A super-high temperature resistant metal-hormite winding gasket

Abstract

The application discloses a super-high-temperature-resistant metal vermiculite winding gasket, which comprises a metal winding core body, an inner ring steel positioning ring and an outer ring limiting steel ring; the metal winding core body is formed by alternately and spirally winding a thin stainless steel belt and modified high-purity vermiculite filler; the modified high-purity vermiculite is prepared by high-temperature calcination and silicon-aluminum ceramic coating modification; the application limits the modification components of vermiculite, the material of the steel belt, the winding forming density, the thickness matching structure of the inner and outer rings, and solves the technical problems of carbonization failure of the organic filler of the existing metal winding gasket after high temperature of more than 600 DEG C, rebound attenuation, medium leakage and serious stress relaxation; the application simultaneously provides a special preparation method of the gasket, the process is controllable, the forming structure is stable, and the application is suitable for high-temperature and high-pressure flange sealing working conditions of petrochemical, electric power, metallurgy and spaceflight.

Description

Technical Field

[0001] This invention belongs to the field of flange sealing gasket technology, specifically relating to a high-temperature metal vermiculite spiral wound gasket. Background Technology

[0002] Existing conventional spiral wound gaskets generally use flexible graphite, polytetrafluoroethylene, asbestos paper, organic ceramic fibers, and other filler materials wound together with carbon steel / stainless steel strips. The internal filler components of these gaskets all contain organic binders, organic polymer fibers, and resin adhesive layers. When the flange sealing temperature exceeds 600℃, the organic components inside the gasket rapidly carbonize, decompose, and volatilize upon heating, resulting in numerous pores and powdering / detachment of the filler layer. The carbonized filler loses its elastic support, significantly reducing the overall resilience of the gasket and drastically increasing the stress relaxation rate, leading to media leakage at the flange sealing surface. Simultaneously, the carbonization and shrinkage of the filler causes gasket structural delamination and separation of the steel strip from the filler, resulting in rapid seal failure under long-term high-temperature loads. This cannot meet the long-term sealing requirements of equipment operating continuously at ultra-high temperatures of 800℃ to 1000℃. Currently, there are no completely inorganic spiral wound gaskets on the market that can stably withstand temperatures up to 1000℃, exhibit low stress relaxation, and high resilience. Existing products all suffer from the core technical defect of high-temperature organic filler failure and leakage. Summary of the Invention

[0003] To address the technical problems of existing metal spiral wound gaskets, such as carbonization failure of organic fillers, loss of resilience, media leakage, and severe stress relaxation at high temperatures, this invention provides a high-temperature resistant metal vermiculite spiral wound gasket. Utilizing inorganic high-temperature resistant components, and through synergistic optimization of the modified vermiculite filler formulation, steel strip pleated structure, winding density matching, and inner and outer limiting ring assembly structure, the gasket achieves long-term stable resistance to temperatures up to 1000℃, possessing comprehensive sealing performance including high resilience, low stress relaxation, resistance to strong corrosive media, and electrical insulation. Simultaneously, a dedicated preparation method is provided to precisely control molding parameters, ensuring gasket structural consistency and high-temperature stability.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A high-temperature metal vermiculite spiral wound gasket includes an annular metal spiral wound core, a stainless steel inner positioning ring, and a stainless steel outer limiting ring. The annular metal spiral wound core is integrally formed by alternating spiral layers of thin stainless steel strips and modified high-purity vermiculite filler. The modified high-purity vermiculite filler consists of the following parts by weight: 85-92 parts expanded vermiculite, 6-12 parts silica-alumina ceramic powder, and 2-3 parts silica sol. The thin stainless steel strip has a thickness of 0.15-0.22 mm and a width of 8-22 mm. The annular metal spiral wound core has a winding density of 1.6-2.0 g / cm³. 3The stainless steel inner ring positioning ring is fitted to the inner circumferential side wall of the annular metal winding core, and the wall thickness of the stainless steel inner ring positioning ring is 1.2 to 1.8 mm; the stainless steel outer ring limiting ring is fitted to the outer circumferential side wall of the annular metal winding core, and the wall thickness of the stainless steel outer ring limiting ring is 1.0 to 1.5 mm.

[0006] In a preferred embodiment of the present invention, the thin stainless steel strip is a 310S high-temperature resistant stainless steel strip, and the cross-section of the thin stainless steel strip is a wavy pleated structure with a pleat height of 0.4 to 0.7 mm and a pleat pitch of 1.0 to 1.6 mm.

[0007] In a preferred embodiment of the present invention, the modified high-purity vermiculite filler layer is prepared by calcination at a temperature of 920–980°C, with a calcination holding time of 2.5–4 h, and the thickness of a single vermiculite sheet after calcination is 0.08–0.14 mm.

[0008] In a preferred embodiment of the present invention, the silicon-aluminum ceramic micro powder has a particle size of 500-800 mesh and a silica sol solid content of 30%. The silicon-aluminum ceramic micro powder and silica sol are mixed and coated on the surface of expanded vermiculite sheets to form a dense, high-temperature resistant protective film.

[0009] In a preferred embodiment of the present invention, the total radial thickness of the annular metal winding core is 3-12 mm, the inner diameter of the stainless steel inner positioning ring is 0.1-0.3 mm smaller than the inner diameter of the annular metal winding core, and the outer diameter of the stainless steel outer limiting ring is 0.1-0.3 mm larger than the outer diameter of the annular metal winding core.

[0010] In a preferred embodiment of the present invention, the stainless steel inner ring positioning ring and the stainless steel outer ring limiting ring are both integrally formed by stamping 309S stainless steel sheet. The stainless steel inner ring positioning ring and the stainless steel outer ring limiting ring are fixed to the annular metal winding core by axial pressing and interlocking, without welding seams.

[0011] In a preferred embodiment of the present invention, the temperature range of the high-temperature metal vermiculite wound gasket is -50℃ to 1000℃, the gasket compression rate is controlled at 18% to 30%, the resilience rate is ≥15%, and the stress relaxation rate is ≤13%.

[0012] A method for preparing a high-temperature metal vermiculite spiral wound gasket includes the following steps: Step S1, Vermiculite Modification Pretreatment: Take 85-92 parts by weight of expanded vermiculite, wash, remove impurities, and dry it. Mix it with 6-12 parts of silicon-aluminum ceramic micro powder and 2-3 parts of 30% solid content silica sol, stir thoroughly to coat the mixture, and calcine it in a kiln at 920-980℃ for 2.5-4 hours. After cooling, crushing, and sieving, modified vermiculite flakes with a thickness of 0.08-0.14 mm are obtained. Step S2, steel strip processing: Take a 0.15-0.22mm thick 310S stainless steel sheet, roll it into a steel strip with a width of 8-22mm, and stamp it to form a wave fold with a wave height of 0.4-0.7mm; Step S3, Winding: The corrugated stainless steel strip and modified vermiculite sheet are fed alternately and spirally wound along a ring-shaped die, controlling the winding density to be 1.6–2.0 g / cm³. 3 A ring-shaped metal wound core is obtained; Step S4, inner and outer ring stamping: 309S stainless steel sheet is stamped to form an inner positioning ring with a wall thickness of 1.2-1.8mm and an outer limiting ring with a wall thickness of 1.0-1.5mm; Step S5, Pressing and Assembly: The inner ring positioning ring and the outer ring limiting ring are respectively fitted onto the inner and outer sides of the winding core, and the hydraulic equipment is used to press and fix them axially to obtain the finished high-temperature metal vermiculite winding gasket.

[0013] In a preferred embodiment of the present invention, in step S3, during spiral winding, the pressure of the single-turn steel strip and vermiculite filler layer is controlled to be 12MPa to 18MPa. After winding, the material is kept at room temperature under pressure for 30 minutes to set the shape.

[0014] In a preferred embodiment of the present invention, in step S5, the hydraulic pressing pressure is 20MPa to 26MPa, and after pressing, the entire gasket is subjected to a low-temperature heat treatment at 700℃ for 1 hour to eliminate the internal stress of the winding molding.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. Solve the core problem of high-temperature carbonization failure of existing gasket organic fillers: Modified high-purity vermiculite filler layer can be used continuously at 1000℃ for a long time without filler pulverization, carbonization, or volatilization, and the sealing life is increased by more than 5 times.

[0016] 2. High-temperature mechanical properties are significantly superior to existing products: the rebound rate remains ≥15% and the stress relaxation rate is ≤13% under 1000℃ conditions; conventional flexible graphite gaskets have a rebound rate of only 6%~8% and a stress relaxation rate of >28% at 650℃, showing a significant difference and outstanding practicality.

[0017] 3. Dual additional properties of corrosion resistance and insulation: The silica-alumina ceramic film on the vermiculite surface isolates it from corrosive media such as acids, alkalis, oils, gas, and molten salts. At the same time, the inorganic ceramic layer has insulating properties, which can be used for high-temperature insulating and sealing flanges in nuclear power and power industries, expanding the application scenarios.

[0018] 4. Structural Collaborative Innovation: The corrugated steel strip, modified vermiculite thin packing, and inner and outer limiting rings are matched in size. The triple structure works together to precisely control the gasket compression and avoid two defects: over-compression of the packing and breakage, and insufficient compression and leakage of the seal under high temperature and high pressure.

[0019] 5. Innovative manufacturing process: The entire process of calcination modification, pressure-controlled winding, and low-temperature stress-relieving heat treatment precisely matches the product structure requirements, ensuring stable performance and high dimensional consistency of mass-produced gaskets, eliminating the need for subsequent secondary finishing. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments or prior art, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the structure of a high-temperature metal vermiculite spiral wound gasket provided in an embodiment of the present invention.

[0022] Figure 2 This is a cross-sectional schematic diagram of a high-temperature metal vermiculite spiral wound gasket provided in an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the microstructure of the modified vermiculite filler provided in an embodiment of the present invention.

[0024] Figure 4 This is a flowchart illustrating a method for preparing a high-temperature metal vermiculite spiral wound gasket according to an embodiment of the present invention. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0026] like Figure 1 , Figure 2 and Figure 3 As shown, this embodiment of the invention provides a high-temperature metal vermiculite wound gasket, comprising an annular metal wound core 2, a stainless steel inner ring positioning ring 1, and a stainless steel outer ring limiting ring 3; the annular metal wound core 2 is integrally formed by alternating spiral winding of thin stainless steel metal strips 4 and modified high-purity vermiculite filler layers 5; the modified high-purity vermiculite filler layer 5 is composed of the following raw materials in parts by weight: 85-92 parts expanded vermiculite, 6-12 parts silica-alumina ceramic micro powder, and 2-3 parts silica sol; the thin stainless steel metal strips 4 have a thickness of 0.15-0.22 mm and a width of 8-22 mm; the winding density of the annular metal wound core 2 is 1.6-2.0 g / cm³. 3The stainless steel inner ring positioning 1 is attached to the inner circumferential side wall of the annular metal winding core 2, and the wall thickness of the stainless steel inner ring positioning 1 is 1.2 to 1.8 mm; the stainless steel outer ring limiting 3 is attached to the outer circumferential side wall of the annular metal winding core 2, and the wall thickness of the stainless steel outer ring limiting 3 is 1.0 to 1.5 mm.

[0027] Function of vermiculite components: Expanded vermiculite itself can withstand high temperatures up to 850℃. After calcination at temperatures above 900℃, silica-alumina ceramic micro powder and silica sol form a continuous ceramic protective film on the vermiculite surface, blocking the thermal decomposition of vermiculite crystals at high temperatures and increasing the filler's temperature tolerance to 1000℃. The weight ratio is limited to 85-92 parts vermiculite, 6-12 parts ceramic powder, and 2-3 parts silica sol. If there is too little ceramic powder, the high-temperature protective film thickness will be insufficient, and the vermiculite will easily pulverize. If there is too much ceramic powder, the overall rigidity of the filler will be too high, and the compression resilience will decrease.

[0028] Inner and outer ring wall thickness matching: The inner ring is 1.2 to 1.8 mm thick and serves as a radial positioning element to prevent the inner ring of the winding core from being deformed by the medium; the outer ring is 1.0 to 1.5 mm thick and limits the maximum compression of the gasket to avoid excessive compression that could cause the vermiculite filler to break; the inner and outer rings have a small gap of 0.1 to 0.3 mm between them and the core, so that they fit tightly after assembly and pressing, with no gaps for medium penetration.

[0029] Thin stainless steel strip 4 is made of 310S high-temperature resistant stainless steel strip. The cross-section of thin stainless steel strip 4 features a wavy, pleated structure with a wave height of 0.4–0.7 mm and a wave pitch of 1.0–1.6 mm. 310S stainless steel strip is the best high-temperature resistant austenitic stainless steel on the market, with an ultimate heat resistance of 1050℃ and a maximum operating temperature of 1000℃ when used with matching gaskets. The wavy, pleated structure with a wave height of 0.4–0.7 mm and a wave pitch of 1.0–1.6 mm creates elastic buffer cavities. Under pressure, the pleat deformation provides rebound support, increasing the rebound rate by more than 40% compared to straight steel strips. Insufficient wave height results in insufficient elasticity, while excessive wave height makes the steel strip prone to fatigue fracture.

[0030] The modified high-purity vermiculite filler layer 5 was prepared by calcining at 920–980℃ for 2.5–4 hours, resulting in a vermiculite sheet thickness of 0.08–0.14 mm after calcination. The silica-alumina ceramic micropowder 6 had a particle size of 500–800 mesh and a silica sol solid content of 30%. The silica-alumina ceramic micropowder and silica sol were mixed and coated onto the surface of the expanded vermiculite sheet to form a dense, high-temperature resistant protective film. In this embodiment, calcination at 920–980℃ for 2.5–4 hours is a key parameter for the formation of the ceramic coating layer: if the temperature is below 920℃, the silica sol cannot be completely ceramicized, and organic residues remain in the film layer; if the temperature is above 980℃, the vermiculite crystal structure collapses and cracks; if the holding time is insufficient, the coating film will be uneven, and local high temperatures will easily cause damage; after calcination, the vermiculite flakes are 0.08–0.14 mm thick, and the thin sheet filler can be completely embedded with the steel strip folds without gaps, reducing the medium leakage channel.

[0031] The total radial thickness of the annular metal winding core 2 is 3 to 12 mm. The inner diameter of the stainless steel inner ring positioning ring 1 is 0.1 to 0.3 mm smaller than the inner diameter of the annular metal winding core 2. The outer diameter of the stainless steel outer ring limiting ring 3 is 0.1 to 0.3 mm larger than the outer diameter of the annular metal winding core 2.

[0032] Both the stainless steel inner ring positioning ring 1 and the stainless steel outer ring limiting ring 3 are integrally formed by stamping 309S stainless steel sheet. The stainless steel inner ring positioning ring 1 and the stainless steel outer ring limiting ring 3 are fixed to the annular metal winding core 2 by axial pressing and interlocking, without welding seams.

[0033] The Naite high-temperature metal vermiculite spiral wound gasket is designed for a temperature range of -50℃ to 1000℃, with a compression ratio controlled between 18% and 30%, a resilience rate ≥15%, and a stress relaxation rate ≤13%. In this embodiment, the wide temperature range of -50℃ to 1000℃ adapts to alternating high and low temperature conditions; the compression ratio of 18% to 30% accommodates different flange tightening forces, with high compression range selected for low-pressure flanges and low compression range selected for high-pressure flanges; the resilience rate ≥15% ensures that the sealing and tightening force remains even after high-temperature load relaxation; and the stress relaxation rate ≤13% is far superior to conventional organic filler gaskets (conventional products have a relaxation rate >25%), resulting in slow degradation of sealing performance during long-term high-temperature operation.

[0034] like Figure 4 As shown in the figure, an embodiment of the present invention provides a method for preparing a high-temperature metal vermiculite spiral wound gasket, comprising the following steps: Step S1, Vermiculite Modification Pretreatment: Take 85-92 parts by weight of expanded vermiculite, wash, remove impurities, and dry it. Mix it with 6-12 parts of silicon-aluminum ceramic micro powder and 2-3 parts of 30% solid content silica sol, stir thoroughly to coat the mixture, and calcine it in a kiln at 920-980℃ for 2.5-4 hours. After cooling, crushing, and sieving, modified vermiculite flakes with a thickness of 0.08-0.14 mm are obtained. Step S2, steel strip processing: Take a 0.15-0.22mm thick 310S stainless steel sheet, roll it into a steel strip with a width of 8-22mm, and stamp it to form a wave fold with a wave height of 0.4-0.7mm; Step S3, Winding: The corrugated stainless steel strip and modified vermiculite sheet are fed alternately and spirally wound along a ring-shaped die, controlling the winding density to be 1.6–2.0 g / cm³. 3 A ring-shaped metal wound core is obtained; Step S4, inner and outer ring stamping: 309S stainless steel sheet is stamped to form an inner positioning ring with a wall thickness of 1.2-1.8mm and an outer limiting ring with a wall thickness of 1.0-1.5mm; Step S5, Pressing and Assembly: The inner ring positioning ring and the outer ring limiting ring are respectively fitted onto the inner and outer sides of the winding core, and the hydraulic equipment is used to press and fix them axially to obtain the finished high-temperature metal vermiculite winding gasket.

[0035] Step S3: During spiral winding, the pressure of the single-turn steel strip and vermiculite filler layer is controlled at 12MPa to 18MPa. After winding, the pressure is maintained at room temperature for 30 minutes to set the shape. Step S5: The hydraulic pressing pressure is 20MPa to 26MPa. After pressing, the entire gasket is subjected to a low-temperature heat treatment at 700℃ for 1 hour to eliminate the internal stress of the winding process.

[0036] In view of the inherent defects of existing technologies that all rely on organic binders / organic fibers to improve the formability of fillers and suffer from carbonization failure at high temperatures above 600°C, this invention adopts a silicon-aluminum ceramic and silica sol all-inorganic modified vermiculite filler system, completely eliminating organic components, solving the technical problem of high-temperature filler leakage from the material source, and has outstanding technical effect. 1. The three components—corrugated elastic steel strip, modified thin vermiculite filler, and double-limiting steel rings—are synergistically structured, with their parameters mutually limiting and working together. This is not a simple superposition of existing structures. The optimal ratio and size range were determined through multiple orthogonal experiments, resulting in high-temperature rebound and low relaxation effects far exceeding those of existing products.

[0037] 2. A complete process for high-temperature ceramic coating and calcination of vermiculite, pressure-controlled winding, and low-temperature stress relief was developed. The parameters of each process are matched to the high-temperature structural requirements of the product. Existing gasket preparation does not have vermiculite ceramic modification and high-temperature stress relief steps, and the process route is not obvious.

[0038] 3. It provides long-term stable sealing at 1000℃, and its rebound, stress relaxation, corrosion resistance, and insulation performance all surpass those of existing commercially available high-temperature gaskets, producing unexpected technical effects. It meets the requirements of ultra-high temperature and harsh working conditions that existing products cannot adapt to, and has substantial application characteristics.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-temperature metal vermiculite spiral wound gasket, characterized in that, It includes an annular metal wound core, a stainless steel inner ring positioning ring, and a stainless steel outer ring limiting ring; the annular metal wound core is integrally formed by alternating spiral stacking of thin stainless steel metal strips and modified high-purity vermiculite filler layers. The modified high-purity vermiculite filler layer raw material is composed of the following parts by weight: 85-92 parts expanded vermiculite, 6-12 parts silica-alumina ceramic micro powder, and 2-3 parts silica sol; the thin stainless steel metal strip has a thickness of 0.15-0.22 mm and a width of 8-22 mm; the annular metal winding core has a winding density of 1.6-2.0 g / cm³. 3 The stainless steel inner ring positioning ring is fitted to the inner circumferential side wall of the annular metal winding core, and the wall thickness of the stainless steel inner ring positioning ring is 1.2 to 1.8 mm; the stainless steel outer ring limiting ring is fitted to the outer circumferential side wall of the annular metal winding core, and the wall thickness of the stainless steel outer ring limiting ring is 1.0 to 1.5 mm.

2. The high-temperature metal vermiculite spiral wound gasket according to claim 1, characterized in that, The thin stainless steel strip is a 310S high-temperature resistant stainless steel strip. The cross-section of the thin stainless steel strip has a wavy pleated structure with a pleat height of 0.4 to 0.7 mm and a pleat pitch of 1.0 to 1.6 mm.

3. The high-temperature metal vermiculite spiral wound gasket according to claim 1, characterized in that, The modified high-purity vermiculite filler layer was prepared by calcining at a temperature of 920–980℃, with a calcination holding time of 2.5–4 h, and the thickness of a single vermiculite sheet after calcination was 0.08–0.14 mm.

4. The high-temperature metal vermiculite spiral wound gasket according to claim 3, characterized in that, The silicon-aluminum ceramic micro powder has a particle size of 500-800 mesh and a silica sol solid content of 30%. The silicon-aluminum ceramic micro powder and silica sol are mixed and coated on the surface of expanded vermiculite sheets to form a dense, high-temperature resistant protective film.

5. The high-temperature metal vermiculite spiral wound gasket according to claim 1, characterized in that, The total radial thickness of the annular metal winding core is 3 to 12 mm. The inner diameter of the stainless steel inner positioning ring is 0.1 to 0.3 mm smaller than the inner diameter of the annular metal winding core, and the outer diameter of the stainless steel outer limiting ring is 0.1 to 0.3 mm larger than the outer diameter of the annular metal winding core.

6. The high-temperature metal vermiculite spiral wound gasket according to claim 1, characterized in that, Both the stainless steel inner positioning ring and the stainless steel outer limiting ring are integrally formed by stamping 309S stainless steel sheet. The stainless steel inner positioning ring and the stainless steel outer limiting ring are fixed to the annular metal winding core by axial pressing and interlocking, without welding seams.

7. The high-temperature metal vermiculite spiral wound gasket according to claim 1, characterized in that, The temperature range of the Naite high-temperature metal vermiculite spiral wound gasket is -50℃ to 1000℃, the gasket compression rate is controlled at 18% to 30%, the resilience rate is ≥15%, and the stress relaxation rate is ≤13%.

8. A method for preparing a high-temperature metal vermiculite spiral wound gasket according to any one of claims 1 to 7, characterized in that, Includes the following steps: Step S1, Vermiculite Modification Pretreatment: Take 85-92 parts by weight of expanded vermiculite, wash, remove impurities, and dry it. Mix it with 6-12 parts of silicon-aluminum ceramic micro powder and 2-3 parts of 30% solid content silica sol, stir thoroughly to coat the mixture, and calcine it in a kiln at 920-980℃ for 2.5-4 hours. After cooling, crushing, and sieving, modified vermiculite flakes with a thickness of 0.08-0.14 mm are obtained. Step S2, steel strip processing: Take a 0.15-0.22mm thick 310S stainless steel sheet, roll it into a steel strip with a width of 8-22mm, and stamp it to form a wave fold with a wave height of 0.4-0.7mm; Step S3, Winding: The corrugated stainless steel strip and modified vermiculite sheet are fed alternately and spirally wound along a ring-shaped die, controlling the winding density to be 1.6–2.0 g / cm³. 3 A ring-shaped metal wound core is obtained; Step S4, inner and outer ring stamping: 309S stainless steel sheet is stamped to form an inner positioning ring with a wall thickness of 1.2-1.8mm and an outer limiting ring with a wall thickness of 1.0-1.5mm; Step S5, Pressing and Assembly: The inner ring positioning ring and the outer ring limiting ring are respectively fitted onto the inner and outer sides of the winding core, and the hydraulic equipment is used to press and fix them axially to obtain the finished high-temperature metal vermiculite winding gasket.

9. The method for preparing the high-temperature metal vermiculite spiral wound gasket according to claim 8, characterized in that, In step S3, during spiral winding, the pressure of the single-turn steel strip and vermiculite filler layer is controlled at 12MPa to 18MPa. After winding, the material is kept at room temperature under pressure for 30 minutes to set.

10. The method for preparing the high-temperature metal vermiculite spiral wound gasket according to claim 8, characterized in that, Step S5: The hydraulic pressing pressure is 20MPa~26MPa. After pressing, the entire gasket is subjected to a low temperature heat treatment at 700℃ for 1 hour to eliminate the internal stress of the winding molding.

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