Expanded Graphite Gaskets Manufacturer in China

In the demanding world of industrial sealing, where extreme temperatures, aggressive chemicals, and high pressures are daily challenges, finding a reliable and versatile solution is paramount. Among the high-performance options available, Expanded graphite gaskets stand out for their exceptional properties and wide applicability. Kaxite Seals, a leader in advanced sealing technology, manufactures premium expanded graphite gaskets engineered to deliver unmatched performance and longevity in the most severe service conditions.

Expanded graphite, also known as exfoliated graphite, is a pure graphite material processed to create a flexible, compressible, and resilient sealing product. Unlike traditional gasket materials, it offers a unique combination of characteristics that make it suitable for a vast array of industrial applications, from chemical processing and power generation to aerospace and pharmaceutical manufacturing.

Why Choose Kaxite Expanded Graphite Gaskets?

Our gaskets are manufactured from high-purity natural graphite, ensuring consistent quality and performance. The expansion process creates a material with inherent advantages that address common sealing failures.

• Exceptional Thermal Stability: They perform reliably from cryogenic temperatures up to 3000°F (1650°C) in non-oxidizing atmospheres, and up to 900°F (482°C) in continuous oxidizing services.
• Superior Chemical Resistance: Highly inert, they resist a broad spectrum of aggressive media, including acids, alkalis, solvents, and hydrocarbons, with the exception of strong oxidizing agents.
• Excellent Compression and Recovery: The material conforms seamlessly to flange surfaces, filling imperfections and maintaining a tight seal even under variable thermal cycling and bolt stress relaxation.
• Creep Relaxation Resistance: Kaxite gaskets exhibit minimal creep, ensuring the sealing force is maintained over long periods, reducing the need for frequent re-torquing.
• Easy Installation and Removal: The soft, pliable nature allows for easy handling and cuts cleanly without fraying. They do not stick to flanges, simplifying maintenance.
• Electrically and Thermally Conductive: This property prevents static buildup and ensures even heat distribution across the flange.

Detailed Product Parameters & Specifications

At Kaxite Seals, we offer expanded graphite gaskets in various forms to meet specific application requirements. Below are the detailed parameters of our standard product range.

Standard Material Properties

Standard Product Forms & Configurations

Kaxite Seals provides expanded graphite in multiple forms for maximum application flexibility.

• Sheets / Rolls: Available in standard sheet sizes (e.g., 1500mm x 1500mm) or rolls of various widths and lengths. Thickness ranges from 0.2mm to 6.0mm.
• Die-Cut Gaskets: Precision die-cut to match exact flange dimensions, including ASME B16.21, DIN, JIS, and custom profiles.
• CNC Machined Gaskets: For complex geometries or prototypes, we utilize CNC routing for high precision and fast turnaround.
• Laminated & Reinforced Gaskets: For added mechanical strength in high-pressure applications or to prevent blow-out.
  • Graphite with Stainless Steel Insert (Tanged or Perforated).
  • Graphite with Stainless Steel Foil Laminate.
  • Graphite with Nickel, Monel, or Inconel inserts/foils.
• Spiral Wound Gasket Filler: Used as the filler material in spiral wound gaskets for high-temperature, high-pressure service.
• Ring Gaskets (RTJ): Machined for Ring Type Joint flanges.

Chemical Compatibility Guide (Selected Media)

*Note: Strong oxidizing agents can attack graphite at high concentrations. Consult Kaxite Seals engineering for specific oxidizing service applications.

Frequently Asked Questions (FAQ) About Expanded Graphite Gaskets

Q: What are the primary limitations of expanded graphite gaskets?
A: While highly versatile, they have two key limitations. First, they are not recommended for prolonged use with strong oxidizing acids (e.g., nitric, chromic, perchloric) at high concentrations and temperatures, as oxidation can degrade the material. Second, pure graphite has lower mechanical strength compared to metallic gaskets, making it susceptible to blow-out in very high-pressure, high-misalignment applications unless reinforced with metal inserts or used in a spiral wound configuration.

Q: Can Kaxite expanded graphite gaskets be used for steam service?
A: Yes, they are an excellent choice for saturated and superheated steam service across a wide range of pressures and temperatures. Their thermal stability and conformability make them ideal for preventing leaks in steam line flanges, valves, and heat exchangers. For long-term steam service above 450°C (842°F), specific grades with enhanced oxidation inhibitors are available.

Q: How do I select the correct density or thickness for my application?
A: Selection depends on flange type, surface finish, pressure, and temperature. Standard density (~1.0 g/cm³) works for most applications. Lower density (softer) grades are used for rough flange surfaces or low bolt load situations. Higher density grades offer better creep resistance for high-temperature service. Thickness is typically chosen based on ASME B16.21 recommendations; 1.5mm is common for standard raised face flanges. Our technical team at Kaxite Seals can provide specific guidance based on your flange details and operating conditions.

Q: Are these gaskets suitable for food, pharmaceutical, or ultra-pure applications?
A: Absolutely. Kaxite Seals offers expanded graphite grades manufactured from high-purity, pharmaceutical-grade natural graphite with certifications to meet FDA requirements and other relevant standards (e.g., USP Class VI, EU 10/2011). They are non-toxic, non-contaminating, and do not leach impurities, making them perfect for food processing, beverage, pharmaceutical, and semiconductor manufacturing.

Q: What is the difference between "expanded graphite" and "exfoliated graphite"?
A: The terms are often used interchangeably in the industry. Technically, "exfoliated" refers to the process of rapidly heating intercalated graphite flakes, causing them to expand volumetrically into a low-density worm-like structure. "Expanded graphite" is the general term for the resulting flexible, matted material used to make sheets and gaskets. At Kaxite, we use controlled exfoliation processes to ensure a consistent, high-quality expanded graphite product.

Q: How should I store and handle expanded graphite gaskets?
A: Store sheets and gaskets in a cool, dry place away from direct sunlight and moisture. They should be kept flat to prevent curling or distortion. While graphite itself is not hygroscopic, moisture can get trapped between layers; keep the original protective packaging until use. Handle with clean hands or gloves to avoid transferring oils or dirt onto the sealing surface. Use sharp, non-serrated blades for cutting.

Q: Can I reuse an expanded graphite gasket after disassembly?
A: It is generally not recommended. While the material has good recovery, the act of compression during installation permanently deforms the graphite structure to match the specific flange imperfections of that joint. Reusing it on a different flange or even the same flange after re-machining may compromise the seal integrity. For critical applications, always install a new Kaxite gasket.

Q: What flange surface finish is recommended for optimal sealing with graphite gaskets?
A: A serrated finish (e.g., concentric or phonographic serrations) with an Ra value between 3.2 and 6.3 micrometers (125-250 microinches) is ideal. This provides enough "bite" for the soft graphite to flow into and create a mechanical lock, preventing lateral movement. Smooth, polished finishes (Ra < 1.6 µm) should be avoided as they offer little grip and can lead to gasket extrusion or blow-out.