Composite Flat Gaskets

Composite flat gaskets are engineered sealing solutions made from two or more different materials bonded or combined together. This design strategy leverages the best properties of each component—typically a resilient core combined with a softer, conformable facing—to achieve superior sealing performance in demanding applications where single-material gaskets fall short.
Key Features and Benefits
Optimized Performance: The multi-material design allows for balancing conflicting requirements, such as high mechanical strength with low seating stress (easy sealing).
Superior Sealing: Facings often feature non-stick or low-friction materials (like PTFE or graphite) that conform easily to flange imperfections, creating a tight seal with less bolting force.
High Strength and Blowout Resistance: Strong core materials like metal ensure structural integrity and prevent the gasket from blowing out under high pressures or temperatures.
Chemical and Temperature Resistance: Composites can be tailored to resist specific aggressive chemicals and operate across wider temperature and pressure ranges than many homogeneous materials.
Versatility: They are available in many configurations to suit a wide range of industrial requirements, from standard piping flanges to intricate heat exchanger applications.
Common Types and Construction
The construction of composite gaskets varies significantly based on the intended application:
Metal-Jacketed Gaskets: A soft filler (graphite, ceramic fiber, or PTFE) is enveloped by a thin metal shell (stainless steel, copper, etc.).
Use: High-pressure and high-temperature applications, such as heat exchangers, engine exhausts, and power generation where resistance to media is required.
Spiro-wound Gaskets (Spiral Wound): A V-shaped metal winding (providing strength and resilience) is wrapped with a soft filler material (like graphite or PTFE) in alternating layers.
Use: Critical applications in refineries, chemical processing, and power generation due to exceptional resilience and blowout resistance under cyclic pressures and temperatures.
Metal-Polymer Composite Gaskets: These combine a metal base with a self-lubricating polymer liner.
Use: High-load plain bearing applications (not typically used as a flange gasket) where durability and self-lubrication are needed.
Graphite-Reinforced Gaskets: Flexible graphite sheets reinforced with a metal insert (e.g., stainless steel foil or mesh).
Use: High-temperature and fire-safe applications where superior chemical resistance and sealability are required, prevalent in the chemical and petrochemical industries.
Applications
Composite flat gaskets are widely used in demanding industrial environments where performance and reliability are critical:
Oil and Gas: In refineries, pipelines, and offshore platforms due to high pressure, temperature, and chemical resistance.
Chemical Processing: For sealing flanges in piping systems and reactors handling aggressive acids, alkalis, and solvents.
Power Generation: Used in boilers, steam lines, and turbines that operate under extreme heat and pressure.
Automotive and Aerospace: In engine components and exhaust systems that require high-temperature tolerance and robust sealing.