Ring Joint Gaskets R, Rx, Bx

RING JOINT GASKETS R, RX, BX

A Ring Joint Gasket (RTJ) provides a strong and durable metal-to-metal seal between two mating RTJ flanges. As the flanges are bolted, the softer material of the ring joint gasket is “squeezed” into the flanges grooves (made of a harder material) and seals the connection very tightly. RTJ gaskets are available in three styles, R (oval, octagonal), RX, and BX.

Ring joint gaskets (RTJ) ensure a long lasting and strong seal for flanges, valves, piping spools and vessels at high pressure and temperatures (which are typical conditions for many petrochemical processes).

RTJ are available in different designs (called “styles”) and dimensions, as illustrated in the picture below (BX, R, and BX).

Rtj Gaskets Types

R Type Ring Joint Gasket (Oval and Octagonal)
“Style R” is the most common RTJ gasket type. R type ring joint gaskets are available in oval or octagonal cross-section and manufactured according to API 6A and ASME B16.20 to suit API 6B and ASME/ANSI B16.5 flanges.

This type of RTJ gasket is machined to tight manufacturing tolerances to ensure correct installation with standard ASME B16.5 and API 6B ring joint faced flanges. “R style” oval and octagonal RTJ gaskets can seal pressures up to 6.250 psi by ASME B16.20 and up to 5.000 psi according to the API 6A pressure ratings.

Type R RTJ gaskets are frequently used for valves covers.

Style RX RTJ Gasket
The RX type RTJ gasket is manufactured according to API 6A and ASME B16.20 to suit API 6B and ASME/ANSI B16.5 flanges.
The RX is a pressure energized version of the R octagonal gasket and fits the R type flat-bottomed groove.
The RX has an increased height and utilizes the internal system pressure to energize and improve the seal as internal pressure increases.
Some RX sizes have a pressure relief hole to equalize pressure on both sides of the sealing faces.

Style BX RTJ Gasket
The BX type RTJ gaskets are manufactured according to API 6A and are suitable for use in high-pressure API 6BX flanges.
The gaskets form a metal to metal seal on assembly and the efficiency improves as internal pressure increases.
All BX sizes have a pressure relief hole to equalize pressure across sealing faces.

Rtj Gasket Materials

The material of RTJ gaskets shall match the flanges material but must have a lower hardness: this to ensure that the gasket, and not the flange, get plastically deformed within the groove of the flange as the two mating flanges are bolted together. In case a harder material for the ring type joint is used, the groove of the flange would be damaged as the flanges are tightened (the hardness values for ring joint gaskets are given below).

Types of Materials for Ring Joint Gaskets

RTJ GASKET MATERIAL	RING ID	ASTM GRADE	DIN GRADE	WKSTOFF NUMBER	AISI GRADE	BS GRADE	OTHER SPECS
Soft Iron	D			1.1003 / 1.0335			Aramco / StW24
LCS	S			1.1003 / 1.0335			Aramco / StW24
CS360 LT	CS360LT	A516 Gr70
4140	4140	UNS G41400	42CrMo4	1.7225	4140
F5	F5	UNS K42544	12CrMo195	1.7362			5Cr 1/2Mo
SS304	S304	S30400	X5CrNi 18 9	1.4301	304	304S15
SS304L	S304L	S30403	X2CrNi 18 9	1.4306	304L	304SS12
SS309	S309	S30900	X15CrNiSi2012	1.4828	309	309S24
SS310	S310	S31008	XX15CrNiSi2520	1.4841	310	310S24
SS316	S316	S31600	X5CrNiMo18 10	1.4401	316	316S16
SS316L	S316L	S31603	X2CrNiMo18 10	1.4404	316L	316S11/316S12
SS316L UREA	S316UG	S31603	X2CrNiMo 18 14 3	1.4435
SS316Ti	S316Ti	S31635	X10CrNiMoTi1810	1.4571	316Ti	320S31/320S17
SS321	S321	S32100	X10CrNiTi18 9	1.4541	321	321S12
SS347	S347	S34700	X10CrNiNb 18 9	1.455	347	347S51
SS410	S410	S41000	X10Cr13	1.4006	410	410S21
Monel 400	Monel400	N04400	NiCu30Fe	2.436
Inconel 600	INC600	N06600	NiCr15Fe	2.4816
Inconel 625	INC625	N06625	NiCr22Mo9Nb	2.4856
Inconel 718	INC718	N07718
Incoloy 800	INC800	N08800	X5NiCrAlTi31-20	1.4958
Incoloy 800H	INC800H	N08810		1.4958
Incoloy 825	INC825	N08825	NiCr21Mo	2.4858
904L	904L	N08904	X1NiCrMoCu25-20-5	1.4539
F51	F51	S31803	X2CrNiMoN22-5-3	1.4462			2205 /Duplex
F53	F53	S32750	X2CrNiMoN25-7-4	1.441
F55	F55	S32760	X2CrNiMoCuWN 25 7 4	1.4501			Zeron 100
F60	F60	S32205					Duplex
Titanium	Ti	R 50400		3.7035
17-4PH	17-4PH	S17400		1.4542			630
S254	S254	S31254	X1CrNiMoCuN20-18-7	1.4547			F44 / 6Mo
C276	C276	N10276	NiMo16Cr15W	2.4819			Hastelloy
Alloy 28	Alloy28	N08028	X1 NiCrMoCuN 31 27 4	1.4563			SANICRO 28

Mechanical Properties Ring Joint Gaskets Materials

	Maximum Hardness of RTJ Gaskets
RTJ Gasket Material	Brinell	HRB	ID
Soft Iron-S	90	56	D
Low Carbon Steel	120	68	S
4 – 6% Chrome 1/2% Moly	130	72	F5
SS 304 Stainless Steel	160	83	S304
SS 316 Stainless Steel	160	83	S316
SS 347 Stainless Steel	160	83	S347
SS 410 Stainless Steel	170	96	S410

RTJ GASKET DIMENSIONS (ASME B16.20)

Style R Ring Joint Gaskets Dimensions (for ASME B16.5 flanges)

RTJ GASKET RING NUMBER	Diameter P	Width A	Height		Oct C	Oct R1	NPS / CLASS
			Oval B	Oct H
R 11	34.14	6.35	11.2	9.7	4.32	1.5	1/2 300 / 600
R 12	39.7	7.95	14.2	12.7	5.23	1.5	1/2 900 / 1500
R 13	42.88	7.95	14.2	12.7	5.23	1.5	3/4 300 / 600 1/2 2500
R 14	44.45	7.95	14.2	12.7	5.23	1.5	3/4 900 / 1500
R 15	47.63	7.95	14.2	12.7	5.23	1.5	1 150
R 16	50.8	7.95	14.2	12.7	5.23	1.5	1 300 / 1500 3/4 2500
R 17	57.15	7.95	14.2	12.7	5.23	1.5	1¼ 150
R 18	60.33	7.95	14.2	12.7	5.23	1.5	1¼ 300 / 1500 1 2500
R 19	65.1	7.95	14.2	12.7	5.23	1.5	1½ 150
R 20	68.28	7.95	14.2	12.7	5.23	1.5	1½ 300 / 1500
R 21	72.24	11.13	17.5	16	7.75	1.5	1¼ 2500
R 22	82.55	7.95	14.2	12.7	5.23	1.5	2 150
R 23	82.55	11.13	17.5	16	7.75	1.5	2 300 600 1½ 2500
R 24	95.25	11.13	17.5	16	7.75	1.5	2 900 / 1500
R 25	101.6	7.95	14.2	12.7	5.23	1.5	2½ 150
R 26	101.6	11.13	17.5	16	7.75	1.5	2½ 300/ 600 2 2500
R 27	107.95	11.13	17.5	16	7.75	1.5	2½ 900 / 1500
R 28	111.13	12.7	19.1	17.5	8.66	1.5	2½ 2500
R 29	114.3	7.95	14.2	12.7	5.23	1.5	3 150
R 30 *	117.48	11.13	17.5	16	7.75	1.5	3 300 / 600
R 31	123.83	11.13	17.5	16	7.75	1.5	3 300 / 900
R 32	127	12.7	19.1	17.5	8.66	1.5	3 2500
R 33	131.78	7.95	14.2	12.7	5.23	1.5	3½ 150
R 34	131.78	11.13	17.5	16	7.75	1.5	3½ 300 / 600
R 35	136.53	11.13	17.5	16	7.75	1.5	3 1500
R 36	149.23	7.95	14.2	12.7	5.23	1.5	4 150
R 37	149.23	11.13	17.5	16	7.75	1.5	4 300 / 900
R 38	157.18	15.88	22.4	20.6	10.49	1.5	4 2500
R 39	161.93	11.13	17.5	16	7.75	1.5	4 1500
R 40	171.45	7.95	14.2	12.7	5.23	1.5	5 150
R 41	180.98	11.13	17.5	16	7.75	1.5	5 300 / 900
R 42	190.5	19.05	25.4	23.9	12.32	1.5	5 2500
R 43	193.68	7.95	14.2	12.7	5.23	1.5	6 150
R 44	193.68	11.13	17.5	16	7.75	1.5	5 1500
R 45	211.15	11.13	17.5	16	7.75	1.5	6 300 / 900
R 46	211.15	12.7	19.1	17.5	8.66	1.5	6 1500
R 47	228.6	19.05	25.4	23.9	12.32	1.5	6 2500
R 48	247.65	7.95	14.2	12.7	5.23	1.5	8 150
R 49	269.88	11.13	17.5	16	7.75	1.5	8 300 / 900
R 50	269.88	15.88	22.4	20.6	10.49	1.5	8 1500
R 51	279.4	22.23	28.7	26.9	14.81	1.5	8 2500
R 52	304.8	7.95	14.2	12.7	5.23	1.5	10 150
R 53	323.85	11.13	17.5	16	7.75	1.5	10 300 900
R 54	323.85	15.88	22.4	20.6	10.49	1.5	10 1500
R 55	342.9	28.58	36.6	35.1	19.81	2.3	10 2500
R 56	381	7.95	14.2	12.7	5.23	1.5	12 150
R 57	381	11.13	17.5	16	7.75	1.5	12 300 900
R 58	381	22.23	28.7	26.9	14.81	1.5	12 1500
R 59	396.88	7.95	14.2	12.7	5.23	1.5	14 150
R 60	406.4	31.75	39.6	38.1	22.33	2.3	12 2500
R 61	419.1	11.13	17.5	16	7.75	1.5	14 300 600
R 62	419.1	15.88	22.4	20.6	10.49	1.5	14 900
R 63	419.1	25.4	33.3	31.8	17.3	2.3	14 1500
R 64	454.03	7.95	14.2	12.7	5.23	1.5	16 150
R 65	469.9	11.13	17.5	16	7.75	1.5	16 300 600
R 66	469.9	15.88	22.4	20.6	10.49	1.5	16 900
R 67	469.9	28.58	36.6	35.1	19.81	2.3	16 1500
R 68	517.53	7.95	14.2	12.7	5.23	1.5	18 150
R 69	533.4	11.13	17.5	16	7.75	1.5	18 300 600
R 70	533.4	19.05	25.4	23.9	12.32	1.5	18 900
R 71	533.4	28.58	36.6	35.1	19.81	2.3	18 1500
R 72	558.8	7.95	14.2	12.7	5.23	1.5	20 150
R 73	584.2	12.7	19.1	17.5	8.66	1.5	20 300 600
R 74	584.2	19.05	25.4	23.9	12.32	1.5	20 900
R 75	584.2	31.75	39.6	38.1	22.33	2.3	20 1500
R 76	673.1	7.95	14.2	12.7	5.23	1.5	24 150
R 77	692.15	15.88	22.4	20.6	10.49	1.5	24 300 600
R 78	692.15	25.4	33.3	31.8	17.3	2.3	24 900
R 79	692.15	34.93	44.5	41.4	24.82	2.3	24 1500

Style R Ring Joint Gaskets Dimensions (for ASME B16.47 Series A flanges)

RTJ GASKET RING NUMBER	Dia P	Width A	Height		Oct C	Oct R1	NPS CLASS
			Oval B	Oct H
R 93	749.3	19.05	…	23.9	12.32	1.5	26 300 600
R 94	800.1	19.05	…	23.9	12.32	1.5	28 300 600
R 95	857.25	19.05	…	23.9	12.32	1.5	30 300 600
R 96	914.4	22.23	…	26.9	14.81	1.5	32 300 600
R 97	965.2	22.23	…	26.9	14.81	1.5	34 300 600
R 98	1022.35	22.23	…	26.9	14.81	1.5	36 300 600
R 100	749.3	28.58	…	35.1	19.81	2.3	26 900
R 101	800.1	31.75	…	38.1	22.33	2.3	28 900
R 102	857.25	31.75	…	38.1	22.33	2.3	30 900
R 103	914.4	31.75	…	38.1	22.33	2.3	32 900
R 104	965.2	34.93	…	41.4	24.82	2.3	34 900
R 105	1022.35	34.93	…	41.4	24.82	2.3	36 900

Style RX Ring Joint Gaskets Dimensions

RTJ GASKET RING NUMBER	720-960	2900#	3000#	5000#	OD	HEIGHT	WIDTH	GASKET Wt. ( kg )
RX20	1 ½	–	1 ½	1 ½	76.2	19.05	8.74	0.24
RX23	2, 2 1/16	–	93.27	25.4	11.91	0.52
RX24	–	–	2, 2 1/16	2, 2 1/16	105.97	25.4	11.91	0.6
RX25	–	–	–	3 1/8	109.55	19.05	8.74	0.5
RX26	2 ½ , 2 9/16	–	–	–	111.91	25.4	11.91	0.64
RX27	–	–	2 ½, 2 9/16	2 ½, 2 9/16	118.26	25.4	11.91	0.68
RX31	3 , 3 1/8	–	3, 3 1/8	134.54	25.4	11.91	0.78
RX35	–	–	–	3, 3 1/8	147.24	25.4	11.91	0.86
RX37	4 , 4 1/16	–	4, 4 1/16	–	159.94	25.4	11.91	0.95
RX39	–	–	–	4, 4 1/16	172.64	25.4	11.91	1.03
RX41	5, 5 1/8	–	5, 5 1/8	–	191.69	25.4	11.91	1.15
RX44	–	–	–	5, 5 1/8	204.39	25.4	11.91	1.23
RX45	6, 7 1/16	–	6, 7 1/16	–	221.84	25.4	11.91	1.34
RX46	–	–	–	6, 7 1/16	222.25	28.58	13.49	1.66
RX47	–	–	–	8	245.26	41.28	19.84	3.88
RX49	8, 9	–	8, 9	280.59	25.4	11.91	1.72
RX50	–	–	–	8, 9	283.36	31.75	16.66	2.43
RX53	10, 11	–	10, 11	334.57	25.4	11.91	2.06
RX54	–	–	–	10, 11	337.34	31.75	16.66	2.92
RX57	12, 13 5/8	–	12, 13 5/8	391.72	25.4	11.91	2.42
RX63	–	–	14	441.73	50.8	27	11.96
RX65	16, 16 3/4	–	–	–	480.62	25.4	11.91	3
RX66	–	–	16, 16 3/4	–	457.99	31.75	16.66	4.25
RX69	18	–	544.12	25.4	11.91	3.41
RX70	–	–	18	–	550.06	41.28	19.84	9.12
RX73	20, 21 1/4	–	–	–	596.11	31.75	13.49	5.27
RX74	–	–	20, 20 3/4	–	600.86	41.28	19.84	10.01
RX82	–	1	–	–	67.87	25.4	11.91	0.36
RX84	–	1 ½	–	–	74.22	25.4	11.91	0.4
RX85	–	2	–	–	90.09	25.4	13.49	0.4
RX86	–	2 ½	–	–	103.58	28.58	15.09	0.81
RX87	–	3	–	–	113.11	28.58	15.09	0.9
RX88	–	4	–	–	139.29	31.75	17.48	1.46
RX89	–	3 ½	–	–	129.77	31.75	18.26	3.09
RX90	–	5	–	–	174.63	44.45	19.84	7.75
RX91	–	10	–	–	286.94	45.24	30.18	1.5
RX99	8	–	8	–	245.67	25.4	11.91	2.2
RX201	–	–	–	1 3/8	51.46	11.3	5.74	0.1
RX205	–	–	–	1 13/16	62.31	11.1	5.56	0.13
RX210	–	–	–	2 9/16	97.64	19.05	9.53	0.35
RX215	–	–	–	4 1/16	140.89	25.4	11.91	0.8

Style BX Ring Joint Gaskets Dimensions

RTJ GASKET RING NUMBER	2000#	3000#	5000#	10000#	15000#	20000#	OUTSIDE DIA	HEIGHT  OF THE RING	WIDTH  OF THE RING	RTJ GASKET  WEIGHT KG
BX 150	–	–	–	1 11/16	1 11/16	–	72.19	9.3	9.3	0.13
BX 151	–	–	–	1 13/16	1 13/16	1 13/16	76.4	9.63	9.63	0.15
BX 152	–	–	–	2 1/16	2 1/16	2 1/16	84.68	10.24	10.24	0.19
BX 153	–	–	–	2 9/16	2 9/16	2 9/16	100.94	11.38	11.38	0.29
BX 154	–	–	–	3 1/16	3 1/16	3 1/16	116.84	12.4	12.4	0.4
BX 155	–	–	–	4 1/16	4 1/16	4 1/16	147.96	14.22	14.22	0.55
BX 156	–	–	–	7 1/16	7 1/16	7 1/16	237.92	18.62	18.62	1.87
BX 157	–	–	–	9	9	9	294.46	20.98	20.98	2.97
BX 158	–	–	–	11	11	11	352.04	23.14	23.14	4.35
BX 159	–	–	–	13 5/8	–	–	426.72	25.7	25.7	6.53
BX 160	–	–	13 5/8	–	–	–	402.59	23.83	13.74	3.06
BX 161	–	–	16 ¾	–	–	–	491.41	28.07	16.21	5.35
BX 162	–	–	16 3/4	16 3/4	16 3/4	–	475.49	14.22	14.22	1.94
BX 163	–	–	18 3/4	–	–	–	556.16	30.1	17.37	6.9
BX 164	–	–	–	18 3/4	18 3/4	–	570.56	30.1	24.59	5.86
BX 165	–	–	21 ¼	–	–	–	624.71	32.03	18.49	8.76
BX 166	–	–	–	21 ¼	–	–	640.03	32.03	26.14	12.82
BX 167	26 3/4	–	–	–	–	–	759.36	35.86	13.11	8.53
BX 168	–	26 3/4	–	–	–	–	765.25	35.86	16.05	10.54
BX 169	–	–	–	5 1/8	–	–	173.51	15.85	12.93	0.73
BX 170	–	–	–	6 5/8	6 5/8	–	218.03	14.22	14.22	1.03
BX 171	–	–	–	8 9/16	8 9/16	–	267.44	14.22	14.22	1.24
BX 172	–	–	–	11 5/32	11 5/32	–	333.07	14.22	14.22	1.56
BX 303	30	30	–	–	–	–	852.75	37.95	16.97	–

HOW TO ORDER RING JOINT GASKET

The following tables shows how to select the correct ring joint gasket depending on the flange size (NPS), manufacturing norm (ASME or API) and flange rating:

Style RX Ring Joint Gaskets

NOMINAL PIPE SIZE	PRESSURE CLASSES
	ASME B16.5						API 6B						ASME B16.47 Series A
	150#	300# – 600#	900#	1500#	2500#	720# – 960# (1)		2000#	3000#	5000#	10000#	150#		300# – 600#	900#
1/2”	–	R-11	R-12	R-12	R-13	–		–	–	–	–	–		–	–
3/4”	–	R-13	R-14	R-14	R-16	–		–	–	–	–	–		–	–
1”	R-15	R-16	R-16	R-16	R-18	R-16		R-16	R-16	R-16	R-82	–		–	–
1 1/4”	R-17	R-18	R-18	R-18	R-21	R-18		R-18	R-18	R-18	–	–		–	–
1 1/2”	R-19	R-20	R-20	R-20	R-23	R-20		R-20	R-20	R-20	R-84	–		–	–
2”	R-22	R-23	R-24	R-24	R-26	R-23		R-23	R-23	R-24	R-85	–		–	–
2 1/2”	R-25	R-26	R-27	R-27	R-28	R-26		R-26	R-26	R-27	R-86	–		–	–
3”	R-29	R-31	R-31	R-35	R-32	R-31		R-31	R-31	R-35	R-87	–		–	–
3 1/2”	R-33	R-34	–	–	–	–		–	–	R-37	R-89	–		–	–
4”	R-36	R-37	R-37	R-39	R-38	R-37		R-37	R-37	R-39	R-88	–		–	–
5”	R-40	R-41	R-41	R-44	R-42	R-41		R-41	R-41	R-44	R-90	–		–	–
6”	R-43	R-45	R-45	R-46	R-47	R-45		R-45	R-45	R-46	–	–		–	–
8”	R-48	R-49	R-49	R-50	R-51	R-49		R-49	R-49	R-50	–	–		–	–
10”	R-52	R-53	R-53	R-54	R-55	R-53		R-53	R-53	R-54	R-91	–		–	–
12”	R-56	R-57	R-57	R-58	R-60	R-57		R-57	R-57	–	–	–		R-57	R-57
14”	R-59	R-61	R-62	R-63	–	R-61		R-61	R-61	–	–	–		R-61	R-62
16”	R-64	R-65	R-66	R-67	–	R-65		R-65	R-65	–	–	–		R-65	R-66
18”	R-68	R-69	R-70	R-71	–	R-69		R-69	R-69	–	–	–		R-69	R-70
20”	R-72	R-73	R-74	R-75	–	R-73		R-73	R-73	–	–	–		R-73	R-74
22”	–	–	–	–	–	–		–	–	–	–	R-80		R-81	–
24”	R-76	R-77	R-78	R-79	–	–		–	–	–	–	–		R-77	R-78
26”	–	–	–	–	–	–		–	–	–	–	–		R-93	R-100
28”	–	–	–	–	–	–		–	–	–	–	–		R-94	R-101
30”	–	–	–	–	–	–		–	–	–	–	–		R-95	R-102
32”	–	–	–	–	–	–		–	–	–	–	–		R-96	R-103
34”	–	–	–	–	–	–		–	–	–	–	–		R-97	R-104
36”	–	–	–	–	–	–		–	–	–	–	–		R-98	R-105

Style BX Ring Joint Gaskets

NPS	PRESSURE RATING
	API 6BX
	2000#	3000#	5000#	10000#	15000#	20000#
1 11/16″	–	–	–	BX-150	BX-150	–
1 13/16″	–	–	–	BX-151	BX-151	BX-151
2 1/16″	–	–	–	BX-152	BX-152	BX-152
2 9/16″	–	–	–	BX-153	BX-153	BX-153
3 1/16″	–	–	–	BX-154	BX-154	BX-154
4 1/16″	–	–	–	BX-155	BX-155	BX-155
5 1/8″	–	–	–	BX-169	–	–
6 5/8″	–	–	–	BX-170	BX-170	–
7 1/16″	–	–	–	BX-156	BX-156	BX-156
8 9/16″	–	–	–	BX-171	BX-171	–
9″	–	–	–	BX-157	BX-157	BX-157
11″	–	–	–	BX-158	BX-158	BX-158
11 5/32″	–	–	–	BX-172	BX-172	–
13 5/8″	–	–	BX-160	BX-159	BX-159	BX-159
16 3/4″	–	–	BX-161  BX-162	BX-162	BX-162	–
18 3/4″	–	–	BX-163	BX-164	BX-164	–
21 1/4″	–	–	BX-165	BX-166	–	–
26 3/4″	BX-167	BX-168	–	–	–	–
30″	BX-303	BX-303	–	–	–	–