ANSI B16.5 - Maximum Pressure and Temperature Ratings of Flanges and Flange Fittings

The Maximum allowable non-shock pressure (psig) and temperature ratings for steel pipe flanges and flanged fittings according the American National Standard ANSI B16.5 are given in the table below. 

Flanges and their Fittings are a common feature in the process plants. The need to accurately determine their pressure rating and corresponding temperature ratings is important for personnel and plant safety and overall plant performance and reliability:

Maximum Allowable Non-Shock Pressure (Psig)
Temperature (°F)	Pressure Class (lb)
	150	300	400	600	900	1500	2500
	Hydrostatic Test Pressure (Psig)
	450	1125	1500	2225	3350	5575	9275
-20 to 100	285	740	990	1480	2220	3705	6170
200	260	675	900	1350	2025	3375	5625
300	230	655	875	1315	1970	3280	5470
400	200	635	845	1270	1900	3170	5280
500	170	600	800	1200	1795	2995	4990
600	140	550	730	1095	1640	2735	4560
650	125	535	715	1075	1610	2685	4475
700	110	535	710	1065	1600	2665	4440
750	95	505	670	1010	1510	2520	4200
800	80	410	550	825	1235	2060	3430
850	65	270	355	535	805	1340	2230
900	50	170	230	345	515	860	1430
950	35	105	140	205	310	515	860
1000	20	50	70	105	155	260	430