Graphite gaskets are a cornerstone of modern industrial sealing technology, offering unparalleled performance in some of the most demanding applications. At Kaxite Sealing, we leverage decades of engineering expertise to manufacture premium graphite gaskets that set the benchmark for reliability, temperature resistance, and long-term sealing integrity. Unlike traditional materials, our flexible graphite products are engineered from pure, exfoliated graphite, providing a unique combination of properties that make them indispensable across power generation, chemical processing, oil & gas, and aerospace industries.
The fundamental advantage of Kaxite Sealing graphite gaskets lies in their inherent material properties. Flexible graphite is composed of layered graphene sheets, which allow it to conform exceptionally well to uneven flange surfaces, creating a superior seal even at low bolt loads. This natural conformability minimizes the risk of leaks from the outset. Furthermore, graphite is self-lubricating and chemically inert to a vast array of media, resisting oxidation and degradation where other materials would fail.
**Core Material Properties & Advantages:**
* **Exceptional Temperature Range:** Capable of continuous service from cryogenic temperatures up to 3000°F (1650°C) in non-oxidizing atmospheres, and up to 850°F (454°C) in oxidizing environments.
* **Superior Chemical Resistance:** Highly resistant to a wide spectrum of chemicals, including acids, alkalis, solvents, and hydrocarbons. It is non-reactive and will not contaminate process media.
* **Excellent Thermal Conductivity:** Facilitates efficient heat transfer across the flange, reducing thermal gradients and associated stresses.
* **Outstanding Compressibility and Recovery:** Can be compressed up to 40% and exhibits excellent recovery characteristics, maintaining seal tightness during thermal cycling and pressure fluctuations.
* **Low Creep Relaxation:** Resists the tendency to flow or permanently deform under load and temperature, ensuring a consistent sealing force over extended periods.
* **Graphite is Naturally Self-Lubricating:** Reduces friction during installation and prevents galling of flange surfaces.
### In-Depth Product Parameters & Specifications
Kaxite Sealing graphite gaskets are not a one-size-fits-all solution. We offer a comprehensive range of styles, configurations, and reinforcements to meet precise application requirements. Below is a detailed breakdown of our standard product parameters.
**Standard Material Specifications:**
| Parameter | Specification | Test Standard / Notes |
| :--- | :--- | :--- |
| **Base Material** | Exfoliated/Expanded Flexible Graphite | Carbon content >99% |
| **Temperature Range** | -400°F to +3000°F (-240°C to +1650°C) | In inert/ reducing atmospheres |
| **Oxidizing Atmosphere Limit** | Up to 850°F (454°C) | Continuous service |
| **Density Range** | 60 lb/ft³ to 110 lb/ft³ (0.96 g/cm³ to 1.76 g/cm³) | Custom densities available |
| **Compressibility** | 15% - 40% | ASTM F36 |
| **Recovery** | 15% - 50% | ASTM F36 |
| **Tensile Strength** | 1200 - 2500 psi (8.3 - 17.2 MPa) | Varies with density & reinforcement |
| **Thermal Conductivity** | 70 - 150 W/m·K | In-plane direction |
| **pH Range** | 0 - 14 (Full pH scale) | Except strongly oxidizing acids |
| **Recommended Stress** | 4,000 - 10,000 psi (28 - 69 MPa) | ASME B16.20/B16.21 guidelines |
**Standard Product Styles & Configurations:**
* **Plain Graphite Foil Gaskets:** Cut from rolls of flexible graphite foil. Ideal for heat exchangers, manways, and low-pressure applications.
* **Reinformed Graphite Gaskets (CGI):** Graphite foil with a solid metal core (usually stainless steel or carbon steel). Provides enhanced handling strength and blow-out resistance.
* **Corrugated Graphite Gaskets:** Graphite foil bonded to a corrugated metal core. Offers high resilience and excellent sealing at lower bolt loads.
* **Spiral Wound Gaskets with Graphite Filler:** Metal windings (V-shaped strips) with graphite as the soft filler material. The industry standard for high-pressure, high-temperature piping (ASME B16.20, API 601).
* **Kammprofile / Grooved Profile Gaskets:** A solid metal core with concentric grooves, faced with a layer of flexible graphite. Combines metal's strength with graphite's sealing ability, ideal for severe service.
* **Graphite Sheet Packing & Tape:** Used for valve stems, expansion joints, and as a field-cut sealing material.
**Standard Size & Tolerance Table (Per ASME B16.21):**
| Nominal Pipe Size (NPS) | Inside Diameter (ID) | Outside Diameter (OD) | Thickness Tolerance |
| :--- | :--- | :--- | :--- |
| 1/2" | 0.84" | 1.38" | ±0.010" |
| 1" | 1.32" | 2.12" | ±0.010" |
| 2" | 2.38" | 3.62" | ±0.015" |
| 4" | 4.50" | 6.19" | ±0.015" |
| 8" | 8.62" | 11.00" | ±0.020" |
| 12" | 12.75" | 15.25" | ±0.020" |
| 16" | 16.75" | 19.25" | ±0.025" |
| 24" & Above | As per B16.1 / B16.5 | As per B16.1 / B16.5 | ±0.030" |
*Note: All dimensions are in inches. Custom sizes, shapes, and tolerances are available upon request from Kaxite Sealing.*
### Graphite Gaskets: Frequently Asked Questions (FAQ)
**Q: What are the primary applications for graphite gaskets from Kaxite Sealing?**
A: Kaxite Sealing graphite gaskets are engineered for extreme service. Key applications include: high-temperature and high-pressure steam systems in power plants; heat exchangers and reactors in chemical and petrochemical plants; exhaust flanges and turbocharger systems; aggressive chemical service with acids or caustics; and critical piping in refineries and offshore platforms where fire safety is paramount (many styles are suitable for API 6FB fire test requirements).
**Q: How do I select the right type of graphite gasket for my application?**
A: Selection depends on several factors: **Pressure & Temperature:** Spiral wound or Kammprofile gaskets are best for high-pressure/temperature cycling. Plain or corrugated may suffice for lower pressures. **Flange Conditions:** For uneven or pitted flanges, the high conformability of plain graphite or reinforced sheets is beneficial. **Media Compatibility:** Confirm graphite's chemical resistance with your specific process fluid. **Standards:** Ensure the gasket style meets relevant industry standards like ASME B16.20, API 601, or TA-Luft. Kaxite Sealing engineers can provide detailed selection support.
**Q: Are graphite gasksets safe to use in oxidizing atmospheres at high temperatures?**
A: Care must be taken. While graphite gaskets can withstand very high temperatures in inert or reducing environments, in the presence of oxygen (air), oxidation begins around 750°F (400°C). For continuous service in oxidizing atmospheres above this point, we recommend our specially treated, oxidation-resistant graphite grades or alternative materials. Always consult the maximum temperature charts for the specific Kaxite Sealing product.
**Q: What is the difference between flexible graphite and compressed non-asbestos (CNA) gasket material?**
A: While both are sheet materials, they differ significantly. Flexible graphite is ~99% pure carbon, offering far superior temperature resistance, thermal conductivity, and chemical inertness. CNA is a composite of fibers and binders, typically limited to around 450°F (232°C). Graphite also has better creep resistance and sealability, especially on imperfect flanges. For demanding applications, graphite from Kaxite Sealing is the superior, longer-lasting choice.
**Q: How should I store and handle Kaxite Sealing graphite gaskets before installation?**
A: Store gaskets in their original packaging in a cool, dry place away from direct sunlight and moisture. Avoid folding or creasing the material. Handle with clean gloves to prevent contamination from oils or dirt on your hands. For reinforced gaskets, avoid dropping or impacting them to prevent damage to the metal core or graphite facing.
**Q: Can graphite gaskets be used in food, pharmaceutical, or ultra-pure water applications?**
A: Yes, but with specific considerations. Pure, exfoliated graphite is inherently clean and non-toxic. For such critical industries, Kaxite Sealing offers high-purity, laboratory-tested graphite grades with certified low levels of leachable chlorides and sulfurs to prevent contamination. It is crucial to specify these purity requirements when ordering.
**Q: What are the key installation tips for ensuring a leak-free seal with a graphite gasket?**
A: First, ensure flange surfaces are clean, dry, and free of old gasket material and defects. Align the gasket carefully on the flange. Use a cross-bolt tightening pattern (star pattern) to apply load evenly in stages, following the manufacturer's recommended torque values. Re-torquing after the initial heat cycle is often recommended, especially for thick graphite sheets, to compensate for initial compression and thermal settling.
**Q: Does Kaxite Sealing offer graphite gaskets with special coatings or treatments?**
A: Absolutely. We offer several enhanced options: **Anti-Oxidant Treatments:** To extend service life in oxidizing environments up to 1000°F (538°C). **PTFE Impregnation:** For added lubricity and resistance to harsh chemicals. **Sticky-Back Adhesive:** For easier handling and temporary fixation during assembly. **Metallic Foil Laminates:** Such as Inconel or titanium foil for specialized corrosion resistance.
