CA1110292A - Flange sealing joint with removable metal gasket - Google Patents
Flange sealing joint with removable metal gasketInfo
- Publication number
- CA1110292A CA1110292A CA341,074A CA341074A CA1110292A CA 1110292 A CA1110292 A CA 1110292A CA 341074 A CA341074 A CA 341074A CA 1110292 A CA1110292 A CA 1110292A
- Authority
- CA
- Canada
- Prior art keywords
- flange
- gasket
- joint
- flanges
- face portion
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000002184 metal Substances 0.000 title claims abstract description 43
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 43
- 238000007789 sealing Methods 0.000 title abstract 2
- 239000000463 material Substances 0.000 claims abstract description 36
- 230000001154 acute effect Effects 0.000 claims description 11
- 230000000149 penetrating effect Effects 0.000 claims description 2
- 230000013011 mating Effects 0.000 abstract description 37
- 238000010168 coupling process Methods 0.000 abstract description 15
- 230000008878 coupling Effects 0.000 abstract description 10
- 238000005859 coupling reaction Methods 0.000 abstract description 10
- 230000002093 peripheral effect Effects 0.000 abstract description 6
- 230000000694 effects Effects 0.000 abstract description 2
- 235000011517 Terminalia chebula Nutrition 0.000 abstract 1
- 241000001522 Terminalia chebula Species 0.000 abstract 1
- 230000006835 compression Effects 0.000 description 5
- 238000007906 compression Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 3
- 238000001125 extrusion Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical group [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 239000002674 ointment Substances 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000035755 proliferation Effects 0.000 description 1
- 230000000452 restraining effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L19/00—Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts
- F16L19/02—Pipe ends provided with collars or flanges, integral with the pipe or not, pressed together by a screwed member
- F16L19/0212—Pipe ends provided with collars or flanges, integral with the pipe or not, pressed together by a screwed member using specially adapted sealing means
- F16L19/0218—Pipe ends provided with collars or flanges, integral with the pipe or not, pressed together by a screwed member using specially adapted sealing means comprising only sealing rings
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L19/00—Joints in which sealing surfaces are pressed together by means of a member, e.g. a swivel nut, screwed on or into one of the joint parts
- F16L19/02—Pipe ends provided with collars or flanges, integral with the pipe or not, pressed together by a screwed member
- F16L19/025—Pipe ends provided with collars or flanges, integral with the pipe or not, pressed together by a screwed member the pipe ends having integral collars or flanges
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L23/00—Flanged joints
- F16L23/02—Flanged joints the flanges being connected by members tensioned axially
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L23/00—Flanged joints
- F16L23/16—Flanged joints characterised by the sealing means
- F16L23/18—Flanged joints characterised by the sealing means the sealing means being rings
- F16L23/20—Flanged joints characterised by the sealing means the sealing means being rings made exclusively of metal
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Flanged Joints, Insulating Joints, And Other Joints (AREA)
- Joints With Pressure Members (AREA)
- Gasket Seals (AREA)
Abstract
PATENT APPLICATION
of DAVID J. HARRA and WILLIAM C. NYSTROM
for FLANGE SEALING JOINT WITH REMOVABLE METAL GASKET
Abstract An all-metal joint is provided wherein a metal gasket disposed between mating flanges can readily be removed when the joint is disassembled. Opposing faces of the mating flanges are configured to provide a recess between the flanges in which a soft metal gasket of annular con-figuration can be received when the flanges are coupled together. Symmetrically disposed ridges on the opposing flange faces penetrate into a peripheral region of the gasket, thereby causing a portion of the gasket material to flow into an annular groove that forms the periphery of the recess between the opposing flange faces. This compressed flange material in the annular groove provides a gas-tight seal between the mating flanges. The configu-ration of the opposing flange faces is such that when the joint is disassembled, the net force tending to retain the gasket in position against either one of the flange faces is minimized. In particular, each flange face is configured so that the residual compressive forces present when the flange coupling mechanism is released, distributed over the surface of the gasket, are in net effect substantially equal to or greater than the frictional and bonding forces that might tend to retain the gasket in contact with either flange. In this way, the gasket tends to break away from the mating flange faces when the joint is disassembled.
of DAVID J. HARRA and WILLIAM C. NYSTROM
for FLANGE SEALING JOINT WITH REMOVABLE METAL GASKET
Abstract An all-metal joint is provided wherein a metal gasket disposed between mating flanges can readily be removed when the joint is disassembled. Opposing faces of the mating flanges are configured to provide a recess between the flanges in which a soft metal gasket of annular con-figuration can be received when the flanges are coupled together. Symmetrically disposed ridges on the opposing flange faces penetrate into a peripheral region of the gasket, thereby causing a portion of the gasket material to flow into an annular groove that forms the periphery of the recess between the opposing flange faces. This compressed flange material in the annular groove provides a gas-tight seal between the mating flanges. The configu-ration of the opposing flange faces is such that when the joint is disassembled, the net force tending to retain the gasket in position against either one of the flange faces is minimized. In particular, each flange face is configured so that the residual compressive forces present when the flange coupling mechanism is released, distributed over the surface of the gasket, are in net effect substantially equal to or greater than the frictional and bonding forces that might tend to retain the gasket in contact with either flange. In this way, the gasket tends to break away from the mating flange faces when the joint is disassembled.
Description
`" l~l(~Z92
2 This invention is an improvement in the gas-tight
3 flange coupling art, and has particular application with
4 respect to high-vacuum and high-pressure flange joints.
A11-metal flange joints for use in applications 6 requiring high-temperature and/or frequent bake-out 7 of an assembled joint are known to the prior art.
8 In particular, U.S. patent 3,208,758 to M. A. Carlson 9 et al., assigned to Varian Associates, Inc., discloses an all-metal flange joint in which a gas-tight seal 11 between mating flanges is provided by the flowing of 12 soft metal gasket material into an annular groove formed 13 between the facing flange surfaces when the two mating 14 flanges are pressed together.
In the flange joint disclosed in U.S. patent 3,208,758, 16 the opposing flange faces were configured so that a soft 17 metal gasket could be received in a recess provided there-18 between when the flanges are pressed together. Corresponding l9 annular ridges were provided on the opposing flange faces to project into the recess so as to penetrate into opposite 21 sides of a peripheral region of the gasket located in the 22 recess. A portion of the gasket material was thereby caused 23 to flow into an annular groove that formed the periphery 24 of the recess between the opposing flange faces. This groove was dimensioned to have a volume larger than the volume 26 of gasket material that could flow into the groove, therby 27 preventing gasket material from completely filling the groove.
28 If an excess of gasket material were permitted to enter the 29 annular groove, the opposing flange faces would be pushed apart. Proper dimensioning of the groove served to provide 31 a gas-tight seal in the nature of a compressed O-ring, 32 which could withstand pressure differentials limited only 3jjmll2878 - 2 - 77-28 . ,. . - - - ' ' '' ' ' ' ' ~
` 1~ii~2~2 1 by the tensile strength of the metal gasket.
2 With prior art flanges of the type described above, 3 however, difficulty was encountered in disassembling the 4 flange joint after a seal had been made. Typically, such prior art flanges were coupled by bolting the two opposing 6 flanges together. Such bolting or other compressive coupling 7 of the mating flange faces caused compression of the gasket 8 disposed therebetween, and resulted in the extrusion of 9 soft metal from the periphery of the gasket into an annular groove formed at the periphery of the recess between the 11 opposing flange faces. When the mating flanges were sub-12 sequently unbolted in order to disassemble the joint, 13 however, the metal g~cket frequently remained stuck to one 14 or the other, or to both, of the flange faces.
When a soft metal gasket has been severely compressed 16 against the surface of a harder metal, a surface bonding 17 phenomenon in the nature of a weld occurs. In addition, 18 a frictional restraining force dependent upon the coefficient l9 of friction of the soft metal gasket material with respect to the harder surface of the flange tends to oppose movement 21 of the gasket away from the flange.
22 In the prior art, the tendency of the metal gasket to 23 remain affixed to one or the other, or to both, of the mating 24 flanges was not an insurmountable problem in disassembling the joint when sufficient leverage was possible for applying 26 an external force to separate the flanges. If, after separa-27 tion of the flanges, the soft metal gasket remained attached 28 to one or other of the flanges, the gasket could usually be 29 removed quite easily by a hand tool for prying the gasket away from the flange to which it was attached. However, with 31 the recent proliferation of applications requiring mini-32 flanges (i.e., flanges having a seal diameter of less 3jjmll2878 - 3 - 77-28 ... . .. , .. . ...... .. _ _ .. . ... ..... . ... ..... .. .. .. . .. .... . . . . . . . . . ..
2~2 1 than about one inch), the inaccessibility of mini-flange 2 gaskets to removal by hand-held prying tools has become 3 a significant problem. Also, with large-diameter flanges 4 (e.g., diameters larger than 2-3/4 inches), difficulty has been encountered in disassembling flange joints 6 because of the large external force required to separate 7 the gasket from either one of the flange faces. In many 8 applications, it is advantageous from a system design 9 standpoint to locate flanged coupling ports in places that are relatively inaccessible; and hence, a flange joint that 11 does not readily disassemble is a serious inconvenience.
12 What is needed, therefore, is an all-metal flange 13 joint in which the gasket tends to break away from the ~ mating flange faces when the joint is disassembled.
SUMMAR~ OF THE INVE~TION
16 It is an object of the present invention to provide 17 an all-metal flange joint having a soft metal gasket dis-18 posed between mating flange faces, which gasket can be l9 easily removed when the joint is disassembled.
It is a particular object of this invention to provide 21 an all-metal joint for coupling mini-flanges (i.e., flanges 22 ~ having a diameter of less than about one inch), the joint 23 comprising a soft metal gasket disposed between opposing 24 faces of the mating mini-flanges, the gasket being easily removable when the joint is disassembled.
26 In order to accomplish the foregoing objects, the 27 opposing faces of the mating flanges are configured to 28 form a recess therebetween in which a soft metal gasket 29 can be disposed when the opposing flange faces are pressed together. Oppositely disposed annular ridges on the faces 31 of the mating flanges project into the recess so as to 32 penetrate into opposite sides of a peripheral portion of 3jjmll2878 - 4 - 77-2 2~2 1 the gasket. Compression of the gasket caused by the pressing 2 of the opposing flange faces together causes a portion of 3 the gasket material to extrude into an annular groove formed 4 at the periphery of the recess between the two opposing flange faces. This compressed gasket material in the annular 6 groove provides a gas-tight seal in the nature of a com-7 pressed metal O-ring in the groove between the flange faces.
As in the prior art, the annular groove is dimensioned to 9 have a volume larger than the volume of the gasket material that can flow into the groove. In this way, the volume of 11 the groove can accommodate all of the gasket material that 12 flows therein: and any excess of gasket material that might 13 otherwise tend to push apart the mating flange faces is 14 prevented from entering the groove. By way of distinction from the prior art, the configuration of the opposing flange 16 faces according to the present invention is such that the 17 residual compressive forces present when the flange coupling1~ mechanism is released, distributed over the surface of 19 the gasket, are substantially equal to or greater than the frictional and bonding forces that tend to retain the 21 gasket in contact with either flange.
22 In particular, according to the present invention, the 23 surface portions of the flange faces defining the annular ~4 groove into which the gasket material can be extruded are inclined at other than a right angle with respect to 26 the interface between the mating flange faces. In this way, 27 the distributed compressive force exerted upon the gasket 28 by each surface defining the groove has a component that 29 tends to push the gasket away from contact with the flange face. Thus, according to the present invention, the gasket 31 tends to break away from the mating flange faces when the 32 joint is disassembled.
. .
3jjmll2878 - 5 - 77-28 .. .. ... .. . . ..... .. .,. ., .. . . . . . . . _ .. .... ... .. .. .... ... .. . . . .
2~Z
-5a-More particularly, there i6 provided:
: An all metal joint compxising:
a pair of flange members, each flange member having a face portion configured to confront a corresponding face portion on the other flange member when said flange members are joined, said flange members making contact with each other at a junction plane;
said face portion of each flange member comprising a first annular surface region, the first surface region on one : 10 flange member intersecting the first surface region on the other flange member at said junction plane, said first surface .~ regions enclosing an angle therebetween that is less than 180;
said face portion of each flange member further comprising a second annular surface region and a third annular surface region, said second and third surface regions intersecting each other to form a ridge, said ridge being spaced apart from said junction plane, said second surface region intersecting i said first surface region on said face portion of each flange : member to form in the face portion of each flange member an : 20 annular recess bounded by said first and second surface regions;
said ridge on one of said flange members confronting and spaced apart from said ridge on the other flange member when said flange members are joined;
a continuous annular gasket of soft metal configured to be received between said face portions, said ridge on the face portion of each of said flange members penetrating into said gasket when said flange members are joined, whereby gasket material extrudes into said recess and contacts the first sur-face region on the face portion of each flange member when said flange members are joined;
~ aid first and second surface regions on the face portion of each of said flange members being configured so that the volume of said recess formed thereby is larger than the volume of gasket material that can be extruded into said recess when said flange members are joined; and the distributive compressive force exerted by each of the first, second and third surface regions of the face portion of each flange member upon the gasket material having a oomponent perpendicular to said ~unction plane, which component acts in a direction tending to ~eparate the gasket from the flange member~
when the flange member~ are moved away from each other.
l~ Z~Z
1 BRIEF DESCRIPTION OF THE ~RAWING
2 FIG. 1 is a cross-sectional view in the longitudinal 3 plane of an all-metal joint between two mating flanges 4 coupled by a union comprising a male member on one flange and a female member on the other flange.
6 FIG. 2 is an enlarged view of a portion of the joint 7 between the mating flanges shown in FIG. 1.
8 FIG. 3 is a cross-sectional view of a portion of the 9 face of one of the flanges shown in FIG. 2.
FIG. 4 is a cross-sectional view in the longitudinal 11 plane of an all-metal joint between two mating flanges 12 coupled by a union comprising a threaded male member 13 bearing on each flange and a double-ended female member 14 for engaging both male members.
FIG. 5 is a cross-sectional view in the longitudinal 16 ~ plane of a portion of an all-metal joint between two mating 17 flanges coupled by bolting.
18 FIG. 6 is a force diagram representing the distributed 19 compressive forces exerted on a gasket by the surfaces of a-flange face configured according to the present invention 21 when the flange coupling mechanism is released.
22 FIG. 7 is a force diagram representing the distributed 23 compressive forces exerted on a gasket by the surfaces of 24 a flange face configured according to the prior art when the flange coupling mechanism is released.
26 DES~RIPTI~N OF PREFERRÉD EM~O~IMENTS
27 FIG. 1 illustrates an all-metal flange joint according 28 to the present invention, whereby a gas-tight seal is pro-29 vided between flanged end portions 10 and 20 of pipes 11 and 21, respectively. The flanges 10 and 20 are coupled by means 31 of a union comprising a male member 12 bearing on the pipe 32 11 and a female member 22 bearing on the pipe 21.
, : . .
.
- 3jjmll2878 - 6 - 77-28 lil~29Z
''"
- 1 As shown in FIG. 1, the male member 12 is of annular2 configuration having a threadecl outer surface portion, and 3 is disposed to slide longitudinally along the pipe 11. The 4 inside dia~eter of the male member 12 is less than the out-side diameter of the flange 10, whereby the male member 12 6 is prevented from slipping off the flanged end of the pipe 7 11. Correspondingly, the female member 22 is of annular 8 configuration having a threaded inner surface portion, and 9 is disposed to slide longitudinally along the pipe 21. The female member 22 has an inside diameter that is less than 11 the outside diameter of the flange 20, whereby the female 12 member 22 is prevented from slipping off the flanged end 13 of the pipe 21.
14 When opposing faces of the flanges 10 and 20 are brought into mating contact, the female member 22 extends over the 16 flanges 20 and 10 and engages the threaded outer surface 17 portion of the male member 12. In this way, coupling of 18 the flanged pipes 11 and 22 is accomplished by tightening 19 the female member 22 around the male member 12.
The opposing faces of the flanged end portions 10 and 21 20 are configured to provide a recess 30 therebetween, 22 in which a soft metal gasket 31 can be disposed. The gasket 23 31 is of annular configuration and is made of a material 24 that is more malleable than the material from which the flanged end portions 10 and 20 are composed. Typically, 26 the flanged end portions 10 and 20 are made of stainless 27 steel, in which case the metal gasket 31 can suitably be an 28 annular copper ring of planar configuration. Other suitable 29 gasket materials for use in conjunction with stainless steel mating flanges include nickel, aluminum, various alloys, 31 and combinations of base metal coated with soft metal.
32 ~s shown in greater detail in FIG. 2, the face of 3jjmll2878 - 7 - 77-28 111~'i2~Z
. ' .
1 the flanged portion 10 of the pipe 11 is configured to 2 have an annular ridge 13 projectiny into the recess 30.
3 Similarly, an opposing annular ridge 23 on the face of the 4 flanged portion 20 of the pipe 21 projects from the opposite direction into the recess 30, whereby the ridges 13 and 23 6 penetrate into the soft metal material on opposite sides 7 of the periphery of the gasket 31. Compression of the 8 gasket 31 by the mating of the flanges 10 and 20 causes 9 extrusion of gasket material into a groove formed at the periphery of the recess 30.
11 With further reference to FIG. 2, the annular ridge 13 12 is formed on the face of the flange 10 by the intersection 13 of conical surface regions 14 and 15; and an annular trough 14 16 is formed by the intersection of conical surface regions 15 and 17. Similarly, the annular ridge 23 is formed on the 16 face of the flange 20 by the intersection of conical surface 17 regions 24 and 25; and an annular trough 26 is formed by 18 the intersection of conical surface regions 25 and 27. When 19 the flan~es 10 and 20 are fitted tightly together, the conical surface regions 15, 17, 25 and 27 together form the boundary 21 of the annular groove into which the soft metal gasket 22 material is extruded. This extruded gasket material forms 23 the equivalent of a compressed metal O-ring, which provides 24 a gas-tight seal between the flanges 10 and 20.
The annular groove, which is bounded by the surface 26 regions 15 and 17 on flange 10 and the surface regions 27 27 and 25 on flange 20, is dimensioned to have a volume that 28 is larger than the volume of gasket material that can be 29 extruded therein due to the pinching effect of the ridges 13 and 23 upon the gasket 31. Thus, the amount of gasket 31 material that can enter the annular groove is small enough 32 to prevent separation of the flanges 10 and 20.
3jjmll287~ - 8 - 77-28 -` lll~Z~Z
1 In FIG. 3, the orientations with respect to each other 2 of surface regions 24, 25 and 27 on the face of the flange 3 20 are shown in greater detail. Correspondingly symmetric 4 orientations of the surface regions 14, 15 and 17 on the face of the flange 10 are similarly provided.
6 As shown in FIG. 3, the surface region 25 declines 7 away from the ridge 23 to the trough 26, from whence the 8 surface region 27 extends to the interface plane between 9 the mating flanges 20 and 10. The conical surface region 24 makes an acute angle ~ with respect to the inter-11 face plane of the mating flanges. Similarly, the surface 12 region 25 makes an acute angle ~ with respect to that same 13 interface plane. The angle ~ is preferably in the range 14 from 60 to 75, and the angle ~ is preferably in the range from 15 to 30.
16 In a symmetrically similar manner, the conical surface 17 region 14 on the face of the flange 10 makes an acute angle 18 ~ with respect to the interface plane between the flanges 19 10 and 20; and the conical surface region 15 makes an acute angle ~ with respect to the same interface plane. Thus, 21 facing surfaces of the flanges 10 and 20 are symmetrically 22 arranged with respect to each other.
23 Both the conical surface region 27 on the flange 20 and 24 the corresponding conical surface region 17 on the flange 10 make an angle ~ with respect to the interface plane 26 of the mating flanges 10 and 20. According to the present 27 invention, the angle ~ is an acute angle. In the prior art, 28 there was no suggestion to make the angle ~ an acute angle.
29 The schematic illustration in FIG. 7 on the other hand is representative of flange joints of the prior art wherein, 31 unlike the joint of the present invention, the terminal 32 wall 27' of the annular groove into which extruded gasket 3jjmll2878 - 9 - 77-28 ", . ~. .
.
1 material was confined was perpendicular to the interface 2 plane between the mating flanges. The angle ~ of the present 3 invention, by way of contrast with the prior art, is an 4 acute angle (preferably in the range from 60 to 75). This novel configuration for the terminal wall of the annular 6 groove (i.e., the wall formed by the surface regions 27 7 and 17), together with the prescribed configuration for 8 the surface regions 24 and 14, enables the gasket 31 to 9 be removed much more easily when the joint is disassembled than was possible in the prior art.
11 For convenience in fabrication, the conical surfaces 24 12 and 27 on the face of the flange 20 could be parallel to 13 each other, i.e., it is possible for ~ = ~ provided that 14 ~ is an acute angle. However, it is not necessary for the practice of this invention that ~ = ~ . It is desirable 16 that the ang~e ~ be less than 75 so that the normal to the 17 ~ surface region 27 will have a relatively large component lS perpendicular to the interface plane between the mating 19 flanges. If ~ becomes too small, however, the outside diameter of the flanges 10 and 20 would correspondingly 21 become inconveniently large for standard design 22 considerations. It is not desirable for ~ to be much 23 smaller than about 30, because the extension of the ridge 24 23 into the recess 30 decreases as ~ decreases. An appropriate range for the angle ~ is from 60 to 75;
26 and an appropriate range for the angle ~ is from 15 to 30.
27 When the flanges 10 and 20 are pressed together, whether 28 by the technique shown in FIG. 1 whereby the threaded 29 female union member 22 is tightened over the threaded male member 12, or by any other appropriate coupling technique 31 such as those to be discussed hereinafter in connection 32 with FIGS. 4 and 5, the ridges 13 and 23 protrude into the 3jjmll2878 - 10 - - 77-28 -' ' soft metal gasket 31 and cause a peripheral portion thereof 2 to be extruded into the annular groove bounded by the surface 3 regions 15, 17, 27 and 25. In the flange coupling technique 4 shown in FIG. 4, the female member 22 of FIG. 1 is replaced by a male member 42 that is disposed to slide longitudinally 6 along the pipe 21. The inside diameter of the male member 42 7 is less than the outside diameter of the flange 20, whereby 8 the male member 42 is prevented from slipping off the flanged 9 end of the pipe 21. An outer surface portion of the male member 42 is threaded, just as is a corresponding outer 11 surface portion of the male member 12 on the pipe 11. A
12 cylindrical female member 52, whose inner surface is 13 threaded, can simultaneously engage the threaded outer 14 surface portions of the male members 12 and 42 when the flanges 10 and 20 are in mating contact. In practice, 16 the female member 52 is first tightened onto one of the 17 male members (e.g., male member 42), and then the other 18 male member 12 is threaded into the female member 52 and 19 tightened. In this way, the flanges 10 and 20 are brought into mating contact.
21 Another flange coupling technique is shown in FIG. 5, 22 wherein a flange member 10' is affixed to an end of the pipe 23 11 by an appropriate technique such as welding. Similarly, 24 a flange member 20' is affixed to an end of the pipe 21.
The soft metal gasket 31 is compressed between the opposing 26 flange members 10' and 20' by bolting one flange member 27 to the other. As shown in FIG. S, a bolt 61 passed through 28 aligned holes in the flange members 10' and 20', and a 29 nut 62 threadably engages the protruding end of the bolt 61. The bolt 61 and the nut 62 are representative of a 31 plurality of similar bolts and nuts peripherally disposed 32 (and preferably uniformly spaced) around the mating flanged 3jjmll2878 ~ 77-28 ..
1 members 10' and 20'.
2 When the flanged portions 10 and 20 as shown in FIGS.
3 1 and 4 (or the flanged members 10' and 20' of the embodiment 4 shown in FIG. 5) are pressed together, the ridges 13 and 23 of the opposing flange faces protrude into the soft metal 6 gasket 31, thereby causing a peripheral portion of the gasket 7 material to flow into an annular groove formed at the peri-8 meter of the recess 30 between the opposing flanged faces.
9 This groove, which is bounded by the surfaces 15 and 17 on flanged portion 10 and by the surfaces 27 and 25 on flanged 11 portion 20, has a total volume that is greater than the 12 volume of gasket material that can be extruded into the 13 groove. As explained above, since less than the entire 14 volume of the groove can be occupied by gasket material, the contacting faces of the flanged portions 10 and 20 16 cannot be pushed apart by gasket material in the groove.
17 The compressed gasket material in the annular groove 18 functions as a metal O-ring under compression to provide 19 a gas-tight seal between the mating faces of the flanged portions 10 and 20.
21 As illustrated in FIG. 6, the residual distribu.ed 22 compressive forces F~ , F and F3 present when the flange 23 coupling mechanism is released, and which are exerted, 24 respectively, by the surface regions 27, 25 and 24 of the flanged portion 20 upon the gasket 31, are represented by 26 arrows normal to their respective surfaces. These 27 compressive forces tend to push the gasket 31 away from 28 contact with the flanged portion 20. Corresponding 29 symmetrically acting distributed compressive forces exerted by the corresponding surface regions 17, 15 and 14 of the 31 flanged portion 10 upon the other side of gasket 31 likewise 32 tend to push the gasket 31 away from contact with the flanged ~, .
3jjmll2778 - 12 - 77-28 ?2~2 1 portion 10.
2 When it is desired to uncouple the flanges 10 and 20 in 3 order to disassemble the joint, it is usually also desirable 4 to remove the gasket 31. Quite often in the prior art, how-ever, it was difficult to break the seai between two mating 6 flanges because of bonding and frictional forces that tended 7 to keep the gasket in contact with the faces of the flanges.
8 Bonding forces in the nature of cold welds would develop due 9 to the compression of the gasket against the flanges.
Frictional forces acting parallel to the surfaces of the 11 flanges in directions opposite to the forces tending to 12 push the gasket away from contact with the flanges would 13 also develop. Even after the two mating flanges were 14 separated in the prior art, the gasket would frequently remain attached to one or other of the flanges. In 16 accordance with the present invention, the faces of the 17 opposing flanges are configured in such a way as to mini-18 mize the forces that tend to prevent removal of the gasket 19 after the flan~e coupling mechanism has been released te-g-, by uncoupling the threaded unions shown in FIGS. 1 and 4, or 21 by loosening and removing the nuts 62 shown in FIG. 5).
22 Referring to FIG. 6, the residual compressive force 23 component F acting to push the gasket 31 away from contact 24 with the flange 20 is given by the equation:
26 F = F, cos ~ ~ F~ cos 4 + F3 cos ~ .
28 This net compressive force component F increases as the 29 angles ~ , 4 and ~ decrease. It is desirable for ~ to be in the range from 15 to 30, and for ~ to be in the 31 range from 60 to 75, so that the ridge 23 will protrude 32 sharply enough into the recess 30 so as to cause extrusion 3jjmll2878 - 13 - 77-28 1 of material from the periphery of the gasket 31. According 2 to the present invention, the angle ~ is minimized to the 3 extent practicable in order to provide a component of the 4 compressive force F~ in the direction opposite to the frictional force component that tends to keep the gasket 6 31 in contact with the surface region 27.
7 Ease in disassembling an all-metal flange joint of 8 the kind used in high-pressure and high-vacuum applications g is the primary objective of this invention. The diameter of the flanges to be joined is not material to the defini-11 tion of this invention, although the invention is of 12 special value with respect to mini-flange joints located 13 in areas that are not readily accessible to disassembly 14 by means of hand-held tools.
The practice of this invention may be accommodated 16 by providing a variety of coupling techniques for mating 17 the opposing faces of the flanges to be joined. In 18 particular, the coupling technique illustrated in FIG.
19 4 (i.e, use of a union comprising a male member on each flange and a female member that engages each male member) 21 provides a convenient way to join a number of sections of 22 flanged piping without having to arrange components so as 23 to provide matching male and female union members on the 24 respective ends of flanges to be joined. Where appropriate, a helium gas access hole could be provided through one or 26 both mating flange members to the peripheral region of the 27 recess formed therebetween, whereby the gas-tight integrity 28 of the flange joint can be monitored by techniques well-known 29 to those skilled in the art. The nature of the piping to be joined can vary according to the type of system in which 31 the piping is used. It is contemplated that a flange joint 32 according to this invention can be used to couple pipes .
3jjmll2878 - 14 - 77-28 ., Zg2 1 of any diameter and configuration, including pipes having 2 expandable "bellows" sections. Other uses for an all-metal 3 joint according to this invention will become apparent 4 to those skilled in the art from a perusal of the foregoing specification. Thus, the scope of the invention is limited 6 only by the following claims.
g 3jjmll2878 - 15 - 77-28
A11-metal flange joints for use in applications 6 requiring high-temperature and/or frequent bake-out 7 of an assembled joint are known to the prior art.
8 In particular, U.S. patent 3,208,758 to M. A. Carlson 9 et al., assigned to Varian Associates, Inc., discloses an all-metal flange joint in which a gas-tight seal 11 between mating flanges is provided by the flowing of 12 soft metal gasket material into an annular groove formed 13 between the facing flange surfaces when the two mating 14 flanges are pressed together.
In the flange joint disclosed in U.S. patent 3,208,758, 16 the opposing flange faces were configured so that a soft 17 metal gasket could be received in a recess provided there-18 between when the flanges are pressed together. Corresponding l9 annular ridges were provided on the opposing flange faces to project into the recess so as to penetrate into opposite 21 sides of a peripheral region of the gasket located in the 22 recess. A portion of the gasket material was thereby caused 23 to flow into an annular groove that formed the periphery 24 of the recess between the opposing flange faces. This groove was dimensioned to have a volume larger than the volume 26 of gasket material that could flow into the groove, therby 27 preventing gasket material from completely filling the groove.
28 If an excess of gasket material were permitted to enter the 29 annular groove, the opposing flange faces would be pushed apart. Proper dimensioning of the groove served to provide 31 a gas-tight seal in the nature of a compressed O-ring, 32 which could withstand pressure differentials limited only 3jjmll2878 - 2 - 77-28 . ,. . - - - ' ' '' ' ' ' ' ~
` 1~ii~2~2 1 by the tensile strength of the metal gasket.
2 With prior art flanges of the type described above, 3 however, difficulty was encountered in disassembling the 4 flange joint after a seal had been made. Typically, such prior art flanges were coupled by bolting the two opposing 6 flanges together. Such bolting or other compressive coupling 7 of the mating flange faces caused compression of the gasket 8 disposed therebetween, and resulted in the extrusion of 9 soft metal from the periphery of the gasket into an annular groove formed at the periphery of the recess between the 11 opposing flange faces. When the mating flanges were sub-12 sequently unbolted in order to disassemble the joint, 13 however, the metal g~cket frequently remained stuck to one 14 or the other, or to both, of the flange faces.
When a soft metal gasket has been severely compressed 16 against the surface of a harder metal, a surface bonding 17 phenomenon in the nature of a weld occurs. In addition, 18 a frictional restraining force dependent upon the coefficient l9 of friction of the soft metal gasket material with respect to the harder surface of the flange tends to oppose movement 21 of the gasket away from the flange.
22 In the prior art, the tendency of the metal gasket to 23 remain affixed to one or the other, or to both, of the mating 24 flanges was not an insurmountable problem in disassembling the joint when sufficient leverage was possible for applying 26 an external force to separate the flanges. If, after separa-27 tion of the flanges, the soft metal gasket remained attached 28 to one or other of the flanges, the gasket could usually be 29 removed quite easily by a hand tool for prying the gasket away from the flange to which it was attached. However, with 31 the recent proliferation of applications requiring mini-32 flanges (i.e., flanges having a seal diameter of less 3jjmll2878 - 3 - 77-28 ... . .. , .. . ...... .. _ _ .. . ... ..... . ... ..... .. .. .. . .. .... . . . . . . . . . ..
2~2 1 than about one inch), the inaccessibility of mini-flange 2 gaskets to removal by hand-held prying tools has become 3 a significant problem. Also, with large-diameter flanges 4 (e.g., diameters larger than 2-3/4 inches), difficulty has been encountered in disassembling flange joints 6 because of the large external force required to separate 7 the gasket from either one of the flange faces. In many 8 applications, it is advantageous from a system design 9 standpoint to locate flanged coupling ports in places that are relatively inaccessible; and hence, a flange joint that 11 does not readily disassemble is a serious inconvenience.
12 What is needed, therefore, is an all-metal flange 13 joint in which the gasket tends to break away from the ~ mating flange faces when the joint is disassembled.
SUMMAR~ OF THE INVE~TION
16 It is an object of the present invention to provide 17 an all-metal flange joint having a soft metal gasket dis-18 posed between mating flange faces, which gasket can be l9 easily removed when the joint is disassembled.
It is a particular object of this invention to provide 21 an all-metal joint for coupling mini-flanges (i.e., flanges 22 ~ having a diameter of less than about one inch), the joint 23 comprising a soft metal gasket disposed between opposing 24 faces of the mating mini-flanges, the gasket being easily removable when the joint is disassembled.
26 In order to accomplish the foregoing objects, the 27 opposing faces of the mating flanges are configured to 28 form a recess therebetween in which a soft metal gasket 29 can be disposed when the opposing flange faces are pressed together. Oppositely disposed annular ridges on the faces 31 of the mating flanges project into the recess so as to 32 penetrate into opposite sides of a peripheral portion of 3jjmll2878 - 4 - 77-2 2~2 1 the gasket. Compression of the gasket caused by the pressing 2 of the opposing flange faces together causes a portion of 3 the gasket material to extrude into an annular groove formed 4 at the periphery of the recess between the two opposing flange faces. This compressed gasket material in the annular 6 groove provides a gas-tight seal in the nature of a com-7 pressed metal O-ring in the groove between the flange faces.
As in the prior art, the annular groove is dimensioned to 9 have a volume larger than the volume of the gasket material that can flow into the groove. In this way, the volume of 11 the groove can accommodate all of the gasket material that 12 flows therein: and any excess of gasket material that might 13 otherwise tend to push apart the mating flange faces is 14 prevented from entering the groove. By way of distinction from the prior art, the configuration of the opposing flange 16 faces according to the present invention is such that the 17 residual compressive forces present when the flange coupling1~ mechanism is released, distributed over the surface of 19 the gasket, are substantially equal to or greater than the frictional and bonding forces that tend to retain the 21 gasket in contact with either flange.
22 In particular, according to the present invention, the 23 surface portions of the flange faces defining the annular ~4 groove into which the gasket material can be extruded are inclined at other than a right angle with respect to 26 the interface between the mating flange faces. In this way, 27 the distributed compressive force exerted upon the gasket 28 by each surface defining the groove has a component that 29 tends to push the gasket away from contact with the flange face. Thus, according to the present invention, the gasket 31 tends to break away from the mating flange faces when the 32 joint is disassembled.
. .
3jjmll2878 - 5 - 77-28 .. .. ... .. . . ..... .. .,. ., .. . . . . . . . _ .. .... ... .. .. .... ... .. . . . .
2~Z
-5a-More particularly, there i6 provided:
: An all metal joint compxising:
a pair of flange members, each flange member having a face portion configured to confront a corresponding face portion on the other flange member when said flange members are joined, said flange members making contact with each other at a junction plane;
said face portion of each flange member comprising a first annular surface region, the first surface region on one : 10 flange member intersecting the first surface region on the other flange member at said junction plane, said first surface .~ regions enclosing an angle therebetween that is less than 180;
said face portion of each flange member further comprising a second annular surface region and a third annular surface region, said second and third surface regions intersecting each other to form a ridge, said ridge being spaced apart from said junction plane, said second surface region intersecting i said first surface region on said face portion of each flange : member to form in the face portion of each flange member an : 20 annular recess bounded by said first and second surface regions;
said ridge on one of said flange members confronting and spaced apart from said ridge on the other flange member when said flange members are joined;
a continuous annular gasket of soft metal configured to be received between said face portions, said ridge on the face portion of each of said flange members penetrating into said gasket when said flange members are joined, whereby gasket material extrudes into said recess and contacts the first sur-face region on the face portion of each flange member when said flange members are joined;
~ aid first and second surface regions on the face portion of each of said flange members being configured so that the volume of said recess formed thereby is larger than the volume of gasket material that can be extruded into said recess when said flange members are joined; and the distributive compressive force exerted by each of the first, second and third surface regions of the face portion of each flange member upon the gasket material having a oomponent perpendicular to said ~unction plane, which component acts in a direction tending to ~eparate the gasket from the flange member~
when the flange member~ are moved away from each other.
l~ Z~Z
1 BRIEF DESCRIPTION OF THE ~RAWING
2 FIG. 1 is a cross-sectional view in the longitudinal 3 plane of an all-metal joint between two mating flanges 4 coupled by a union comprising a male member on one flange and a female member on the other flange.
6 FIG. 2 is an enlarged view of a portion of the joint 7 between the mating flanges shown in FIG. 1.
8 FIG. 3 is a cross-sectional view of a portion of the 9 face of one of the flanges shown in FIG. 2.
FIG. 4 is a cross-sectional view in the longitudinal 11 plane of an all-metal joint between two mating flanges 12 coupled by a union comprising a threaded male member 13 bearing on each flange and a double-ended female member 14 for engaging both male members.
FIG. 5 is a cross-sectional view in the longitudinal 16 ~ plane of a portion of an all-metal joint between two mating 17 flanges coupled by bolting.
18 FIG. 6 is a force diagram representing the distributed 19 compressive forces exerted on a gasket by the surfaces of a-flange face configured according to the present invention 21 when the flange coupling mechanism is released.
22 FIG. 7 is a force diagram representing the distributed 23 compressive forces exerted on a gasket by the surfaces of 24 a flange face configured according to the prior art when the flange coupling mechanism is released.
26 DES~RIPTI~N OF PREFERRÉD EM~O~IMENTS
27 FIG. 1 illustrates an all-metal flange joint according 28 to the present invention, whereby a gas-tight seal is pro-29 vided between flanged end portions 10 and 20 of pipes 11 and 21, respectively. The flanges 10 and 20 are coupled by means 31 of a union comprising a male member 12 bearing on the pipe 32 11 and a female member 22 bearing on the pipe 21.
, : . .
.
- 3jjmll2878 - 6 - 77-28 lil~29Z
''"
- 1 As shown in FIG. 1, the male member 12 is of annular2 configuration having a threadecl outer surface portion, and 3 is disposed to slide longitudinally along the pipe 11. The 4 inside dia~eter of the male member 12 is less than the out-side diameter of the flange 10, whereby the male member 12 6 is prevented from slipping off the flanged end of the pipe 7 11. Correspondingly, the female member 22 is of annular 8 configuration having a threaded inner surface portion, and 9 is disposed to slide longitudinally along the pipe 21. The female member 22 has an inside diameter that is less than 11 the outside diameter of the flange 20, whereby the female 12 member 22 is prevented from slipping off the flanged end 13 of the pipe 21.
14 When opposing faces of the flanges 10 and 20 are brought into mating contact, the female member 22 extends over the 16 flanges 20 and 10 and engages the threaded outer surface 17 portion of the male member 12. In this way, coupling of 18 the flanged pipes 11 and 22 is accomplished by tightening 19 the female member 22 around the male member 12.
The opposing faces of the flanged end portions 10 and 21 20 are configured to provide a recess 30 therebetween, 22 in which a soft metal gasket 31 can be disposed. The gasket 23 31 is of annular configuration and is made of a material 24 that is more malleable than the material from which the flanged end portions 10 and 20 are composed. Typically, 26 the flanged end portions 10 and 20 are made of stainless 27 steel, in which case the metal gasket 31 can suitably be an 28 annular copper ring of planar configuration. Other suitable 29 gasket materials for use in conjunction with stainless steel mating flanges include nickel, aluminum, various alloys, 31 and combinations of base metal coated with soft metal.
32 ~s shown in greater detail in FIG. 2, the face of 3jjmll2878 - 7 - 77-28 111~'i2~Z
. ' .
1 the flanged portion 10 of the pipe 11 is configured to 2 have an annular ridge 13 projectiny into the recess 30.
3 Similarly, an opposing annular ridge 23 on the face of the 4 flanged portion 20 of the pipe 21 projects from the opposite direction into the recess 30, whereby the ridges 13 and 23 6 penetrate into the soft metal material on opposite sides 7 of the periphery of the gasket 31. Compression of the 8 gasket 31 by the mating of the flanges 10 and 20 causes 9 extrusion of gasket material into a groove formed at the periphery of the recess 30.
11 With further reference to FIG. 2, the annular ridge 13 12 is formed on the face of the flange 10 by the intersection 13 of conical surface regions 14 and 15; and an annular trough 14 16 is formed by the intersection of conical surface regions 15 and 17. Similarly, the annular ridge 23 is formed on the 16 face of the flange 20 by the intersection of conical surface 17 regions 24 and 25; and an annular trough 26 is formed by 18 the intersection of conical surface regions 25 and 27. When 19 the flan~es 10 and 20 are fitted tightly together, the conical surface regions 15, 17, 25 and 27 together form the boundary 21 of the annular groove into which the soft metal gasket 22 material is extruded. This extruded gasket material forms 23 the equivalent of a compressed metal O-ring, which provides 24 a gas-tight seal between the flanges 10 and 20.
The annular groove, which is bounded by the surface 26 regions 15 and 17 on flange 10 and the surface regions 27 27 and 25 on flange 20, is dimensioned to have a volume that 28 is larger than the volume of gasket material that can be 29 extruded therein due to the pinching effect of the ridges 13 and 23 upon the gasket 31. Thus, the amount of gasket 31 material that can enter the annular groove is small enough 32 to prevent separation of the flanges 10 and 20.
3jjmll287~ - 8 - 77-28 -` lll~Z~Z
1 In FIG. 3, the orientations with respect to each other 2 of surface regions 24, 25 and 27 on the face of the flange 3 20 are shown in greater detail. Correspondingly symmetric 4 orientations of the surface regions 14, 15 and 17 on the face of the flange 10 are similarly provided.
6 As shown in FIG. 3, the surface region 25 declines 7 away from the ridge 23 to the trough 26, from whence the 8 surface region 27 extends to the interface plane between 9 the mating flanges 20 and 10. The conical surface region 24 makes an acute angle ~ with respect to the inter-11 face plane of the mating flanges. Similarly, the surface 12 region 25 makes an acute angle ~ with respect to that same 13 interface plane. The angle ~ is preferably in the range 14 from 60 to 75, and the angle ~ is preferably in the range from 15 to 30.
16 In a symmetrically similar manner, the conical surface 17 region 14 on the face of the flange 10 makes an acute angle 18 ~ with respect to the interface plane between the flanges 19 10 and 20; and the conical surface region 15 makes an acute angle ~ with respect to the same interface plane. Thus, 21 facing surfaces of the flanges 10 and 20 are symmetrically 22 arranged with respect to each other.
23 Both the conical surface region 27 on the flange 20 and 24 the corresponding conical surface region 17 on the flange 10 make an angle ~ with respect to the interface plane 26 of the mating flanges 10 and 20. According to the present 27 invention, the angle ~ is an acute angle. In the prior art, 28 there was no suggestion to make the angle ~ an acute angle.
29 The schematic illustration in FIG. 7 on the other hand is representative of flange joints of the prior art wherein, 31 unlike the joint of the present invention, the terminal 32 wall 27' of the annular groove into which extruded gasket 3jjmll2878 - 9 - 77-28 ", . ~. .
.
1 material was confined was perpendicular to the interface 2 plane between the mating flanges. The angle ~ of the present 3 invention, by way of contrast with the prior art, is an 4 acute angle (preferably in the range from 60 to 75). This novel configuration for the terminal wall of the annular 6 groove (i.e., the wall formed by the surface regions 27 7 and 17), together with the prescribed configuration for 8 the surface regions 24 and 14, enables the gasket 31 to 9 be removed much more easily when the joint is disassembled than was possible in the prior art.
11 For convenience in fabrication, the conical surfaces 24 12 and 27 on the face of the flange 20 could be parallel to 13 each other, i.e., it is possible for ~ = ~ provided that 14 ~ is an acute angle. However, it is not necessary for the practice of this invention that ~ = ~ . It is desirable 16 that the ang~e ~ be less than 75 so that the normal to the 17 ~ surface region 27 will have a relatively large component lS perpendicular to the interface plane between the mating 19 flanges. If ~ becomes too small, however, the outside diameter of the flanges 10 and 20 would correspondingly 21 become inconveniently large for standard design 22 considerations. It is not desirable for ~ to be much 23 smaller than about 30, because the extension of the ridge 24 23 into the recess 30 decreases as ~ decreases. An appropriate range for the angle ~ is from 60 to 75;
26 and an appropriate range for the angle ~ is from 15 to 30.
27 When the flanges 10 and 20 are pressed together, whether 28 by the technique shown in FIG. 1 whereby the threaded 29 female union member 22 is tightened over the threaded male member 12, or by any other appropriate coupling technique 31 such as those to be discussed hereinafter in connection 32 with FIGS. 4 and 5, the ridges 13 and 23 protrude into the 3jjmll2878 - 10 - - 77-28 -' ' soft metal gasket 31 and cause a peripheral portion thereof 2 to be extruded into the annular groove bounded by the surface 3 regions 15, 17, 27 and 25. In the flange coupling technique 4 shown in FIG. 4, the female member 22 of FIG. 1 is replaced by a male member 42 that is disposed to slide longitudinally 6 along the pipe 21. The inside diameter of the male member 42 7 is less than the outside diameter of the flange 20, whereby 8 the male member 42 is prevented from slipping off the flanged 9 end of the pipe 21. An outer surface portion of the male member 42 is threaded, just as is a corresponding outer 11 surface portion of the male member 12 on the pipe 11. A
12 cylindrical female member 52, whose inner surface is 13 threaded, can simultaneously engage the threaded outer 14 surface portions of the male members 12 and 42 when the flanges 10 and 20 are in mating contact. In practice, 16 the female member 52 is first tightened onto one of the 17 male members (e.g., male member 42), and then the other 18 male member 12 is threaded into the female member 52 and 19 tightened. In this way, the flanges 10 and 20 are brought into mating contact.
21 Another flange coupling technique is shown in FIG. 5, 22 wherein a flange member 10' is affixed to an end of the pipe 23 11 by an appropriate technique such as welding. Similarly, 24 a flange member 20' is affixed to an end of the pipe 21.
The soft metal gasket 31 is compressed between the opposing 26 flange members 10' and 20' by bolting one flange member 27 to the other. As shown in FIG. S, a bolt 61 passed through 28 aligned holes in the flange members 10' and 20', and a 29 nut 62 threadably engages the protruding end of the bolt 61. The bolt 61 and the nut 62 are representative of a 31 plurality of similar bolts and nuts peripherally disposed 32 (and preferably uniformly spaced) around the mating flanged 3jjmll2878 ~ 77-28 ..
1 members 10' and 20'.
2 When the flanged portions 10 and 20 as shown in FIGS.
3 1 and 4 (or the flanged members 10' and 20' of the embodiment 4 shown in FIG. 5) are pressed together, the ridges 13 and 23 of the opposing flange faces protrude into the soft metal 6 gasket 31, thereby causing a peripheral portion of the gasket 7 material to flow into an annular groove formed at the peri-8 meter of the recess 30 between the opposing flanged faces.
9 This groove, which is bounded by the surfaces 15 and 17 on flanged portion 10 and by the surfaces 27 and 25 on flanged 11 portion 20, has a total volume that is greater than the 12 volume of gasket material that can be extruded into the 13 groove. As explained above, since less than the entire 14 volume of the groove can be occupied by gasket material, the contacting faces of the flanged portions 10 and 20 16 cannot be pushed apart by gasket material in the groove.
17 The compressed gasket material in the annular groove 18 functions as a metal O-ring under compression to provide 19 a gas-tight seal between the mating faces of the flanged portions 10 and 20.
21 As illustrated in FIG. 6, the residual distribu.ed 22 compressive forces F~ , F and F3 present when the flange 23 coupling mechanism is released, and which are exerted, 24 respectively, by the surface regions 27, 25 and 24 of the flanged portion 20 upon the gasket 31, are represented by 26 arrows normal to their respective surfaces. These 27 compressive forces tend to push the gasket 31 away from 28 contact with the flanged portion 20. Corresponding 29 symmetrically acting distributed compressive forces exerted by the corresponding surface regions 17, 15 and 14 of the 31 flanged portion 10 upon the other side of gasket 31 likewise 32 tend to push the gasket 31 away from contact with the flanged ~, .
3jjmll2778 - 12 - 77-28 ?2~2 1 portion 10.
2 When it is desired to uncouple the flanges 10 and 20 in 3 order to disassemble the joint, it is usually also desirable 4 to remove the gasket 31. Quite often in the prior art, how-ever, it was difficult to break the seai between two mating 6 flanges because of bonding and frictional forces that tended 7 to keep the gasket in contact with the faces of the flanges.
8 Bonding forces in the nature of cold welds would develop due 9 to the compression of the gasket against the flanges.
Frictional forces acting parallel to the surfaces of the 11 flanges in directions opposite to the forces tending to 12 push the gasket away from contact with the flanges would 13 also develop. Even after the two mating flanges were 14 separated in the prior art, the gasket would frequently remain attached to one or other of the flanges. In 16 accordance with the present invention, the faces of the 17 opposing flanges are configured in such a way as to mini-18 mize the forces that tend to prevent removal of the gasket 19 after the flan~e coupling mechanism has been released te-g-, by uncoupling the threaded unions shown in FIGS. 1 and 4, or 21 by loosening and removing the nuts 62 shown in FIG. 5).
22 Referring to FIG. 6, the residual compressive force 23 component F acting to push the gasket 31 away from contact 24 with the flange 20 is given by the equation:
26 F = F, cos ~ ~ F~ cos 4 + F3 cos ~ .
28 This net compressive force component F increases as the 29 angles ~ , 4 and ~ decrease. It is desirable for ~ to be in the range from 15 to 30, and for ~ to be in the 31 range from 60 to 75, so that the ridge 23 will protrude 32 sharply enough into the recess 30 so as to cause extrusion 3jjmll2878 - 13 - 77-28 1 of material from the periphery of the gasket 31. According 2 to the present invention, the angle ~ is minimized to the 3 extent practicable in order to provide a component of the 4 compressive force F~ in the direction opposite to the frictional force component that tends to keep the gasket 6 31 in contact with the surface region 27.
7 Ease in disassembling an all-metal flange joint of 8 the kind used in high-pressure and high-vacuum applications g is the primary objective of this invention. The diameter of the flanges to be joined is not material to the defini-11 tion of this invention, although the invention is of 12 special value with respect to mini-flange joints located 13 in areas that are not readily accessible to disassembly 14 by means of hand-held tools.
The practice of this invention may be accommodated 16 by providing a variety of coupling techniques for mating 17 the opposing faces of the flanges to be joined. In 18 particular, the coupling technique illustrated in FIG.
19 4 (i.e, use of a union comprising a male member on each flange and a female member that engages each male member) 21 provides a convenient way to join a number of sections of 22 flanged piping without having to arrange components so as 23 to provide matching male and female union members on the 24 respective ends of flanges to be joined. Where appropriate, a helium gas access hole could be provided through one or 26 both mating flange members to the peripheral region of the 27 recess formed therebetween, whereby the gas-tight integrity 28 of the flange joint can be monitored by techniques well-known 29 to those skilled in the art. The nature of the piping to be joined can vary according to the type of system in which 31 the piping is used. It is contemplated that a flange joint 32 according to this invention can be used to couple pipes .
3jjmll2878 - 14 - 77-28 ., Zg2 1 of any diameter and configuration, including pipes having 2 expandable "bellows" sections. Other uses for an all-metal 3 joint according to this invention will become apparent 4 to those skilled in the art from a perusal of the foregoing specification. Thus, the scope of the invention is limited 6 only by the following claims.
g 3jjmll2878 - 15 - 77-28
Claims (6)
1. An all metal joint comprising:
a pair of flange members, each flange member having a face portion configured to confront a corresponding face portion on the other flange member when said flange members are joined, said flange members making contact with each other at a junction plane;
said face portion of each flange member comprising a first annular surface region, the first surface region on one flange member intersecting the first surface region on the other flange member at said junction plane, said first surface regions enclosing an angle therebetween that is less than 180°;
said face portion of each flange member further comprising a second annular surface region and a third annular surface region, said second and third surface regions intersecting each other to form a ridge, said ridge being spaced apart from said junction plane, said second surface region intersecting said first surface region on said face portion of each flange member to form in the face portion of each flange member an annular recess bounded by said first and second surface regions;
said ridge on one of said flange members confronting and spaced apart from said ridge on the other flange member when said flange members are joined;
a continuous annular gasket of soft metal configured to be received between said face portions, said ridge on the face portion of each of said flange members penetrating into said gasket when said flange members are joined, whereby gasket material extrudes into said recess and contacts the first sur-face region on the face portion of each flange member when said flange members are joined;
said first and second surface regions on the face portion of each of said flange members being configured so that the volume of said recess formed thereby is larger than the volume of gasket material that can be extruded into said recess when said flange members are joined; and the distributive compressive force exerted by each of the first, second and third surface regions of the face portion of each flange member upon the gasket material having a component perpendicular to said junction plane, which component acts in a direction tending to separate the gasket from the flange members when the flange members are moved away from each other.
a pair of flange members, each flange member having a face portion configured to confront a corresponding face portion on the other flange member when said flange members are joined, said flange members making contact with each other at a junction plane;
said face portion of each flange member comprising a first annular surface region, the first surface region on one flange member intersecting the first surface region on the other flange member at said junction plane, said first surface regions enclosing an angle therebetween that is less than 180°;
said face portion of each flange member further comprising a second annular surface region and a third annular surface region, said second and third surface regions intersecting each other to form a ridge, said ridge being spaced apart from said junction plane, said second surface region intersecting said first surface region on said face portion of each flange member to form in the face portion of each flange member an annular recess bounded by said first and second surface regions;
said ridge on one of said flange members confronting and spaced apart from said ridge on the other flange member when said flange members are joined;
a continuous annular gasket of soft metal configured to be received between said face portions, said ridge on the face portion of each of said flange members penetrating into said gasket when said flange members are joined, whereby gasket material extrudes into said recess and contacts the first sur-face region on the face portion of each flange member when said flange members are joined;
said first and second surface regions on the face portion of each of said flange members being configured so that the volume of said recess formed thereby is larger than the volume of gasket material that can be extruded into said recess when said flange members are joined; and the distributive compressive force exerted by each of the first, second and third surface regions of the face portion of each flange member upon the gasket material having a component perpendicular to said junction plane, which component acts in a direction tending to separate the gasket from the flange members when the flange members are moved away from each other.
2. The joint of claim 1 wherein said first surface region on the face portion of each of said flange members intersects said junction plane at an acute angle in the range from 60° to 75°, and said third surface region on the face por-tion of each of said flange members intersects said junction plane at an acute angle in the range from 60° to 75°.
3. The joint of claim 1 wherein said ridge subtends an angle no smaller than 90°.
4. The joint of claim 1 wherein said second surface intersects said junction plane at an acute angle in the range from 15° to 30°.
5. The joint of claim 2 wherein said ridge subtends an angle no smaller than 90°.
6. The joint of claim 1 wherein said face portion of each flange member further comprises a fourth annular surface region intersecting said third surface region, and said gasket has a portion thereof located between and spaced from said forth surface regions of the two flange members when said flange members make contact with each other at said junction plane.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US96623078A | 1978-12-04 | 1978-12-04 | |
| US966,230 | 1978-12-04 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1110292A true CA1110292A (en) | 1981-10-06 |
Family
ID=25511083
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA341,074A Expired CA1110292A (en) | 1978-12-04 | 1979-12-03 | Flange sealing joint with removable metal gasket |
Country Status (6)
| Country | Link |
|---|---|
| CA (1) | CA1110292A (en) |
| DE (1) | DE2948286A1 (en) |
| FR (1) | FR2443635B1 (en) |
| GB (1) | GB2038972B (en) |
| IT (1) | IT1125885B (en) |
| NL (1) | NL188244C (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB8505157D0 (en) * | 1985-02-28 | 1985-04-03 | Anson Ltd | Pipeline couplings |
| US4724200A (en) * | 1985-09-03 | 1988-02-09 | Eastman Kodak Company | Emulsions and photographic elements containing silver halide grains having icositetrahedral crystal faces |
| JPS63243585A (en) * | 1986-11-18 | 1988-10-11 | 株式会社 リガルジヨイント | Joint for multiple pipe |
| JP2656102B2 (en) * | 1987-10-09 | 1997-09-24 | エフェレル エス．アー． | Exchangeable annular metal coupling joint for tightly coupling two cylindrical elements at the end face, and a universal seal used therefor |
| US5135269A (en) * | 1990-07-09 | 1992-08-04 | Cajon Company | Tube coupling |
| DE9011772U1 (en) * | 1990-08-13 | 1990-10-31 | Karl Rafeld KG Spritzgußwerk, Elektronik und Formenbau, 8954 Biessenhofen | Pressure fitting for hot water and aggressive liquids |
| US5366261A (en) * | 1992-04-27 | 1994-11-22 | Fujikin Incorporated | Pipe joint with a gasket retainer |
| TW396380B (en) * | 1997-06-13 | 2000-07-01 | Swagelok Marketing Co | A modular fluid component system and a face seal assembly for the same |
| JP3876351B2 (en) | 1997-06-18 | 2007-01-31 | 忠弘 大見 | Pipe fitting |
| DE102005045731B4 (en) * | 2005-09-23 | 2010-09-23 | Benteler Automobiltechnik Gmbh | Connecting arrangement for pipes |
| EP1908998A1 (en) * | 2006-10-08 | 2008-04-09 | Ludwig Hiss | Soft metal seal |
| US8505983B2 (en) | 2007-10-29 | 2013-08-13 | Ludwig Hiss | Expansion seal, especially for gases |
| DE102007051921A1 (en) | 2007-10-29 | 2009-04-30 | Ludwig Hiss | O-ring-like-spreading gas seal for providing flange connection of pipe, has cut with profile provided around periphery parallel to surfaces so that cross section guided inwardly through seal, has Y shape on contact zone of seal |
| DE102007058126A1 (en) | 2007-11-30 | 2009-06-04 | Ludwig Hiss | Expansive metal-to-metal ring-seal used between e.g. flanges of pipes carrying hydrogen or helium, has Y-shaped edge profile |
| WO2014152139A1 (en) * | 2013-03-15 | 2014-09-25 | Flowserve Management Company | Sanitary fitting for fluid handling equipment |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1228871B (en) * | 1960-03-19 | 1966-11-17 | Sedimmeci Soc D Expl D Inv S M | Sealing arrangement for high vacuum flange connections |
| US3208758A (en) * | 1961-10-11 | 1965-09-28 | Varian Associates | Metal vacuum joint |
| US3747963A (en) * | 1972-05-17 | 1973-07-24 | Cajon Co | High vacuum flange assembly with o-ring gasket |
| DE2629548B2 (en) * | 1976-07-01 | 1978-07-27 | Kempchen & Co Gmbh, 4200 Oberhausen | Use of a seal with a metallic core and an It layer on both sides for systems and apparatus made of austenitic material |
-
1979
- 1979-11-28 NL NLAANVRAGE7908624,A patent/NL188244C/en not_active IP Right Cessation
- 1979-11-30 DE DE19792948286 patent/DE2948286A1/en not_active Withdrawn
- 1979-12-03 CA CA341,074A patent/CA1110292A/en not_active Expired
- 1979-12-03 GB GB7941657A patent/GB2038972B/en not_active Expired
- 1979-12-04 IT IT27818/79A patent/IT1125885B/en active
- 1979-12-04 FR FR7929741A patent/FR2443635B1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| NL188244B (en) | 1991-12-02 |
| NL7908624A (en) | 1980-06-06 |
| NL188244C (en) | 1992-05-06 |
| FR2443635A1 (en) | 1980-07-04 |
| IT7927818A0 (en) | 1979-12-04 |
| GB2038972A (en) | 1980-07-30 |
| IT1125885B (en) | 1986-05-14 |
| FR2443635B1 (en) | 1986-06-20 |
| DE2948286A1 (en) | 1980-06-26 |
| GB2038972B (en) | 1983-03-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |