Stainless Steel 304 Flanges | Stainless Steel 304L Flanges

Stainless steel 304/ 304L flanges may be manufactured in accordance with ASME B16.5 or ASME B16.47 with nominal composition of 18Cr-8Ni. The letter “L” denotes low-carbon version of the 304 stainless steel. The flanges may be made from forgings, castings, or plates covering various types and classes of ASME B16.5 and ASME B16.47 (both Series A and Series B). Stainless steel 304/ 304L flanges of ASME B16.5 are available in Classes 150, 300, 400, 600, 900, 1500, 2500; that of ASME B16.47 Series A are available in Classes 150, 300, 400, 600, 900; that of ASME B16.47 Series B are available in Classes 75, 150, 300, 400, 600, 900.

Chemical Composition Requirements

Element	F304	F304L
C	≤0.08	≤0.03
Mn	≤2.00	≤2.00
P	≤0.045	≤0.045
S	≤0.030	≤0.030
Si	≤1.00	≤1.00
Ni	8.0-11.0	8.0-13.0
Cr	18.0-20.0	18.0-20.0
N	≤0.10	≤0.10

*Composition requirements for ASTM A182 Gr. F304 and F304L, %.

Element	TP304	TP304L
C	≤0.08	≤0.03
Mn	≤2.00	≤2.00
P	≤0.045	≤0.045
S	≤0.030	≤0.030
Si	≤0.75	≤0.75
Ni	8.0-11.0	8.0-12.0
Cr	18.0-20.0	18.0-20.0
N	≤0.10	≤0.10

*Composition requirements for ASTM A240 Gr. 304 and 304L, %.

Element	CF8	CF3
C	≤0.08	≤0.03
Mn	≤1.50	≤1.50
P	≤0.040	≤0.040
S	≤0.040	≤0.040
Si	≤2.00	≤2.00
Ni	8.0-11.0	8.0-12.0
Cr	18.0-21.0	17.0-21.0
Mo	≤0.50	≤0.50

*Composition requirements for ASTM A351 Gr. CF8 and CF3, %.

Mechanical Properties

Mechanical Requirements	F304	F304L
Tensile Strength, min. MPa [ksi]	515 [75]	485 [70]
Yield Strength, min. MPa [ksi]	205 [30]	170 [25]
Elongation in 2" min. %	30	30
Reduction of area, min. %	50	50

*Tensile requirements for ASTM A182 Gr. F304 and F304L.

Mechanical Requirements	TP304	TP304L
Tensile Strength, min. MPa [ksi]	515 [75]	485 [70]
Yield Strength, min. MPa [ksi]	205 [30]	170 [25]
Elongation in 2" min. %	40	40
Brinell Hardness max. HBW	201	201
Rockwell Hardness Max. HRBW	92	92

*Tensile & hardness requirements for ASTM A240 Gr. 304 and 304L.

ASTM A351	CF8	CF3
Tensile Strength, min. MPa [ksi]	485 [70]	485 [70]
Yield Strength, min. MPa [ksi]	205 [30]	205 [30]
Elongation in 2" min. %	35	35

*Tensile requirements for ASTM A351 Gr. CF8 and CF3.

Manufacture & Heat Treatment

Stainless steel 304/ 304L flanges made of ASTM A182 F304/ F304L forgings shall be solution treated at the temperature no less than 1900°F [1040°C] with subsequent quenching treatment to cool it down to below 500°F [260°C] rapidly. SS 304/ 304L flanges made of ASTM A351 CF8/ CF3 castings shall be solution treated at the minimum temperature of 1900°F [1040°C] followed by a quench in water. Flanges without hub (blind, S/O plate) may be manufactured directly from stainless steel plates of ASTM A240 Gr. 304 or 304L, which shall be solution annealed.

Pressure-Temperature Ratings

Both ASME B16.5 and ASME B16.47 have consistently presented the pressure-temperature ratings for stainless 304/ 304L flanges in various material grades. Based on the pressure-temperature ratings, diverse stainless steel 304 and 304L flange materials can be classified into two groups: Group 2.1 – including ASTM A182 Gr. F304, ASTM A351 Gr. CF3 & CF8, ASTM A240 Gr.304; Group 2.3 – including ASTM A182 F304L, ASTM A240 Gr. 304L.

Temp. °F	75# psi	150# psi	300# psi
-20~100	140	275	720
200	115	230	600
300	105	205	540
400	95	190	495
500	85	170	465
600	70	140	440
650	60	125	430
700	-	110	420
750	-	95	415
800	-	80	405
850	-	65	395
900	-	50	390
950	-	35	380
1000	-	20	355
1050	-	-	325
1100	-	-	255
1150	-	-	205
1200	-	-	165
1250	-	-	135
1300	-	-	115
1350	-	-	95
1400	-	-	75
1450	-	-	60
1500	-	-	40

*Table A-1.

Temp. °F	400# psi	600# psi	900# psi
-20~100	960	1440	2160
200	800	1200	1800
300	715	1075	1615
400	660	995	1490
500	620	930	1395
600	590	885	1325
650	575	865	1295
700	565	845	1265
750	550	825	1240
800	540	810	1215
850	530	790	1190
900	520	780	1165
950	510	765	1145
1000	470	710	1065
1050	435	650	975
1100	345	515	770
1150	275	410	615
1200	220	330	495
1250	180	265	400
1300	150	225	340
1350	125	185	280
1400	100	150	225
1450	80	115	175
1500	55	85	125

*Table A-2.

Temp. °F	1500# psi	2500# psi
-20~100	3600	6000
200	3000	5000
300	2690	4480
400	2485	4140
500	2330	3880
600	2210	3680
650	2160	3600
700	2110	3520
750	2065	3440
800	2030	3380
850	1980	3300
900	1945	3240
950	1910	3180
1000	1770	2950
1050	1630	2715
1100	1285	2145
1150	1030	1715
1200	825	1370
1250	670	1115
1300	565	945
1350	465	770
1400	380	630
1450	290	485
1500	205	345

*Table A-3.

Temp. °F	75# psi	150# psi	300# psi
-20~100	115	230	600
200	100	195	510
300	85	175	455
400	80	160	420
500	75	150	395
600	70	140	370
650	60	125	365
700	-	110	360
750	-	95	355
800	-	80	345
850	-	65	340

*Table B-1.

Temp. °F	400# psi	600# psi	900# psi
-20~100	800	1200	1800
200	680	1020	1535
300	610	910	1370
400	560	840	1260
500	525	785	1180
600	495	745	1115
650	485	730	1095
700	480	720	1080
750	470	705	1060
800	460	690	1035
850	450	675	1015

*Table B-2.

Temp. °F	1500# psi	2500# psi
-20~100	3000	5000
200	2555	4260
300	2280	3800
400	2100	3500
500	1970	3280
600	1860	3100
650	1825	3040
700	1800	3000
750	1765	2940
800	1730	2880
850	1690	2820

*Table B-3.

Tables A-1, A-2 and A-3 list pressure-temperature ratings for Group 2.1 materials, which are the maximum allowable working gage pressures in psi units at the temperatures in degrees Fahrenheit. Tables B-1, B-2 and B-3 list pressure-temperature ratings for Group 2.3 materials, which are the maximum allowable working gage pressures in psi units at the temperatures in degrees Fahrenheit. Values of Class 75 through Class 900 are applicable to SS304/304L flanges of ASME B16.47 Series B; Values of Class 150 through Class 900 are applicable to SS304/ 304L flanges of ASME B16.47 Series B; Values of Class Class through Class 2500 are applicable to SS304/ 304L flanges of ASME B16.5.