Abstract: An endoscope includes an endoscope shaft (3), which has a cylindrical shaft tube (4), and an endoscope head (2), which is arranged at a proximal end of the endoscope shaft (3). A distal end region (11) of the endoscope head (2), has a cylindrical interior (13) with a peripheral groove (15). The shaft tube (4) is inserted into the cylindrical interior (13) and folded into the peripheral groove (15). The groove (15) is not rotationally symmetrical. An endoscope head and a method for producing an endoscope are also provided.

Abstract: An interference fit fastener (FIG. 1) and method of fabricating same is described.

Abstract: A furnace heat exchanger assembly includes first and second heat exchanger halves. The first heat exchanger half includes a first half of an exhaust channel and an inner joint flange half at an end thereof. The second heat exchanger half includes a second half of the exhaust channel and an outer joint flange half at an end thereof having first and second capturing tabs. The first and second heat exchanger halves are coupled together such that the first and second capturing tabs substantially overlap the inner joint flange half to form a joint flange.

Abstract: A cylindrical hole is formed between peripheral belt portions of two container constituent plates of a thermal storage material container of an evaporator with a cool storage function. A cylindrical portion of a thermal storage material charging member having a thermal storage material charging passage is disposed in the cylindrical hole and brazed to the two container constituent plates. That portion of the thermal storage material charging member which protrudes from the cylindrical hole includes a crushed portion and a cylindrical uncrushed portion. The crushed portion seals the thermal storage material passage. The cylindrical portion of the thermal storage material charging member is smaller in outside diameter than the uncrushed portion, and the cylindrical portion and the uncrushed portion have the same inside diameter. The cylindrical portion has an inward protrusion protruding into a thermal storage material containing space, and the inward protrusion has a radially expanding engagement portion.

Abstract: A delivery system for remotely driving an eddy current probe through the tubing of a heat exchanger. The system uses a flexible shaft and air pressure to move an inspection probe through the heat exchanger tubes. The flexible shaft initially drives the probe through a sealed conduit to deliver the probe to the tube end at which point a seal on the shaft near the probe head contacts the tube inner surface allowing a buildup of air pressure behind the seal, thus driving the probe through the tube.

Abstract: The invention relates to a method for producing a heat exchanger, in particular for a motor vehicle, a method whereby fluid circulation tubes (3) are inserted into through holes in heat exchange fins (4) and the fluid circulation tubes (3) are subjected to expansion in such a way as to expand a contour (22) of said tubes (3) to ensure contact with said fins (4) at said through holes and, additionally, for at least one of said tubes (3), to deform a concave portion (24) of the contour (22) of said tube or tubes (3), in such a way as to correspondingly deform said through holes. The invention also relates to a device for implementing said method and an exchanger obtained by said method.

Abstract: A system and a method for plugging a heat exchanger tube or the like. The system includes a plug member having a central shaft having a compressible member mounted on the central shaft such that axial compression of the compressible member radially expands the compressible member into sealing engagement with an inner wall of a tube in which the plug member is inserted. The system further includes a drive means removably engaged with the plug member for inserting the plug member into the tube and for providing axial force on the compressible member to cause radial expansion of the compressible member into sealing engagement with the inner wall of the tube.

Abstract: The present invention solves a problem with conventional tube expanding method for heat exchanger tubes that is susceptible, when carrying out tube expansion on U-shaped heat exchanger tubes that have a narrower diameter than in the past and forming flare portions in opening portions that have been subjected to tube expansion, to a buckling phenomenon at boundaries between straight portions and hairpin portions of the heat exchanger tubes or a vicinity thereof. Opening portions of U-shaped heat exchanger tubes 56 that pass through a fin layer 54 protrude from an upper end surface of the fin layer 54, hairpin portions 56b of the heat exchanger tubes 56 protrude from a lower end surface of the fin layer 54, and tube expanding billets 22 are inserted into each opening portion of the heat exchanger tubes 56 to carry out primary tube expansion that expands the diameter of each straight tube portion 56a of the heat exchanger tubes 56 to integrate the heat exchanger tubes 56 and fins 50.

Abstract: A pipe expansion method capable of reducing an inspection range (area) of a heat-transfer pipe secured to a pipe plate and capable of shortening the time required for inspection is provided. In a pipe expansion method for securing a heat-transfer pipe inserted in a pipe hole of a pipe plate by expanding the pipe, after tightly fitting an outer circumferential surface of the heat-transfer pipe to an inner circumferential surface of the pipe hole from a primary-side end face to a secondary-side end face of the pipe plate, surface pressure between the heat-transfer pipe and the pipe plate is further increased in a predetermined range from the secondary-side end face, or close to the secondary-side end face, towards the primary-side end face.

Abstract: A system and method for radially expanding hollow cylindrical objects, through the use of a tube expansion tooling, affixing a mandrel in place, the tooling rendered operative through the generation of hydraulic pressure, to provide the axial force necessary for pulling of the mandrel into the tool, and the mandrel having concentrically applied thereon various spacers, cams, and curved segments, which when the drawbar of the mandrel is pulled, manual forces are generated through the cams and segments into an expansion capacity to force the expansion of any tube in which the mandrel locates, to be expanded into a tight binding fit within a tube sheet or any other bore hole formed in equipment.

Abstract: Disclosed is a heat exchanger wherein warping (bending) of an intervening member and a frame is suppressed when the intervening member and a wall portion of the frame member having different linear expansion coefficients are welded with each other. A method for manufacturing the heat exchanger, a semiconductor device wherein warping (bending) of an intervening member and a frame is suppressed, and a method for manufacturing the semiconductor device are also disclosed. Specifically disclosed is a heat exchanger wherein a fin member provided with a plurality of fins forming flow channels for a refrigerant is arranged within a frame which forms the outer casing. The frame has a first frame member (a first wall portion) to which insulating plates (intervening members) interposed between the frame and heat-generating bodies (semiconductor elements are welded. The insulating plates (intervening members) have a linear expansion coefficient different from that of the frame.

Abstract: There is disclosed a manufacturing method of a heat pipe type heat-dissipating device. The method includes the steps of: winding a pipe on a loop forming mold in a spiral shape to form a pipe loop; and pressing at least a section of an outer circumference of the pipe loop so that the pipe loop is plastically deformed in a shape corresponding to the shape of the loop forming mold.

Abstract: One aspect of this disclosure provides an expansion rod holder for the assembly of fin and tube heat exchangers. The expansion rod holder includes a first plate having a first aperture therethrough and a ring located in the first aperture and that has a second aperture therethrough. The first and second apertures are configured to receive a tapered end of an expansion rod having an annular groove proximate the tapered end. A biasing member is located in the first aperture between the ring and a wall of the first aperture. The biasing member is configured to bias the ring in a first direction toward an opposite wall of the first aperture and into the annular groove. A method of manufacturing the expansion rod holder is also disclosed, as well as a tube expander system used to manufacture heat exchangers.

Abstract: The current invention provides a tube-grasping body for grasping an insert tube in a heat exchanger, and heat exchanger production methods and apparatuses utilizing the tube-grasping body, wherein the tube-grasping body enables to enlarge and connect an insert tube to a heat radiating fin for producing a heat exchanger, still keeping the total length of insert tubes at an almost same level even after the enlargement; and the tube-grasping body is connected at its exterior to the guide-pipe.

Abstract: A method of manufacturing a heat exchanger having a brazed core with parallel tubes separated by and contacting centers that extend parallel to the tubes. The method utilizes a brazing fixture that enables the core to expand during brazing due to thermal expansion of the tubes and centers and maintains tube to center contact as the core shrinks due to melting of the braze alloy. The resulting brazed core has a post-brazed tube spacing pattern that facilitates assembly of the brazed core with headers of the heat exchanger.

Abstract: A modular heat exchanger suitable for automotive applications, and methods for forming the modular heat exchanger. The modular heat exchanger construction incorporates a monolithic brazed core assembly composed of flat-type cooling tubes and sinusoidal centers. The required positional tolerances of the tubes for mating with the remainder of the heat exchanger are maintained within the brazed core assembly by minimizing core shrinkage resulting from the brazing operation during which the tubes are brazed to the centers.

Abstract: A method for joining members capable of firmly joining a first member made of a tubular member, such as, e.g., a pipe, to a second member is provided. The following items are prepared: a tubular first member 1 having a polygonal cross-section and a hollow portion 3, a second member 5 having an insertion hole 6 with a cross-sectional shape corresponding to a cross-sectional shape of the first member 1, and a split die 11 circumferentially split into multiple segments at positions corresponding to flat wall portions 1a of the first member 1. Then, the first member 1 is inserted into the insertion hole 6 of the second member 5, and the split die 11 is disposed in the hollow portion 3 of the first member 1. Next, each segment 11a of the split die 11 is moved radially outward of the first member 1 toward each corner 1b of the first member.

Abstract: According to the preferred embodiment, an improved method and apparatus for the manufacturing of an aluminum tube and aluminum fin heat exchanger that includes steps for pneumatic cleaning, thermal cleaning, and uncontrolled-atmosphere open-flame autobrazing of hairpins to return bend fittings. The method uses a tube lubrication system that is adjustable to control amount of lubrication applied to the tube prior to final expansion. The method uses a pneumatic coil cleaning station that is adjusted to reduce the residual oil particulate from the expansion process required to be thermally cleaned.

Abstract: An improved hairpin expander machine equipped with a closed-loop-controlled hydraulically positioned bolster plate and a heat exchanger-holding fixture characterized by a full-length, continuous front plate, back plate, and side rails. The hairpin expander includes a novel heat exchanger bottom end plate clamping mechanism as part of the fixture. These features enable the hairpin expander to provide larger expansion ratios and exert greater forces with tighter control, which is required for producing heat exchangers with reduced diameter hairpin tubes according to a preferred embodiment of the invention.

Abstract: According to a preferred embodiment, an improved method and apparatus for manufacturing tube and fin heat exchangers that includes a step for reducing the outer diameter of stock tubing to a value well below nominal prior to bending the tubing into hairpins. The reduced diameter increases the stiffness of the resultant hairpins and allows for efficient lacing of the heat exchanger fins and end plates. The method uses pre-size rollers that are adjustable for reducing the diameter of the tubing. The invention also includes a hairpin and heat exchanger manufactured according to the method.

Abstract: There is provided a method of manufacturing a heat exchanger, including a first step of mounting an end part of flat tube to a header, assembling the flat tube and fins, and sealing a part where the header and the end part is attached, and a second step of increasing an internal pressure of the flat tube to expand other part of flat tubes aside from the end parts with respect to the end part of the tube in order to make the fins and the other part of the flat tube in contact each other. According to this method of manufacturing, in the second step, the other part of the flat tube that passes through the fins is expanded, so that it is possible to mechanically join the flat tube and the fins, and a plate fin-type heat exchanger with high strength and heat exchange efficiency can be easily provided.

Abstract: A heat exchanger comprises a shell comprising a hollow shell body and separate shell end members attached thereto. A number of tubes is disposed within the shell body which is sized to permit both ends of the tubes to project outwardly therefrom to facilitate access for attaching the tubes ends to respective tube header plates, after which time the shell end members are slid over the shell body towards the shell body ends for attachment to respective header plates. The heat exchanger can include an expansion element attached between a shell end member and the shell body, wherein the expansion element is positioned adjacent a slidable joint formed by an overlapping section of the shell body and shell end member. Together, the expansion element accommodates axial movement and the slidable joint carries vibration loads between the shell body and shell end member.

Abstract: A method for the production of heat exchangers (10, 110, 210) of the so-called plate type, comprising the operative steps of: —juxtaposing a couple of substantially identical metal plates (12, 14), —fixing together said juxtaposed plates (12, 14) to one another by means of welding performed at respective perimetric sides (13a, 13b, 13c, 13d), —further fixing together said juxtaposed plates to each other by means of a plurality of welding tracts (22), arranged in at least two alignments, parallel and adjacent to a couple of opposite perimetric sides (13a, 13c) of the plates themselves (12, 14), and at a pre-established spaced relationship from said sides, —introducing a fluid under pressure between said juxtaposed metal plates (12, 14), to form a hollow, substantially box-shaped body (17), in which an internal chamber (16) and two substantially tubular passages (16a, 16b), formed between said couple of opposite perimetric sides (13a, 13c) and the respective adjacent alignments of the welding tracts (22), are d

Abstract: A method prevents a cylindrical body from buckling in externally curling edges of both side portions by pressing curling dies in an axial direction after molding the cylindrical body having a drop portion whose outer diameter is small and two side portions whose outer diameter is large by enlarging a cylindrical material made of aluminum alloy by electromagnetic molding. In curling the edges of the side portions, a buckling preventing die restrains an outer periphery of the drop portion of the cylindrical body. Because the buckling preventing die receives the axial compression force of the curling dies, it can prevent the cylindrical body from buckling and deforming. The buckling preventing die is what a split die disposed on the side of an outer periphery of the cylindrical material in the electromagnetic molding is used as.

Abstract: A heat exchanger, such as an air-to-air after-cooler assembly, having reduced and/or eliminated leakage at the tube/header joint is provided. The assembly comprises a series of tubular members formed from a first metal, each of the tubular members including an end portion and a header formed from a second metal, wherein the first metal and the second metal have similar coefficients of thermal expansions. The header includes a plurality of openings extending therethrough and each of the end portions of the tubular members is mechanically secured within corresponding openings within the header to form an after-cooler assembly. A method for forming the air-to-air after-cooler assembly is also provided.

Abstract: In a state where the expanded protruding portion of the heat-exchanging tube, which has been expanded inside a grip portion of a chucking sleeve whose diameter has been reduced by a clamp bushing, is gripped by the grip portion, a tube expanding billet is inserted into a yet-unexpanded part of the heat-exchanging tube to cause tube expansion. When doing so, a guide portion, which is formed on a flare punch and has the same diameter as the maximum outer diameter of the tube expanding billet, is inserted inside the expanded protruding portion of the heat-exchanging tube gripped by the grip portion.

Abstract: A method and a reactor made by a method for increasing heat transfer from a heat source outside a vessel to the fluid inside the vessel are characterized by expanding a structure within the vessel toward the inner vessel surface so as to decrease the spacing between the structure and the vessel wall. The structure may be any of the various so-called structured packings, for example, ceramic honeycombs, metal honeycombs, plate stacks, and the like. The structure may comprise catalyst. The reactor provides high activity, low pressure drop, and high heat transfer. The reactor may be especially suitable for steam hydrocarbon reforming.

Abstract: A method and apparatus for providing a fluid channel on a surface that is subject to extreme temperatures is described. The embodiments described herein provide a fluid channel wherein the surface that is subject to the extreme temperatures forms one side of the fluid channel.

Abstract: Tools for expanding (i.e., flaring and swedging) the ends of metal tubes are configured for attachment to a powered impact hammer, such as an air hammer. A swedging tool for swedging an end of a metal tube has a swedging body with a die section for expanding the tube when driven thereinto and a flanged shank attached to the swedging body and configured for engagement by a powered impact hammer. A flaring tool for flaring an end of a metal tube includes a flaring body having a die section for flaring the tube when driven thereinto. A flanged shank is attached to the flaring body and configured for engagement by a powered impact hammer. A method for expanding an end of a metal tube entails attaching a die body for expanding the end of the metal tube to a powered impact hammer, aligning the die body with the inner diameter of the metal tube, activating the powered impact hammer, and urging the die body a determined distance into the metal tube.

Abstract: A method for joining members capable of firmly joining a first member made of a tubular member, such as, e.g., a pipe, to a second member is provided. The following items are prepared: a tubular first member 1 having a polygonal cross-section and a hollow portion 3, a second member 5 having an insertion hole 6 with a cross-sectional shape corresponding to a cross-sectional shape of the first member 1, and a split die 11 circumferentially split into multiple segments at positions corresponding to flat wall portions 1a of the first member 1. Then, the first member 1 is inserted into the insertion hole 6 of the second member 5, and the split die 11 is disposed in the hollow portion 3 of the first member 1. Next, each segment 11a of the split die 11 is moved radially outward of the first member 1 toward each corner 1b of the first member.

Abstract: There is provided a method of manufacturing a heat exchanger, including a first step of mounting an end part of flat tube to a header, assembling the flat tube and fins, and sealing a part where the header and the end part is attached, and a second step of increasing an internal pressure of the flat tube to expand other part of flat tubes aside from the end parts with respect to the end part of the tube in order to make the fins and the other part of the flat tube in contact each other. According to this method of manufacturing, in the second step, the other part of the flat tube that passes through the fins is expanded, so that it is possible to mechanically join the flat tube and the fins, and a plate fin-type heat exchanger with high strength and heat exchange efficiency can be easily provided.

Abstract: A tube expander for heat exchangers is capable of organizing an ideal production line where the transportation efficiency is increased and the productivity is improved by having a transportation path in a straight line through which the heat exchangers are carried into one end and carried out from the other end. Left and right ends of an end plate at the front side are inserted by a pair of first guide bars, and the left and right ends at the back side are inserted by a pair of second guide bars. A guide path for a carrying device or a transportation device is established on a base that supports the first guide bars and the second guide bars in a clearance between the first guide bars and support columns. The heat exchangers are transported from one end to the other of the base via the guide path.

Abstract: A tube expanding apparatus includes mandrels, each mandrel having a billet on a leading end; a reciprocating actuator for supporting rear ends of the mandrels, the reciprocating actuator being supported to reciprocate in an axial direction of hairpin tube straight portions; a pressure cylinder for raising and lowering the reciprocating actuator and expanding the straight portions by pressing the billets into the hairpin tube straight portions; hairpin receivers for supporting curved portions of hairpin tubes; a fin receiver for supporting a lower end portion of the laminated radiating fins; and a hydraulic cylinder for raising and lowering the fin receiver in the axial direction of the hairpin tube straight portions. The hydraulic cylinder lowers the fin receiver to a predetermined position as the mandrels descend and the billets begin to be inserted into the hairpin tubes.

Abstract: A collar for a fin-tube heat exchanger is provided. The collar extends outwardly from a thermally conductive plate in order to receive a tube. The collar generally includes a wall having a proximal end integral to the conductive plate, and a distal end defining an opening configured for receiving a tube. The wall includes a reflare portion at its distal end, with the reflare portion being curled into either the inner diameter or the outer diameter of the wall. Preferably, the reflare portion is curled into the inner diameter of the wall, and then further flared outwardly to form a double flare. A method for forming the double flare collar is also provided. The method involves progressively moving fin stock through a metal-stamping machine in order to sequentially form double flare collars.

Abstract: A method for the production of plate type heat exchangers (10) comprising the operative steps of: juxtaposing a couple of metal plates (12, 14), welding each other said juxtaposed plates (12, 14) at least perimetrically, defining an inner chamber (16) between said metal plates (12, 14), intended to be crossed by an operating heat exchange fluid, said operative welding step of the juxtaposed plates (12, 14) being carried out by supplying heat directly to each of said metal plates (12, 14).

Abstract: A tubular hydrogen permeable metal membrane and fabrication process comprises obtaining a metal alloy foil having two surfaces, coating the surfaces with a metal or metal alloy catalytic layer to produce a hydrogen permeable metal membrane, sizing the membrane into a sheet with two long edges, wrapping the membrane around an elongated expandable rod with the two long edges aligned and overlapping to facilitate welding of the two together, placing the foil wrapped rod into a surrounding fixture housing with the two aligned and overlapping foil edges accessible through an elongated aperture in the surrounding fixture housing, expanding the elongated expandable rod within the surrounding fixture housing to tighten the foil about the expanded rod, welding the two long overlapping foil edges to one another generating a tubular membrane, and removing the tubular membrane from within the surrounding fixture housing and the expandable rod from with the tubular membrane.

Abstract: A method of manufacturing a cross fin tube and a cross fin type heat exchanger including the cross fin tube obtained in accordance with the manufacturing method. A tube-expanding plug has cutout-forming protuberances which are formed on an outer circumferential surface thereof with a number of 60-160 per circumference such that the cutout-forming protuberances extend in a direction which intersects primary grooves which are previously formed on an inner circumferential surface of a heat transfer tube, and at the same time when the heat transfer tube and plate fins are fixed integrally to each other in accordance with the mechanically tube-expanding operation, secondary grooves which are cross grooves with respect to the primary grooves are formed to have a depth (d2) which is held in a range of 10-40% of a depth (d1) of the primary grooves.

Abstract: A heat exchanger finned tube 10 for use in fabricating a heat exchanger 1 useful as the evaporator for refrigerators or the like wherein a hydrocarbon refrigerant is used. Two tube insertion holes spaced apart from each other are formed in each of plate fins 12, and two straight tube portions 11a of a hairpin tube 11 are inserted through the respective holes of each plate fin to arrange the plate fins 12 in parallel into a plurality of fin groups 13 spaced apart on the straight tube portions 11a longitudinally thereof. The hairpin tube 11 is enlarged with use of a fluid to fixedly fit the plate fins 12 of each tin group 13 around an enlarged tube portion 14 of the hairpin tube 11 and provide a finless part 19 between each pair of adjacent fin groups 13 on each of the straight tube portions 11a. A restrained small-diameter portion 15 is provided in each of the finless parts 19 of each straight tube portion 11a.

Abstract: A system and method for expanding, joining or securing a plurality of tubes by electromagnetic expansion to a plurality of sheets in a tubular heat transfer system. The system and method involve the automatic sensing and positioning of a electromagnetic coil in operative relationship with at least a portion of a tube and an inner wall of a sheet and then energizing the electromagnetic coil to expand the portion of the tube to engage the inner wall of the sheet, thereby securing the tube thereto. A tubular heat transfer system tube expander and method are also shown.

Abstract: A method of securing a plurality of oblong tubes into a plurality of circular openings in a header of a CT or Serpentine style fin core exchanger. One end of each tube is shaped into a circle, inserted into a circular opening in the header and bonded into place thus forming a Flat-Round joint.

Abstract: A system and method for expanding, joining or securing a plurality of tubes by electromagnetic expansion to a plurality of sheets in a tubular heat transfer system. The system and method involve the automatic sensing and positioning of a electromagnetic coil in operative relationship with at least a portion of a tube and an inner wall of a sheet and then energizing the electromagnetic coil to expand the portion of the tube to engage the inner wall of the sheet, thereby securing the tube thereto. A tubular heat transfer system tube expander and method are also shown.

Abstract: A method and apparatus are described for inserting a cooling tube into a metal component to remove heat generated at the surface by flowing fluid through the tube, thereby cooling the metal component. A cooling tube is placed into a groove of a metal component having first and second surfaces, where the width of the groove at the surfaces is approximately equal to the outer diameter of the cooling tube. The metal component also has two ridges: a first ridge on one end of the groove at the first surface of the metal component, and a second ridge on the other end of the groove at the second surface of the metal component. After the cooling tube is placed in the groove of the metal component, the cooling tube is swaged into the groove of the metal component by applying pressure to the first and second ridges until the first ridge, second ridge, and cooling tube are flush with the top surface.

Abstract: A sheet hydroforming method is disclosed wherein two stacked metallic sheets are clamped between a pair of upper and lower dies 10, 11 and a fluid is introduced and pressurized between mating surfaces of the metallic sheets, causing the metallic sheets to bulge into a space defined by die cavities 10b and 11b. A thru-hole 11d for introducing the fluid is formed in one of the dies so as to lead to a holding surface of the die, while a pierced hole for introducing the fluid is formed in one of the metallic sheets in a portion of the one metallic sheet which portion is in contact with a holding surface 10a (10b) of one of the dies, the pierced hole being positioned with the thru-hole 11d, then the fluid is introduced in a pressurized state between mating surfaces of the metallic sheets from the thru-hole through the pierced hole, thereby causing the metallic sheets to bulge. According to this method, a pressurized fluid can be introduced between the mating surfaces of blanks easily without leakage of the fluid.

Abstract: A flat or a flared tubular end portion devoid of dimples is provided at the end of a tube 11 which is to be inserted into a header with the length, of the flat tubular portion being 1.5 mm or less along the direction of the length of the tube to prevent rapid reduction and enlargement of the cross-sectional area of the refrigerant path in the vicinity of the joint of the tube and the header, so as to reduce the pressure loss of the refrigerant which flows in and out from the header to the tube. A tube insertion stop is also provided consisting either, of a cut formed in the longitudinal edge of the flat end portion or a guard member which is formed aft of the flared, end portion so as to abut the header and seal off the tube insertion aperture of the header.

Abstract: A vertical pipe expander to be used to expand the pipes assembled with fins of finned heat exchangers comprises, on a supporting frame, supports for rods of pipe expanding cones, performing vertical translational motion and arranged above a seat for a heat exchanger to be subjected to pipe expansion. At least one cone supporting rod magazine is further provided that is arranged vertically with the cones directed downward, for arrangement, during machine setup, at the seat, the supports for the rods being constituted by a rod engaging and supporting device. The rod engagement and support device is associated with a device for selecting the rods of the magazine to be engaged or released.

Abstract: A method of hydraulically prestraining the tubes of a once-through steam generator by welding the tubes to their respective tubesheets prior to the application of hydraulic expansion to produce tensile stresses which shorten the tubes an equal and predetermined amount to increase the margin to buckling and increase the natural frequency of the tubes reducing flow induced vibration.

Abstract: A method for manufacturing a heat exchanger for a cooling cycle includes the steps of: preparing the pipes and the fins having through-holes through which the pipes are inserted, arranging the fins parallel depth-wise and in several separate groups depth-wise and then inserting the pipes through the through-holes of the fin groups, bending the outer portions of the pipes so that the fin groups separated from each other are piled in layers along the longitudinal direction of air flow and the inner portions of the pipes are arranged in at least two coplanar rows along the longitudinal direction of air flow, and wrenching the bending portion of the pipes to form each pipe row into a zigzag shape.

Abstract: A method of securing intake tubes in an intake manifold is provided in which leakage of brazing material from the joint between the intake tubes and the intake tube mounting rings is prevented. For securing each intake tube in the intake manifold, the intake tube 3 is fitted into the intake tube mounting ring 5. Then, a jig 13 of a tubular shape is inserted into insert areas of the intake tube 3 and the intake tube mounting ring 5. The jig 13 includes separate sections 16 defined by slits extending to a predetermined length in parallel to the axis and has a plurality of projections 19 and 20 provided on the outer side of the separate sections 16 thereof. A bar-like pressing tool 14 reduced in the diameter towards its front end is inserted into the interior of a tubular shape of the peen locking jig 13, and it is then advanced relatively towards the insert area by the action of pressing means.

Abstract: A method for making a heat exchanger assembly (10) includes inserting tubes (20) through fin holes (32) in heat exchanger fins (30) and headers (40, 42) to form a bundle (50), and expanding the tubes (20) forming an interference fit with the heat exchanger fins (30). The bundle (50) is inserted into a housing (60) open at both end; (67, 68) and having a wall (62) surrounding the headers (40, 42) with inlet and outlet lines (64, 66) in the wall (62), and sealing the wall (62) of the housing (60) to the first and second headers (40, 42) with the inlet and outlet lines (64, 66) disposed between the headers (40, 42). A plurality of mandrel heads (70) are inserted through the open ends (67, 68) of the housing (60) into the tubes (20) expanding the tubes (20) into the headers (40, 42) to form a sealed joint between the tubes (20) and the headers (40, 42).