|Publication number||USRE30802 E|
|Application number||US 06/014,654|
|Publication date||Nov 24, 1981|
|Filing date||Feb 22, 1979|
|Priority date||Mar 26, 1976|
|Publication number||014654, 06014654, US RE30802 E, US RE30802E, US-E-RE30802, USRE30802 E, USRE30802E|
|Inventors||George D. Rogers, Jr.|
|Original Assignee||Combustion Engineering, Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (14), Referenced by (71), Classifications (27)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The invention relates generally to a method and apparatus for securing a tubular sleeve coaxially within a fluid conduit.
There exists, in a variety of embodiments, fluid conduits which themselves are surrounded by a fluid environment. One such example is that of a tube and shell heat exchanger wherein a first fluid is contained within the fluid conduit and a second fluid surrounds the exterior of the conduit such that heat exchange between the two fluids is effected. Such fluid conduits may from time to time develop leaks due to rupturing of the conduit wall, which may occur due to initial imperfections or through subsequent deterioration of the conduit. The resulting leak permits fluid communication between the first and second conduits which may not always be tolerable. Such would be the case if the two fluids in combination reacted violently or if one fluid would introduce some undesirable property to the second fluid. An example of this latter problem arises in the steam generating heat exchangers associated with pressurized water nuclear steam supply wherein the fluids are at substantially different pressures and one fluid contains radioactivity while the other does not. For these reasons, continued, large amounts of fluid communication between the two fluids through a leak in the tube must be prevented.
When the fluid conduits are readily accessible, a variety of techniques may be employed to repair the ruptured conduit directly or to install a sleeve device or a plug into the conduit which stops the leak or completely isolates the entire conduit from a fluid source. However, in some environments, including that of a nuclear heat exchanger, it may be difficult for reasons of inaccessibility or biological hazard to effect such repairs. In such instances, techniques have been developed for plugging the fluid conduits from a remote location and thus totally removing them from service. Either rolling, explosive expansion and/or welding have been used to secure plugs in the tube ends. Rolling and welding are rather difficult to apply as remote operation and explosive expansion has emerged as the most viable means of plugging tubes by remote operation.
A serious drawback to plugging both ends of a heat exchanger tube is that eventually as more and more tubes are plugged the capacity of the steam generator becomes less and less. Plugging requires removing an entire tube from operation when in general only a small localized zone of the tube is involved in the leak. Attempts have been made to install sleeving within the tube to isolate the portion of the tube which has degraded thereby stopping the leak. Previous sleeving development work has been primarily concerned with obtaining an absolutely leak proof joint by brazing, arc welding, explosive welding, or some other means. All of these metallurgical bonding techniques have problems which are not immediately amendable except in very closely controlled laboratory situations. This is due to the need for cleanliness, close fittings, heat application and atmosphere control.
The present invention relates to a method of forming an interference mechanical joint for securing a coaxially disposed tubular sleeve within a conduit. The tubular sleeve is first inserted into an open end of the conduit and moved to the desired location therein. A radially outwardly directed force is then applied from within the tube along a selected axial portion thereof. The magnitude of the force is sufficient to cause the portion of the sleeve to which it is applied to expand outwardly into contact with the inner wall of the conduit and to continue expanding a predetermined amount to expand the surrounding conduit, resulting in the desired interference mechanical joint.
One particularly advantageous application of the invention permits repair of a metal tube having a degraded wall section. A tubular metal sleeve is selected having a length greater than the axial extent of the degraded wall section. The sleeve is positioned within the tube with a portion extending beyond the degraded section at each end. An interference mechanical joint is then formed at each end of the sleeve/tube in the portion of the tube extending beyond the degraded section. The sleeve, so mounted isolates the degraded section from flow within the tube and further substantially increases the axial strength of the tube in this region.
FIG. 1 is a sectional view showing a tubular sleeve secured with a fluid conduit in a manner according to the principles of the invention;
FIG. 2 illustrates a hydraulic apparatus for applying a radially outwardly directed force to a portion of the interior wall of the sleeve/tube according to the invention; and
FIG. 3 illustrates a mechanical apparatus for performing the same function as the apparatus of FIG. 2 by applying a compressive force to an elastomeric material.
Referring first to FIG. 1, a sleeve 10 is shown positioned within a fluid conduit 12 having a region of degradation 14 in the exterior wall thereof. This figure shows the joint of the invention at an intermediate stage on the right side and, on the left side, after it has been secured within the tube by application of internal radially extending pressure on the interior wall of the sleeve. FIGS. 2 and 3 illustrate two alternate embodiments of apparatus which permit remote application of the necessary internal force upon the sleeve to cause the sleeve and the tube to expand outwardly to form an interference mechanical joint.
Referring back now to FIG. 1, the method of securing the repair sleeve 10 within the tube 12 will be described in greater detail. The outer diameter of the repair sleeve is somewhat smaller than the inner diameter of the tube being repaired permitting the sleeve to be easily inserted within the tube and moved axially therealong to a desired position with the ends thereof extending beyond the degraded area which it is desired to isolate from the fluid flow within the conduit. As pointed out above, upon close inspection of FIG. 1 it will be noted that the joint 16 on the right side illustrates an intermediate step in the securing of the sleeve within the tube wherein the sleeve has been expanded into contact with the inner wall of the tube, however, the tube wall itself has not yet been expanded to form the final interference mechanical joint as illustrated by the joint 18 on the left end.
Once the sleeve is positioned in the desired location within the tube suitable means are used to apply a radially outwardly directed force from within the tubular sleeve, first at one end and then at the other end of the tube to cause the sleeve to expand radially outwardly first, into contact with the inner wall of the tube and then to further expand along with the tube resulting in a mechanical interference. Because the sleeve and the tube have essentially equivalent elastic constants and, accordingly the outer tube is stressed to the same level as the sleeve, a slight mechanical clearance may exist between the sleeve and the tube at the joint. As a result, the joint will not obtain absolute leak tightness but will limit the leakage thereby to a very small amount estimated at less than 100 cc's per minute. The sleeve will provide mechanical strength in the axial direction capable of preventing separation of the tube in the degraded area should the tube wall fail completely.
In a typical application, a 3/4 inch outside diameter Inconel 600 tube of the type commonly used in a nuclear steam generator having a wall thickness of 0.048 inch is provided with a 5/8 inch outside diameter having a 0.032 inch thickness wall also made from Inconel 600. The sleeve length is selected so that it extends beyond the degraded area by an amount required to provide for inaccuracies in axial location. Internal pressure is then applied to a limited portion of one end of the sleeve to cause expansion of the sleeve and the tube together to form the desired interference mechanical joint. Internal pressures of 14,000 to 15,000 psig are necessary in order to obtain the desired expansion of the tube and sleeve described above as will be described more fully hereinafter in connection with apparatus for imparting the necessary radially directed pressure.
Turning now to FIG. 2, hydraulic apparatus 20 is shown for applying the radially outwardly directed force necessary to cause the expansion joint. The apparatus is shown positioned adjacent to the end of a sleeve 10 which has been positioned in the desired axial location within the outer tube 12. The apparatus comprises a center mandrel 22 having a fixed stop 24 and a movable stop 26. The fixed stop 24 comprises a radially enlarged section of the mandrel which is sized to fit closely with the inner diameter of the sleeve 10. The movable stop 26 comprises an annular ring having an outer diameter the same as that of the fixed stop and an inner diameter permitting a close tolerance sliding fit on the outer diameter of the mandrel. The end of the mandrel extending into the sleeve is provided with a threaded nut 28 which engages mating threads 30 on the mandrel and which is used to adjust, within limits, the position of the movable stop 26 axially with respect to the mandrel 22. The fixed and the movable stop along with the section 32 of the mandrel extending therebetween and the interior wall 34 of the sleeve 10 cooperate to define an annular chamber 36 in fluid communication with the inner wall of the sleeve. A pair of opposed "U"-cup seals 38 are positioned about the mandrel within the chamber 36 and are situated with their flat annular surface 40 abutting the fixed stop and the movable stop and their "U"-shaped cross section in fluid communication with the annular chamber. The "U"-cup seals 38 are the primary hydraulic fluid sealing elements and act positively with pressure, i.e., as internal pressure is increased, their sealing effect increases. The mandrel is provided with an axially extending hydraulic passageway 40 through the center thereof which terminates within the mandrel adjacent to the annular chamber 36. A second passageway 42 substantially perpendicular to the first extends from the end of the first passageway through the mandrel wall to provide fluid communication between the first hydraulic passageway and the annular chamber 36. A suitable hydraulic fitting 44 at the end of the mandrel connects to a tube 46 supplying a suitable hydraulic fluid from a positive displacement pump 48. A predetermined fixed volumetric input of hydraulic fluid controlled by control means 50 following application of an initial set pressure, determines the maximum diameter of expansion of the joint. As an example, for the 3/4 inch O.D. tube and 5/8 inch O.D. sleeve described above the pressure required to plastically expand the sleeve into contact with steam generator tube I.D. is 6000 to 7000 psig. The pressure is then increased while applying the fixed volumetric input to a peak of 14,000 psig to 15,000 psig to expand both tubes to the final configuration. For a one inch long expanded zone in the above example a final volumetric input of 1 cc results in a final diameter expansion of the outer tube of 0.025±0.005 inch.
In order to obtain a good seal at the outer surface 52 of the "U"-cup seals, the interior wall 34 of the sleeve 10 is provided with a smooth surface, usually 16 micro inch RMS or better is sufficient to provide a good substantially leakproof seal while the hydraulic pressure is being applied. It has also been found that to prevent damage to the seals during assembly it is desirable to provide lead in chambers and a seal lubricant to improve ease of assembly.
Referring now to FIG. 3, a mechanical expanding apparatus 54 is shown wherein an annular elastomer plug 56 is caused to expand within a sleeve 10 thereby causing expansion of the sleeve and tube to form the desired interference mechanical joint. The apparatus comprises an elongated mandrel 58 threaded at one end 60 and having an adjusting nut 62 engaging said end for adjusting the axial position of a movable stop 64. The movable stop comprises an annular ring whose inside diameter and outside diameter are in relatively close tolerance engagement with the mandrel 58 and the inner wall 34 of the sleeve 10, respectively. A fixed stop 66 identical in structure to the movable stop is positioned on the mandrel 58 axially spaced from the movable stop 64 to define an annular chamber within which the annular elastomer plug 56 is retained. The fixed stop 66 is maintained in the desired position within the sleeve 10 by means of an elongated reaction tube 68 which is held in a fixed position by means external to the tube and not shown in the drawing. The reaction tube has a central opening 70 therethrough through which the mandrel extends. Once the mandrel assembly is inserted into a sleeve/tube arrangement in the desired position as shown in FIG. 3 a hydraulic ram or other mechanical means not shown but represented by arrow 72 is used to pull upon the mandrel and force the movable stop or piston 64 and mandrel toward the stationary stop or piston 66. The axial motion increases pressure on the elastomer plug 56 which, when confined, acts similar to a fluid in exerting uniform outwardly directed pressure on the sleeve and tube.
The permissible axial movement of the mandrel, and as a result the total expansion of the elastomer 56 is limited to a predetermined amount by a mechanical stop comprising an enlarged diameter section 74 upon the mandrel which defines an annular shoulder engages a hard stop 76 comprising a second annular shoulder provided in the fixed reaction tube 68.
For the 3/4 inch O.D. tube and 5/8 inch O.D. sleeve described above a mandrel 58 having a shaft diameter of 5/16 inch has been used with a urethane plug having an I.D. of 5/16 inch and an O.D. 9/16 inch to fit within the sleeve. A typical material for the plug is a cast urethane such as a product of the Acushnet Co., available under the trade name of Elastocast Urethane.
With this material axial forces (72) of around 3,000 lbs. are required to obtain a forming pressure on the elastomer plug of 15,000 psi. The diametral clearances between the stops or pistons 64, 66 and the sleeve inner wall 34 and the mandrel are on the order of 0.001 inch to prevent extrusion of the elastomer at the high forming pressures obtained.
It will be obvious to one skilled in the art that two or more hydraulic chambers and elastomeric expanders may be assembled on a common mandrel and accordingly have the capability of forming more than one expansion joint in one operation. While such arrangements are not shown or described in detail herein they are intended to fall within the scope of the invention.
Further, while this preferred embodiment of the invention has been shown and described, it should be understood that it is merely illustrative and that changes may be made without departing from the scope of the invention as claimed.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US249783 *||Sep 3, 1880||Nov 22, 1881||morgan|
|US1471184 *||Aug 13, 1920||Oct 16, 1923||Arthur Miles||Means for repairing tubes|
|US1930745 *||Oct 20, 1930||Oct 17, 1933||Doherty Res Co||Method and means for cold treating metal tubing|
|US2228139 *||Sep 30, 1938||Jan 7, 1941||Universal Oil Prod Co||Lining tubes|
|US2460580 *||Mar 18, 1943||Feb 1, 1949||Sulzer Ag||Method and device for fixing and sealing tubes in a partition wall by use of fluid pressure|
|US2704104 *||Dec 9, 1949||Mar 15, 1955||Mueller Co||Pipe expanding tool|
|US2756779 *||Jun 18, 1952||Jul 31, 1956||Mueller Co||By-pass assembly for service pipe and method of installation|
|US2773538 *||Nov 10, 1950||Dec 11, 1956||Solar Aircraft Co||Convolution forming machine|
|US2784627 *||Jul 6, 1954||Mar 12, 1957||Mueller Co||By-pass assembly for service pipes and wrench for installation of the same|
|US2857660 *||Dec 9, 1955||Oct 28, 1958||Reynolds Metals Co||Method of expanding pressure welded passageway panels to precise volume|
|US2893465 *||Jul 5, 1957||Jul 7, 1959||Mueller Co||Tool for installation of by-pass assembly for service pipe|
|US2954064 *||Apr 6, 1956||Sep 27, 1960||Solar Aircraft Co||Machine for forming ring reinforced convolutions in a tube|
|US3643701 *||Sep 14, 1970||Feb 22, 1972||Foster Wheeler Corp||Emergency monowall tube repair kit|
|US3885298 *||Sep 28, 1973||May 27, 1975||Texaco Inc||Method of sealing two telescopic pipes together|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4960650 *||Jun 15, 1989||Oct 2, 1990||Societe Anonyme||Method of repairing or protecting an end of a metal tube in a heat exchanger and sleeve for implementing same|
|US5022135 *||Apr 12, 1990||Jun 11, 1991||Brazeway, Inc.||Method of manufacturing a fluid conduit having exterior detail|
|US5027507 *||Mar 1, 1989||Jul 2, 1991||Westinghouse Electric Corp.||Method for controlling leakage through degraded heat exchanger tubes in the tubesheet region of a nuclear generator|
|US5367768 *||Dec 17, 1992||Nov 29, 1994||Mpr Associates, Inc.||Methods of repairing inconel 600 nozzles of pressurized water reactor vessels|
|US5372391 *||Feb 22, 1993||Dec 13, 1994||The United States Of America As Represented By The United States Department Of Energy||Internal pipe attachment mechanism|
|US5400827 *||Oct 8, 1993||Mar 28, 1995||Abb Reaktor Gmbh||Metallic sleeve for bridging a leakage point on a pipe|
|US5644829 *||Dec 5, 1995||Jul 8, 1997||T I Corporate Services Limited||Method for expansion forming of tubing|
|US5787933 *||Feb 17, 1995||Aug 4, 1998||Abb Reaktor Gmbh||Method of obtaining a leakproof connection between a tube and a sleeve|
|US5815901 *||Feb 28, 1997||Oct 6, 1998||Ti Corporate Services||Apparatus for expansion forming of tubing forming of tubing|
|US6098717||Oct 8, 1997||Aug 8, 2000||Formlock, Inc.||Method and apparatus for hanging tubulars in wells|
|US6233826 *||Jun 23, 1998||May 22, 2001||Henkel Corp||Method for reinforcing structural members|
|US6240965 *||Apr 22, 1999||Jun 5, 2001||Link-Pipe (H.K.), Ltd.||Apparatus for repair of high temperature and pressure conduits, method for repairing high temperature and pressure conduits, and a sealing device for repairing high temperature and pressure conduits|
|US6328113||Nov 15, 1999||Dec 11, 2001||Shell Oil Company||Isolation of subterranean zones|
|US6415863||Mar 4, 1999||Jul 9, 2002||Bestline Liner System, Inc.||Apparatus and method for hanging tubulars in wells|
|US6421913 *||Jan 19, 2000||Jul 23, 2002||Delphi Technologies, Inc.||Retention feature for assembling a pole pieces into a tube of a fuel injector|
|US6470966||May 7, 2001||Oct 29, 2002||Robert Lance Cook||Apparatus for forming wellbore casing|
|US6497289||Dec 3, 1999||Dec 24, 2002||Robert Lance Cook||Method of creating a casing in a borehole|
|US6557640||Jun 7, 2000||May 6, 2003||Shell Oil Company||Lubrication and self-cleaning system for expansion mandrel|
|US6561227||May 9, 2001||May 13, 2003||Shell Oil Company||Wellbore casing|
|US6568471||Feb 24, 2000||May 27, 2003||Shell Oil Company||Liner hanger|
|US6575240||Feb 24, 2000||Jun 10, 2003||Shell Oil Company||System and method for driving pipe|
|US6575250||Nov 15, 2000||Jun 10, 2003||Shell Oil Company||Expanding a tubular element in a wellbore|
|US6604763||Apr 26, 2000||Aug 12, 2003||Shell Oil Company||Expandable connector|
|US6631759||Feb 12, 2002||Oct 14, 2003||Shell Oil Company||Apparatus for radially expanding a tubular member|
|US6631760||May 9, 2001||Oct 14, 2003||Shell Oil Company||Tie back liner for a well system|
|US6631769||Feb 15, 2002||Oct 14, 2003||Shell Oil Company||Method of operating an apparatus for radially expanding a tubular member|
|US6634431||Oct 3, 2001||Oct 21, 2003||Robert Lance Cook||Isolation of subterranean zones|
|US6640903||Mar 10, 2000||Nov 4, 2003||Shell Oil Company||Forming a wellbore casing while simultaneously drilling a wellbore|
|US6684947||Feb 20, 2002||Feb 3, 2004||Shell Oil Company||Apparatus for radially expanding a tubular member|
|US6705395||Feb 12, 2002||Mar 16, 2004||Shell Oil Company||Wellbore casing|
|US6712154||Oct 18, 2001||Mar 30, 2004||Enventure Global Technology||Isolation of subterranean zones|
|US6725919||Sep 25, 2001||Apr 27, 2004||Shell Oil Company||Forming a wellbore casing while simultaneously drilling a wellbore|
|US6739392||Sep 25, 2001||May 25, 2004||Shell Oil Company||Forming a wellbore casing while simultaneously drilling a wellbore|
|US6745845||Dec 10, 2001||Jun 8, 2004||Shell Oil Company||Isolation of subterranean zones|
|US6758278||Sep 25, 2001||Jul 6, 2004||Shell Oil Company||Forming a wellbore casing while simultaneously drilling a wellbore|
|US6823937||Feb 10, 2000||Nov 30, 2004||Shell Oil Company||Wellhead|
|US6948225 *||Jan 23, 2003||Sep 27, 2005||Arvinmeritor Technology||Hydroformed tubular structure and method of making same|
|US7128162||Mar 26, 2004||Oct 31, 2006||Desmond Quinn||Method and apparatus for positioning a sleeve down hole in a hydrocarbon producing well and pipelines|
|US7181846||Jul 8, 2004||Feb 27, 2007||Torque-Traction Technologies, Inc.||Method of manufacturing a combined driveshaft tube and yoke assembly|
|US7210219||Aug 30, 2002||May 1, 2007||Cinetic Automation Corporation||Cir-clip to shaft insertion tool|
|US7363690 *||Mar 2, 2005||Apr 29, 2008||Shell Oil Company||Method and apparatus for forming a mono-diameter wellbore casing|
|US7527584 *||Mar 15, 2004||May 5, 2009||Ina-Schaeffler Kg||Belt-tensioning roller|
|US7665532||Oct 19, 2007||Feb 23, 2010||Shell Oil Company||Pipeline|
|US7712522||Apr 3, 2007||May 11, 2010||Enventure Global Technology, Llc||Expansion cone and system|
|US7739917||Aug 18, 2003||Jun 22, 2010||Enventure Global Technology, Llc||Pipe formability evaluation for expandable tubulars|
|US7740076||Mar 4, 2003||Jun 22, 2010||Enventure Global Technology, L.L.C.||Protective sleeve for threaded connections for expandable liner hanger|
|US7775290||Apr 15, 2004||Aug 17, 2010||Enventure Global Technology, Llc||Apparatus for radially expanding and plastically deforming a tubular member|
|US7793721||Mar 11, 2004||Sep 14, 2010||Eventure Global Technology, Llc||Apparatus for radially expanding and plastically deforming a tubular member|
|US7819185||Aug 12, 2005||Oct 26, 2010||Enventure Global Technology, Llc||Expandable tubular|
|US7861744||Dec 12, 2007||Jan 4, 2011||Expansion Technologies||Tubular expansion device and method of fabrication|
|US7886831||Aug 6, 2007||Feb 15, 2011||Enventure Global Technology, L.L.C.||Apparatus for radially expanding and plastically deforming a tubular member|
|US7918284||Mar 31, 2003||Apr 5, 2011||Enventure Global Technology, L.L.C.||Protective sleeve for threaded connections for expandable liner hanger|
|US8235075 *||Nov 10, 2006||Aug 7, 2012||Saltel Industries||Method and apparatus for patching a well by hydroforming a tubular metal patch, and a patch for this purpose|
|US8286319 *||Aug 17, 2009||Oct 16, 2012||Benteler Automobiletechnik Gmbh||Method of connecting chassis parts, and a chassis assembly|
|US20040146340 *||Jan 23, 2003||Jul 29, 2004||Smith Mark C.||Hydroformed tubular structure|
|US20040192527 *||Mar 15, 2004||Sep 30, 2004||Ina-Schaeffler Kg||Belt-tensioning roller|
|US20060005393 *||Jul 8, 2004||Jan 12, 2006||Nelson Wagner||Method of manufacturing a combined driveshaft tube and yoke assembly|
|US20090188569 *||Nov 10, 2006||Jul 30, 2009||Saltel Industries||Method and apparatus for patching a well by hydroforming a tubular metal patch, and a patch for this purpose|
|US20100038893 *||Aug 17, 2009||Feb 18, 2010||Benteler Automobiltechnik Gmbh||Method of connecting chassis parts, and a chassis assembly|
|CN101460699B||Nov 10, 2006||Jul 17, 2013||索泰尔实业公司||A method and apparatus for patching a well by hydroforming a tubular metal patch, and a patch for this purpose|
|EP0112612A2 *||Sep 23, 1983||Jul 4, 1984||THE BABCOCK & WILCOX COMPANY||Repairing degraded tubes of steam generators|
|EP0112612A3 *||Sep 23, 1983||Aug 1, 1984||The Babcock & Wilcox Company||Sleeves for repairing degraded tubes in steam generators and methods of installing such sleeves|
|EP0137984A2 *||Aug 24, 1984||Apr 24, 1985||Lummus Crest S.A.R.L.||Tube repair insert for steam generator|
|EP0142985A2 *||Nov 14, 1984||May 29, 1985||RAYCHEM CORPORATION (a Delaware corporation)||Method for providing a tubular insert within an aperture|
|EP0142985A3 *||Nov 14, 1984||Feb 5, 1986||Raychem Corporation||Annular memory metal driver|
|EP0227535A1 *||Dec 3, 1986||Jul 1, 1987||Framatome||Method and device for withdrawing part of a tube from a heat exchanger|
|EP0309078A2 *||Jul 22, 1988||Mar 29, 1989||Foster Wheeler Energy Corporation||Method of apparatus for expanding and sealing a sleeve into a surrounding tube|
|EP0309078A3 *||Jul 22, 1988||Oct 24, 1990||Foster Wheeler Energy Corporation||Method of apparatus for expanding and sealing a sleeve into a surrounding tube|
|EP0669490A1 *||Jun 30, 1994||Aug 30, 1995||ABB Reaktor GmbH||Method for achieving a tight connection between a pipe and a sleeve|
|WO1984001118A1 *||Sep 24, 1982||Mar 29, 1984||Babcock & Wilcox Co||Explosive welding device|
|WO1984001119A1 *||Sep 24, 1982||Mar 29, 1984||Babcock & Wilcox Co||Method of repairing leaks in steam generator tubes|
|U.S. Classification||29/421.1, 29/402.09, 138/98, 29/890.036, 29/523|
|International Classification||B21D26/041, B21D26/045, B21D39/20, B21D39/04, F16L55/163, B21D22/10|
|Cooperative Classification||Y10T29/49732, F16L55/163, B21D39/04, B21D39/203, Y10T29/49361, B21D26/045, B21D26/041, Y10T29/49805, Y10T29/4994, B21D22/105|
|European Classification||B21D26/041, B21D26/045, B21D22/10H, F16L55/163, B21D39/04, B21D39/20B|