Large Size Spiral Wound Gasket Dimensions Rating 900# Series B

Dimensions of Large Size Spiral Wound Gaskets of Rating 900# used with Large Size Raised Face flanges ASME B16.47 Series B


150# | 300# | 400# | 600# | 900#

Class 900 NPS 26″ – 60″
NPSInner Ring Sealing ElementOuter Ring
Inside (d1) Inside (d2)Outside (d3)Outside (d4)
Dia.Dia.mmDia.mmDia.mm
26666.8692.2749.3838.2
28717.6743.0800.1901.7
30781.1806.5857.3958.9
32838.2863.6914.41016.0
34895.4920.8971.61073.2
36920.8946.2997.01124.0
381009.71035.11085.91200.2
401060.51098.61149.41251.0
421111.31149.41200.21301.8
441155.71206.51257.31368.6
461219.21270.01320.81435.1
481270.01320.81371.61485.9

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General notes:

  1. Dimensions are in millimeters unless otherwise indicated.
  2. Image shows a Spiral Wound gasket with Inner – and Outer ring.
  3. d1 = Inside diameter when Inner ring is used.
  4. d2 = Inside diameter sealing element when no Inner ring is used.
  5. d3 = Outside diameter of sealing element.
  6. d4 = Outside diameter of Outer ring.
  7. Thickness of inner and outer ring: 2.97 mm – 3.33 mm.
  8. Thickness sealing element: 4.45 mm.
  9. Tolerance Outside diameter for NPS 1/2 through NPS 8 is ± 0.8 mm; for NPS 10 trough NPS 24 tolerance is + 1.5 mm – 0.8 mm.
  10. ASME B16.20 does not covers class 400 flanges up to NPS 3 and class 900 flanges up to NPS 2½.
  11. There are no class 400 flanges NPS 1/2 thru NPS 3 (use Class 600), class 900 flanges NPS 1/2 thru NPS 2½ (use Class 1500), or class 2500 flanges NPS 14 or larger.
  12. The inner ring inside diameters shown for NPS 1¼ thru 2½ in class 1500 and 2500 will produce inner ring widths of 0.12 inches, a practical minimum for production purposes.
  13. ASME B16.20 which covers spiral wound gaskets requires the use of solid metal inner rings in: Pressure Class 900, nominal pipe sizes 24 and larger, Pressure Class 1500 from nominal pipe sizes 12 and larger, Pressure Class 2500 from nominal pipe sizes 4 and larger and all PTFE filled gaskets.

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