Monel 400 flanges manufactured to ASME B16.5 are usually made from two forms of raw material: ASTM B564 UNS N04400 forgings or ASTM B127 UNS N04400 plates. According to the standard, the pressure-temperature ratings can be furnished in two unit systems: ISO and US customary.

Pressure-Temperature Ratings for Monel 400: ISO Unit

Temp. °C	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
-29~38	15.9	41.4	55.2	82.7	124.1	206.8	344.7
50	15.4	40.2	53.7	80.5	120.7	201.2	335.3
100	13.8	35.9	47.9	71.9	107.8	179.7	299.5
150	12.9	33.7	45.0	67.5	101.2	168.7	281.1
200	12.5	32.7	43.6	65.4	98.1	163.5	272.4
250	12.1	32.6	43.5	65.2	97.8	163.0	271.7
300	10.2	32.6	43.5	65.2	97.8	163.0	271.7
325	9.3	32.6	43.5	65.2	97.8	163.0	271.7
350	8.4	32.6	43.4	65.1	97.7	162.8	271.3
375	7.4	32.4	43.2	64.8	97.2	161.9	269.9
400	6.5	32.1	42.8	64.2	96.2	160.4	267.4
425	5.5	31.6	42.2	63.3	94.9	158.2	263.6
450	4.6	26.9	35.9	53.8	80.7	134.5	224.2
475	3.7	20.8	27.7	41.5	62.3	103.8	173.0

*Working pressures by classes, unit: bar.

Pressure-Temperature Ratings for Monel 400: US Customary Unit

Temp. °F	Class 150	Class 300	Class 400	Class 600	Class 900	Class 1500	Class 2500
-20~100	230	600	800	1200	1800	3000	5000
200	200	525	700	1050	1575	2630	4380
300	190	490	655	980	1470	2450	4080
400	180	475	630	945	1420	2365	3940
500	170	475	630	945	1420	2365	3940
600	140	475	630	945	1420	2365	3940
650	125	475	630	945	1420	2365	3940
700	110	470	625	940	1410	2350	3920
750	95	465	620	930	1395	2330	3880
800	80	460	610	915	1375	2290	3820
850	65	375	505	755	1130	1885	3145
900	50	275	365	550	825	1370	2285

*Working pressures by classes, unit: psig.