Dimensions of spiral wound gaskets accoring to ASME B16.20
used with raised face flanges ASME B16.47 series B
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.
- There are no Class 900 flanges NPS 50 and larger.