In the demanding world of industrial sealing, reliability is non-negotiable. Spiral wound gaskets stand as a cornerstone technology for creating leak-proof seals in high-pressure and high-temperature applications. Engineered with precision, these gaskets are the go-to solution for flanged connections in pipelines, pressure vessels, heat exchangers, and valves across industries such as oil and gas, petrochemical, power generation, and refining. Their unique construction allows them to withstand extreme conditions while maintaining a tight seal, preventing costly leaks, ensuring operational safety, and minimizing environmental impact. At Kaxite, we leverage decades of engineering expertise to produce spiral wound gaskets that meet and exceed the most rigorous international standards, providing our clients with unparalleled performance and peace of mind.
A spiral wound gasket is a semi-metallic sealing element manufactured by winding a pre-formed metal strip and a filler material (typically non-metallic) in a spiral (V-shaped) formation around a central metal ring. This combination is then compressed to a specified density. The outer ring, known as a centering ring, guides the gasket into the flange and provides radial stability. The inner ring, when used, prevents inward buckling of the spiral wound element and protects it from corrosive media. This composite structure harnesses the resilience of the filler material and the strength and spring-like recovery of the metal winding, creating a seal that adapts to flange rotation, bolt stress relaxation, and thermal cycling.
Kaxite spiral wound gaskets are manufactured to precise specifications to ensure optimal performance. Understanding these parameters is crucial for correct selection and application.
The performance of a spiral wound gasket is directly determined by its material composition. Kaxite offers a wide range of material combinations to suit various media, temperatures, and pressures.
Kaxite gaskets are designed in compliance with global dimensional and quality standards.
| Parameter | Description | Kaxite Standards & Options |
|---|---|---|
| Size Range | Nominal Pipe Size (NPS) or flange inner/outer diameter. | NPS ½” to 120” and larger. Custom sizes available. |
| Pressure Class | Designed for specific flange pressure ratings (e.g., ASME B16.5, B16.47). | 150#, 300#, 600#, 900#, 1500#, 2500#. Custom designs for higher pressures. |
| Temperature Range | Operating temperature limits depend on material combination. | -240°C to +1000°C (-400°F to +1832°F) based on filler/metal selection. |
| Density | Controlled during winding to ensure consistent sealing force and recovery. | Manufactured to optimal density profiles for maximum performance. |
| Standards Compliance | Adherence to international manufacturing and testing standards. | ASME B16.20, B16.21, API 6A, DIN EN 1514, ISO 7483, GOST, and customer-specific standards. |
| Gasket Styles | Configuration based on flange type and application needs. | Style R (with outer ring), Style N (without outer ring), Style B (with inner & outer ring), Style C (jacketed). |
Kaxite engineers each spiral wound gasket with features that deliver superior performance:
Q: What is the main difference between a spiral wound gasket with and without an inner ring?
A: The inner ring (also called an inner guard ring) serves multiple critical functions. It provides radial support to the spiral wound element, preventing it from buckling inward under high pressure, which could cause seal failure. It also acts as a barrier, protecting the soft filler material from being eroded or chemically attacked by the internal process fluid. For applications with high internal turbulence, corrosive media, or high pressure, an inner ring is strongly recommended. Kaxite can advise on the necessity based on your specific service conditions.
Q: How do I select the right metal and filler material for my application?
A: Material selection is a three-fold process considering the process media, temperature, and pressure. First, identify the chemical compatibility of potential materials with your process fluid using corrosion charts. Second, ensure the temperature rating of the filler (e.g., graphite for very high heat, PTFE for moderate temperatures) exceeds your maximum operating temperature. Finally, the metal winding must have sufficient mechanical strength for the flange pressure class and also resist corrosion. Kaxite's technical team provides comprehensive selection support using this methodology.
Q: Can spiral wound gaskets be reused?
A: It is generally not recommended to reuse a spiral wound gasket. During initial installation and operation, the gasket undergoes permanent compression set and conforms to the specific imperfections of the flange faces. Reusing it on a different sealing surface or even the same one after disassembly can compromise its ability to create a reliable seal, leading to potential leaks. For safety and integrity, always install a new Kaxite spiral wound gasket during reassembly.
Q: What is the proper installation torque for a spiral wound gasket?
A: There is no single "correct" torque value; it depends on the gasket size, pressure class, bolt size and grade, and flange material. The correct procedure is to follow a controlled bolt tightening sequence (e.g., criss-cross pattern) to achieve a target bolt stress or gasket seating stress as specified in standards like ASME PCC-1. This ensures even compression across the flange. Kaxite gaskets are supplied with recommended seating stress values based on their style and materials, which should be used to calculate the appropriate bolt torque.
Q: How does a spiral wound gasket handle thermal cycling better than other gaskets?
A: The inherent spring-like characteristic of the wound metal strip is key. When a flange assembly heats up, the bolts, flanges, and pipe expand at different rates, which can reduce the clamping force on the gasket (bolt load loss). The stored energy in the compressed spiral winding allows it to expand and maintain contact with the flange faces, compensating for this thermal movement. Solid metal gaskets lack this resilience, while soft gaskets can experience excessive creep under constant heat.
Q: Are Kaxite spiral wound gaskets traceable?
A> Yes, Kaxite implements full material traceability and quality documentation. Each batch of raw material is logged, and finished gaskets can be supplied with a material test certificate (MTC) or certificate of conformity (COC) as required. For critical applications, we provide detailed traceability documentation, ensuring compliance with industry QA/QC standards like ISO 9001 and specific customer material verification protocols.
Q: What flange surface finish is required for spiral wound gaskets?
A> Spiral wound gaskets typically require a serrated flange finish to "bite" into and create an effective seal. The recommended surface finish is usually between 125 and 250 microinches Ra (3.2 to 6.3 micrometers Ra), often with concentric or spiral serrations. A smooth, polished finish is not suitable as it may not provide enough friction, potentially allowing the gasket to be extruded. Kaxite can provide specific recommendations based on the gasket style and pressure class.
The versatility of spiral wound gaskets makes them indispensable in numerous high-performance sealing scenarios. Common applications include:
For each application, Kaxite analyzes the specific operating envelope to recommend the optimal gasket configuration, ensuring longevity and leak-free operation.
