SEMIMETALLDICHTUNG

Description

[0001] The present invention relates to a semi-metallic seal having the features of the preamble of claim 1.

[0002] Semi-metallic gaskets of this type are generally used in ring form to seal an annular gap between two opposing sealing surfaces of two flanges, which are attached to the ends of a pipe, for example, by a weld. Such flanges are technically defined, for example, in the European standard EN 1092. The flanges are connected to each other on a bolt circle in a radially outer section by a number of bolts. The semi-metallic gasket is ring-shaped, with its inner diameter dimensioned so that it does not protrude into the free flow cross-section of the pipes being joined. To prevent the semi-metallic gasket from slipping radially and thus protruding into the free flow cross-section of the pipes, its outer diameter is dimensioned so that it is supported by the bolts on the radial inner sides and is thereby centered.After inserting the semi-metallic gasket and clamping the flanges using the fastening screws, the semi-metallic gasket rests against a sealing surface of each flange on both sides under surface pressure, thus sealing the gap between the flanges against the environment.

[0003] The applicant's semi-metallic gaskets have proven their worth in various industrial sectors, even in the most demanding sealing applications, and are used, for example, in conventional power plants, in the primary circuit of nuclear power plants, as heat exchanger gaskets, as valve cover gaskets, or as manhole cover gaskets on steam generators or pressure regulators. Furthermore, these semi-metallic gaskets have also proven their worth in the chemical and petrochemical industries. Such semi-metallic gaskets are available, for example, on the website [website address missing in original text]. https: / / www.klinger-awschultze.de / produkte / dichtungen / metall-weichstoff-dichtungen / kammprofilierte-dichtungen / published, one embodiment of which is formed by a comb profile seal.

[0004] The semi-metallic gasket itself comprises a dimensionally stable, profiled metal core, which is coated with a soft material layer of PTFE, graphite, aluminum, or silver to prevent damage to the flanges. Furthermore, the soft material layer improves the sealing of the gap while simultaneously reducing minimum surface pressures. When the flanges are clamped, the material of the soft layer is pressed into the profile of the metal core of the semi-metallic gasket and simultaneously pressed against the sealing surfaces of the flanges under surface pressure, creating a tight seal.

[0005] The profiled metal core features a comb-like grooved surface with annular grooves. In a standard gasket, the tips of the grooves and the bases of the grooves between them form two parallel planes in the radial cross-sectional area. This is achieved by maintaining a constant height and depth relative to the central plane of the metal core across its surface. Consequently, after installation and clamping of the semi-metallic gasket, a nearly constant surface pressure is maintained, with identical pressure distribution between the soft material layer and the metal core across the entire radial extent of the profiled surface.

[0006] Improved sealing performance can be achieved with convex semi-metallic gaskets, where the metal core does not have a constant thickness but instead is convex, with an increased thickness in the center and a decreasing thickness towards the edges. The groove structure is then profiled such that the groove tips form a flat surface. This is achieved by increasing the depth of the grooves or the height of the tips from the convex metal core towards the radial edges of the core.

[0007] German patent application DE 27 56 351 B1 discloses a sealing arrangement for flange gaskets with a semi-metallic gasket referred to therein as a comb gasket element, in which the comb gasket element has a base body with a longitudinal cross-section that is convex at least on one side and is tangent to the valleys of the gasket profile. The advantage of this profile is that a specific sealing condition can be achieved with lower sealing forces.

[0008] To achieve the required sealing effect, the semi-metallic gasket must fit as tightly as possible against the sealing surfaces of the flanges, which requires a certain minimum surface pressure. At the same time, it must be prevented that the semi-metallic gasket protrudes into the free cross-section of the pipes being joined. One solution to prevent this displacement is to ensure that the semi-metallic gasket rests centrally against the radially inner edges of the fastening bolts connecting the flanges. For this purpose, the semi-metallic gasket has a radially outer centering rim that does not serve a sealing function. The outer diameter of this centering rim is dimensioned such that it rests radially on the inner edges of the fastening bolts, thereby holding the semi-metallic gasket in its intended position. The outer diameter of this centering rim thus forms a centering diameter for the semi-metallic gasket.Since the centering rim is only intended for centering the semi-metallic gasket and does not itself have a sealing function, it is specifically designed to rest against the radially inner sides of the mounting bolts. The centering rim is dimensioned with such a thickness that a slight gap exists between it and the flange faces. This ensures that the semi-metallic gasket always rests with its outer surface centered against the inner surfaces of the mounting bolts, and is not fixed in an uncentered position with the sides of the centering rim against the flange faces. Furthermore, the centering rim must under no circumstances impair the sealing function of the semi-metallic gasket by preventing a sealing connection between the gasket and the flange sealing surfaces through its stiffness or any potential misalignment.The centering rim is intentionally designed to be slightly thinner than the metal core and slightly thinner than the gap between the flanges, resulting in a small gap between the surfaces of the centering rim and the opposing flange faces. A disadvantage of this design is that dirt particles or liquids such as water can accumulate in these gaps, potentially leading to contamination and corrosion of the flanges, which can ultimately impair the sealing performance of the semi-metallic gasket. Furthermore, if the centering rim and the metal core are formed as a single piece, the centering rim requires a complex machining process, specifically machining it to a significantly reduced thickness.

[0009] Against this background, the invention aims to provide a more cost-effective semi-metallic gasket which, with a reduced probability of corrosion and contamination of the flanges in the area of ​​the gap in the installed state, should have a good sealing effect and at the same time be reliably centered during assembly.

[0010] To solve the problem, a semi-metallic seal with the features of claim 1 is proposed according to the invention. Further preferred developments can be found in the dependent claims, the figures and the associated description.

[0011] According to the basic idea of ​​the invention, it is proposed that the metal core with its radial outer surface forms a centering diameter of the semi-metallic seal, and that the tips of the groove-shaped profiles have a wave shape in cross-section with a radius of 0.4 to 0.8 mm, and that the radially successive tips of the groove-shaped profiles have a distance of 1.0 to 2.5 mm from each other, and that the grooves between the radially successive tips of the groove-shaped profiles have a depth of 0.2 to 0.8 mm.

[0012] According to the proposed solution, the metal core itself forms the centering diameter, extending to the radial inner surfaces of the fastening bolts. This eliminates the previously required centering ring, thereby reducing manufacturing costs. Furthermore, the metal core features a grooved profile with a soft material layer applied to it, extending to its radial outer surface. This reduces the remaining gaps between the semi-metallic gasket and the sealing surfaces of the flanges, ideally eliminating them entirely when the soft material layer is in contact with the sealing surfaces. This significantly reduces the likelihood of contamination and corrosion of the flanges.

[0013] It is further proposed that the tips of the grooved profiles have a wave-like cross-section with a radius of 0.4 to 0.8 mm. This rounded shape simplifies the reuse of the semi-metallic seal, as it makes it much easier to detach the soft material layer from the metal core and to clean the metal core more easily for the application of a new soft material layer.

[0014] It is further proposed that the radially successive peaks of the groove-shaped profiles be spaced 1.0 to 2.5 mm apart. This proposed spacing of the peaks results in grooves wide enough to facilitate the removal of the soft material layer after use of the semi-metallic gasket and the removal of soft material residue from the bottom of the grooves. This significantly simplifies the reprocessing of the semi-metallic gasket for reuse, with the metal core, being the most expensive component, thus improving sustainability.

[0015] It is further proposed that the grooves between the radially successive peaks of the groove-shaped profiles have a depth of 0.2 to 0.8 mm. This proposed groove depth also facilitates improved cleaning of the metal core of the semi-metallic gasket for reuse.

[0016] Due to the decreasing height of the tips relative to the center of the metal core, the grooved profiles, unlike profiles known from the prior art, deliberately exhibit a convex shape in the outer form defined by the tips of the corrugated profiles. This ensures that, after clamping, the semi-metallic gasket, in the area of ​​a sealing section, exerts increased surface pressure on the sealing surfaces of the flanges to be joined, thus achieving the desired sealing effect. In this area of ​​the sealing section, the semi-metallic gasket bears a higher surface pressure against the sealing surfaces of the flanges, while in the radially outer section of the metal core, with its lower-height tips, it is compressed only to the extent necessary to reduce or close the existing gap, or to bear against the surfaces of the flanges with a significantly lower surface pressure.Before the flanges are tightened, only the sealing section of the semi-metallic gasket makes contact with the sealing surfaces. This is also advantageous for centering the semi-metallic gasket, as its smaller contact area with the sealing surfaces means it is subject to less friction before tightening. This simplifies alignment, and the metal core, with its radial outer surface against the inner edges of the fastening bolts, centers itself.

[0017] The proposed semi-metallic seal thus consists of only a single-piece metal core with soft material layers applied to it, making it significantly less expensive to manufacture. Furthermore, the proposed design provides an improved sealing effect and allows the seal to self-center during insertion. This eliminates the need for machining the centering ring, which may have been previously required. Additionally, after use, the semi-metallic seal can be reconditioned for reuse by removing the soft material layer, cleaning the metal core (if necessary), and applying a new soft material layer.

[0018] The semi-metallic gasket with its convex, grooved profile can be intentionally given a convex cross-sectional shape by means of a soft material layer of constant thickness, so that the increased surface pressure in the central sealing section is defined solely, or at least primarily, by the shape of the metal core. The soft material layer thus forms only a layer of constant thickness, which, apart from its material properties, is not subject to any further requirements and is therefore easier to apply.

[0019] It is further proposed that the average thickness of the soft material layer towards the metal core be greater than the difference between the maximum heights of the peaks of the sealing section and the minimum heights of the peaks in the radially outer section of the metal core. This proposed dimensioning of the soft material layer thickness allows the semi-metallic gasket to come into contact with the side surface of the opposite flange with its entire side surface up to its radially outer edge, without the metal core fully penetrating the soft material layer with its profile and making direct contact with the opposite sealing surface of the flange.

[0020] It is further proposed that the difference in height between the peaks of the sealing section and the peaks in the radially outer section of the metal core is preferably 0.1 to 0.3 mm. This proposed height difference enables the sealing function of the semi-metallic seal while simultaneously ensuring reliable closure of the gap.

[0021] It is further proposed that the thickness of the soft material layer be greater than the maximum depth between the tips of the grooved profile. The proposed solution also prevents the metal core from completely penetrating the soft material layer with its profile and from making direct contact with the opposite sealing surface of the flange at its tips.

[0022] It is further proposed that the metal core have a decreasing thickness from the sealing section towards the radial outer and / or radial inner surface. This proposed development further supports the convex shape of the grooved profile and can further improve the sealing effect.

[0023] It is further proposed that the section where the thickness of the metal core decreases from the sealing section towards the radial outer surface has a greater radial extent than the section where the thickness of the metal core decreases from the sealing section towards the radial inner surface. This proposed development shifts the sealing section in the semi-metallic gasket towards the radial inner surface of the gasket, i.e., towards the free cross-section of the pipe. This further improves the sealing effect. Moreover, such a shift of the sealing section is beneficial for the stresses acting in the semi-metallic gasket when the flanges are tightened using the radially outer mounting bolts.

[0024] The invention is explained below with reference to preferred embodiments and the accompanying figures. Fig. 1 shows a semi-metallic gasket according to the invention in the installed state; and Fig. 2 shows an enlarged section of the semi-metallic gasket between two sealing surfaces of two flanges before clamping; and Fig. 3 shows an enlarged section of the semi-metallic gasket between two sealing surfaces of two flanges after clamping.

[0025] In the Figure 1A semi-metallic gasket 5 according to the invention is shown, which is arranged between two sealing surfaces 6 and 7 of two flanges 1 and 2. The flanges 1 and 2 are forged blanks and undergo separate surface treatment in the area of ​​the sealing surfaces 6 and 7 so that the sealing surfaces 6 and 7 have a corresponding surface accuracy. For this purpose, the flanges 1 and 2 are machined accordingly in the area of ​​the sealing surfaces 6 and 7 and, if necessary, ground. The flanges 1 and 2 are dimensioned, for example, according to DIN EN 1092 and serve to connect two pipelines (not shown). The flanges 1 and 2 are annular in shape, wherein in the Figure 1Only one side of flanges 1 and 2 is shown in the area of ​​their fastening. To connect flanges 1 and 2, these flanges have a plurality of openings 18 and 19 arranged on identical diameters in their radially outer sections. Fastening screws 3 are provided for fastening flanges 1 and 2; these screws pass through the openings 18 and 19 and are tightened in a known manner by means of nuts 20 screwed onto their free ends.

[0026] The semi-metallic seal 5 is ring-shaped and has a ring-shaped and disc-shaped metal core 15, which has a soft material layer 8 and 9 on both axial side surfaces, with which the semi-metallic seal 5 bears against the sealing surfaces 6 and 7. The ring-shaped metal core 15 is dimensioned such that, in a centered position of the semi-metallic seal 5, its radial outer surface 17 bears against the radial inner surfaces 4 of the fastening screws 3, while its free radial inner surface 14 faces the free cross-section of the pipe. The Figure 1 The small gap visible is merely due to the enlarged representation, whereby a small gap may also be provided insofar as the semi-metallic seal 5 is arranged in all possible positions so that it does not protrude into the free cross-section of the pipelines.

[0027] The soft material layers 8 and 9 are made of a softer material than the metal core 15 and can be made of, for example, PTFE, graphite, aluminum, or silver, depending on the properties of the medium to be sealed and the requirements for the sealing itself. The soft material layers 8 and 9 can also consist of a graphite layer with a stainless steel layer, with an additional thin PTFE layer between the graphite layer and the stainless steel layer.

[0028] In the Figure 2 is an enlarged section X of the Figure 1The semi-metallic seal 5 can be seen before the fastening screws 3 are tightened. The basic structure of the semi-metallic seal 5 comprises a metal core 15, which has a groove-shaped profile 10 and 11 on each of its two axial side surfaces. The groove-shaped profiles 10 and 11 can be realized with various geometries, such as spiral grooves R or ring-shaped grooves R as a convex design. The circumferential points 16 in the groove-shaped profiles 10 and 11, with the grooves R arranged between them, can be seen in the sectional view as a wave profile.

[0029] The metal core 15 is disc-shaped and covered on its lateral surfaces by a soft material layer 8 and 9. The tips 16 of the profiles 10 and 11 have a height H relative to the central axis M of the metal core 15, while the grooves R between the tips 16 have a depth T from the outer edge of the tip to the bottom of the groove.

[0030] The height H of the tips 16 of the profiles 10 and 11 decreases successively from a sealing section 12 towards the radial outer surface 17 of the metal core 15, as can be seen from the decreasing heights H1, H3, and H5 of the successive tips 16.1, 16.3, and 16.5 towards the radial outer surface 17 in the radially outer section 13 of the metal core 15. Furthermore, the height H of the tips 16 of the profiles 10 and 11 decreases successively from the sealing section 12 towards the radial inner surface 14 in the radially inner section 21 of the metal core 15, as can be seen from the decreasing heights H2, H4, and H6 of the successive tips 16.2, 16.4, and 16.6.

[0031] In the sealing section 12, the profiles 10 and 11 have two peaks 16.1 and 16.2, which have a maximum and identical height H1 and H2. Of course, in the area of ​​the sealing section 12, or also in the radially outer section 13 and the radially inner section 21, two or more adjacent peaks 16 can also have an identical height H, insofar as larger surface areas of the semi-metallic seal 5 with identical sealing properties are to be created. The height H of the peaks 16 is in the Figure 3This is represented by the spacing of the paired peaks 16 of the two profiles 10 and 11. The paired peaks 16.1, 16.2 of the sealing section 12 have a spacing of 4.1 to 4.8 mm, the adjacent peaks 16.3, 16.4 a spacing of 4.05 to 4.6 mm, and the peaks 16.5, 16.6 a spacing of 4.0 mm. These spacings are ranges and represent only preferred dimensions, with the height difference between the successive peaks 16 being implemented as described above.

[0032] In the Figure 3 is section X of the Figure 2The tensioned state of the semi-metallic gasket 5 is evident. Due to the clamping force exerted by the fastening screws 3, the semi-metallic gasket 5, with its soft material pads 8 and 9, seals against the sealing surfaces 6 and 7 of the flanges 1 and 2. The soft material pads 8 and 9 are pressed into the grooved profiles 10 and 11 by the acting surface pressure. In the sealing section 12 of the semi-metallic gasket 5, a high surface pressure force is exerted by the points 16.1 and 16.2 with their greater height H, which almost completely penetrate the soft material pads 8 and 9. If the soft material layers 8 and 9 are formed in multiple layers with a graphite layer, a stainless steel layer and, if necessary, with a PTFE layer provided in between, the tips 16 of the profiles 10 and 11 penetrate the soft material layers 8 and 9 through the graphite layer and, if necessary, through the PTFE layer to the stainless steel layer.The sealing effect of the semi-metallic seal 5 is thus deliberately achieved through the design of the tips 16.1 and 16.2 of the profiles 10 and 11 in the sealing section 12, due to the high surface pressure acting there. In the radially outer section 13 and in the radially inner section 21, a lower surface pressure force acts due to the tips 16.3, 16.4, 16.5 and 16.6 with their lower heights H3 to H6, so that these sections still have a sealing effect, albeit a weaker one. The sealing section 12 is designed with a local contact force defined by the heights H1 and H2 of the tips 16.1 and 16.2 such that it performs the actual sealing function of the semi-metallic seal 5, whereby the sealing zone of the semi-metallic seal 5 is defined by the arrangement of the sealing section 12 and the tips 16.1 and 16.2 relative to the semi-metallic seal 5.

[0033] Due to the inventive design of the semi-metallic gasket 5, it also rests against the sealing surfaces 6 and 7 in the radial inner and outer sections 21 and 13 with the soft material layers 8 and 9, whereby a significantly lower surface pressure is exerted. Because the semi-metallic gasket 5 rests against these areas, any existing gap is reduced and ideally closed, preventing the accumulation of dirt particles and moisture. This prevents corrosion and contamination of the flanges 1 and 2 in these areas of the sealing surfaces 6 and 7. Consequently, the effort required for reconditioning and / or cleaning the flanges 1 and 2 after removing the old semi-metallic gasket 5 and before installing a new one is considerably reduced.Ideally, this even makes it possible to completely forego the reconditioning and cleaning of flanges 1 and 2 before inserting a new or reconditioned semi-metallic gasket 5. This is particularly advantageous in complex piping systems where, after loosening flanges 1 and 2, the pipes cannot be pulled apart arbitrarily or only with considerable effort to expose the sealing surfaces 6 and 7.

[0034] An advantage of the semi-metallic seal 5 according to the invention is that the manufacturing costs are significantly reduced due to the elimination of the centering ring. This is made possible by the semi-metallic seal 5 self-centering via the metal core 15. Additionally, this increased radial extent of the metal core 15 is used to also increase the radial extent of the profiles 10 and 11 with the soft material pads 8 and 9 provided thereon, thereby reducing and ideally closing the gap between the sealing surfaces 6, 7 and the semi-metallic seal 5.

[0035] The semi-metallic seal 5 is specifically designed by the shaping of the profiles 10 and 11 such that, in the area of ​​the sealing section 12, it performs its sealing function through the tips 16 with their greater height H. This greater height H of the tips 16 in the area of ​​the sealing section 12 can be achieved either by designing the tips 16 of the profiles 10 and 11 on a metal core 15 with a constant thickness or by giving the metal core 15 a convex shape, in which case the grooves R can also have a constant depth T. Furthermore, the shape of the grooved profiles 10 and 11 can also be achieved by a combination of a convex metal core 15 with corrugated profiles 10 and 11, the latter having a groove depth T that increases radially outwards and inwards from the sealing section 12.

[0036] It has been found that a dimensioning of the profiles 10 and 11 with a height difference of 0.1 to 0.3 between the peaks 16.1 and 16.2 of the sealing section 12 and the peaks 16.3, 16.4, 16.5, and 16.6 of the radially outer section 13 or the radially inner section 21 is sufficient to achieve both the desired sealing function and the closure of the gap. It is preferred that the radially outer section 13, extending from the sealing section 12, has a greater radial extent than the radially inner section 21, extending inwards from the sealing section 12. This means that the sealing section 12 in the semi-metallic seal 5 is offset radially inwards towards the free cross-section of the pipe to be sealed, relative to the center radius of the semi-metallic seal 5. This allows for more favorable force distribution in the semi-metallic seal 5 while simultaneously improving the sealing performance.

[0037] Since the profiles 10 and 11 are provided on both sides of the metal core 15, the different heights H of the tips 16 can also be regarded as different thicknesses of the metal core 15 in the area of ​​the tips 16 of the profiles 10 and 11, wherein the profiles 10 and 11 are preferably identical and symmetrical to the central plane M.

[0038] The tips 16 of the groove-shaped profiles 10,11 have a wave-like cross-section with a radius R1 of 0.4 to 0.8 mm, as shown in the Figure 2This can be seen. The tips 16 are thus formed into a wave shape with a correspondingly large radius compared to the previously used, rather sharp tips 16, so that the profiles 10 and 11 can also be described as wave profiles. This makes it easier to separate the material of the soft material layers 8 and 9 from the metal core 15 for processing the semi-metallic seal 5. Furthermore, the radially successive tips 16 of the groove-shaped profiles 10, 11 have a distance A of 1.0 to 2.5 mm from each other, as shown in the Figure 3 This distance A makes it easier to remove the material of the soft material pads 8 and 9 from the grooves R, for example using a brush. The removal of the soft material pads 8 and 9 is further facilitated by the fact that the grooves R between the radially successive tips 16 of the groove-shaped profiles 10, 11 have a depth T of 0.2 to 0.8 mm.

[0039] The semi-metallic gasket 5 is deformed during clamping between the flanges 1 and 2 exclusively in the area of ​​the soft material pads 8 and 9, for which purpose these are made of a softer and correspondingly more deformable material. The semi-metallic gasket 5, with its soft material pads 8 and 9, conforms to the sealing surfaces 6 and 7, and the soft material pads 8 and 9 are simultaneously pressed into the grooved profiles 10 and 11. Due to the proposed shape of the grooved profiles 10 and 11, the sealing section 12 of the semi-metallic gasket 5 bears against the sealing surfaces 6 and 7 with a very high surface pressure, while the radially outer section 13 and the radially inner section 21 bear against the sealing surfaces 6 and 7 with a much lower surface pressure.This ensures that the semi-metallic gasket 5 rests against the sealing surfaces 6 and 7 of the flanges 1 and 2 along its entire radial extent, thus protecting them from contamination, corrosion, or mechanical damage. This eliminates the need to recondition the flanges 1 and 2 when replacing the semi-metallic gasket 5 with a new or reconditioned one.

[0040] The metal core 15 of the semi-metallic seal 5 is not deformed when the semi-metallic seal 5 is clamped, and forms the dimensionally stable core of the semi-metallic seal 5, which, through its shape with the groove-shaped profiles 10 and 11, defines the surface pressures in the area of ​​the sealing section 12 and in the radially outer section 13 and in the radially inner section 21.

Claims

1. Semimetal gasket (5) comprising - a dimensionally stable, annular, disk-shaped metal core (15), which - on each of the lateral surfaces thereof a groove-shaped profile (10,11) comprising a plurality of peaks (16) is provided, - a soft material coating (8,9) made of a material softer than the metal core (15) being provided on the groove-shaped profiles (10,11), and - the groove-shaped profiles (10,11) on the lateral surfaces extending up to the radial outer side (17) of the metal core (15), - the peaks (16) of the groove-shaped profiles (10,11), which peaks succeed one another toward the radial outer side (17), having a height (H) that decreases, from a sealing portion (12) toward the radial outer side (17), in relation to a central plane (M) of the metal core (15), and - the metal core (15), by means of its radial outer side (17), forming a centering diameter of the semimetal gasket (5), characterized in that - the peaks (16) of the groove-shaped profiles (10,11) have the cross section of a wave shape with a radius (R1) of 0.4 to 0.8 mm, and - the radially successive peaks (16) of the groove-shaped profiles (10,11) have a distance (A) from one another of 1.0 to 2.5 mm, and - the grooves (R) have a depth (T), between the radially successive peaks (16) of the groove-shaped profiles (10,11), of 0.2 to 0.8 mm.

2. Semimetal gasket (5) according to claim 1, characterized in that - the soft material coating (8,9) has a constant thickness relative to the metal core (15).

3. Semimetal gasket (5) according to either of claims 1 or 2, characterized in that - the average thickness of the soft material coating (8,9) relative to the metal core (15) is greater than the difference between the heights (H) of the peaks (16) of the sealing portion (12) and the heights (H) of the peaks (16) in the radially outer portion (13) of the metal core (15).

4. Semimetal gasket (5) according to any of claims 1 to 3, characterized in that - the difference between the heights (H) of the peaks (16) of the sealing portion (12) and the heights (H) of the peaks (16) in the radially outer portion (13) of the metal core (15) is preferably 0.1 to 0.3 mm.

5. Semimetal gasket (5) according to any of claims 1 to 4, characterized in that - the thickness of the soft material coating (8,9) is greater than the maximum depth (T) between the peaks (16) of the groove-shaped profile (10,11).

6. Semimetal gasket (5) according to any of claims 1 to 5, characterized in that - the metal core (15) has a thickness that decreases from the sealing portion (12) toward the radial outer side (17) and / or toward the radial inner side (14).

7. Semimetal gasket (5) according to any of claims 1 to 5, characterized in that - the metal core (15) has a thickness that decreases from the sealing portion (12) toward the radial outer side (17) and toward the radial inner side (14), and - the portion in which the thickness of the metal core (15) decreases from the sealing portion (12) toward the radial outer side (17) has a greater radial extent than the portion in which the thickness of the metal core (15) decreases from the sealing portion (12) toward the radial inner side.

8. Semimetal gasket (5) according to either of claims 6 or 7, characterized in that - the grooves (R) of the groove-shaped profiles (10,11) have an identical depth (T) between the peaks (16).