STANDARD · ASME-B16-47-B

ASME B16.47 Series B Flange Dimensions

ASME B16.47-2025 · ASME B16.47 Series B

ASME B16.47-2025North America, Middle Eastpressure class

ASME B16.47 Series B is the former API 605 large-diameter flange standard, covering NPS 26 to NPS 60 in classes 150 to 900. Its outside diameters are smaller than Series A for the same size and class, which makes it attractive where space or weight is constrained.

Series B is dimensionally different from Series A and from B16.5. Always quote the series explicitly, and check the mating flange before ordering — a Series B flange will not bolt to a Series A flange of the same nominal size. B16.47 covers weld-neck and blind flanges only, and Class 900 is published up to NPS 48.

Base materialASTM A105

Size notationNPS (inch)

Material options5 groups

Reference data5 topics

DIMENSIONS

Dimension tables

One row per specification. Open a size for the drawing, pressure ratings and printable A4 sheet.

Weld Neck 84 Blind 84

Weld Neck: Butt-welded to the pipe with a tapered hub; used for high pressure, high temperature and cyclic service. 84 specifications.

84 specifications

Size	Rating	Outside Ø D	Thickness C	Raised face D2	Bolt circle K	Bolting	Hub A	Length H	Weight
26″DN650	Class 150	786	39.9	711	744.5	36 × Ø22.2	684	87	54.4 kg	Spec sheet
26″DN650	Class 300	867	87.3	737	803.1	32 × Ø34.9	702	143	181 kg	Spec sheet
26″DN650	Class 400	851	88.9	711	781	28 × Ø38.1	689	149	163 kg	Spec sheet
26″DN650	Class 600	889	111.3	727	806.4	28 × Ø44.5	698	181	249 kg	Spec sheet
26″DN650	Class 900	1022	134.9	762	901.7	20 × Ø66.7	743	259	476 kg	Spec sheet
28″DN700	Class 150	837	42.9	762	795.3	40 × Ø22.2	735	94	63.5 kg	Spec sheet
28″DN700	Class 300	921	87.3	787	857.2	36 × Ø34.9	756	148	204 kg	Spec sheet
28″DN700	Class 400	914	95.3	762	838.2	24 × Ø41.3	740	159	204 kg	Spec sheet
28″DN700	Class 600	952	115.9	784	863.6	28 × Ø47.6	752	190	295 kg	Spec sheet
28″DN700	Class 900	1105	147.6	819	971.6	20 × Ø73	797	276	689 kg	Spec sheet
30″DN750	Class 150	887	42.9	813	846.1	44 × Ø22.2	787	98	68 kg	Spec sheet
30″DN750	Class 300	991	92.1	845	920.8	36 × Ø38.1	813	156	249 kg	Spec sheet
30″DN750	Class 400	972	101.6	819	895.4	28 × Ø41.3	794	170	240 kg	Spec sheet
30″DN750	Class 600	1022	125.4	841	927.1	28 × Ø50.8	806	205	367 kg	Spec sheet
30″DN750	Class 900	1181	155.4	876	1035	20 × Ø79.4	851	289	826 kg	Spec sheet
32″DN800	Class 150	941	44.5	864	900.1	48 × Ø22.2	840	106	77.1 kg	Spec sheet
32″DN800	Class 300	1054	101.6	902	977.9	32 × Ø41.3	864	167	311 kg	Spec sheet
32″DN800	Class 400	1035	108	873	952.5	28 × Ø44.5	845	179	288 kg	Spec sheet
32″DN800	Class 600	1086	130	895	984.2	28 × Ø54	861	216	431 kg	Spec sheet
32″DN800	Class 900	1238	160.3	927	1092.2	20 × Ø79.4	908	303	937 kg	Spec sheet
34″DN850	Class 150	1005	47.8	921	957.3	40 × Ø25.4	892	109	95.3 kg	Spec sheet
34″DN850	Class 300	1108	101.6	952	1031.7	36 × Ø41.3	917	171	340 kg	Spec sheet
34″DN850	Class 400	1086	111.3	927	1003.3	32 × Ø44.5	899	187	313 kg	Spec sheet
34″DN850	Class 600	1162	141.3	952	1054.1	24 × Ø60.3	914	233	547 kg	Spec sheet
34″DN850	Class 900	1314	171.5	991	1155.7	20 × Ø85.7	962	319	1111 kg	Spec sheet
36″DN900	Class 150	1057	50.8	972	1009.6	44 × Ø25.4	945	116	109 kg	Spec sheet
36″DN900	Class 300	1171	101.6	1010	1089.2	32 × Ø44.5	965	179	381 kg	Spec sheet
36″DN900	Class 400	1156	119.1	981	1066.8	28 × Ø47.6	952	200	388 kg	Spec sheet
36″DN900	Class 600	1213	146.1	1010	1104.9	28 × Ø60.3	968	243	608 kg	Spec sheet
36″DN900	Class 900	1346	173	1029	1200.2	24 × Ø79.4	1016	325	1143 kg	Spec sheet
38″DN950	Class 150	1124	52.6	1022	1069.8	40 × Ø28.6	997	122	132 kg	Spec sheet
38″DN950	Class 300	1222	109.5	1060	1140	36 × Ø44.5	1016	190	415 kg	Spec sheet
38″DN950	Class 400	1206	124	1035	1117.6	32 × Ø47.6	1003	206	—	Spec sheet
38″DN950	Class 600	1270	152.4	1054	1162	28 × Ø60.3	1022	254	—	Spec sheet
38″DN950	Class 900	1460	190.5	1099	1289	20 × Ø92.1	1073	353	—	Spec sheet
40″DN1000	Class 150	1175	54	1080	1120.6	44 × Ø28.6	1049	127	141 kg	Spec sheet
40″DN1000	Class 300	1273	114.3	1115	1190.8	40 × Ø44.5	1067	197	449 kg	Spec sheet
40″DN1000	Class 400	1270	130	1092	1174.8	32 × Ø50.8	1054	216	—	Spec sheet
40″DN1000	Class 600	1321	158.8	1111	1212.8	32 × Ø60.3	1073	264	—	Spec sheet
40″DN1000	Class 900	1511	196.9	1162	1339.8	24 × Ø92.1	1127	363	—	Spec sheet
42″DN1050	Class 150	1226	57.2	1130	1171.4	48 × Ø28.6	1102	132	156 kg	Spec sheet
42″DN1050	Class 300	1334	117.5	1168	1244.6	36 × Ø47.6	1118	203	515 kg	Spec sheet
42″DN1050	Class 400	1321	133.4	1143	1225.6	32 × Ø50.8	1108	224	—	Spec sheet
42″DN1050	Class 600	1403	168.1	1168	1282.7	28 × Ø66.7	1127	279	—	Spec sheet
42″DN1050	Class 900	1562	206.2	1213	1390.6	24 × Ø92.1	1176	371	—	Spec sheet
44″DN1100	Class 150	1276	58.9	1181	1222.2	52 × Ø28.6	1153	135	141 kg	Spec sheet
44″DN1100	Class 300	1384	125.4	1219	1295.4	40 × Ø47.6	1173	213	560 kg	Spec sheet
44″DN1100	Class 400	1384	139.7	1200	1282.7	32 × Ø54	1159	233	—	Spec sheet
44″DN1100	Class 600	1454	173	1226	1333.5	32 × Ø66.7	1181	289	—	Spec sheet
44″DN1100	Class 900	1648	214.3	1270	1463.5	24 × Ø98.4	1235	391	—	Spec sheet
46″DN1150	Class 150	1341	60.5	1235	1284.3	40 × Ø31.8	1205	143	197 kg	Spec sheet
46″DN1150	Class 300	1460	127	1270	1365.2	36 × Ø50.8	1229	221	667 kg	Spec sheet
46″DN1150	Class 400	1441	146.1	1257	1339.8	36 × Ø54	1213	244	—	Spec sheet
46″DN1150	Class 600	1511	179.4	1276	1390.6	32 × Ø66.7	1235	300	—	Spec sheet
46″DN1150	Class 900	1734	225.6	1334	1536.7	24 × Ø104.8	1292	411	—	Spec sheet
48″DN1200	Class 150	1392	63.5	1289	1335.1	44 × Ø31.8	1257	148	218 kg	Spec sheet
48″DN1200	Class 300	1511	127	1327	1416	40 × Ø50.8	1278	222	714 kg	Spec sheet
48″DN1200	Class 400	1511	152.4	1308	1403.4	28 × Ø60.3	1267	257	—	Spec sheet
48″DN1200	Class 600	1594	188.9	1334	1460.5	32 × Ø73	1289	316	—	Spec sheet
48″DN1200	Class 900	1784	233.4	1384	1587.5	24 × Ø104.8	1343	419	—	Spec sheet
50″DN1250	Class 150	1443	66.7	1340	1385.9	48 × Ø31.8	1308	152	236 kg	Spec sheet
50″DN1250	Class 300	1562	136.7	1378	1466.8	44 × Ø50.8	1330	233	776 kg	Spec sheet
50″DN1250	Class 400	1568	157.2	1362	1460.5	32 × Ø60.3	1321	268	—	Spec sheet
50″DN1250	Class 600	1670	196.9	1384	1524	28 × Ø79.4	1343	329	—	Spec sheet
52″DN1300	Class 150	1494	68.3	1391	1436.7	52 × Ø31.8	1360	156	236 kg	Spec sheet
52″DN1300	Class 300	1613	141.3	1429	1517.6	48 × Ø50.8	1383	241	835 kg	Spec sheet
52″DN1300	Class 400	1619	162.1	1413	1511.3	32 × Ø60.3	1372	276	—	Spec sheet
52″DN1300	Class 600	1721	203.2	1435	1574.8	32 × Ø79.4	1394	337	—	Spec sheet
54″DN1350	Class 150	1549	69.9	1441	1492.2	56 × Ø31.8	1413	161	281 kg	Spec sheet
54″DN1350	Class 300	1673	135.1	1480	1577.8	48 × Ø50.8	1435	238	898 kg	Spec sheet
54″DN1350	Class 400	1702	169.9	1470	1581.2	28 × Ø66.7	1425	289	—	Spec sheet
54″DN1350	Class 600	1778	209.6	1492	1632	32 × Ø79.4	1448	349	—	Spec sheet
56″DN1400	Class 150	1600	71.6	1492	1543	60 × Ø31.8	1465	165	295 kg	Spec sheet
56″DN1400	Class 300	1765	152.4	1537	1651	36 × Ø60.3	1494	267	1041 kg	Spec sheet
56″DN1400	Class 400	1753	174.8	1527	1632	32 × Ø66.7	1480	298	—	Spec sheet
56″DN1400	Class 600	1854	217.5	1543	1695.4	32 × Ø85.7	1502	362	—	Spec sheet
58″DN1450	Class 150	1675	73.2	1543	1611.3	48 × Ø34.9	1516	173	354 kg	Spec sheet
58″DN1450	Class 300	1827	152.4	1594	1712.9	40 × Ø60.3	1548	273	1256 kg	Spec sheet
58″DN1450	Class 400	1803	177.8	1578	1682.8	32 × Ø66.7	1530	306	—	Spec sheet
58″DN1450	Class 600	1905	222.3	1600	1746.2	32 × Ø85.7	1553	370	—	Spec sheet

REFERENCE

Pressure ratings, materials and tolerances

Transcribed from ASME B16.47-2025 with table and page references.

Pressure-temperature ratings

ASME B16.47-2025 pressure–temperature ratings (Group 1.1)

Table 3 (SI, bar) and Table 3C (U.S. customary, psig) of ASME B16.47-2025 give the maximum working pressure o…

Open reference Material groups

ASME B16.47-2025 material groups (Table 1)

ASME B16.47-2025 sorts every permitted flange material into a numbered group, and the group number — not the …

Open reference Tolerances

ASME B16.47-2025 flange tolerances (Section 7)

Section 7 of ASME B16.47-2025 sets the permissible manufacturing deviations for large-diameter flanges: raise…

Open reference Marking

ASME B16.47-2025 marking requirements (Section 4)

Section 4 of ASME B16.47-2025 defines the identification markings that must appear on every large-diameter fl…

Open reference Edition changes

ASME B16.47-2025 changes and record numbers

ASME B16.47-2025 was approved by the American National Standards Institute on 4 March 2025 and issued on 30 M…

Open reference

How to read the pressure class

Series B follows the former API 605 dimensions, with a smaller outside diameter and a different bolt pattern from Series A. Ratings are ASME classes 150, 300, 400, 600 and 900, with allowable pressure from the B16.47 tables.

Edition and verification

Dimension values on this page have been checked against ASME B16.47-2025 (SI tables, cross-checked against the U.S. Customary tables). The 2025 edition prints exact metric equivalents of the inch dimensions rather than the old 5 mm-rounded values (for example 36.50 in is printed as 927 mm, not 925 mm), and defines flange thickness as excluding the raised face. Both corrections are reflected here; Series B NPS 38 and above follows Series A per the standard’s General Note (h).

Data imported 2026-11-05 08:05.