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In the intricate world of industrial machinery and fluid systems, the integrity of every connection is paramount. At the heart of these critical seals lies a component often overlooked yet fundamentally essential: the gasket. For over two decades, Kaxite Seals has been at the forefront of gasket technology, engineering solutions that ensure leak-proof performance, operational safety, and long-term reliability in the most demanding environments. This guide delves into the technical specifications, material science, and application expertise that define premium gasketing solutions.
A gasket is a manufactured sealing material placed between two or more mating surfaces, typically flanges, to prevent leakage of fluids or gases under compression. They must accommodate surface irregularities, withstand system pressure, temperature extremes, and chemical exposure. Kaxite Seals specializes in designing gaskets that are not just barriers but engineered components contributing to system efficiency and safety.
Selecting the correct gasket requires a detailed understanding of several interlocking parameters. Kaxite Seals provides comprehensive data for each product to ensure perfect specification.
| Product Code | Material Type | Thickness (mm/in) | Pressure Rating (PSI/Bar) | Temp. Range (°C/°F) | Primary Media Compatibility | Standard Compliance |
|---|---|---|---|---|---|---|
| KS-NAO150 | Non-Asbestos Organic | 1.5mm / 1/16" | Up to 1500 PSI / 103 Bar | -50°C to +200°C / -58°F to +392°F | Water, Oil, Air, Low-Pressure Steam | ASTM F104, DIN 3754 |
| KS-CNA400 | Compressed Non-Asbestos | 1.6mm / 1/16" | Up to 2500 PSI / 172 Bar | -40°C to +400°C / -40°F to +752°F | Hot Oils, Hydraulic Fluids, Mild Chemicals | API 601, ASME B16.21 |
| KS-EG1000 | Expanded Graphite | 0.8mm, 1.5mm / 1/32", 1/16" | Up to 3000 PSI / 207 Bar | -240°C to +650°C (Air) / -400°F to +1202°F | Steam, Hot Gases, Cryogenics, Heat Transfer Fluids | FDA Compliant, ASTM F38 |
| KS-PTFE-V | Virgin PTFE | 0.5mm - 3.0mm / 0.02" - 1/8" | Up to 1000 PSI / 69 Bar (varies with design) | -260°C to +260°C / -436°F to +500°F | Strong Acids, Caustics, Solvents, Ultra-Pure Media | USP Class VI, FDA 21 CFR 177.1550 |
| KS-SW-304/Graph | Spiral Wound (304 SS/Graphite) | Standard: 4.5mm / 0.177" | Class 150 to 2500 (ASME B16.20/API 601) | -240°C to +540°C / -400°F to +1004°F | Refinery Streams, High-Pressure Steam, Process Gas | ASME B16.20, API 601, EN 1514 |
Beyond material, a successful gasket installation depends on precise specification. Kaxite Seals engineers consider the following matrix for every application.
| Selection Factor | Considerations | Kaxite Seals Guidance |
|---|---|---|
| Flange Type & Surface Finish | Raised face (RF), flat face (FF), ring-type joint (RTJ). Surface roughness (Ra value in microns). | Softer gaskets (e.g., NAO) suit smoother finishes. Harder gaskets (semi-metallic) require serrated finishes. We provide Ra compatibility charts. |
| Bolt Load & Gasket Stress | Available bolt torque, flange rating (Class 150, 300, etc.), required sealing stress (y-value) and maintenance factor (m). | Our datasheets list minimum seating stress (y) and gasket factor (m) per ASME PCC-1 guidelines for accurate bolt load calculation. |
| Media & Permeability | Chemical composition, phase (liquid/gas), viscosity, and potential for thermal cycling. | PTFE and graphite offer low permeability to gases. We cross-reference chemical resistance with our proprietary database for 1000+ media. |
| Thermal & Pressure Cycling | Frequency and magnitude of temperature and pressure changes during operation. | Expanded graphite and spiral wound gaskets from Kaxite Seals exhibit excellent recovery and creep relaxation resistance under cycling conditions. |
| Regulatory & Industry Standards | FDA, USP Class VI, NSF, WRAS, ATEX, NORSOK, TA-Luft. | Kaxite Seals maintains comprehensive certifications. Products are traceable with mill test reports (MTRs) and material certificates. |
Q: How do I determine the correct gasket thickness for my application?
A: Gasket thickness is a critical design choice. Thinner gaskets (e.g., 1/32" or 0.8mm) offer better resistance to creep and high bolt stress but require very flat flanges. Thicker gaskets (1/16" or 1.5mm and above) compensate for flange misalignment, warpage, and surface irregularities better. For dynamic conditions with thermal cycling, a thicker gasket can absorb more movement. Kaxite Seals technical support can perform a flange condition analysis to recommend the optimal thickness, balancing sealability, bolt load, and flange condition.
Q: What is the main difference between Compressed Non-Asbestos (CNA) and Expanded Graphite gaskets?
A: While both are used for elevated temperatures, their base materials and behaviors differ fundamentally. CNA gaskets are composite sheets of organic fibers and elastomers, offering good mechanical strength and resilience for a broad range of industrial fluids. Expanded Graphite gaskets are made from exfoliated pure graphite, providing exceptional thermal conductivity, natural lubricity, and superior sealability at both high and cryogenic temperatures. Graphite is also more chemically inert to many media but can be oxidized in strong oxidizing atmospheres above 400°C without proper inhibitors. Kaxite Seals formulates proprietary grades to mitigate this.
Q: Can I reuse a gasket after disassembling a flange connection?
A: As a universal rule, gaskets should never be reused. Once compressed during installation, a gasket undergoes plastic and elastic deformation to conform to the flange surfaces. Upon removal, its internal structure is permanently altered—the initial seating stress is lost, and compression set has occurred. Reusing it will almost certainly lead to a leak path. Kaxite Seals always recommends using a new, certified gasket for every reassembly to ensure a reliable, leak-free seal and maintain system safety.
Q: How does flange surface finish impact gasket selection and performance?
A: Flange surface finish (measured in Ra, microinches or microns) is paramount. A finish that is too smooth (e.g., a mirror polish) may not provide enough "bite" for the gasket, leading to slippage under pressure. A finish that is too rough can cause excessive gasket wear, embedding, and difficulty in achieving a seal. General guidelines: Soft gaskets (rubber, NAO) perform best on smoother finishes (Ra 125-250 µin). Harder, semi-metallic gaskets require serrated finishes (Ra 250-500 µin) to prevent blowout. Kaxite Seals provides detailed compatibility matrices matching our gasket materials to ideal surface roughness values.
Q: What are spiral wound gaskets, and when should they be used?
A: Spiral wound gaskets are semi-metallic gaskets constructed by winding a pre-formed metal strip (e.g., 304 stainless steel) and a soft filler material (e.g., graphite, PTFE) in a V-shape around a center ring. They are the industry standard for high-pressure, high-temperature applications in oil & gas, chemical, and power plants. Their design allows for excellent resilience and recovery under thermal cycling and high internal pressure. They are used with raised face flanges and require specific seating stress. Kaxite Seals manufactures spiral wound gaskets to ASME B16.20 and API 601 standards, offering a wide range of metal/filler combinations for precise service matching.
Q: Are PTFE gaskets suitable for all chemical applications?
A: PTFE is renowned for its near-universal chemical resistance, being inert to virtually all industrial chemicals, acids, and solvents. However, there are important exceptions. Molten alkali metals (e.g., sodium), certain fluorine compounds, and some halogenated organics at high temperatures and pressures can affect PTFE. Furthermore, PTFE is subject to cold flow (creep) under sustained load. For such demanding applications, Kaxite Seals offers filled PTFE compounds (with glass, carbon, or bronze) to improve creep resistance or recommends alternative materials like expanded graphite with appropriate chemical inhibitors.
