Spiral Wound Gaskets

A spiral wound gasket is a commonly used metallic gasket often found in industrial plants.  These gaskets are designed to withstand high temperatures and pressures, preventing leaks throughout their intended lifespan.

A spiral wound gasket consists of three elements:

  1. Outer ringMade of carbon steel, this outer ring is sometimes called the centering ring or guide ring. It’s used to center the gasket when you insert it into a bolted flange joint.
  2. Inner ringThe inner ring is pivotal for the gasket because it prevents windings from buckling inside the pipe. When a gasket buckles, parts of it gets sucked into the pipe. From there, pieces of the gasket will typically flow through the pipeline until they get caught on something. Often, they’ll get wrapped around rotating equipment like a pump. The mess that results is known as a “bird’s nest.” Inner rings help to avoid this problem.
  3. Sealing elementThe sealing element creates the seal that prevents leaks. A sealing element encompasses both windings and filler material. Most spiral wound gaskets in oil and gas refineries will use a flexible graphite filler material rated for high temperatures. A flexible graphite filler also allows the gasket to be more tolerant of flange distortion and joint misalignment. Polytetrafluoroethylene (PTFE) is another common filler material, however PTFE is not rated for high-temperature applications. Most winding materials in refineries will be stainless steel and Monel.

Spiral Wound Gasket Specifications and Color Chart

Spiral Wound Gasket Specifications and Color Chart

Colors play an important role on spiral wound gaskets. The color of the outside rim, and the color of the stripe along the rim, both are important indicators of the material within the gasket.

  1. Outside rim colors indicate the gasket’s windings materials
  2. Rim stripe colors tell you the gasket’s filler materials