Unlocking Superior Sealing Performance with Expanded Graphite Gaskets
In the demanding world of industrial sealing, where extreme temperatures, aggressive chemicals, and high pressures are the norm, finding a reliable, versatile, and long-lasting sealing solution is paramount. For over two decades, Kaxite Sealing has been at the forefront of this challenge, engineering high-performance sealing materials that set the industry standard. Among our flagship products, Expanded Graphite Gaskets stand out as a cornerstone technology for modern sealing applications. Unlike traditional gasket materials that may fail under stress, our Expanded Graphite Gaskets offer an exceptional combination of resilience, conductivity, and chemical resistance, making them the preferred choice for engineers and maintenance professionals worldwide.
Our commitment at Kaxite Sealing is not just to supply a product but to provide a comprehensive sealing solution. We understand that downtime is costly, and seal failure is not an option. Therefore, every sheet and roll of Kaxite expanded graphite is manufactured under stringent quality controls, ensuring consistent density, uniform expansion, and optimal sealing performance right out of the box. This material, often referred to as exfoliated graphite, is crafted from high-purity natural graphite that undergoes a thermal expansion process, creating a flexible, compressible, and highly adaptive sealing mat.
Key Advantages of Kaxite Expanded Graphite Gaskets
The superior performance of our Expanded Graphite Gaskets stems from a unique set of material properties. These advantages translate directly into increased safety, reduced maintenance intervals, and lower total cost of ownership for your operations.
- Exceptional Temperature Resistance: Capable of continuous operation from cryogenic temperatures as low as -240°C (-400°F) up to oxidizing atmospheres of 450°C (842°F) and in non-oxidizing or reducing environments up to 3000°C (5432°F) when used with appropriate flanges.
- Outstanding Chemical Stability: Highly resistant to a vast array of chemicals, including strong acids, alkalis, organic solvents, and hot oils. It is also immune to aging and hardening.
- Superior Creep Relaxation Resistance: Maintains bolt load exceptionally well, preventing leaks caused by stress relaxation common in other soft gasket materials.
- Excellent Thermal and Electrical Conductivity: Promotes even heat distribution and provides effective grounding, preventing galvanic corrosion and static buildup.
- Inherent Flexibility and Conformability: Easily conforms to irregular or slightly damaged flange surfaces, creating a tight, leak-free seal even at low bolt loads.
- No Asbestos or Hazardous Materials: A completely safe, environmentally friendly sealing solution that complies with global health and safety regulations.
Technical Specifications & Product Parameters
To ensure you select the perfect gasket for your application, Kaxite Sealing provides expanded graphite in various forms with precise technical specifications. Below are the detailed parameters for our standard sheet and roll stock.
Standard Material Properties
| Property | Test Standard | Typical Value | Unit |
|---|---|---|---|
| Density (Nominal) | ASTM F1315 | 1.0 - 1.1 | g/cm³ |
| Tensile Strength (MD) | ASTM F152 | > 4.5 | N/mm² |
| Compressibility | ASTM F36 | 40 - 60 | % |
| Recovery | ASTM F36 | > 15 | % |
| Creep Relaxation | ASTM F38 | < 15 | % |
| Thermal Conductivity | ASTM D5470 | 5 - 150 (in-plane) | W/m·K |
| pH Value | ASTM E70 | 5 - 7 | - |
| Chloride Content | ASTM D512 | < 50 | ppm |
| Sulfur Content | ASTM D4239 | < 800 | ppm |
Available Product Forms & Sizes
Kaxite Expanded Graphite Gaskets are available in multiple forms to suit various fabrication and installation needs.
- Sheets: Standard sheet sizes include 1000mm x 1000mm, 1260mm x 1260mm, and 1500mm x 1500mm. Thicknesses range from 0.5mm to 6.0mm.
- Rolls: Convenient for long runs or custom cutting. Standard roll dimensions are 1260mm wide x 25 meters long, available in thicknesses from 0.5mm to 3.0mm.
- Pre-Cut Gaskets: Custom die-cut, CNC machined, or laser-cut gaskets to your exact drawings and specifications.
- Reinforced Composites: Laminated with stainless steel, tinplate, or other inserts for enhanced handling strength and burst pressure resistance.
- Tanged & Perforated Sheets: For improved handling and reduced dusting during installation.
Frequently Asked Questions (FAQ)
Here are some of the most common questions we receive at Kaxite Sealing regarding Expanded Graphite Gaskets.
General & Application Questions
Q: What are the primary industries and applications for Expanded Graphite Gaskets?
A: Expanded Graphite Gaskets from Kaxite Sealing are extensively used across a wide range of industries due to their versatility. Key sectors include chemical and petrochemical processing (for reactors, heat exchangers, flanges), power generation (in turbines, boilers, exhaust systems), pharmaceutical manufacturing (sterile and corrosive fluid lines), food and beverage processing, and automotive/ aerospace (exhaust gaskets, fuel cells). They are ideal for sealing flanges, manholes, heat exchangers, valves, and pumps handling steam, hot oils, acids, alkalis, and hydrocarbons.
Q: Can Expanded Graphite Gaskets be used for high-pressure applications?
A: While pure expanded graphite is excellent for a wide range of pressures, its application in very high-pressure systems (e.g., ASME Class 900 and above) often benefits from reinforcement. Kaxite Sealing offers composite gaskets where the graphite is laminated with a stainless steel or other metal core. This reinforcement provides exceptional blowout resistance, reduces creep relaxation under high bolt load, and allows the gasket to withstand significantly higher internal pressures while maintaining the superb sealing characteristics of graphite.
Q: How do I choose the correct thickness and density for my application?
A: The selection depends on flange conditions, pressure, temperature, and medium. As a general rule:
- For standard ANSI B16.5 flanges with smooth finishes, a 1.5mm thickness is common.
- For uneven or worn flange surfaces, a thicker gasket (e.g., 3.0mm) offers better conformability.
- Higher density (e.g., 1.1 g/cm³) provides better mechanical strength and creep resistance for higher-pressure services.
- Lower density offers higher compressibility for excellent sealing on low bolt load flanges.
Installation & Handling Questions
Q: What is the proper installation procedure for a pure expanded graphite gasket?
A: Proper installation is critical for optimal performance. Ensure flanges are clean, aligned, and undamaged. Place the gasket carefully onto the flange. Use a crisscross bolt tightening pattern, gradually torqueing in multiple stages (typically 30%, 60%, and 100% of the final torque value) to achieve an even compressive load. Refer to the EN 1591 or ASME PCC-1 guidelines for detailed bolt torque procedures. Avoid over-torquing, as this can over-compress and damage the graphite structure. Always use new gaskets for reassembly.
Q: Does expanded graphite produce dust, and how should it be handled?
A: Pure expanded graphite can produce some fine particles during handling and cutting. Kaxite Sealing recommends handling with care. To minimize dust, we offer tanged or perforated sheets and rolls, which have better cohesion. When cutting, use sharp tools and clean the gasket surface with a dry cloth or air blast before installation to remove any loose particles. Wearing gloves is also advised for cleanliness. For critical clean-room applications, ask about our specially processed low-dust grades.
Q: Can I reuse an expanded graphite gasket after it has been compressed?
A: No. Like most soft gaskets, Expanded Graphite Gaskets from Kaxite Sealing are designed for single use. Once compressed, the material's cellular structure has been permanently deformed to conform to the specific flange surfaces. Reusing a compressed gasket will not provide the same level of seal integrity and significantly increases the risk of leakage. Always install a new gasket during maintenance or reassembly.
Performance & Compatibility Questions
Q: Is expanded graphite suitable for strong oxidizing agents like nitric acid or oxygen service?
A: Caution is required. While expanded graphite has excellent chemical resistance, its resistance to strong oxidizing agents at elevated temperatures can be limited. In continuous service with media like concentrated nitric acid, hot concentrated sulfuric acid, or pure oxygen under pressure, oxidation of the graphite can occur above certain temperature thresholds. For such applications, Kaxite Sealing strongly recommends consulting our engineering team. We may suggest alternative materials or provide specific, high-purity grades with treatment to enhance oxidation resistance for your particular operating conditions.
Q: How does expanded graphite perform against fire?
A> Expanded graphite is inherently fire-resistant. It is non-flammable and will not burn. Under extreme heat in a fire situation, the graphite may slowly oxidize, but it will not melt, drip, or contribute significant fuel to a fire. This makes Kaxite Expanded Graphite Gaskets an excellent choice for applications where fire safety is a critical concern. They often meet the requirements for fire-safe sealing as per standards like API 607 and API 6FB.
Q: What is the shelf life of Kaxite Expanded Graphite Gaskets?
A: When stored correctly, Kaxite Expanded Graphite Gaskets have an virtually indefinite shelf life. The material does not degrade, harden, or lose its sealing properties over time. For optimal storage, keep the material in its original packaging in a cool, dry, and clean environment away from direct sunlight, extreme moisture, and corrosive fumes. Avoid placing heavy objects on top of sheets or rolls to prevent permanent deformation.
Why Partner with Kaxite Sealing?
Choosing Kaxite Sealing means more than just purchasing a gasket; it means investing in reliability, expertise, and partnership. Our dedicated R&D team continuously refines our manufacturing processes to enhance material consistency and performance. We offer comprehensive technical support, from material selection and application engineering to on-site troubleshooting. With a global distribution network and a commitment to on-time delivery, Kaxite Sealing ensures you have the right sealing solution when and where you need it. Trust the brand that engineers and facility managers rely on for the most challenging sealing applications—trust Kaxite Sealing for your expanded graphite needs.
