Stainless steel 316 flanges(16Cr–12Ni–2Mo) may be manufactured from forgings (A182 Gr. F318), castings (A351 Gr. CF8M), or plates (A240 Gr. 316), respectively. The working pressures for which SS 316 flanges can be applied at elevated temperatures are listed in below two tables (it is also known as “pressure-temperature ratings” for the material).

Pressure-Temperature Ratings for SS 316 Flanges

Temp. °F	Class 150	Class 300	Class 600
-20~100	275	720	1,440
200	235	620	1,240
300	215	560	1,120
400	195	515	1,025
500	170	480	955
600	140	450	900
650	125	440	885
700	110	435	870
750	95	425	855
800	80	420	845
850	65	420	835
900	50	415	830
950	35	385	775
1000	20	365	725
1050	-	360	720
1100	-	305	610
1150	-	235	475
1200	-	185	370
1250	-	145	295
1300	-	115	235
1350	-	95	190
1400	-	75	150
1450	-	60	115
1500	-	40	85

*The working pressures by classes of 150, 300, 600, unit: psig.

Temp. °F	Class 900	Class 1500	Class 2500
-20~100	2,160	3,600	6,000
200	1,860	3,095	5,160
300	1,680	2,795	4,660
400	1,540	2,570	4,280
500	1,435	2,390	3,980
600	1,355	2,255	3,760
650	1,325	2,210	3,680
700	1,305	2,170	3,620
750	1,280	2,135	3,560
800	1,265	2,110	3,520
850	1,255	2,090	3,480
900	1,245	2,075	3,460
950	1,160	1,930	3,220
1000	1,090	1,820	3,030
1050	1,080	1,800	3,000
1100	915	1,525	2,545
1150	710	1,185	1,970
1200	555	925	1,545
1250	440	735	1,230
1300	350	585	970
1350	290	480	800
1400	225	380	630
1450	175	290	485
1500	125	205	345

*The working pressures by classes of 900, 1500, 2500, unit: psig.

Since pipe flanges of Class 400 are rarely used in engineering practice, its data are not listed. All values in the above two tables are in US customary unit. You may contact us to get the technical specification in metric unit. Pipe flanges made of A351 CF3M are not to be used over 850°F. At temperatures over 1000°F, SS 316 flanges shall be used only when the carbon content is 0.04% or higher. The listed data are also applicable for ASTM A182 Gr. F316H/ F317, A240 Gr. 316H/ 317, and ASTM A351 CF3M/ CG8M.