High Mechanical Strength and Corrosion Resistance Graphite-Reinforced Sealing Gasket for Industrial Sealing Applications

Product Description

Product Description

Graphite-Reinforced Sheet (also known as reinforced graphite sheet, high-strength graphite sheet, or flexible graphite composite sheet) is a high-performance sealing material that utilizes flexible graphite as a matrix, with its mechanical strength enhanced through the incorporation of metallic materials.

It is typically manufactured by subjecting metal sheets, such as perforated plates, mesh plates, or solid plates made of stainless steel (e.g., SS304, SS316) or tinplate to high-temperature compression alongside expanded graphite particles; in this structure, the metal layer serves as a reinforcing skeleton, while the graphite layer provides excellent sealing performance.

This material combines the corrosion resistance and high/low-temperature tolerance of flexible graphite with the high-strength characteristics of metal; possessing excellent compressibility, resilience, and compressive strength, it is ideally suited for industrial sealing applications under demanding operating conditions.

performance

1. Extreme Temperature Resistance
Capable of stable, long-term operation within a temperature range of -200°C to +850°C. Certain models can withstand temperatures up to 3000°C in non-oxidizing environments, making them ideal for applications involving high-temperature furnaces, thermal cycling systems, and similar scenarios.

2. High Strength and Resilience
Reinforced with metal layers, such as stainless steel (e.g., SS304, SS316) or tinplate to significantly enhance compressive strength and impact resistance. The compression recovery rate reaches 30%-55%, effectively compensating for flange deformation.

3. Exceptional Chemical Stability
Exhibits excellent resistance to acids, alkalis, steam, oils, and a wide range of corrosive media (with the exception of strong oxidizing acids). Suitable for use across a pH range of 0-14, making it ideal for highly corrosive environments found in the chemical and pharmaceutical industries.

4. Low Installation Preload
Requires significantly less seating stress (clamping force) compared to traditional metal gaskets. It places minimal demands on flange face flatness and does not adhere to the flange surface upon removal, thereby facilitating easier maintenance.

5. Self-Lubricating and Age-Resistant
The inherent lamellar structure of graphite provides self-lubricating properties and a low coefficient of friction. It resists embrittlement and aging during thermal cycling, ensuring a long service life.

6. Eco-Friendly and Safe Materials
Features a carbon content of ≥99.5%, sulfur content of ≤200 ppm, and chlorine content of ≤30 ppm. Compliant with clean process requirements, it does not contaminate the process media, making it suitable for use in the food and pharmaceutical industries.

7. Customizable Fabrication
Supports various fabrication methods, including punching and cutting, to produce circular or complex geometric shapes (e.g., gaskets for liquid level gauges or cylinder heads). Optional edging processes (inner or outer edging) are available to further enhance pressure resistance and ease of installation.

Applications

1. Petrochemical Industry
Used for flange sealing in equipment such as pipelines, valves, pumps, heat exchangers, and reactors within refining, ethylene production, and fertilizer plants, effectively resisting corrosion from acids, alkalis, salts, and organic solvents.

2. Power and Energy Industry
Widely utilized for sealing high-temperature and high-pressure components in power plants-including boiler systems, steam turbines, condensers, and air compressors-as well as in specific areas such as generator end covers and exhaust pipe connections.

3. Metallurgy and Coal Mining Industries
Employed in blast furnaces, coke ovens, and gas purification systems to seal high-temperature flue gases and corrosive gases, demonstrating excellent thermal stability and resistance to thermal shock.

4. Pharmaceutical and Food Industries
Due to its non-toxic nature and its inability to contaminate the process medium, it is suitable for sealing connections in pharmaceutical reactors and food processing equipment where strict hygiene and cleanliness standards are required.

5. Refrigeration and Air Conditioning Systems
In refrigeration units, chillers, and ammonia-based systems, graphite-reinforced sheets can withstand exposure to refrigerants such as liquid ammonia and Freon, while remaining resistant to aging and embrittlement.

6. Automotive Manufacturing Sector
Commonly used for components such as cylinder head gaskets and exhaust manifold gaskets in diesel engines, capable of withstanding frequent temperature fluctuations and vibration loads.

7. Water Treatment and Environmental Engineering
Applied in the pump and valve sealing systems of seawater desalination and wastewater treatment facilities, effectively resisting chloride ion corrosion and extending the service life of the equipment.

Process Features

1. Adhesive-Free Lamination, Robust Mechanical Interlocking
The process utilizes a punched-tooth metal core plate (feauring a perforated structure) pressed directly against expanded graphite. Under high pressure, the graphite embeds itself into the metal's pores, creating an "anchoring effect" that achieves a binder-free physical bond. This method prevents performance degradation caused by the aging and carbonization of adhesives at high temperatures, thereby significantly enhancing long-term operational reliability.

2. High-Pressure Densification, Uniform and Stable Structure
By applying pressures ranging from 10 to 200 MPa via isostatic pressing or roll-pressing, the expanded graphite particles are arranged into a highly dense configuration. The resulting sheet density reaches 1.6-1.9 g/cm³, effectively reducing permeability and enhancing compressive strength and sealing performance. The uniform pressure distribution ensures material isotropy and minimizes localized weak points.

3.Versatile Molding Processes, Supporting Diverse Product Range
A variety of molding techniques-including extrusion molding, compression molding, vibration molding, and isostatic molding-can be employed. This flexibility allows for the efficient production of ultra-thin, oversized, or spliced structures, meeting the customized size and shape requirements of various equipment.

4.Synchronous Double-Sided Processing, Enhanced Production Efficiency
The integration of flipping mechanisms and multi-station calendering equipment enables the continuous, simultaneous processing of both sides of the composite sheet. This resolves the issues of low efficiency and susceptibility to deformation inherent in traditional single-sided processing, making the system highly suitable for large-scale industrial production.

5.Post-Processing Enhancement, Further Functional Upgrades
1) Edging Process:
Optional stainless steel or carbon steel edging can be applied to the inner, outer, or both edges of the material. This prevents media corrosion, improves pressure resistance, and facilitates installation and positioning.
 
2) Surface Modification:
Immersion treatments using solutions such as phosphoric acid or molybdic acid are applied to enhance oxidation resistance and creep resistance, making the material suitable for long-term service under high pressure or high-temperature conditions. 

3) Precision Cutting:
Utilizing CNC punching or laser cutting technologies, the process allows for the precise fabrication of circular and irregularly shaped gaskets (e.g., liquid level gauge gaskets, cylinder head gaskets), fully supporting non-standard customization requirements.

6. Environmental Protection and Sustainable Manufacturing
Certain advanced processes have successfully implemented the recycling and reuse of graphite waste, enabling the production of high-strength, eco-friendly graphite plates through composite fabrication with ceramic-phase reinforcements, thereby fostering the development of green manufacturing.

Product Parameters