Material Spotlight Series: Spiral Wound Gaskets
Posted on 10/23/24
What is a Spiral Wound Gasket?
A spiral wound gasket (SWG) is an engineered sealing solution designed for a wide range of industrial applications, offering reliable performance in various challenging environments.
The Durlon® Spiral Wound Gasket is manufactured using an alternating combination of a preformed engineered metal strip and a more compressible filler material, such as graphite, ETG, or PTFE. This design creates an exceptional seal when compressed, making it suitable for both high-pressure and high-temperature applications.
The unique shape of the metal strip acts as a spring under load, providing a resilient seal under varying conditions. The choice of strip metallurgy and filler material can be customized to meet specific sealing requirements across different industries.
Durlon® Spiral Wound Gasket Styles
Gasket Resources Inc. offers three styles of Durlon® spiral wound gaskets, each designed to cater to specific sealing needs:
- Style D: Composed solely of a sealing element made of metal strip and filler material, ideal for use in tongue & groove or male & female flanges. An inner ring (Style DI) is available for added strength and support in more demanding applications.
- Style DR: Consists of a sealing element combined with a centering ring, which reinforces the gasket and acts as a compression stop. The centering ring also helps to accurately position the gasket on a flange face. This style is typically used with raised face and full-face flanges and offers enhanced corrosion resistance through its epoxy-coated centering ring.
- Style DRI: Comprises a sealing element, a centering ring, and an inner ring. The inner ring improves the gasket’s radial strength, protects against erosion and inward buckling, and is mandatory for specific applications. Per ASME B16.20-2023, inner rings are required for:
- All spiral-wound gaskets with PTFE filler material.
- Flexible graphite-filled spiral-wound gaskets, unless specified otherwise.
- NPS 24 and larger in Class 900, NPS 12 and larger in Class 1500, and NPS 4 and larger in Class 2500.
Advantages of Using Durlon® Spiral Wound Gaskets
Durlon® spiral wound gaskets offer several key benefits over conventional gaskets due to their precise manufacturing and design:
- Lower Stress Sealing: They achieve effective sealing at lower bolt loads, reducing the need for high torque applications.
- Superior Performance Under Low Bolt Stress: These gaskets create an initial seal with very low seating stress, ensuring a tight and reliable seal.
- Enhanced Durability and Resilience: Durlon® gaskets exhibit high mechanical durability and resiliency under fluctuating pressures and temperatures.
- Corrosion Resistance: The epoxy-coated centering rings in DR and DRI styles provide excellent protection against atmospheric corrosion.
- Extended Gasket Life: Inner rings in the DRI style enhance radial strength, protect against erosion, and prevent inward buckling, ensuring long-lasting performance.
Common Applications
Durlon® spiral wound gaskets are ideal for various applications, including:
- Flanged joints
- Heat exchangers
- Boiler handholes and manholes
- Valve bonnets
They are particularly suited for high-pressure and high-temperature applications, especially where corrosive and toxic substances are involved. Durlon® spiral wound gaskets are a versatile choice for industries such as oil & gas, petrochemical, power generation, chemical processing, mining, food & beverage, pulp & paper, and heavy industrial.
For more detailed information on Durlon® SWGs, download a free copy of the Durlon® Spiral Wound Gasket Data Sheet. To learn more about our other products, download our product catalog or contact us today.