enclosure which contains the granular material is insulated so that heat generated by the absorption of carbon dioxide onto the granular material is retained by the return air stream emitted from the enclosure. Insulated tubing can be provided to be connected between the device and the patient so as to decrease heat loss and condensation of moisture from the circulating air.

Abstract: A flexible hose construction and method of making the same are provided, the flexible hose construction comprising an inner tube made of polymeric material, an outer sleeve of reinforcing material disposed in telescoping relation on the inner tube from one end thereof to the other end thereof, rib structure disposed between the sleeve of reinforcing material and the inner tube, the rib structure being disposed on the inner tube so as to define alternating coil structure of rib structure and coil structure of non-rib structure serially along the longitudinal axis of the inner tube in a like repeating pattern thereof, the coil structure of non-rib structure comprise coil structure of void space, and an outer tube of polymeric material disposed between the rib structure and the sleeve of reinforcing material so as to extend in a generally straight-line manner from coil structure of the rib structure to coil structure of the rib structure so as to tend to prevent the sleeve of reinforcing material from entering i

Abstract: In a coaxial piping system for the transport of toxic and hazardous gases having an inner conduit wherein hazardouses gases are transported therethrough and having a spacer helically wound about the inner conduit within a volume between the inner conduit and an outer conduit.

Abstract: A spiral-wound tube formed of a hollow section 1 is provided wherein the hollow section is joined together by extruder welding or gluing. The hollow section is coextruded and comprises an outer layer (2) of pastic with a homogenous surface and good weldability. An intermediate layer 3 is provided of a modified polymer and an inner layer (4) is also provided. The interior space defined by the tubular layers (2, 3, 4) is preferably rectangular in cross-section.

Abstract: A one-end closed ceramic double tube has an integral structure comprising: a one-end closed outer cylinder; an inner cylinder extending concentrically with said outer cylinder; and at least one support portion extending laterally to bridge said outer and inner cylinders and longitudinally from near the closed end at least up to the open end of said outer cylinder, wherein the ratio of a total thickness of the support portions in contact with the inner circumference of the outer cylinder to the inner circumference of the outer cylinder at cross section is most 25%, and preferably, the outside diameter ratio of the outer cylinder to the inner cylinder is at most 3.3. An air passage formed on the inner cylinder near the closed end side of the tube communicates between the inner passageway inside the inner cylinder and the outer passageway defined by the inner and outer cylinders.

Abstract: Composite tube, which is a sandwich structure, comprising a plurality of fiber strata, each made of epoxy-saturated fibers, and at least one layer of a honeycomb material sandwiched between. The fiber strata and the honeycomb layers are in alternating sequence. Each fiber stratum may include a fiber web surrounded by a fiber cable, which consists essentially of a large number of twisted fibers arranged in the axial direction and parallel to each other. The composite tube of this invention is very light in weight, yet has tensile strength and other mechanical properties corresponding to those of conventional tubes made of steel. The tube of this invention is especially useful as a guide roller or an expansion shaft.

Abstract: A pipeline casing insulator to support a coated pipe within a tubular, metallic casing. The pipeline casing insulator comprises a flexible belt formed of a material that is capable of bonding to an organic resin. A plurality of parallel bar-like runnners are formed fron an insulative and non-abrasive polymer concrete that is cast onto an outer facing surface of the belt. The belt is preferably a strip of an organic non-woven material. The polymer concrete is preferably a mixture of a thermosetting polymer resin, such as epoxy, polyester or polyrethane, and an aggregate. The aggregate preferably comprises a mixture of substantially incompressible coarse particulate material, such as sand or gravel, and fine filler material, such as calcium carbonate, silica flour, or kaolin. The inner facing surface of the belt preferably has a mastic coating covered by a release paper that can be removed, to allow attachement of the belt to the outer surface of the pipe by circumferentially wrapping the belt around the pipe.

Abstract: There is disclosed a method of fabricating a double pipe capable of attenuating vibration. The pipe can be used in an automobile exhaust system. The method is initiated with forming a coating either on the outer surface of an inner pipe or on the inner surface of the outer pipe. The coating is made from an epoxy resin, an acrylic resin, or other resin. The inner pipe is inserted into the outer pipe, and then they are brought into intimate contact with each other via the coating to couple them together. The coupled pipes are heated beyond 400.degree. C.

Abstract: A swimming pool bi-flow filter has been described herein. The invention includes the following integral structural components: an influent conduit, an effluent conduit, an influent trough and a plurality of influent and effluent laterals. Ports in the influent conduit and the influent trough receive water from a source, such as swimming pool. The water entering the influent conduit flows upwards through the influent laterals to the effluent laterals, while the water entering the influent trough overflows into the filter and flows downwards to the effluent laterals. The water then passes through the effluent laterals and into the effluent conduit. As previously mentioned, the conduits, trough and laterals are an integral part of the structure, which necessarily means that thinner materials may be used in constructing the filter, without the loss of strength or durability.

Abstract: A method and apparatus for reducing friction at the interface between a liquid and a solid. A solid interface member includes a plurality of apertures over the entire surface which are to be in contact with the liquid. The apertures are of a size and dimension such that the surface tension of the liquid will not allow the liquid to pass through the apertures, but which will allow a gaseous material with less surface tension than the liquid to pass therethrough. The gaseous material is thereafter motivated through the apertures to interpose a gaseous layer at the liquid solid interface which reduces the drag coefficient therebetween, which would otherwise result from relative motion between the solid interface member and the liquid.

Abstract: A double-containment pipe assembly is provided with an inner carrier pipe, an outer containment pipe and supports for maintaining concentrically therebetween. The supports may define resilient support clips of unitary construction. Each resilient support clip includes a mounting portion defining a section of a cylinder from which a plurality of support legs extend. One end of each support leg may be tapered to facilitate insertion into the containment pipe. One end of the support clip may also include a reinforcement flange extending partly thereabout to prevent overstress related damage to the support clip. The support clips may alternatively define unitarily molded planar structures having a circular inner support surface and a plurality of spaced apart outer support surfaces defining arcs of a circle concentric with the inner support surface.

Abstract: The nonfreezing pipe with a double wall construction comprises an inner shell having openings at its opposite ends, an outer shell extending axially around the inner shell to form an annular space surrounding the inner shell, and at least one end closure member connecting between one end of the outer shell and the external wall portion of the inner shell. The annular space is evacuated.

Abstract: A coaxial vapor recovery hose assembly comprising an inner hose, an outer hose, and structure for holding said hoses in concentric relationship; wherein the inner hose is substantially reinforced to be relatively incompressible as well as being capable of bearing tensile stress applied to the assembly and having an outside diameter; wherein the outer hose is corrugated and has an inside diameter larger than the outside diameter to define a vapor passageway therebetween.

Abstract: A pipe section of an outer metallic pipe and a nonmetallic inner lining is provided so that the lining can be removed. To this end, the lining consists of lining segments, the terminal members of which are braced against the ends of the pipe in a form fitting manner and the successive lining segments can interfit with, for example, complementary frustoconical formations.

Abstract: Two concentric corrugated metal tubes have a space therebetween in which there is arranged a superinsulation layer. Between the inner tube and the superinsulation layer there is located a helical spacer to ensure an annular channel to facilitate the evacuation of the space between the corrugated tubes. The spacer is formed of interlaced strands to reduce heat conduction therethrough.

Abstract: An underground valve box for encapsulating a service valve selected from a variety of valves having vertical or horizontal cylindrical bodies with horizontal inlet and outlet lines disposed linearly through the body consists of an upright with a horizontal member defining upper and lower portions therein, a plurality of concentric steps descending downwardly and inwardly from the horizontal member into the lower portion of the base, a pair of V-shaped seats diametrically disposed in the member, a pair of diametrically oposed topwardly accessible notches in the upper portion of the base aligned with the V-shaped seats and a horizontal external lip and a body with lower and upper vertical concentric barrels integrally connected by an inwardly and upwardly tapering intermediate segment.

Abstract: A transition pipe for location between an afterburner pipe and a jet nozzle in a jet pipe assembly for a turbojet engine comprises a funnel shaped inner casing tapering downstream from a circular section at its upstream end to a quadrangular section at its downstream end, a horn shaped outer casing surrounding the inner casing and flared downstream from a circular upstream end section to a downstream end section formed of four joined segments of generally parabolic shape, and a plurality of peripherally spaced, longitudinally extending stiffeners interconnecting the inner and outer casings in the space therebetween.

Abstract: An apparatus for pneumatically conveying bulk material in particular bulk material which is difficult to handle includes a conveyor line having a plurality of conveyor line sections for transporting the bulk material. Each of the conveyor line sections comprises a rigid outer pipe and an elastic inner pipe of an outer diameter which is smaller than the inner diameter of the outer pipe in pressureless state. The connection of adjacent conveyor line sections is attained by a sectional ring which is placed over each axial end of the outer pipe and about which the elastic pipe is folded outwardly, a flange element arranged between the thus shaped axial ends of adjoining conveyor line sections, and external brace elements extending between successive flange elements for bracing the latter so as to connect adjoining conveyor line sections in pressure-sealed manner.

Abstract: A double-containment thermoplastic pipe assembly is provided to prevent against potentially hazardous spills or leaks of chemicals and the like. The double-containment pipe assembly comprises a containment pipe and at least one carrier pipe disposed therein. The carrier pipe is retained in spaced relationship to the containment pipe by support clips with outwardly extending radially aligned legs. Restraint couplings may be disposed at selected locations along the double-containment pipe assembly. The restraint couplings include a carrier portion, a containment portion and a connecting portion extending therebetween. Double-containment pipe fittings also are provided to ensure complete double-containment protection throughout an entire double-containment pipe assembly.

Abstract: A multiple walled metal chimney formed of a plurality of axially joined chimney sections each of which utilizes positionally captured spacer rings. Joint clamps are used to connect the chimney sections for formation of the complete chimney conduit. The spacer rings are positionally captured between annular shoulders formed in the inner and outer walls of the chimney sections to eliminate welding of the rings. The rings may include an expansion joint to allow circumferential expansion and contraction of the ring with the walls.

Abstract: A pipeline casing insulator to support a coated pipe within a tubular, metallic casing. The pipeline casing insulator comprises a flexible belt formed of a material that is capable of bonding to an organic resin. A plurality of parallel bar-like runners are formed from an insulative and non-abrasive polymer concrete that is cast onto an outer facing surface of the belt. The belt is preferably a strip of an organic non-woven material. The polymer concrete is preferably a mixture of a thermosetting polymer resin, such as epoxy, polyester or polyurethane, and an aggregate. The aggregate preferably comprises a mixture of substantially incompressible coarse particulate material, such as sand or gravel, and fine filler material, such as calcium carbonate, silica flour, or kaolin. The inner facing surface of the belt preferably has a mastic coating covered by a release paper that can be removed, to allow attachment of the belt to the outer surface of the pipe by circumferentially wrapping the belt around the pipe.

Abstract: A support assembly (1,11,31) for mounting within a vessel (3) which may be subjected to an inwardly acting pressure differential, comprises a support member (2,12) which is in contact with an internal surface, of the vessel so as to define a recess (4,14). In use the recess is filled with an incompressible fluid, which may be an hydraulic oil. The support member (2,12) may be further provided with an intensifier (19,32) which produces a positive pressure differential between the fluid in the recess (4,14) and the pressure acting on the vessel 3. The effect of this is to induce a tensile loading in the vessel wall in the vicinity of the recess (4,14) and thereby provide support for the vessel.

Abstract: A flexible, thermally insulated conduit has a central pipe and a coaxial casing spaced therefrom by annular spacers, defining a series of seated chambers. The chambers are filled with a foam material.

Abstract: The irrigation hose comprises two tubes disposed one within the other, at least one of the tubes being grooved. The ungrooved tube forms with the groove or grooves of the other tube continuous secondary ducts over the entire length of the hose. Inlet ports and outlet ports delimit in the secondary ducts sections of a predetermined length, each yielding a flow capable of continuously drip-irrigating a plant in the area to be irrigated. The outlet ports and the inlet ports are distributed along spiral lines if the secondary ducts are straight and along straight lines constituting generatrices of the hose if the secondary ducts run along spirals.

Abstract: Multi-layer compensator with spacers arranged between the layers and with the spacers having the shape of flat strips distributed parallel to the longitudinal axis of the compensator over the circumference, with a gap between spacers.

Abstract: A sandwich-type structure comprises two external metal plates and an inner core held between the two external plates and constituted by a metallic screen netting or grid. In order to be easily stamped said structure comprises, between the plates, a layer of adhesive making the bond between the plates and the core. This adhesive is located only inside the meshes of the core, whereas the contact zones between the core and the plates are left free of adhesive. In the case where all three elements are in weldable metal, spot welding remains possible, if necessary, on the periphery or through the mass, these weld points being in this latter case sufficiently far apart to allow a geometrical deformation of the meshes of the metallic netting or grid constituting the core.

Abstract: A plastic pipe consisting of an outer corrugated plastic pipe and an inner smooth wall consisting of a wear resistant elastomer, particularly a thermoplastic rubber fixed in the inner bottoms wave valleys to said outer corrugated pipe. The inner wall consists of a pipe which has been coextruded with the outer corrugated pipe so that the inner and outer pipe are heat welded to each other.The cavities between the inner pipe and the corrugations may be filled with a foam plastic.This plastic pipe is used for repairing or renewing a sewage pipe by installing such a pipe from a vertical shaft of the sewage system into the sewage pipes. The interstices between the outer side of the corrugation and the inner side of the sewage pipe may be filled with a mortar.

Abstract: A heat exchanger utilizes a double walled heat transfer tube wherein the inner tube has a knurled external surface engaging the inner surface of an outer tube to provide multiple interconnected leak paths. The inner and outer tubes are attached to inner and outer tube sheets by roller expansion.

Abstract: The phonic deadening device comprises a cylindrical sleeve (5) with double walls, made of an elastic material and the axial traversing opening of which serves for the passage of the flux of the liquid. Both walls of this sleeve define between them an empty annular space (6), which is closed in a tight manner by an annular sealing element (7). This element further serves to position and to maintain the sleeve in a service position in the conduit.

Abstract: A protective spacer for fittings and the like consists of tubular plastic body member with a transverse end wall having a plurality of radiating slits therein forming plural gripper tabs. The body member is formed of thermoplastic material and the tabs are resiliently deformable into a tunnel configuration adapted to receive a portion of a fitting member and to be self-supported thereon. The spacer provides radial spacing from the thus supported fitting portion and axial spacing for opposed structures in abutment with the transverse end wall and free end of the body member.

Abstract: A double-walled chimney comprising inner and outer concentric pipes providing an annular insulating space between them is made up of coaxial end-to-end inner pipes surrounded by concentric, coaxial outer pipes. The inner pipes meet at a junction transverse or radial to the basic axis and are interconnected by an inner, annular ring. The outer pipes stop axially short of meeting so that an annular gap exists that exposes or opens to the junction of the inner pipes. Circumferentially spaced apart spacers are secured to the inner ring and project outwardly as well as axially in opposite directions to engage the outer pipes to keep the latter spaced outwardly from the inner pipes and further to stabilize the outer pipes axially. An outer band connects the outer pipes together and functions also to close the gap between the outer pipes and thus to complete the insulating space at the outer pipe gap.

Abstract: A double-walled quartz-glass tube for semiconductor-technology processes. The overall structure comprises an inner tube surrounded by a coaxially positioned outer tube. An annular space is left between them. The ends of the tubes that face in the same direction each have a closure. A processing-gas supply connection is mounted on the inner-tube closure and extends tight through the outer-tube closure. The outer tube is sealed tight at the other end against the outside of the inner tube. The outer tube has connections for supplying and removing a scrubbing gas. The object is to prevent the occurrence of defects due to differences in the extent that the two tubes expand to as the result of the heat generated during processing. The inner tube has a diameter of at least 150 mm. At least one of the closures is essentially flat. The axis of the processing-gas supply connection is in alignment with the axis of the inner tube.

Abstract: A transport conduit for bulk material is formed of a rigid outer tube and an elastic inner tube of substantially smaller diameter. The inner tube is hermetically sealed at each of its ends to the conduit section so as to form a closed annular chamber between the inner elastic tube and the rigid outer tube. Communicating through the wall of both the outer and inner elastic tubes are relief and check valves sealed with respect to the elastic inner tube so as to maintain the integrity of the annular chambers. The valves are connected to a secondary gas supply from which air under pressure is directed into the conduit to assist in the transport of the bulk material. The annular chambers are serially connected by bridging tubes passing from one section to the adjacent section, thereby interconnecting each of the annular chambers in an outer parallel conduit to permit atmospheric air to move serially through them from one end of the transport conveyor to the other.

Abstract: A pipeline system designed for withstanding elevated levels of pressure from external sources. Pressurized gas is introduced into an annulus between an outer pipe jacket and insulation material, which in turn surrounds a pipe, to supply structural support.