Spiral Wound ANSI Class 900 Gasket, B16.20 (in)

Dimensions to ASME B16.20 - Metallic Gaskets for Pipe Flanges: Ring-Joint, Spiral-Wound, and Jacketed
Inner rings are recommended for all graphite filled gaskets, required for all PTFE filled gaskets.
The gasket outside diameter tolerance for NPS 1/2" through NPS 8" is ±0.03"; for NPS 10" through NPS 24", +0.06", –0.03".
The gasket inside diameter tolerance for NPS 1/2" through NPS 8" is ±0.016"; for NPS 10" through NPS 24", ±0.03".
The centering ring outside diameter tolerance is ±0.03".
(*) There are no Class 900 flanges in NPS 1/2" through NPS 2 1/2" (use Class 1500), or Class 2500 flanges NPS 14" and larger.
ASME B16.20 does not include gaskets with no internal ring dimensions for NPS 1/4" or 3 1/2" and Class 900 flanges up to NPS 2 1/2".

Pipe Size (NPS)	Inner Ring Inside Diameter A	Sealing Element Inside Diameter B	Sealing Element Outside Diameter C	Outer Ring Outside Diameter D
1/2 (*)	—	0.75	1.25	2.50
3/4 (*)	—	1.00	1.56	2.75
1 (*)	—	1.25	1.88	3.13
1 1/4 (*)	—	1.56	2.38	3.50
1 1/2 (*)	—	1.88	2.75	3.88
2 (*)	—	2.31	3.38	5.63
2 1/2 (*)	—	2.75	3.88	6.50
3	3.10	3.75	4.75	6.63
3 1/2	—	4.13	5.25	7.50
4	4.04	4.75	5.88	8.13
5	5.05	5.81	7.00	9.75
6	6.10	6.88	8.25	11.38
8	7.75	8.75	10.13	14.13
10	9.69	10.88	12.25	17.13
12	11.50	12.75	14.50	19.63
14	12.63	14.00	15.75	20.50
16	14.75	16.25	18.00	22.63
18	16.75	18.25	20.50	25.13
20	19.00	20.50	22.50	27.50
24	23.25	24.75	26.75	33.00