NONMETALLIC FLAT RING GASKET DIMENSIONS FOR CLASS 250 CAST IRON FLANGES


Nonmetallic flat ring gasket dimensions for ASME/ANSI B16.1 Class 250 cast iron pipe flanges and flanged fittings per ASME B16.21.


Flat Ring Gasket

Flat Ring Gasket Dimensions for Class 250 Cast Iron Pipe Flanges (inches)
NPS Gasket ID Gasket OD
1 1.31 2.88
1 1/4 1.66 3.25
1 1/2 1.91 3.75
2 2.38 4.38
2 1/2 2.88 5.12
3 3.50 5.88
3 1/2 4.00 6.50
4 4.50 7.12
5 5.56 8.50
6 6.62 9.88
8 8.62 12.12
10 10.75 14.25
12 12.75 16.62
14 14.00 19.12
16 16.00 21.25
18 18.00 23.50
20 20.00 25.75
24 24.00 30.50
30 30.00 37.50
36 36.00 44.00
42 42.00 50.75
48 48.00 58.75

Notes:

NPS - Nominal Pipe Size, OD - Outer Diameter, ID - Inner Diameter


Reference::

  • ASME B16.21-1992, Nonmetallic Flat Gaskets for Pipe Flanges