DIMENSIONS CHART FOR NONMETALLIC FLAT GASKETS FOR CLASS 150 PIPE FLANGES

Flat ring and full face nonmetallic gasket dimensions for Class 150 pipe flanges and flanged fittings per ASME B16.21.

Flat Ring Gasket Dimensions for Class 150 Pipe Flanges (inches)
NPS	Gasket ID	Gasket OD
1/2	0.84	1.88
3/4	1.06	2.25
1	1.31	2.62
1 1/4	1.66	3.00
1 1/2	1.91	3.38
2	2.38	4.12
2 1/2	2.88	4.88
3	3.50	5.38
3 1/2	4.00	6.38
4	4.50	6.88
5	5.56	7.75
6	6.62	8.75
8	8.62	11.00
10	10.75	13.88
12	12.75	16.13
14	14.00	17.75
16	16.00	20.25
18	18.00	21.62
20	20.00	23.88
24	24.00	28.25

Notes:

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

Full Face Gasket Dimensions for Class 150 Pipe Flanges (inches)
NPS	ID	OD	Number of Holes	Hole Diameter	Bolt Circle Dia.
1/2	0.84	3.50	4	0.62	2.38
3/4	1.06	3.88	4	0.62	2.75
1	1.31	4.25	4	0.62	3.12
1 1/4	1.66	4.63	4	0.62	3.50
1 1/2	1.91	5.00	4	0.62	3.88
2	2.38	6.00	4	0.75	4.75
2 1/2	2.88	7.00	4	0.75	5.50
3	3.50	7.50	4	0.75	6.00
3 1/2	4.00	8.50	8	0.75	7.00
4	4.50	9.00	8	0.75	7.50
5	5.56	10.00	8	0.88	8.50
6	6.62	11.00	8	0.88	9.50
8	8.62	13.50	8	0.88	11.75
10	10.75	16.00	12	1.00	14.25
12	12.75	19.00	12	1.00	17.00
14	14.00	21.00	12	1.12	18.75
16	16.00	23.50	16	1.12	21.25
18	18.00	25.00	16	1.25	22.75
20	20.00	27.50	20	1.25	25.00
24	24.00	32.00	20	1.38	29.50

Notes:

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