DIMENSIONS CHART FOR NONMETALLIC FLAT GASKETS FOR CLASS 300, 400, 600 AND 900 PIPE FLANGES


Flat ring nonmetallic gasket dimensions for Class 300, 400, 600 and 900 pipe flanges and flanged fittings per ASME B16.21.


Flat Ring Gasket
Flat Ring Gasket Dimensions for Class 300, 400, 600 and 900 Pipe Flanges (inches)
NPS Gasket ID Gasket OD
Class 300 Class 400 Class 600 Class 900
1/2 0.84 2.12 2.12 2.12 2.50
3/4 1.06 2.62 2.62 2.62 2.75
1 1.31 2.88 2.88 2.88 3.12
1 1/4 1.66 3.25 3.25 3.25 3.50
1 1/2 1.91 3.75 3.75 3.75 3.88
2 2.38 4.38 4.38 4.38 5.62
2 1/2 2.88 5.12 5.12 5.12 6.50
3 3.50 5.88 5.88 5.88 6.62
3 1/2 4.00 6.50 6.38 6.38 -
4 4.50 7.12 7.00 7.62 8.12
5 5.56 8.50 8.38 9.50 9.75
6 6.62 9.88 9.75 10.50 11.38
8 8.62 12.12 12.00 12.62 14.12
10 10.75 14.25 14.12 15.75 17.12
12 12.75 16.62 16.50 18.00 19.62
14 14.00 19.12 19.00 19.38 20.50
16 16.00 21.25 21.12 22.25 22.62
18 18.00 23.50 23.38 24.12 25.12
20 20.00 25.75 25.50 26.88 27.50
24 24.00 30.50 30.25 31.12 33.00

Notes:

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

Reference::

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