Dimensions of Spiral Wound Gaskets ASME B16.20
used with Raised Face flanges ASME B16.47 series A
Spiral Wound Gasket

Class 150 | 300 | 400 | 600 | 900

Spiral Wound Gasket

General notes:

  • Dimensions are in millimeters unless otherwise indicated.
  • Image shows a Spiral Wound gasket with Inner - and Outer ring.
  • d1 = Inside diameter when Inner ring is used.
  • d2 = Inside diameter sealing element when no Inner ring is used.
  • d3 = Outside diameter of sealing element.
  • d4 = Outside diameter of Outer ring.
  • The gasket thickness tolerance is ± 0.13 mm measured across the metallic portion of the gasket, not including the filler, which may protrude slightly beyond the metal.
  • The gasket inside diameter tolerance for NPS 26 through NPS 34 is ± 0.8 mm, and the tolerance for NPS 36 through NPS 60 is ± 1.3 mm.
  • The gasket outside diameter tolerance for NPS 26 through NPS 60 is ± 1.5 mm.
  • The centering ring outside diameter tolerance is ± 0.8 mm.
  • The inside diameter tolerance is ± 3.0 mm.
  • Thickness of inner and outer ring: 2.97 mm - 3.33 mm.
  • ASME B16.47 Series A flanges NPS 12 through NPS 24 have the same raised face dimensions as ASME B16.5 flanges.
  • There are no Class 900 flanges NPS 50 and larger.

Marking of Spiral Wound Gaskets

Marking of Spiral Wound Gaskets