Flange Gaskets | ASME B16.20 | ASME B16.21

PM Industries manufactures, supplies, and stocks Flange Gaskets across a full range of types, materials, pressure classes, and pipe sizes. A flange gasket seals the joint between two mating flange faces, preventing leakage of process fluid or gas under operating pressure and temperature. Getting the gasket selection right for the specific service condition is as important as getting the flange rating right. The wrong gasket in a demanding application fails prematurely, and a failed gasket joint causes unplanned downtime, product loss, and safety exposure.

Gasket type and material selection is driven by four factors: the media being contained, the operating temperature, the operating pressure, and the flange face type. Each combination of those factors points to a specific gasket type and material class. Mismatching any one of them shortens gasket service life or causes immediate joint failure.

Gasket types stocked:

Soft gaskets cover lower-pressure general service. Full face gaskets span the entire flange face including the bolt holes and are used with flat face flanges, particularly in cast iron and non-metallic flanged equipment where flange rigidity is limited. Ring gaskets fit within the bolt circle on raised face flanges and are the standard configuration for most carbon and stainless steel piping systems.

Spiral wound gaskets are the standard choice for high-temperature and high-pressure process service in oil and gas, chemical, and power generation applications. A metallic winding strip alternates with a soft filler material, typically graphite or PTFE, to produce a gasket that handles thermal cycling, pressure fluctuation, and flange rotation better than soft gaskets. Available with inner and outer rings to control compression and prevent blowout.

Kammprofile gaskets provide a rigid metal core with serrated grooves, faced with a soft sealing layer of graphite or PTFE. They reseal reliably after pressure cycling and are reusable in many service conditions, which reduces replacement frequency in high-maintenance systems.

Ring type joint gaskets are solid metal rings used in the ring groove of RTJ flanges for high-pressure and sour service applications. Available in oval and octagonal cross-sections in soft iron, low-carbon steel, 316 stainless, and nickel alloy grades to NACE MR0175.

Jacketed gaskets use a soft metal jacket around a compressible filler core, providing both resilience and the chemical resistance of the jacket material. Used in heat exchanger, pressure vessel, and specialized process equipment connections.

Materials available:

Soft gasket materials include natural rubber, neoprene, EPDM, PTFE, compressed non-asbestos fiber (CAF), and flexible graphite, each suited to specific media and temperature ranges. Metal gasket materials include soft iron, low-carbon steel, 304/316 stainless, duplex stainless, Inconel 625, Hastelloy C-276, and other nickel alloys for the most demanding corrosive and high-temperature service.

Gaskets are available to ASME B16.20, ASME B16.21, API 601, and applicable specifications across pressure classes from 150 to 2500 in all standard pipe sizes. Custom sizes and special material grades are available to order. Contact PM Industries for type selection, material recommendations, dimensions, and pricing.

Specification-Slip On Flange

Standards	ANSI/ASME B16.5, B16.48, GOST, DIN, EN-1092, B16.47 Series A & B, AWWA, BS Flanges
JIS Standard	5K, 10K, 16K, 20K, 30K, 40K, 63K
DIN Flanges	DIN 2527, 2627, 2631, 2656, 2576, 2673, 2629, 2628, 2566

Flanges are Available in Following Materials

Stainless Steel	SS 304, 304L, 310, 316L, 317L, 321, 347, 410, 430, 904L
Duplex Steel	UNS S32205, S31803
Super Duplex	UNS S32750, S32760
Carbon Steel	A105, A36, IS 2062, A350 LF2, A694
Alloy Steel	F1, F5, F9, F11, F22, F91
Copper Alloys	Cu-Ni 70/30, 90/10 and other grades
Nickel Alloys	Nickel 200, 201
Inconel	600, 601, 625, 718, 800, 825
Monel	400, K500
Hastelloy	C-22, C-276, C-4
Titanium	Grade 1, 2, 5, 7, 12
Aluminium	6061, 6063, 5083, 7075
Pressure Rating	Class 150 to 2500 LBS
Types	Threaded, Plate, Screwed, Forged
Size Range	1/2" to 48" (DN10–DN5000)
Production Technique	Forged, Machined, Heat Treated
Origin	India / USA / Europe / Japan
Surface Treatment	Zinc Plated, Anti-rust Paint, Galvanized
Test	Spectrograph, X-ray, Ultrasonic, Hydro Testing

Class 150 Slip On Flange Dimensions In Mm

Normal pipe sizes	Inside Diameter	Outside Diameter	Bolt circle	Raised Face (RF)	Raised Face )RF)	H	RF thickness	T1	Flat Face thickness	Bolt Holes	Number of Bolt Holes
3/4	1.09	3.88	2.75	1.69	.063	1.50	.62	.44	.56	.62	4
1	1.36	4.25	3.12	2.00	.063	1.94	.69	.50	.63	.62	4
1-1/4	1.70	4.62	3.50	2.50	.063	2.31	.81	.56	.75	.62	4
6	6.72	11.00	9.50	8.50	.063	7.56	1.56	.94	1.50	.88	8
1-1/2	1.97	5.00	3.88	2.88	.063	2.56	.88	.62	.82	.62	4
2	2.44	6.00	4.75	3.62	.063	3.06	1.00	.69	.94	.75	4
1/2	0.88	3.50	2.38	1.38	.063	1.19	.62	.38	.56	.62	4
2-1/2	2.94	7.00	5.50	4.12	.063	3.56	1.12	.82	1.06	.75	4
3-1/2	4.07	8.50	7.00	5.50	.063	4.81	1.25	.88	1.19	.75	8
4	4.57	9.00	7.50	6.19	.063	5.31	1.31	.88	1.25	.75	8
5	5.66	10.00	8.50	7.31	.063	6.44	1.44	.88	1.38	.88	8
3	3.57	7.50	6.00	5.00	.063	4.25	1.19	.88	1.13	.75	4
8	8.72	13.50	11.75	10.62	.063	9.69	1.75	1.06	1.69	.88	8
10	10.88	16.00	14.25	12.75	.063	12.00	1.94	1.13	1.88	1.00	12
12	12.88	19.00	17.00	15.00	.063	14.38	2.19	1.19	2.13	1.00	12
16	16.16	23.50	21.25	18.50	.063	18.00	2.50	1.38	2.44	1.12	16
18	18.18	25.00	22.75	21.00	.063	19.88	2.69	1.50	2.63	1.25	16
20	20.20	27.50	25.00	23.00	.063	22.00	2.88	1.63	2.83	1.25	20
22	22.22	29.50	27.25	25.25	.063	24.25	3.13	1.75	3.07	1.38	20
14	14.14	21.00	18.75	16.25	.063	15.75	2.25	1.32	2.19	1.12	12
24	24.25	32.00	29.50	27.25	.063	26.12	3.25	1.82	3.19	1.38	20

Ansi 300 Slip On Flange Dimensions

Normal pipe size	Inside Diameter	Outside Diameter	Bolt Circle	Raised Face	Raised Face	H	Raised Face thickness	T1	Flat Face thickness	Bolt holes	Number of Bolt Holes
1-1/4	1.70	5.25	3.88	2.50	.063	2.50	1.06	0.69	1.00	0.75	4
1/2	0.88	3.75	2.62	1.38	.063	1.50	0.88	0.50	0.82	0.62	4
3/4	1.09	4.62	3.25	1.69	.063	1.88	1.00	.056	0.94	0.75	4
1	1.36	4.88	3.50	2.00	.063	2.12	1.06	0.63	1.00	0.75	4
1-1/2	1.95	6.12	4.50	2.88	.063	2.75	1.19	0.75	1.13	0.88	4
3	3.57	8.25	6.62	5.00	.063	4.62	1.69	1.06	1.63	0.88	8
2	2.44	6.50	5.00	3.62	.063	3.31	1.31	0.82	1.25	0.75	8
2-1/2	2.94	7.50	5.88	4.12	.063	3.94	1.50	0.94	1.44	0.88	8
8	8.72	15.00	13.00	10.62	.063	10.25	2.44	1.56	2.38	1.00	12
3-1/2	4.07	9.00	7.25	5.50	.063	5.25	1.75	1.13	1.69	0.88	8
4	4.57	10.00	7.88	6.19	.063	5.75	1.88	1.19	1.82	0.88	8
5	5.66	11.00	9.25	7.31	.063	7.00	2.00	1.32	1.94	0.88	8
6	6.72	12.50	10.62	8.50	.063	8.12	2.06	1.38	2.00	0.88	12
18	18.18	28.00	24.75	21.00	.063	21.00	3.50	2.32	3.44	1.38	24
10	10.88	17.50	15.25	12.75	.063	12.62	2.62	1.82	2.56	1.12	16
12	12.88	20.50	17.75	15.00	.063	14.75	2.88	1.94	2.82	1.25	16
14	14.14	23.00	20.25	16.25	.063	16.75	3.00	2.06	2.94	1.25	20
24	24.25	36.00	32.00	27.25	.063	27.62	4.19	2.69	4.13	1.62	24
16	16.16	25.50	22.50	18.50	.063	19.00	3.25	2.19	3.19	1.38	20
20	20.20	30.50	27.00	23.00	.063	23.12	3.75	2.44	3.69	1.38	24
22	22.22	33.00	29.25	25.25	.063	25.25	4.00	2.57	3.94	1.63	24

Class 600 SORF Flange Dimensions

Normal pipe size	Inside Diameter	Outside Diameter	Bolt circle	Raised Face	Raised Face	H	Raised Face thickness	T1	Flat face thickness	Bolt Hole	Number of Bolt holes
1	1.36	4.88	3.50	2.00	.250	2.12	1.31	0.69	1.06	0.75	4
1/2	0.88	3.75	2.62	1.38	.250	1.50	1.13	0.56	0.88	0.62	4
3/4	1.09	4.62	3.25	1.69	.250	1.88	1.25	0.62	1.00	0.75	4
1-1/4	1.7	5.25	3.88	2.50	.250	2.50	1.37	0.81	1.12	0.75	4
3	3.57	8.25	6.62	5.00	.250	4.62	2.06	1.25	1.81	0.88	8
1-1/2	1.95	6.12	4.50	2.88	.250	2.75	1.50	0.88	1.25	0.88	4
2	2.44	6.50	5.00	3.62	.250	3.31	1.69	1.00	1.44	0.75	8
2-1/2	2.94	7.50	5.88	4.12	.250	3.94	1.87	1.12	1.62	0.88	8
3-1/2	4.07	9.00	7.25	5.50	.250	5.25	2.19	1.38	1.94	1.00	8
8	8.72	16.50	13.75	10.62	.250	10.75	3.25	2.19	3.00	1.25	12
4	4.57	10.75	8.50	6.19	.250	6.00	2.37	1.5	2.12	1.00	8
5	5.66	13.00	10.50	7.31	.250	7.44	2.63	1.75	2.38	1.12	8
6	6.72	14.00	11.50	8.50	.250	8.75	2.87	1.88	2.62	1.12	12
10	10.88	20.00	17.00	12.75	.250	13.5	3.63	2.50	3.38	1.38	16
12	12.88	22.00	19.25	15.00	.250	15.75	3.87	2.62	3.62	1.38	20
14	14.14	23.75	20.75	16.25	.250	17.00	3.94	2.75	3.69	1.50	20
22	22.22	34.25	30.63	25.25	.250	26.25	5.50	3.75	5.25	1.75	24
16	16.16	27.00	23.75	18.50	.250	19.50	4.44	3.00	4.19	1.62	20
24	24.25	37.00	33.00	27.25	.250	28.25	5.75	4.00	5.50	2.00	24
18	18.18	29.25	25.75	21.00	.250	21.50	4.87	3.25	4.62	1.75	20
20	20.20	32.00	28.50	23.00	.250	24.00	5.25	3.50	5.00	1.75	24

ASME B16.5 Class 900 Slip On Flange Dimensions

Normal pipe size	Inside diameter	Outside diameter	Bolt circle	Raised Face	Raised Face	H	Raised Face thickness	T1	Face flat thickness	Bolt hole	Number of bolt holes
6	6.72	15.00	12.50	8.50	.250	9.25	3.63	2.19	3.38	1.25	12
3	3.57	9.50	7.50	5.00	.250	5.00	2.38	1.50	2.13	1.00	8
5	5.66	13.75	11.00	7.31	.250	7.50	3.38	3.00	3.13	1.38	8
16	16.16	27.75	24.25	18.50	.250	20.00	5.50	3.50	5.25	1.75	20
8	8.72	18.50	15.50	10.63	.250	11.75	4.25	2.50	4.00	1.50	12
10	10.88	21.50	18.50	12.75	.250	14.50	4.50	2.75	4.25	1.50	16
4	4.57	11.50	9.25	6.19	.250	6.25	3.00	1.75	2.75	1.25	8
24	24.25	41.00	35.50	27.25	.250	29.50	8.25	5.50	8.00	2.63	20
12	12.88	24.00	21.00	15.00	.250	16.50	4.88	3.13	4.63	1.50	20
14	14.14	25.25	22.00	16.25	.250	17.75	5.38	3.38	5.13	1.63	20
18	18.18	31.00	27.00	21.00	.250	22.25	6.25	4.00	6.00	2.00	20
20	20.20	33.75	29.50	23.00	.250	24.50	6.50	4.25	6.25	2.13	20

Slip On Flange Weight Chart In Kg

Nominal Pipe Size		Dimension		Weight in Kg
Normal Pipe Size (Inche)	Diameter Nominal	Flange Outer Diameter in MM	Flange Thickness in MM	Socket Weld	Weld Neck	Blind
8	200	342.9	28.4	12.1	17.6	19.6
3/4	20	98.6	12.7	0.6	0.7	0.6
1	25	108	14.2	0.8	1	0.9
1 1/4	32	117.3	15.7	1	1.3	1.2
1 1/2	40	127	17.5	1.3	1.7	1.5
2	50	152.4	19.1	2.1	2.6	2.4
2 1/2	65	177.8	22.4	3.3	4.1	3.9
1/2	15	88.9	11.2	0.4	0.5	0.4
3	80	190.5	23.9	3.9	4.9	4.9
24	600	812.8	47.8	86.9	115	185.0
3 1/2	90	215.9	23.9	4.8	6.1	6.2
4	100	228.6	23.9	5.3	6.8	7.0
5	125	254	23.9	6.1	8.6	8.6
6	150	279.4	25.4	7.5	10.6	11.3
10	250	406.4	30.2	16.5	24	28.6
14	350	533.4	35.1	34.6	48.4	58.1
12	300	482.6	31.8	26.2	36.5	43.2
16	400	596.9	36.6	44.8	60.6	76.1
18	450	635	39.6	48.9	68.3	93.7
20	500	698.5	42.9	61.9	84.5	122.0

SS SORF Flange Pressure Rating

Nominal Pipe Size	Class #150			Class #300			Class #600			Class #900			Class #1500			Class #2500
	Weld Neck	Slip on	Blind	Weld Neck	Slip on	Blind	Weld Neck	Slip on	Blind	Weld Neck	Slip on	Blind	Weld Neck	Slip on	Blind	Weld Neck	Slip on	Blind
1/2"	2	1	1	2	1	1	2	2	2	1500# WEIGHTS			5	4	4	7	7	7
3/4"	2	2	2	3	3	3	4	3	3	1500# WEIGHTS			6	5	6	8	8	8
1"	3	2	2	4	3	3	4	4	4	1500# WEIGHTS			9	8	8	12	11	11
1 1/2"	4	3	3	7	6	6	8	7	8	1500# WEIGHTS			13	12	13	25	22	23
2"	6	5	5	9	7	8	12	9	10	1500# WEIGHTS			25	25	25	42	37	39
2 1/2"	8	7	7	12	10	12	18	13	15	1500# WEIGHTS			36	36	35	52	55	56
3"	10	8	9	15	13	16	23	16	20	31	26	29	48	48	48	94	83	86
4"	15	13	17	25	22	27	42	37	41	53	53	54	73	73	73	145	125	130
5"	19	15	20	32	28	35	68	63	68	86	83	87	130	130	140	245	210	225
8"	39	30	45	67	58	81	120	115	140	175	170	200	275	260	300	580	485	530
6"	24	19	26	42	39	50	81	80	86	110	110	115	165	165	160	380	325	345
10"	52	43	70	91	81	124	190	170	230	260	245	290	455	435	510	1075	930	1025
18"	150	130	220	320	250	395	475	400	630	680	600	850	1625	NA	1750	NA	NA	NA
12"	80	64	110	140	115	185	225	200	295	325	325	415	690	580	690	1525	1100	1300
24"	260	220	430	580	475	790	830	730	1250	1500	1400	2025	3325	NA	3625	NA	NA	NA
14"	110	90	140	180	165	250	280	230	355	400	400	520	940	NA	975	NA	NA	NA
16"	140	98	180	250	190	295	390	330	495	495	425	600	1250	NA	1300	NA	NA	NA
20"	180	165	285	400	315	505	590	510	810	830	730	1075	2050	NA	2225	NA	NA	NA
22"	225	185	355	465	370	640	720	590	1000	NA	NA	NA	NA	NA	NA	NA	NA	NA