MXPA98010420A - Pipe joint and seal therefor - Google Patents

Abstract

A joint seal (10) has a through bore (12) and two spherical spaced convex surfaces (20, 22) which mate with respective concave spherical surfaces (38, 44) on a pair of adjacent flanges (26, 42). The flanges are welded to and about the periphery of corresponding spaced pipes (6, 8) one of which is inserted in the bore (12) of the seal. The flanges are joined by two bolts (52), one flange (26) being fixedly secured to the bolts (52) and the other resiliently movably secured to the bolts by a pair of springs (62) to permit that other flange (42) to rotate in response to rotation of the pipe (8) affixed thereto. The one flange forms a static wedge-like seal joint with one of the pipes and the other flange a dynamic seal joint with the respective seal spherical surfaces, the spherical seal and flange surfaces being urged together in wedged relation by the springs.

Description

"PIPE JOINT AND SEAL FOR THE SAME" This invention relates to pipe joints using spherical seals for automotive exhaust systems. Pipe joints for certain automotive exhaust systems employ seals with spherical surfaces. For example, seals and seals of the prior art are disclosed in U.S. Patent Nos. 5,499,825 and 5,040,805, which are incorporated by reference herein. Typical exhaust gaskets comprise a seal, usually formed in a preform of a wire mesh or filling or loading material, and then crushed by matrices to the shape of the end seal as illustrated in the aforementioned patents. Seals can be rigid or flexible, in accordance with seal construction. A lubricant or lubricating material is incorporated in the seal to provide a lubricating surface. The seals are annular with a surface of a radially outer convex spherical segment and flat opposing end surfaces as shown in Patent Number 5,499,825. In this patent, the circular cylindrical through-hole communicates with the flat end surfaces to receive a pipe concentric with the spherical annular surface. A flange is welded in a fixed position to the received pipe separated from the end edge of the pipe and has a flat surface that abuts one of the flat surfaces of the seal. The tab fixed to the axial position of the seal. The spherical surface of the seal ends adjacent to the flange. The other flat surface of the seal ends approximately flush with the end edge of the pipe. The seal therefore has an annular drilling surface that abuts the outer circumference of the pipe and a flat surface similar to a circular disk perpendicular to the bore that abuts the flange. A second movable flange has a concave surface that coincides with the convex surface of the seal to form a dynamic engagement therewith. The two tabs each have a pair of perforated flange members aligned. A bolt is screwed into the flange members of the fixed flange. A compression spring is between each flange member of the movable flange and is retained on the bolt by a bolt head. The springs resiliently push the concave surface of the dynamic flange into engagement with the convex surface of the seal. A second pipe is secured with the dynamic flange. The second pipe can therefore turn - resiliently relative to the first pipe around the spherical gear surfaces. A similar seal is illustrated in Patent Number 5,040,805. The purpose of these joints is to provide a relatively fluid-tight seal for the exhaust gases conducted through the pipes in the joint, while allowing the pipes to move relative to each other. The present inventors recognize a problem with these joints. They recognize that in these prior art joints, the cylindrical and planar mating surfaces bumping together do not provide a sufficiently fluid tight seal for the exhaust gases at the interface of the two pipes joined or joined together. They recognize that the fixed flange and coincident cylindrical pipe matching surfaces and the flat surface of the seal with the matching flat flange surface provide a relatively high gas escape path. A seal and a seal in accordance with the present invention are directed to solve this gas leak problem, minimizing this leakage. A seal according to one aspect of the present invention comprises a circular member having opposite ends and an axially extending central cylindrical through-hole which extends between and towards the ends forming an internal cylindrical surface extending to the ends to receive in it a first pipe, along an axis. A first radially outwardly oriented surface of the circular member, terminating at one of the ends, is concentric with and tapers towards the axis and toward the inner surface at one end forming an annular convex wedge-like member at the end. A second surface of a convex spherical segment oriented radially outwardly at the other end is concentric with the axis, the second segment tapering towards the axis and the inner cylindrical surface at the other end generally in separate mirror image relation with respect to the first surface. A radially outward axially extending segment lies between the first and second surfaces to axially separate the first and second surfaces. As a result, the flat static escape path between the seal and the prior art flange is changed by means of the present invention towards a wedge-like seal which improves the sealing action compared to the sealing action of the flat surfaces. of the prior art. A fluid pipe joint according to a further aspect of the present invention comprises first and second aligned pipes for transporting a fluid, each pipe having an outer cylindrical surface. A seal has a central opening therethrough which defines an axis and in whose opening the first pipeline is placed, the opening being defined by a cylindrical surface coaxial with the axis and abutting against the first pipe, the seal having a first surface annular radial, tapering the outer surface in relation to and extending around the axis and tapering toward and extending around the cylindrical surface adjacent a first edge of the seal to form an annular wedge-like member between the tapered outer surface and the adjacent internal cylindrical surface to the first edge, and a second annular convex spherical surface extending around the axis adjacent to a second edge of the seal opposite the first edge. A first flange with a tapered surface is for engaging and engaging the first surface and is secured in a fixed position and in substantially fluid-impermeable relationship with and around the outer surface of the first pipe, forming the outer surface of the first pipe. and the first flange a recess similar to a wedge to receive the seal in a wedge-like relationship with respect thereto.

A second flange with a concave spherical surface is for coinciding with and engaging the second surface of the seal and is secured in a fixed position and in an essentially fluid-impermeable relationship with and around the external surface of the second pipe. Bolt means are secured in the first flange in a fixed position, the second flange being secured in the bolt means in movable resilient relation to allow the second pipe to rotate relative to the first pipe around the spherical surface of the second seal and to axially resiliently pushing the tabs against the corresponding seal surface, and the tapered surfaces and to push the first edge of the seal toward the recess to wedge the seal between the first flange and the outer cylindrical surface of the first pipe in a similar relationship to cradle.

IN THE DRAWING: The single figure is a sectional elevation view of a seal and gasket according to the present invention. In the Figure, the joint assembly 2 is particularly adapted for use with automotive exhaust systems. However, the assembly can be used in other fluid distribution systems where it is desired that a pipe be relatively movable with respect to a second pipe in the system. The assembly 2 comprises a gasket 4 for sealingly securing a cylindrical circular pipe 6 preferably made of stainless steel to a second cylindrical circular pipe 8, preferably made of stainless steel. Pipes 6 and 8 are conventional for use in automotive exhaust systems to convey the exhaust gases of the hot toxic combustion engine. In these exhaust systems, the joint must be essentially leak proof while allowing a pipe to rotate with three degrees of freedom of rotation and no translation relative to the other. When cars are parked, for example, leaking exhaust fumes can undesirably infiltrate the passenger cabin of the vehicle. If the gasket remains before the catalytic converter, the untreated exhaust gas can escape. Under certain operating conditions, the air can be attracted to the joint by a lower pressure inside the joint. In sophisticated systems, an oxygen sensor detects the oxygen content of exhaust gas in the exhaust pipes. If air is drawn to the joint through a leak, the sensor can detect a poorly erroneous condition. A computer, in response, can cause the engine to be supplied with a richer fuel-air mixture resulting in higher undesirable emissions and poor fuel economy. The gasket and seal of the present invention minimize these leaks. A seal 10 in accordance with one embodiment of the present invention is preferably formed with a reinforcement matrix of a knitted wire mesh, which may be made of stainless steel and which comprises a wire of a given diameter by an implementation determined, a filling or loading material that may be vermiculite or mica and a lubricant such as graphite. These materials can be combined in accordance with a certain implementation and can form a preform during a step of manufacturing the seal. Examples of these preform materials are disclosed in the aforementioned US Patent Nos. 5,449,825 and 5,040,805, which are incorporated by reference herein. Also, techniques for forming preforms for use in an automotive exhaust seal arrangement using seals of the type disclosed herein are disclosed in these patents.

The resulting, generally flat, preform is flexible and is wound around a mandrel to form a cylindrical structure as shown for example in US Patent Numbers 5, 499,825 and 5,040,805. For example, in Patent Number 5,499,825, a wire network of fine wire wire knitted stainless steel is combined with a sheet of heat resistant material, such as expanded graphite, mica or asbestos. A lubricant composition is then coated onto the material in the sheet that is placed inside the knitted wire mesh. This structure is then wrapped around a mandrel in a cylindrical female matrix. A male cylindrical matrix is inserted into the female matrix by compressing the material of the preform into the female matrix, forming the preform in the desired seal configuration. Other forms of the composite material may include powdered matrices added to the female matrix after the wire mesh is wrapped around a core in the female matrix. This powder matrix material tends to remain outside of wire mesh in the formed seal. The combination of materials is then compressed with a male matrix to form the seal. In Patent Number 5,040,805, a knitted wire mesh is wound around a core.

An expanded graphite sheet is placed over the uncoiled wire mesh. Both are wound cylindrically in succession into a partial cylindrical part and a preform body is formed with a refractory material projecting into an end portion from the body of the preform. Depending on the wire mesh parameters, e.g., the size of the wire and the separation of the gauze from knitted fabric, and the filling or loading material, the resulting seal may be flexible or relatively stiff. In one form, the lubricant may be a graphite sheet material wrapped around the wire mesh preform. In a further embodiment, a powder compound, a lubricant material such as graphite and the wire mesh are placed in the female matrix. When compressed, the resulting structure is relatively hard and rigid. The lubricant material is placed to form a lubricating surface in the seal for dynamic action with a matching flange surface. The seal 10 is circular with a through bore 12 extending in the axial direction 14. The seal 10 has a segment 16 of circular cylindrical outer surface. Then, adjacently and positioned oppositely to the segment, are the cylindrical circular portions 18 that form a segment with the segment 16. The segment 16 is shown as a raised edge but this raised edge is not essential and is provided only for purposes of improving the manufacturing tool not connected with the present invention. In the alternative, the segment 16 can be flush with the adjacent radial outer surfaces of the portions 18 to form a single continuous circular cylindrical segment (not shown). An annular convex spherical segment surface 20 lies on the side of the segment 16 and a second surface 22 of the mirror convex annular spherical segment is on the opposite side of the segment 16. The surfaces 20 and 22 are flush with the respective corresponding surfaces of the portions 18 and end at the ends of the seal in respective annular radial planar surfaces 24. The surfaces 20 and 22 can be generated from a radius that leaves a common center or preferably from separate centers. The surface 22 is inclined in an inclined manner relative to the cylindrical internal annular surface 12 and the axis 25 around which it is concentric to the surface 12. The angle of inclination is such that the surfaces 12 and 22 form a configuration similar to taper wedge in section as shown in the figure, ending in end surface 24 perpendicular to axis 25. Specular image surface 20 is identical to surface 22 so that it does not matter which surface is assembled in the joint in the directions 14 and 14 '. This is to facilitate fabrication of the joint assembly so that the assembly does not require selection of any surface 20 or 22 in a given seal orientation with respect to the pipes 6 and 8 and the direction 14. As a result, the surface 20 The seal also forms a wedge-like configuration with the surface 12 of the seal. This wedge-like configuration is important as will be described. In the alternative, the surface 20 need not be a mirror image of the surface 22. The surface 20 may be conical, a segment of an oval or other configurations so as to form a wedge-like structure with the surface 12. That is, the tapered end of the surface 22 corresponding to the opposite end surface 24 must be narrower and the more central region is the wider portion of the seal at this end of the seal. A relatively small angle of inclination of the convex spherical surfaces 20 and 22 (or the otherwise tapered or conical surface 20) to the axis 25 adjacent the end surface 24 at the ends of the opposite seal, v. g., of about 35 ° for example, is desirable in order to obtain the wedge-like configuration. In the alternative, when the surface 20 of the seal is conical, or of other tapered configurations, the inclination of preference is similar to the angle mentioned above to form the desired wedge configuration. However, it should be understood that only the surface 20 can be non-spherical, since this surface is for static engagement as will be explained below. In contrast, the surface 22 remains in dynamic engagement and is spherical to allow a rotation action with the matching flange which will be described below. A static flange 26 preferably comprises a die-cut stainless steel blade having an annular leg 28 forming a perforation for closely receiving the pipe 6. The edge of the leg 28 is welded to the pipe 6 in the weld 30 to form a seal gas impermeable between leg 28 and pipe 6, in a continuous annular seam. The weld 30 secures the flange 26 axially to the pipe 6. The weld is used to allow the exit of the hot exhaust gases. In the alternative, in an environment where the heat is not a factor, other sealing arrangements can be employed to seal and securely secure the pipe 6 in the flange 26. The flange 26 has a generally triangular preference configuration in the flange member 27. Plant view tab. The member 27 comprises a generally triangular planar configuration in the plan view leg 32, which extends radially from one side of the leg 28. A peripheral reinforcement rib 34 emerges from the leg 32. The shape and configuration of the flange can be in other forms in accordance with a particular implementation. A through opening 36 is in the leg 32. A concave ring portion 38 preferably spherical extends from the leg 28 spaced around the pipe 6 and connects with the leg 32. The concave spherical surface of the flange portion 38 it meshes and coincides with the convex spherical surface of the seal in relatively static gas sealing relationship around the pipe 6. _ In the alternative, in case the surface is conical or otherwise tacked into other shapes, the concave surface of the flange portion 38 is configured to coincide with and engage this tapered surface. A second flange member 40 preferably identical in construction to the member 27 extends from the concave portion 38 on one side of the flange 26 opposite the member 27. A second flange 42 preferably identical to the flange 26 in shape and configuration with the except for its openings (and only when the flange portion 38 is spherical). The flange 42 has a cylindrical circular leg 43 which receives the pipe 8. The leg 43 is welded to the pipe 8 in the weld 45 forming a seam impervious to the continuous fluid around the pipe 8. In the alternative, the fixing and sealing of the pipe 8 in the flange 42 can be effected by another construction as described above for use with fluids at a lower temperature. The leg 43 is connected to the portion 44 of the annular flange. The portion 44 has a preferably spherical concave shape which is preferably identical to the flange portion 38 (only when the portion 38 is spherical). The portion 44 extends around and remains in matching sealing engagement with the spherical surface 22 of the seal 10. The flange members 46 and 50 extend radially outwardly from the portion 44, in opposite directions. The flange members 46 and 50 each have an opening 48 different from the corresponding opening 36 in the flange member 32, and the opening 36 - - corresponding in the tab member 40. The openings 48 are larger in diameter than the openings 36. A second flange member 50 in mirror image relation to identical to the member 46 remains on the opposite side of the flange 42 connected to the portion 44. Otherwise, the flange 42 may be identical to the flange 26. The openings 48 of the flange members 46 and 50 are aligned axially parallel to the axis 25 with the openings 36 of the respective flange members 27 and 40. A bolt 52 is in each of the aligned opening pairs of the respective aligned flange members 34, 46 and 40, 50. Bolt 52 has a head 54 at one end and a stud 56 threaded at its other end. A shoulder 58 is adjacent to the stud 56. A nut 60 axially interlocks the flange member 27 to the shoulder 58, in a fixed axial position. The other bolt 52 is similarly secured to the flange member 40. The seal 10 is therefore axially meshed in wedge relation between the pipe 6 and the matching spherical seal surface 20 and the flange portion 38 in a direction opposite to the direction 14. In this way, the seal 10 remains in relation static wedge with respect to flange 26 and pipe 6.

A spiral spring 62 of compression lies between an annular flange 63 on each of the heads 54 of the bolt 52 and the flange member 46 receives the respective bolts 52 therethrough. With the nuts 60 in place, the spring 62 compresses and elastically pushes the flange 42 in a direction opposite to the direction 14. This action seats the spherical portion 44 of the flange 42 against the spherical seal surface 22 in essentially airtight relationship to the fluid but dynamic. This action also seats the spherical surface 20 of the seal 10 in a fluid-tight static relationship with the spherical concave surface of the flange portion 38. The bolts 52 have a smaller diameter than the openings 48 so as to float transversely in these openings. This floating action allows the flange 42 to rotate in response to the rotation of the pipe 8 with respect to the pipe 6 with three degrees of freedom of rotation and without movement. During operation, exhaust gas 64 flows through pipes 6 and 8 and gasket 66 therebetween. The gas 64 can not flow between the pipe 8 and the leg 43 of the flange 42 towards the ambient atmosphere, due to the welding 45. Similarly, the gas can not flow between the leg 28 and the pipe 6 to the ambient atmosphere, due to the welding 30. The gas 64 can follow two other paths. A path lies between the surface 12 of the seal 10_ and the pipe 6 towards the interface between the convex surface 20 of the seal 10 and the portion 38 of the concave flange. However, because the seal 10 is in static engagement with the flange portion and is spherical, the leakage between them is minimized compared to the flat surfaces of the prior art gaskets. The resilient axial load of the springs 62 forces the seal 10 generally in the axial direction 14 '. The tapered seal 10 at the end adjacent the surface 20 and the mating surface of the static flange portion 38 is wedged toward the configuration similar to that of the cavity between the flange portion 38 and the pipe 6. This wedging action produces a relatively high normal sealing force between the seal 10, the flange portion 38 and the pipe 6. This action provides an improved fluid-tight seal as compared to the non-wedged flat surfaces of the prior art, as discussed in FIG. the introduction portion. In this context, the wedging action can be obtained with non-spherical surfaces in the static flange, e.g., by matching conical surfaces in a similar manner between the flange and the seal. In those cases, where the seal 10 is flexible, it can be flexible in a radial direction perpendicular to the pipe 6. In this case, the flexible seal in response to the wedging action provides an improved sealing action with the pipe 6 in the radial direction inwards, also reducing the potential leaks between them. A second path would lie between the surface 22 of the spherical seal and the portion 44 of the concave flange. This is also a relatively fluid-tight seal and minimizes gas leakage. Therefore, the escape of gas is essentially prevented by means of the double spherical sealing surfaces of the seal 10. It will occur to a person skilled in the art that modifications can be made to the embodiments disclosed. For example, the spherical seal surfaces need not be separated by a cylindrical or vertical surface but by surfaces of other shapes such as a channel or a non-cylindrical edge. The seal 10 and its two spherical surfaces 20 and 22 preferably correspond to the surfaces of a hemisphere. The hemisphere is cut into three parallel segments wherein the seal 10 is in the form of an intermediate sliced segment. Therefore, the two spherical convex seal surfaces can have a radius that leaves a common center. However, this is not essential. The radii of the two spherical surfaces can leave two centers axially separated. Although preferential seals are formed of knitted wire mesh, they can be formed as solid metal structures, e.g., a powdered composite without a mesh reinforcement. Likewise, the seal can be forged, machined, molded or otherwise formed. The mesh may or may not be knitted. The reinforcement can be made of non-metallic materials. It is intended that the scope of the invention is defined by the appended claims, the description herein being provided by way of illustration and not limitation.

Claims (18)

- - CLAIMS:

1. A fluid pipe joint comprising: first and second pipes aligned to transport a fluid, each pipe having an outer cylindrical surface; a seal having a central opening therethrough which defines an axis in which opening the first pipe is placed, the opening is defined by a cylindrical surface coaxial with the axis which abuts against the first pipe, the seal having an outer surface of the first annular radial surface, tapering in relation to and extending around the axis and tapering towards and extending around the cylindrical surface adjacent a first edge of the seal to form an annular member similar to a wedge between the taper outer surface and the internal cylindrical surface adjacent to the first edge, and a second annular convex spherical surface extending about the axis adjacent a second edge of the seal opposite the first edge; a first flange with a tapered surface to coincide with and engage the first surface of the seal and which is secured in fixed position and in substantially permeable relationship to the fluid with respect to and around the external surface of the first pipe, the outer surface of the first The pipe and the first flange form a recess similar to an annular wedge to receive the seal in a relation similar to one with respect thereto; a second flange with a concave spherical surface to coincide with and engage the second surface of the seal and which is secured in a fixed position and in substantially fluid-impermeable relationship with and around the external surface of the second pipe; and a bolt means secured in the first flange in fixed position, the second flange is secured in the bolt means in resilient movable relation to allow the second pipe to rotate relative to the first pipe around the second spherical surface of the seal and to resiliently axially push the tabs against the spherical and tapered surfaces of the corresponding seal and to push the first edge of the seal toward the recess to wedge the seal between the first flange and the outer cylindrical surface of the first pipe in a wedge-like relationship .

The gasket of claim 1, wherein the first seal and the second surface are axially spaced apart.

3. The gasket of claim 1, wherein the seal is formed of a flexible material.

The gasket of claim 1, wherein the first surface of the seal is convex and the first flange has a concave spherical surface for coupling the first surface of the seal.

The gasket of claim 1, wherein the bolt means comprises first and second bolts each secured with the first flange in fixed relation to the second flange in spaced relation and a spring secured between each bolt and the second flange.

The gasket of claim 1, wherein the seal is formed of a knitted wire mesh wound with a solid lubricant sheet material and compressed.

The gasket of claim 1, wherein the first and second flanges are respectively welded to the first and second corresponding pipes in an annular continuous seam around the corresponding pipe.

The seal of claim 1, wherein the first and second seal surfaces are spherical and mirror images are relative to each other.

9. A fluid pipe joint comprising: - - an annular seal having a central opening formed by an internal cylindrical surface defining an axis and a first annular external surface extending around the opening and tapering relative to the internal cylindrical surface so as to form an annular member in wedge-shaped with the internal cylindrical surface of the seal adjacent one end of the first seal, the first surface tapers radially outward towards a relatively wider intermediate section spaced from the end of the first seal and a second annular convex spherical surface extending around from the tapering opening from an intermediate section to the inner surface of the seal at one end of the seal opposite the first end, the internal cylindrical surface extends to and between the first and second ends; a first pipe extending in an axial direction and having an outer cylindrical surface which abuts against the internal cylindrical surface of the seal in the central opening; a first flange having a first tapered surface meshed with and coinciding with the first tapered surface forming an annular recess in a wedge-like manner with the outer cylindrical surface of the first pipe, the first flange being secured in - fixed position in fluid-impermeable relation with and around the outer cylindrical surface of the section of the first pipe, the first flange has at least one first flange member extending radially outwardly relative to the seal whereby the seal adjacent to the tapered surface of the seal sits completely between the first flange and the first pipe in wedge-like sealing relationship against the tapered surface of the first flange; a second flange having a second concave spherical surface meshed with and coinciding with the spherical surface of the second seal in arcuate sliding relation thereto, the second flange having at least one second flange member extending radially outwardly in relation to the seal, at least one first tab member which is placed in juxtaposition with and corresponding to at least one second tab member; a second pipe aligned with the first pipe to receive for a fluid flowing axially from the first pipe, the second pipe has a cylindrical outer surface affixed to the second flange in fluid impermeable relation to the second flange; Y - "a bolt means secured with at least a first flange member and with at least a second flange member for axially resiliently urging the first and second flange surfaces to abut the first and second seal surfaces respective in wedge-like sealing gear, while allowing the second pipe to move relative to the first pipe

10. The gasket of claim 9, wherein the first and second seal surfaces are spherical, axially spaced apart. of the other and are mirror images one with respect to the other

11. The gasket of claim 10, wherein the flanges are mirror images with respect to each other

12. The gasket of claim 9, wherein the surface The annular tapered of the first seal and the annular tapered surface of the first flange are spherical

13. In a joint for fluid coupling the first and second fluid pipes include with a first flange for movably engaging the first pipe with the sealing engagement movable with the seal with respect to a second flange with respect to the second pipe, with the second flange for securing the second pipe with the same and with the seal eñ. relatively fixed position, the joint includes a means for resiliently urging the first flange and the seal towards the second flange with the seal and the sealing engagement flanges while allowing the first flange and the first pipe to move relative to the second tab, towards the second pipe and towards the seal, the seal comprises: an annular member having first and second annularly radially outwardly facing surfaces terminating adjacent the respective opposite annular seal edges and which are oriented in opposite axial directions and a central opening extending axially therethrough forming a cylindrical internal seal surface extending to the edges to receive the second pipe, the first surface tapers towards the internal cylindrical surface on one of the edges generally in the direction axial and is sized for wedge-like sealing engagement with the The second flange and the wedge-like engagement with the second pipe, the second surface is spherical and is dimensioned for rotation sealing engagement with the first flange, the first flange for pushing the seal in engagement and between the second flange and the second pipe .

14. In the gasket of claim 13, wherein the seal includes a circular cylindrical segment between the first and second surfaces. - -

15. In the gasket of claim 13, wherein the first tapered surface is spherical.

16. A seal comprising: a circular member having opposite ends and an axially extending central cylindrical through-hole extending between and toward the ends forming an internal cylindrical surface extending to the ends to receive therein a first pipe along an axis; a first radially outwardly oriented surface of the circular member terminating at one of the concentric ends with and tapering towards the axis and towards the inner surface at one end forming a wedge-like convex annular member at one end; a second convex spherical segment surface oriented radially outwardly at the other end concentric with the axis, the second segment tapers towards the axis and the internal cylindrical surface at the other end generally in separate mirror image relation with respect to to the first surface; and a segment oriented radially outward and axially extending between the first and second surfaces to axially separate the first and second surfaces; - the seal comprises a wire mesh with a filling material or compressed load to form a solid structure.

17. The seal of claim 16, wherein the first surface is convex and spherical.

18. A fluid pipe joint comprising: first and second pipes aligned to transport a fluid, each pipe has an outer cylindrical surface; a seal having a central opening therethrough which defines a continuous internal cylindrical surface extending through the seal and an axis and in whose opening the first pipe is placed, the seal has first annular surface oriented radially outwardly forming a wedge-like member extending around the axis with the internal cylindrical surface and the second convex annular spherical surface extending around the axis; a first flange with a first surface for coupling the first annular surface of the seal in sealing relation of seated fluid completely wedge-like in cooperation with the first pipe and secured in a fixed position and essentially in relation to - fluid impermeable to and around the outer surface of the first pipe; a second flange with a concave spherical surface for dynamically engaging the second annular spherical surface and secured in substantially fluid-impermeable relation to and around the external surface of the second pipe; and a fastener securing means secured in the first flange in fixed relation and in the second flange in resilient movable relation to allow the second pipe to rotate relative to the first pipe around the second spherical surface of the seal and to resiliently push the pipe. second tab against the spherical surface of the corresponding seal and to push the first annular surface of the seal in wedge-like relationship.