Spiral Wound ANSI Class 400 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 internal ring gaskets for Class 400 flanges in NPS 1/2" through NPS 3" (use Class 600).
ASME B16.20 does not include gaskets with no internal ring dimensions for NPS 1/4" or 3 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	2.13
3/4 (*)	—	1.00	1.56	2.63
1 (*)	—	1.25	1.88	2.88
1 1/4 (*)	—	1.88	2.38	3.25
1 1/2 (*)	—	2.13	2.75	3.75
2 (*)	—	2.75	3.38	4.38
2 1/2 (*)	—	3.25	3.88	5.13
3 (*)	—	4.00	4.75	5.88
3 1/2	—	4.13	5.25	6.38
4	4.04	4.75	5.88	7.00
5	5.05	5.81	7.00	8.38
6	6.10	6.88	8.25	9.75
8	8.10	8.88	10.38	12.00
10	10.05	10.81	12.50	14.13
12	12.10	12.88	14.75	16.50
14	13.50	14.25	16.00	19.00
16	15.35	16.25	18.25	21.13
18	17.25	18.50	20.75	23.38
20	19.25	20.50	22.75	25.50
24	23.25	24.75	27.00	30.25