Abstract: A heat exchange system for heating, ventilation, and air conditioning (HVAC) may comprise a burner box, a hot collector box, and a heat exchanger tube. The heat exchanger tube may be disposed between, and in fluid communication with, the hot collector box and the burner box. The heat exchanger tube may be rigidly connected to at least one of the hot collector box or burner box by a swaged joint.

Abstract: A pipe joining structure adapted to join a pipe to a fluid passage of an equipment housing. An end portion of a pipe is bent by about 90 degrees to form a bend portion and a tip of the bend portion is fitted into an opening of the fluid passage. The pipe joining structure includes a stay fitted over the bend portion of the pipe, a tip of the pipe is formed with a flange, and an O-ring fitted between the stay and the flange of the pipe. The tip of the pipe is joined to the equipment housing by fixing the stay to the equipment housing.

Abstract: A piston with a piston rod coupled thereto is inserted in a cylinder, which sealingly contains oil. An oil flow generated by movement of the piston is controlled by a damping force generation mechanism, thereby generating a damping force. A separator tube is disposed around the cylinder, and the oil is transmitted to the damping force generation mechanism through a branch tube integrally formed on a cylindrical sidewall of the separator tube. The branch tube is tapered at the outer circumferential portion thereof with the outer diameter thereof reducing toward the distal end of the branch tube.

Abstract: A sealing system with sealing ring for coupling members for connecting pipes to user devices such as pumps, compressors, tanks and the like, by means of a shank that screws into a seat provided on the said user devices, comprises a groove and an annular seal. The groove, which is shaped according to the teaching of international standard ISO UNI 5711-65, is situated in a position adjacent to the shank of the coupling member, at the opposite end from the end of the shank. The groove is able to receive the annular seal designed to be pressed against an abutting wall or a flared portion of the seat of the user device in order to establish the seal. In the original configuration prior to assembly, the sealing ring is of an essentially cylindrical shape, whereas, in the configuration of compression on the groove, it assumes a shape adapted to the profile of the groove, which is generally frustoconical.

Abstract: A drain fitting includes a cylindrical body that is sealed against a floor drain cover to confine condensate liquid, such as from an air conditioner, inside the perimeter of the drain fitting by tightening a self-tapping screw that is inserted into a hollow stem in the center of the central body portion of the drain fitting, pulling a gasket in the bottom surface of the drain fitting against a floor drain cover. A nipple connected to the drain fitting receives a condensate drain hose. A vent opening is formed into a side wall of drain fitting.

Abstract: A short cylindrical connection cup is fitted and brazed to a pipe fitting port of a metallic tank. Afterward, the extremity of a resin pipe is inserted via an O-ring into the connection cup, and a caulking claw of the connection cup is caulked to press a flanged portion of the resin pipe.

Abstract: A watertight, through wall connector has a tubular body, an O-ring and a holder. A neck is formed on one end of the body has to be bent to hold the holder. With such a connector, the neck is not easily cracked during the pressing process, and the deformation of the body will not occur. This can provide a watertight seal. In addition, the O-ring can fully expand by means of being squeezed between the inside wall of the reservoir and the holder. This can provide a watertight seal due to the full expansion of the O-ring.

Abstract: An cylindrical convex portion of which opposite ends are open is integrally formed onto a fuel tank made of RDPE therewith so as to inwardly extend in the fuel tank, to provide an opening thereon. A press-fit portion of a filler hose connecting pipe made of PA as a tubular member is press-fitted in the cylindrical convex portion to connecting the tubular member to the fuel tank. At least one annular projection is provided on the outer peripheral surface of the press-fit portion of the tubular member so as to bite in the inner peripheral surface of the cylindrical connvex portion. A face of the annular projection in direction axially of one end of tubular member is formed so as to extend outwardly and inclinedly with respect to the axial direction of the tubular member form one end toward the other end thereof.

Abstract: A pipe fitting for pipelines comprises at least one seating (12) for receiving the end of a pipe to be coupled. The seating surface which is intended to come into contact with the surface of the pipe end, is made of a material having a chemical adhesion reaction on reaching of a predetermined temperature and, around the seating (12), the pipe fitting incorporates an electric winding (14) for heating of the material when an electric current passes therethrough in order that said predetermined temperature can be reached. Advantageously, the seating (12) is formed in a sleeve (17) incorporating the electric winding (14) which in turn is incorporated into the pipe fitting body.

Abstract: A method and apparatus are disclosed for a thermoplastic profile wall pipe joint or weld assembly without the use of a coupler to provide for a leak free pipe joint with substantially flush interior and exterior surfaces. The pipe joint consists of configuring the two pipe ends to be joined by removing substantially all of a first wall and the helical rib from the first pipe end, removing a portion of the helical rib from the second pipe end, coupling the pipe ends together and heating the weld assembly couple to fusion weld the pipe ends together. An electrical resistance element is provided for and placed within the pipe joint to provide the required heat. Also disclosed is the use of a thermoplastic sheet with the electrical resistance element to allow the end margins of the electrical resistance element to overlap without shorting by separating the end margins radially from one another and to allow for a more uniform fusion welded pipe joint.

Abstract: Multilayer fluid conduits are formed by adhering to a tubular outer surface of a metal pipe, a thermoplastic outer layer. The outer layer permits ends of the multilayer conduit to be joined together in leak-proof fluid conduit systems simply by adhering the conduit ends with compatible thermoplastic fittings. For fire protection systems, the preferred metal is steel, the preferred thermoplastic is CPVC and the preferred adhesive is heat activated. The adhesive coated metal pipe is preheated and the CPVC is extruded onto the outer surface of the heated metal pipe. Through the use of fire resistive CPVC, the multilayer conduit systems of the present invention can be installed in more severe fire threat areas than can existing, all plastic piping, including all CPVC piping systems. The conduit is assembled into systems on site simply by cutting and direct bonding with ordinary, all plastic fittings using appropriate bonding agents such as solvent based adhesives.

Abstract: The present invention provides improved heat-shrinkable electrofusion fittings and methods. The fittings are basically comprised of an electrically heatable tubular plastic outer member which is shrinkable when heated to a transition temperature, an electrically heatable tubular plastic inner member positioned within the outer member which has a fusion temperature higher than the transition temperature and an electrically activated induction coil for energizing the inner and outer members.

Abstract: An assembly mating first and second tubular bodies is disclosed. The mating assembly includes at least a sleeve structure forming a part of the first tubular body and defining an inner receptacle surface region, a compression loading assembly integrally formed with, constituted by, or otherwise securable to the second tubular body and at least partially received in the sleeve structure, and a cured adhesive bond positioned between an exterior surface region of the compression loading assembly and the inner receptacle surface region to couple the sleeve structure to the compression loading assembly. The compression loading assembly is laterally expandable at at least the exterior surface region thereof and constructed and arranged relative to the cured adhesive bond so that expansion of the exterior surface region compressively loads the cured adhesive bond in a substantially lateral direction.

Abstract: A repair fitting is provided for sealably connecting ends of a pipeline, when a damaged section of the pipeline has been removed. In a preferred embodiment, the pipeline ends are connected using the repair fitting with two stab fittings. The repair fitting includes a first and second piston and a first and second cylinder, wherein the first piston is slidable in the first cylinder and the second piston is slidable in the second cylinder. In an alternate embodiment, two fusion joints are used with the repair fitting to sealably connect the ends of the pipeline. A method is provided for making a repair fitting and a method is also provided for repairing a damaged section of a pipeline.

Abstract: A through wall connector assembly which provides a substantially water-tight and air-tight seal around the circumference of an opening in a wall to allow for sealed extension of a line through the opening in the wall. The assembly includes a male member adapted to extend through the opening in the wall. The male member receives a first section and a second section of the line to be extended through the wall. A female member is attached to the male member to secure the male member and the female member in the wall. A first seal is positioned adjacent the male member on one side of the wall and a second seal is positioned adjacent the female member on the opposite side of the wall to prevent the ingress of air, moisture and water through the opening in the wall.

Abstract: A vacuum cleaner hose assembly has a corrugated, flexible hose with fittings at opposite ends for connection to the vacuum cleaner suction inlet and to a cleaning head. A tube or cable extends along the assembly for supply of cleaning fluid or electrical power to the cleaning head. The tube or cable is retained with the hose by means of a U-shape channel provided as a separate member bonded to the outside of the hose. The tube or cable extends within the channel as a loose fit so that it can move along the channel on flexing of the hose, thereby helping maintain flexibility of the assembly.

Abstract: For nozzle replacement, repair and initial installation in ASME pressure vessels, disclosed are nozzles, nozzle assemblies and nozzle repair assemblies, all of which are mechanically attached and mechanically sealed to the vessel, i.e., without any welding to the vessel, and in most embodiments without any welding at all. For nozzle replacement, a part or the entire existing nozzle is removed and a partial or full replacement nozzle or nozzle assembly is mechanically attached and mechanically sealed to the vessel. For nozzle repair, the existing nozzle within the bore is not removed, and a mechanical seal is provided for the existing nozzle which may also be welded or mechanically attached to the repair assembly.

Abstract: A method for producing a microfluidic coupler includes the step of producing a first mask on a top surface of a wafer. The first mask defines an insertion channel pattern selected to correspond to the cross sectional shape of a capillary. The wafer is etched through the first mask to form an insertion channel. A second mask is produced on a bottom surface of the wafer. The second mask defines a subchannel pattern selected to match the diameter of the bore of the capillary. The wafer is etched through the second mask to form a subchannel connected to the insertion channel. The capillary is inserted into the insertion channel such that the capillary is in fluid communication with the subchannel. In one embodiment, a capillary guide is secured to the wafer to facilitate insertion of the capillary into the insertion channel. The capillary guide has a tapered guide channel aligned with the insertion channel for guiding the capillary into the insertion channel.

Abstract: The present invention relates mainly to a sealing ring and to a method of mounting it in a groove. According to the present invention, the sealing ring is twisted before being mounted in the groove so that the reaction forces retain it therein. The retention capabilities of the present invention is improved for sealing rings of a section that includes a projection directed towards a wall of the groove that provides radial support. The present invention applies more particularly to the mechanical, motor vehicle, and aircraft industries. The sealing ring of the present invention can be used, in particular, in association with the manifolds of turbocompressors, and with air inlet and outlet manifolds, in particular those made of plastics materials, as used in the motor vehicle industry.

Abstract: Multilayer fluid conduits are formed by adhering to a tubular outer surface of a metal pipe, a thermoplastic outer layer. The outer layer permits ends of the multilayer conduit to be joined together in leak-proof fluid conduit systems simply by adhering the conduit ends with compatible thermoplastic fittings. For fire protection systems, the preferred metal is steel, the preferred thermoplastic is CPVC and the preferred adhesive is heat activated. The adhesive coated metal pipe is preheated and the CPVC is extruded onto the outer surface of the heated metal pipe. Through the use of fire resistive CPVC, the multilayer conduit systems of the present invention can be installed in more severe fire threat areas than can existing, all plastic piping, including all CPVC piping systems. The conduit is assembled into systems on site simply by cutting and direct bonding with ordinary, all plastic fittings using appropriate bonding agents such as solvent based adhesives.

Abstract: A reinforced plastic pipe fitting is made by using interference fit techniques to apply an outer pipe over a straight section of inner pipe. Appropriate sections of the outer pipe are then cutout. After arranging the fitting to the desired shape, faces of the cutout section are butt-fused together to form a fitting having a reinforcing layer over the shaped inner pipe.

Abstract: In a process for the connecting of plastic tubes the wall of which has a corrugated cross section by electro-thermal welding, filling cores of plastic are inserted in the corrugation troughs of the tubes to be connected on both sides of a welding joint in order to form a resting surface on the outer circumference of the tubes and an electric heating mat which surrounds the resting surface of all filling cores is placed on the resting surface.

Abstract: A joint between two hollow pipes is formed by inserting the pipes into a sleeve. The sleeve is made of a similar or compatible material to that of the pipes which are to be joined. The inner diameter of the sleeve increases from a middle portion outwardly to two end portions. The sleeve includes a pair of tapered collars which engage each end portion and abut the middle portion. Relative rotation of the pipes and sleeve causes melting and mixing of the pipe and sleeve surfaces. This mixing action eliminates the weld line present in known systems.

Abstract: A flangeless pipe joint for polymer-lined piping in which the piping is joined by a coupling and the lining is slip, loose, interference or swaged fitted into the pipes and joined at the ends thereof against relative movement.

Abstract: In a closure fitting assembly two identical fittings are adapted to be coupled together in a mirror-image relationship for closing a gap between containment components in a double-containment system. Each fitting defines a first axially-extending fusion surface located on one side of the fitting; a second axially-extending fusion surface located on an opposite side of the fitting relative to the first axially-extending fusion surface; a first circumferentially-extending fusion surface located on one end of the fitting; and a second circumferentially-extending fusion surface located on an opposite end of the fitting. Axially-extending fusion wires are interposed within the seams formed between opposing axially-extending fusion surfaces, and circumferentially-extending fusion wires are seated against each circumferentially-extending fusion surface for receiving electric current to heat the wires and in turn fuse opposing surfaces together.

Abstract: A molded part has welding sleeve portions (2) which are each provided with a heating coil (3a, 3b) for joining to tubular parts. A cylindrical sleeve end part (7) can be tensioned by at least one tensioning system against the inserted tubular part, thus providing fixing and holding of the parts before welding and during welding.

Abstract: A welding sleeve includes a sleeve body having a recess for receiving a plug contact. The recess has sidewalls and a bottom wall. The bottom wall is provided with a projection which defines with the side walls of the recess a pair of slots. The plug contact includes an insertion part adapted to be received within the recess. The insertion part includes leg portions to be received in the slots of the recess and a slit between the legs adjacent the top surface of the projection. The slit receives a portion of the heating element which rests on the top surface of the projection. The width (b) of the slit is less than the diameter (d) of the heating element so as to insure good electrical contact.

Abstract: The apparatus enables a saddle-shaped parallel connection tapping to be installed on a pipe from the top of a hole in the ground. The apparatus comprises a frame having a tipping thrust device in the form of a spade controlled by rodding and designed to take up a position beneath the pipe, and a removable tapping positioner guided in the frame and including a tubular column that is split along one of its generator lines and that is fitted at its bottom end with a disconnectable module engaging the rims of the tapping. Means are provided on the frame to exert downwards pressure on the tapping support module in selective manner, and the removable module includes means for welding the tapping to the pipe. A device for driving a plug or a perforator device can be inserted in the cylindrical column of the tapping positioner from above.

Abstract: The present invention is directed to a method for making service connection to polyethylene replacement sewer pipe. Specifically, the method involves the steps of (1) locating the service; (2) excavating an opening less than two feet in diameter from the surface to the polyethylene replacement pipe at the service; (3) introducing a fusing apparatus on top of the polyethylene pipe and fusing a stack to the polyethylene pipe; and (4) drilling a opening into the polyethylene pipe through the fused stack. Before drilling the opening into the polyethylene pipe, the stack may be tested to make certain that there are no leaks in the fusing step and that the stack is securely connected to the polyethylene pipe.

Abstract: A pipe connector for liquid-conducting conduits is made of polymers and comprises a core part and a sleeve part for receiving the core part. The core part and sleeve part are each adapted for spin-welding with a polymer conduit to form a permeation-tight connection of pipe conduits made of the same polymers. The core part and the sleeve part each have a cylindrical connection region for spin-welding which includes a cross-sectional narrowing and an annular groove.

Abstract: A flangeless pipe joint including lined pipes with the end section of the outer pipe spaced radially outwardly from the liner and insulating material filling the space between the end sections of pipe and liners. The ends of the liners are sealed to each other and the outer pipe ends are joined by an outer sleeve.

Abstract: A boltless, reusable flange system for joining metal piping includes a circular, wedge-shaped tongue on an upper flange for mating with a groove containing a fusible alloy in a lower flange. The lower flange includes a heating element for melting the fusible alloy, and a thermocouple device to sense the alloy temperature. Heat can be controlled and supplied from a remote source and monitored by a remote temperature indicator. The upper flange is positioned above the lower flange, tongue and groove aligned, and the lower flange is heated until the fusible alloy melts to allow the upper tongue to settle down within the lower groove. Upon removal of the heat, the alloy hardens to further bring the two flanges together in a solid and sealed couple, compressing an optional gasket.

Abstract: The invention disclosed herein provides nozzles for vessels such as a pressurizer vessel, reactor vessel or piping in a nuclear power facility, and methods for attaching and sealing the nozzles to the vessels without any welding at all, i.e., without using a structural or seal weld. The nozzles are clamped or bolted to the vessel or attached by an interference fit, and a mechanical seal is obtained using gasket material and/or contacting, preferably polished, metal surfaces. Some embodiments of clamping the nozzle to the vessel comprise tightening a nut on the threaded end of the nozzle projecting from the bore in the vessel against the vessel, and structure which prevents the nozzle from being withdrawn through the bore, thereby clamping the nozzle against the vessel. Another embodiment of clamping a nozzle to the vessel comprises a sleeve threaded in the bore and forcing an interfering portion of the nozzle body into engagement with the bore.

Abstract: An apparatus for winding a heating wire on a core for forming the inner periphery of an electric melt-bonding joint which comprises a core in a generally cylindrical shape which is capable of rotating around its axial center, the core being relatively moved in the axial direction with respect to a heating wire, an engaging piece mounted on the core, which has a holding portion for holding a heating wire, and a fixing means to fix a terminal pin to the leading end of the heating wire, wherein the engaging piece has a holding portion for holding the terminal pin, whereby the heating wire is wound on an outer peripheral portion of the core by rotating the core.

Abstract: A quick connect coupling for tubing. The coupling includes a tubular male connector member adapted to be telescopically received within a tubular female connector member assembly. The female assembly includes a first member defining a seal bore and a cylindrical socket portion forwardly of the seal bore. A second female member includes a cylindrical portion which plugs into the socket of the first member and is held in position relative to the first member by sonic welding. A plurality of circumferentially spaced feet on the inner end of the second member are positioned proximate the seal to hold the seal in the seal bore and further engage the outer periphery of the pilot portion of the male member to minimize cocking of the male member relative to the female assembly.

Abstract: A resin hose connecting structure includes a resin hose including a hose body and a connecting portion formed coaxially and integrally with an end portion of the hose body and having an inserting inner peripheral surface, and a mating member made of structural material having a tubular inserting end portion for inserting into the connecting portion of the resin hose. The tubular inserting end portion includes a ring-shaped contacting surface and an inserting outer peripheral surface. In the hose body, at least the end portion is made of hard thermoplastic resin and is molded by a blow molding method. The connecting portion is made of soft thermoplastic resin and is molded by an injection molding method.

Abstract: An apparatus which creates a pre-engineered solvent bond is disclosed which allows the bond characteristics of the resultant solvent bond to be predetermined. These characteristics can thus be chosen by the part designer with confidence that inherent variations in the assembly process will not unduly impact the resultant bond. The design establishes a specific volume through removable shims. Solvent added to this volume acts to dissolve material so that the predetermined bond characteristics are created.

Abstract: An externally threaded fitting for use in coupling a fluid-conducting tube to a fluid-processing system threaded entrance opening is provided with a tapered-bottom groove immediately above and adjacent the fitting external thread, and with a doubly-tapered, polytetrafluoroethylene material seal element contained in the tapered-bottom groove. Upon proper installation in the system threaded entrance opening, the doubly-tapered seal element is fully isostatically compressed with total concealment of fitting external threads.

Abstract: A sealed connection system for connecting a pipe carrying a hot fluid to a plastic member. The plastic member has a wall having an orifice extending therethrough. The sealed connection includes an internal projection formed in the wall and projecting into the orifice, and an annular seal lining the internal projection. The connection further includes a lip positioned on an exterior surface of the wall and at least partially surrounding the orifice. Also provided is a heat shield bell fastened to the pipe and having a flared portion. The flared portion has an external flange bearing on the annular seal. The bell is insertable into the orifice. Further, the connection includes a pin insertable into the lip for fixing the external flange against the annular seal.

Abstract: A device for installation in a building wall or floor to provide a passthrough opening for pipes, tubing, and the like includes an axially open first end and a second end closed by a transverse wall. A ring of intumescent material fills the axially open first end of the housing, and in one embodiment, a foam plastic filler material substantially fills the housing between the intumescent ring and the transverse wall. The intumescent ring can be provided with a central opening sized to engage with an interference fit a tube or pipe passing through the device. Alternatively, the ring can support a tube coupling for providing a tubular connection within the device to receive and couple pipes on opposite sides of the building wall or floor in which the device is installed.

Abstract: A combination fluid flow port which can be used as both a full size threaded port and a full size flange port is provided with an annular ring constructed and arranged to fit closely within a counterbore in the end of a threaded hole in the port to provide a face aligned with and extending radially inwardly from the mating face of the port body for use in enclosing the O-ring seal of a flange type male half connected to the port.

Abstract: A connector assembly includes a connecting block and mating adapter for attaching an automotive refrigerant line to a condenser tank. A port/passageway is provided within the connecting block to receive a nipple on the adapter for communicating fluid from the refrigerant line to the condenser tank. The connecting block is securely welded or brazed to the side wall of the condenser tank providing a secure, leak-proof joint. A retaining bolt securely maintains the connection of the adapter to the connecting block.

Abstract: A high pressure fitting system includes a body having a passage therethrough to provide fluid communication between an associated fluid system and a female port. The body includes a first groove adapted to receive a seal member that defines a primary seal when inserted in the female port. A frusto-conical portion on the body cooperates with a frusto-conical region of the female port to define a secondary metal-to-metal seal. A second groove in the body receives a pressure transfer ring which is partially captured by a fastening sleeve freely received around the body. Rotation of the fastening sleeve results in axial advancement of the male fitting assembly via the pressure transfer ring to establish the secondary seal.

Abstract: A pressure tank connector apparatus is described, including a fitting body having an integral hollow sleeve portion projecting from one end thereof adapted to extend into an opening in the tank wall and be crimped about an internal flange or lip portion of the tank wall surrounding such opening with a sealing ring of elastomer compressed between a gripping flange portion of the fitting and the tank. As a result, the crimped tank attachment is positioned within the tank so it is protected from vandalism or damage from other causes. The pressure tank connector is coupled by an improved coupling to a flexible conduit such as a hose for supplying compressed air or other gas from the tank to an external device, such as the air brakes of a truck or other vehicle.

Abstract: A system for sealing a pool or spa fitting includes a wall having a frustoconical hole therethrough, the hole expanding towards the outer side of the wall. A conduit or inlet fitting is disposed in the hole and has an integrally formed enlarged end portion which abuts the inner surface of the wall. The fitting also has an externally threaded portion opposite the enlarged end, and a nut is threadably disposed on the fitting. A resilient, rubber seal such as a V-gasket or O-ring is disposed interjacent the fitting, the nut, and the surface of the hole. This construction ensures a positive seal of the spa or pool fluid system, while being of substantially simpler and less expensive construction than prior sealing systems.

Abstract: The inlet and outlet tubes on each side of the valve body are connected to the valve body by a notched plate engaging the shoulder upset from the tube. The upset forms a metal-to-metal seal against the seat in the body while the O-ring engages the wall of the flared section of the inlet leading to the smaller bore which receives the end of the tube.

Abstract: This invention relates to an adapter for coupling a toilet bowl, such as residential toilet bowl, to a flush device that is generally utilized in a commercial close coupled water-closet combination. The adapter includes a substrate having a hole therethrough, fasteners on opposite sides of the hole for attaching the substrate to a toilet bowl, a hollow fitting extending through the hole and attached to the substrate and extending both above and below the substrate and a rigidly flexible gasket frictionally attached to the fitting below the bottom surface of the substrate. The fitting has threads on the outer surface thereof for at least that portion of the fitting that extends above the substrate. The fitting has a flared circumference on that portion of its surface below the substrate. The flexible gasket is attached to the flared circumference below the substrate to form an extension of the fitting.

Abstract: A hard outer member generally centered on an axis and having a concave inner surface is injection molded of a relatively hard synthetic resin to have on its inner surface at one end a recess formed with a radially throughgoing passage. Parts of the mold in which this member is molded are then displaced before the resin has time to cure and another softer synthetic resin is injected through this radially throughgoing passage to form in the recess a relatively soft seal having a sprue extending through the passage. The seal therefore adheres in surface contact with the inner surface at the recess and the sprue further ensures excellent holding of the seal on the member.

Abstract: A tank assembly utilized in a heat exchanger such as a radiator and the method of connecting a cylindrical spout such as a filler tube in an opening in the tank wall. An opening is formed in the tank wall with a skirt extending inwardly from the tank wall. A plurality of cam/lock sections are formed at the lower extremity of the skirt with each cam/lock section having a cam surface leading from a receiving end to a locking recess, the opposite wall of which is extended to define a stop. A plurality of radial slots are formed in the tank wall to extend radially of the skirt adjacent the receiving ends of the cam surfaces. A spout is formed having a radially extending shoulder and a lower portion with a plurality of radially extending tabs. An annular seal recess is disposed in the tank wall for receiving a seal.

Abstract: A recuperator having refractory walls has ceramic recuperator tubes which are located at each of their ends in tapering bores in the recuperator walls. The ends of the tubes are sealed in the bores in the walls by a number of precompressed fibrous refractory rings of different diameter which are in turn held in place and prevented from expanding by refractory locking rings that engage the sidewalls of the bores through a bayonet fitting. Ceramic inserts may be provided in the recuperator walls to form the bores. Buffer rings are provided between the locking rings and the tube ends, and a thrust washer is provided between the fibrous rings and the locking rings.