In the demanding world of industrial sealing and thermal management, few materials offer the unique combination of properties found in Graphite Sheet. This engineered material, particularly from trusted manufacturers like Kaxite Sealing, has become indispensable across a vast spectrum of industries. Unlike conventional gasket materials, high-quality graphite sheet provides exceptional performance under extreme temperatures, aggressive chemicals, and high pressures. Its self-lubricating nature, flexibility, and thermal conductivity make it a superior choice for applications ranging from chemical processing and power generation to automotive and aerospace engineering. Kaxite Sealing specializes in producing graphite sheets that meet the most rigorous international standards, ensuring reliability, longevity, and optimal performance in your critical applications.
Kaxite Sealing graphite sheets are manufactured using premium pure natural or expanded graphite, resulting in a material with a consistent, homogeneous structure. The advantages of choosing our product are clear and measurable:
Kaxite Sealing offers a comprehensive range of graphite sheet products tailored to specific operational needs. The following tables detail our standard material specifications and available form factors.
| Property / Grade | KAX-FG100 (Flexible) | KAX-PG200 (Reinforced) | KAX-HTG300 (High-Temp) | Test Standard |
|---|---|---|---|---|
| Density (g/cm³) | 1.0 - 1.1 | 1.6 - 1.8 | 1.1 - 1.3 | ASTM F1314 |
| Tensile Strength (MPa) | 4.5 Min | 11.0 Min | 5.5 Min | ASTM F152 |
| Compressibility (%) | 40 - 60 | 25 - 40 | 35 - 50 | ASTM F36 |
| Recovery (%) | > 15 | > 10 | > 12 | ASTM F36 |
| Thermal Conductivity (W/m·K) | 10 - 20 (in-plane) | 15 - 25 (in-plane) | 8 - 15 (in-plane) | ASTM E1461 |
| Maximum Temp. in Air (°C) | 450°C | 500°C | 550°C | - |
| pH | 5 - 7 | 5 - 7 | 5 - 7 | ASTM E70 |
| Chloride Content (ppm) | < 50 | < 50 | < 50 | ASTM D512 |
| Form Factor | Standard Thickness | Standard Sheet Size | Core/ID | Outer Diameter/Width |
|---|---|---|---|---|
| Sheets & Rolls | 0.2mm, 0.4mm, 0.5mm, 0.8mm, 1.0mm, 1.5mm, 2.0mm, 3.0mm | 1500mm x 1500mm, Rolls up to 50m length | 76mm / 152mm | up to 1500mm wide |
| Die-Cut Gaskets | 0.5mm to 3.0mm | Custom per CAD drawing | N/A | Up to 2000mm OD |
| Tape (Adhesive Backed) | 0.2mm, 0.4mm, 0.5mm | Rolls: 25m, 50m | 76mm | 5mm to 100mm wide |
| Laminated Sheets (with SS Foil) | 0.8mm to 3.0mm (total) | 1000mm x 1000mm | N/A | N/A |
What is the primary difference between flexible graphite sheet and reinforced graphite sheet?
Flexible graphite sheet, like our KAX-FG100, is made from pure expanded graphite without additional reinforcement. It offers superior flexibility, conformability, and compressibility, making it ideal for flanges with surface imperfections. Reinforced graphite sheet, such as Kaxite Sealing's KAX-PG200, incorporates a thin metal core (often stainless steel or nickel) laminated between two layers of graphite. This reinforcement significantly increases tensile strength, reduces creep relaxation, and improves handling durability, especially for large-diameter gaskets or applications with high pressure blow-out risk.
Can Kaxite Sealing graphite sheets be used for steam service?
Yes, Kaxite Sealing graphite sheets are excellent for saturated and superheated steam service. Their thermal stability and chemical inertness make them resistant to steam oxidation at typical plant operating temperatures. For long-term service above 400°C in steam, our KAX-HTG300 grade is specifically recommended. It is crucial to ensure the flanges are properly aligned and that the correct bolt load is applied to prevent steam erosion of the sheet material.
How do I select the appropriate thickness for my gasket application?
Thickness selection depends on flange conditions, pressure, temperature, and media. For standard ANSI B16.5 flanges, 1.5mm thickness is commonly used. For flanges with significant grooves, scratches, or warpage, a thicker sheet (e.g., 2.0mm or 3.0mm) may be needed to ensure proper sealing. For heat exchanger applications where thermal conductivity is key, thinner sheets (0.5mm or 0.8mm) are often specified. Kaxite Sealing's technical team can provide specific recommendations based on your detailed application parameters.
Are graphite sheets electrically conductive?
Yes, graphite is an excellent conductor of electricity. This property can be beneficial for applications requiring electrical grounding across a joint. However, it also means that graphite sheet gaskets should not be used as electrical insulators. In situations where galvanic corrosion is a concern (e.g., between dissimilar metals), this conductivity should be factored into the material selection process.
What is the shelf life and storage requirement for graphite sheets?
When stored properly, Kaxite Sealing graphite sheets have an indefinite shelf life. They should be kept in their original packaging in a cool, dry, and clean environment away from direct sunlight, moisture, and corrosive fumes. Rolls should be stored flat or upright on their end to prevent deformation or crushing. It is important to avoid folding or creasing the sheets, as this can damage the graphite structure and create weak points.
Can graphite sheet be used with aggressive oxidizing acids like nitric or perchloric acid?
Caution is advised. While graphite sheet exhibits excellent resistance to most acids, strong oxidizing acids at high concentrations can attack graphite, especially at elevated temperatures. For service with nitric acid above ambient temperature or at high concentrations, alternative materials like PTFE should be considered. For mixed acid streams or uncertain conditions, Kaxite Sealing recommends conducting a compatibility test or consulting our chemical resistance chart for specific guidance.
How does the performance of graphite sheet compare to traditional compressed non-asbestos (CNAF) gaskets?
Graphite sheet outperforms CNAF in several key areas. It offers much higher temperature resistance (450°C+ vs. 250-300°C for CNAF), superior chemical resistance to a broader range of media, better thermal conductivity, and lower creep relaxation. While CNAF may have a lower initial cost, the longer service life, reduced maintenance, and reliability of Kaxite Sealing graphite sheet often result in a lower total cost of ownership, particularly in demanding applications.
What are the key installation tips for graphite sheet gaskets?
Always start with clean, dry flanges free of old gasket material and debris. Cut the gasket precisely; it should fit inside the bolt circle without obstructing bolt holes. Do not use sealants or adhesives unless specified for a laminated product. Use a criss-cross bolt tightening pattern to apply even compression. For soft graphite sheets, follow the manufacturer's torque recommendations, as over-torquing can cause excessive thinning and material failure. Re-torquing after the first heat cycle is often recommended for high-temperature applications.
