Spiral-Wound Gasket Color Code Chart

What it is

A spiral-wound gasket is made of a V-shaped metal strip wound in a spiral with a soft filler between the windings. Most have an outer centering ring that locates the gasket inside the bolts, and many have an inner ring that protects the windings from the bore. ASME B16.20 covers spiral-wound gaskets for ASME flanges. It sets a color code painted on the outer edge of the centering ring: a solid color shows the winding metal, and stripes show the filler.

How to identify

1. Look at the outside edge of the centering ring.
2. Read the solid color for the winding metal.
3. Read the stripe color for the filler.
4. Read the stamp on the centering ring face. It shows the maker, size, class, winding, filler and ring materials.
5. Use the stamp to confirm the colors. The stamp governs.

Winding metal colors (solid)

Filler colors (stripes)

Colors follow the ASME B16.20 scheme as commonly applied. Confirm with the gasket stamp and the current edition of the standard.

Key points

• The winding metal and filler must suit the fluid and temperature. The color code only identifies them.
• The centering ring is often carbon steel even when the winding is stainless. The ring material is stamped.
• Inner rings are needed in some sizes and classes and with PTFE filler. Check B16.20 and the piping spec.
• Spiral-wound gaskets are made to the flange class. A Class 150 gasket does not fit a Class 300 flange of the same size.
• Do not reuse spiral-wound gaskets. They are made to compress once.

Common mistakes

• Reading the stripe color as the winding metal.
• Assuming a yellow ring means the whole gasket is stainless.
• Ordering by size only, without class, winding, filler and inner ring.
• Fitting a gasket made for B16.47 Series A onto a Series B flange.

Governing standards: ASME B16.20 (metallic gaskets for pipe flanges); the piping specification for materials.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.