Spiral Wound Gasket Dimensions – Class 150 to Class 2500

During the inspection of Spiral Wound Gasket Dimensions, you should check for

Diameter – Inside / Outside
Thickness
Centering ring dimensions
Permissible Variations of Gasket dimensions are covered in
ASME B16.20– that covered dimensions for Metallic Gaskets such as Ring-Joint, Spiral-Wound, and Jacketed

Spiral Wound Gasket Dimensions Tables

(NPS)	Classes 150, 300	Class 150	Class 300	Class 150	Class 300
Inch	mm	Inside Diameter		Outside Diameter
1⁄2	31.8	19.1	19.1	47.8	54.1
3⁄4	39.6	25.4	25.4	57.2	66.8
1	47.8	31.8	31.8	66.8	73.2
1 1⁄4	60.5	47.8	47.8	76.2	82.6
1 1⁄2	69.9	54.1	54.1	85.9	95.3
2	85.9	69.9	69.9	104.9	111.3
2 1⁄2	98.6	82.6	82.6	124	130.3
3	120.7	101.6	101.6	136.7	149.4
4	149.4	127	127	174.8	181.1
5	177.8	155.7	155.7	196.9	215.9
6	209.6	182.6	182.6	222.3	251
8	263.7	233.4	233.4	279.4	308.1
10	317.5	287.3	287.3	339.9	362
12	374.7	339.9	339.9	409.7	422.4
14	406.4	371.6	371.6	450.9	485.9
16	463.6	422.4	422.4	514.4	539.8
18	527.1	474.7	474.7	549.4	596.9
20	577.9	525.5	525.5	606.6	654.1
24	685.8	628.7	628.7	717.6	774.7
(NPS)	Classes 400, 600	Class 400	Class 600	Class 400	Class 600
Inch	mm	Inside Diameter		Outside Diameter
1⁄2	31.8	.	19.1	.	54.1
3⁄4	39.6	.	25.4	.	66.8
1	47.8	.	31.8	.	73.2
1 1⁄4	60.5	.	47.8	.	82.6
1 1⁄2	69.9	.	54.1	.	95.3
2	85.9	.	69.9	.	111.3
2 1⁄2	98.6	.	82.6	.	130.3
3	120.7	.	101.6	.	149.4
4	149.4	120.7	120.7	177.8	193.8
5	177.8	147.6	147.6	212.9	241.3
6	209.6	174.8	174.8	247.7	266.7
8	263.7	225.6	225.6	304.8	320.8
10	317.5	274.6	274.6	358.9	400.1
12	374.7	327.2	327.2	419.1	457.2
14	406.4	362	362	482.6	492.3
16	463.6	412.8	412.8	536.7	565.2
18	527.1	469.9	469.9	593.9	612.9
20	577.9	520.7	520.7	647.7	682.8
24	685.8	628.7	628.7	768.4	790.7
(NPS)	Classes 900, 1500	Class 900	Class 1500	Class 900	Class 1500
Inch	mm	Inside Diameter		Outside Diameter
1⁄2	31.8	.	19.1	.	63.5
3⁄4	39.6	.	25.4	.	69.9
1	47.8	.	31.8	.	79.5
1 1⁄4	60.5	.	39.6	.	88.9
1 1⁄2	69.9	.	47.8	.	98.6
2	85.9	.	58.7	.	143
2 1⁄2	98.6	.	69.9	.	165.1
3	120.7	95.3	92.2	168.4	174.8
4	149.4	120.7	117.6	206.5	209.6
5	177.8	147.6	143	247.7	254
6	209.6	174.8	171.5	289.1	282.7
8	263.7	222.3	215.9	358.9	352.6
10	317.5	276.4	266.7	435.1	435.1
12	374.7	323.9	323.9	498.6	520.7
14	406.4	355.6	362	520.7	577.9
16	463.6	412.8	406.4	574.8	641.4
18	527.1	463.6	463.6	638.3	704.9
20	577.9	520.7	514.4	698.5	755.7
24	685.8	628.7	616	838.2	901.7
(NPS)	Class 2500	Class 2500		Class 2500
Inch	mm	Inside Diameter		Outside Diameter
1⁄2	31.8	19.1		69.9
3⁄4	39.6	25.4		76.2
1	47.8	31.8		85.9
1 1⁄4	60.5	39.6		104.9
1 1⁄2	69.9	47.8		117.6
2	85.9	58.7		146.1
2 1⁄2	98.6	69.9		168.4
3	120.7	92.2		196.9
4	149.4	117.6		235
5	177.8	143		279.4
6	209.6	171.5		317.5
8	263.7	215.9		387.4
10	317.5	270		476.3
12	374.7	317.5		549.4
14	406.4	.		.
16	463.6	.		.
18	527.1	.		.
20	577.9	.		.
24	685.8	.		.

All dimensions are in millimeters.

The gasket thickness tolerance is ±0.13 mm measured across the metallic portion of the gasket, not including the filler, which may protrude slightly beyond the metal.

The gasket outside diameter tolerance for NPS 1⁄2 through NPS 8 is ±0.8 mm; for NPS 10 through NPS 24, +1.5 mm, −0.8 mm.

The gasket inside diameter tolerance for NPS 1⁄2 through NPS 8 is ±0.4 mm; for NPS 10 through NPS 24, ±0.8 mm.

The centering ring outside diameter tolerance is ±0.8 mm.