In demanding industrial sealing applications, standard gaskets often reach their performance limits when faced with extreme pressures, temperatures, or aggressive media. This is where the superior engineering of Double Jacketed Gaskets becomes critical. Unlike conventional gasket designs, a double jacket gasket features a robust, soft filler material—typically a resilient graphite or PTFE sheet—that is completely enclosed within a two-piece metallic jacket. This innovative construction combines the compressive sealing force of the metal jacket with the exceptional conformability and chemical resistance of the filler, creating a seal that is both highly resilient and incredibly robust. Engineered for the most severe service conditions, these gaskets are the go-to solution for preventing leaks in critical pipeline flanges, heat exchangers, reactors, and pressure vessel connections across industries like oil & gas, chemical processing, power generation, and pharmaceuticals.
At Kaxite, we specialize in the design and manufacture of high-performance sealing solutions. Our Double Jacketed Gaskets are not just products; they are precision-engineered components built to ensure operational safety, environmental compliance, and long-term reliability for your most challenging applications.
Selecting the correct double jacket gasket requires careful consideration of the operating environment. The table below outlines the standard specifications and material combinations offered by Kaxite. Custom configurations are available to meet unique application requirements.
| Parameter | Specifications & Options | Notes / Typical Applications |
|---|---|---|
| Jacket Material |
|
Selected based on corrosion resistance requirements, temperature, and cost. 316L is common for general chemical service. |
| Filler Material |
|
Graphite offers excellent temperature range. PTFE is for corrosive chemicals at lower temperatures. Selection depends on media compatibility. |
| Standard Sizes | DN 15 to DN 1200 (1/2" to 48") and larger | Manufactured to ASME B16.20, EN 1514, and other international standards. Custom sizes available. |
| Pressure Rating | Up to Class 2500 (PN 420) | Capable of sealing in high-pressure systems like wellheads, reactor outlets, and steam lines. |
| Temperature Range |
|
Specific limits depend on the exact material combination. Consult Kaxite engineering for critical applications. |
| Facing / Surface Finish | Standard is serrated concentric or phonographic finish. Smooth finish available. | The serrated finish bites into the filler for superior grip and prevents filler extrusion. |
Q: What is the primary advantage of a double jacket gasket over a spiral wound gasket?
A: While both are used for high-pressure services, the key difference lies in construction and sealing mechanism. A spiral wound gasket has a "V"-shaped metal winding that acts like a spring. A double jacket gasket has a solid, pre-compressed soft filler contained within a rigid metal envelope. This makes Double Jacketed Gaskets generally more resistant to blow-out under severe pressure spikes and thermal cycling, and they often provide a tighter initial seal with lower required bolt load.
Q: Can Double Jacketed Gaskets be used in heat exchangers?
A: Yes, they are an excellent choice for heat exchanger applications, especially for channel covers, bonnets, and floating heads. Their ability to handle thermal expansion/contraction cycles and high differential pressures makes them ideal for this service. Kaxite provides gaskets specifically designed for TEMA and other heat exchanger standards.
Q: Are these gaskets suitable for vacuum service?
A: Absolutely. Double Jacketed Gaskets, particularly those with a flexible graphite filler, are highly effective for vacuum applications. The metal jacket provides structural integrity to prevent collapse, while the graphite filler flows to seal micro-leak paths that could compromise vacuum levels.
Q: How do I select the right material combination for my application?
A: Material selection is a three-step process: First, identify the chemical compatibility of the filler with your process fluid (e.g., PTFE for strong acids, graphite for hydrocarbons). Second, select the jacket material to resist corrosion from both the internal fluid and external environment. Third, verify the temperature and pressure ratings of the chosen combination. Kaxite's technical support team can assist with this critical analysis based on your specific operating data.
Q: What is the proper bolt torque procedure for installing a double jacket gasket?
A: Correct installation is paramount. Always follow a cross-pattern bolting sequence (star pattern) in multiple incremental passes (typically 30%, 60%, and 100% of the final target torque). The final torque value should be calculated based on the flange rating, bolt size/grade, and gasket type—using standards like ASME PCC-1. Never use impact wrenches for the final pass. Over-torquing can crush the filler and damage the jacket, while under-torquing will lead to leakage.
Q: How do I identify if a used double jacket gasket can be re-used?
A: Inspect the gasket carefully after disassembly. A reusable gasket will have the metal jacket intact with no severe dents, cracks, or significant corrosion. The filler should not be extruded significantly beyond the jacket edges, and there should be no signs of chemical attack or burning. If the flange faces are in perfect condition and the gasket passes visual inspection, re-use may be possible. When in doubt, replace it with a new Kaxite gasket to ensure reliability.
Q: Why did my Double Jacketed Gaskets fail, showing filler material extruding from the sides?
A: Filler extrusion is typically a sign of one of three issues: 1) Excessive Internal Pressure beyond the gasket's design rating. 2) Insufficient Bolt Load during installation, failing to contain the filler properly. 3) Excessive Flange Rotation or Separation under load, creating a gap. Review the system pressure, ensure proper bolt torque was applied, and check the flange rigidity and alignment.
Q: Can a double jacket gasket seal on less-than-ideal flange surfaces?
A: While they are more forgiving than metal-to-metal seals, Double Jacketed Gaskets still require a reasonably good flange surface to perform optimally. They can accommodate minor scratches, light pitting, or tool marks. However, deep grooves, severe corrosion, or warped flanges will compromise the seal. Flange faces should meet the required surface finish (typically 125-250 µin Ra) and flatness specifications for the pressure class.
Q: What makes Kaxite Double Jacketed Gaskets different from other brands?
A: Kaxite gaskets are distinguished by precision manufacturing. We use high-purity filler materials, precisely formed and annealed metal jackets for consistent hardness, and advanced sealing technologies in the jacket seam to prevent leak paths. Every batch undergoes rigorous quality control for dimensions, material verification, and pressure testing. Furthermore, our engineering team provides direct application support to ensure the gasket is not just a part, but an integral, reliable component of your system.
