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

Blind: A solid disc bolted over a line end or vessel opening for isolation, testing and future tie-ins. 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	42.9	711	744.5	36 × Ø22.2	—	—	170 kg	Spec sheet
26″DN650	Class 300	867	87.3	737	803.1	32 × Ø34.9	—	—	411 kg	Spec sheet
26″DN650	Class 400	851	88.9	711	781	28 × Ø38.1	—	—	397 kg	Spec sheet
26″DN650	Class 600	889	111.3	727	806.4	28 × Ø44.5	—	—	542 kg	Spec sheet
26″DN650	Class 900	1022	154	762	901.7	20 × Ø66.7	—	—	991 kg	Spec sheet
28″DN700	Class 150	837	46.2	762	795.3	40 × Ø22.2	—	—	206 kg	Spec sheet
28″DN700	Class 300	921	87.3	787	857.2	36 × Ø34.9	—	—	464 kg	Spec sheet
28″DN700	Class 400	914	95.3	762	838.2	24 × Ø41.3	—	—	490 kg	Spec sheet
28″DN700	Class 600	952	115.9	784	863.6	28 × Ø47.6	—	—	647 kg	Spec sheet
28″DN700	Class 900	1105	166.7	819	971.6	20 × Ø73	—	—	1253 kg	Spec sheet
30″DN750	Class 150	887	49.2	813	846.1	44 × Ø22.2	—	—	247 kg	Spec sheet
30″DN750	Class 300	991	92.1	845	920.8	36 × Ø38.1	—	—	567 kg	Spec sheet
30″DN750	Class 400	972	101.6	819	895.4	28 × Ø41.3	—	—	591 kg	Spec sheet
30″DN750	Class 600	1022	127	841	927.1	28 × Ø50.8	—	—	816 kg	Spec sheet
30″DN750	Class 900	1181	176	876	1035	20 × Ø79.4	—	—	1512 kg	Spec sheet
32″DN800	Class 150	941	52.6	864	900.1	48 × Ø22.2	—	—	294 kg	Spec sheet
32″DN800	Class 300	1054	101.6	902	977.9	32 × Ø41.3	—	—	706 kg	Spec sheet
32″DN800	Class 400	1035	108	873	952.5	28 × Ø44.5	—	—	712 kg	Spec sheet
32″DN800	Class 600	1086	134.9	895	984.2	28 × Ø54	—	—	980 kg	Spec sheet
32″DN800	Class 900	1238	185.7	927	1092.2	20 × Ø79.4	—	—	1753 kg	Spec sheet
34″DN850	Class 150	1005	55.6	921	957.3	40 × Ø25.4	—	—	355 kg	Spec sheet
34″DN850	Class 300	1108	101.6	952	1031.7	36 × Ø41.3	—	—	780 kg	Spec sheet
34″DN850	Class 400	1086	111.3	927	1003.3	32 × Ø44.5	—	—	807 kg	Spec sheet
34″DN850	Class 600	1162	144.3	952	1054.1	24 × Ø60.3	—	—	1200 kg	Spec sheet
34″DN850	Class 900	1314	195	991	1155.7	20 × Ø85.7	—	—	2075 kg	Spec sheet
36″DN900	Class 150	1057	57.2	972	1009.6	44 × Ø25.4	—	—	404 kg	Spec sheet
36″DN900	Class 300	1171	101.6	1010	1089.2	32 × Ø44.5	—	—	871 kg	Spec sheet
36″DN900	Class 400	1156	119.1	981	1066.8	28 × Ø47.6	—	—	980 kg	Spec sheet
36″DN900	Class 600	1213	150.8	1010	1104.9	28 × Ø60.3	—	—	1367 kg	Spec sheet
36″DN900	Class 900	1346	201.6	1029	1200.2	24 × Ø79.4	—	—	2251 kg	Spec sheet
38″DN950	Class 150	1124	61.9	1022	1069.8	40 × Ø28.6	—	—	494 kg	Spec sheet
38″DN950	Class 300	1222	109.5	1060	1140	36 × Ø44.5	—	—	1024 kg	Spec sheet
38″DN950	Class 400	1206	124	1035	1117.6	32 × Ø47.6	—	—	—	Spec sheet
38″DN950	Class 600	1270	155.4	1054	1162	28 × Ø60.3	—	—	—	Spec sheet
38″DN950	Class 900	1460	215.9	1099	1289	20 × Ø92.1	—	—	—	Spec sheet
40″DN1000	Class 150	1175	65.3	1080	1120.6	44 × Ø28.6	—	—	566 kg	Spec sheet
40″DN1000	Class 300	1273	114.3	1115	1190.8	40 × Ø44.5	—	—	1157 kg	Spec sheet
40″DN1000	Class 400	1270	130	1092	1174.8	32 × Ø50.8	—	—	—	Spec sheet
40″DN1000	Class 600	1321	162.1	1111	1212.8	32 × Ø60.3	—	—	—	Spec sheet
40″DN1000	Class 900	1511	223.8	1162	1339.8	24 × Ø92.1	—	—	—	Spec sheet
42″DN1050	Class 150	1226	66.7	1130	1171.4	48 × Ø28.6	—	—	632 kg	Spec sheet
42″DN1050	Class 300	1334	117.5	1168	1244.6	36 × Ø47.6	—	—	1304 kg	Spec sheet
42″DN1050	Class 400	1321	133.4	1143	1225.6	32 × Ø50.8	—	—	—	Spec sheet
42″DN1050	Class 600	1403	171.5	1168	1282.7	28 × Ø66.7	—	—	—	Spec sheet
42″DN1050	Class 900	1562	231.6	1213	1390.6	24 × Ø92.1	—	—	—	Spec sheet
44″DN1100	Class 150	1276	69.9	1181	1222.2	52 × Ø28.6	—	—	716 kg	Spec sheet
44″DN1100	Class 300	1384	125.4	1219	1295.4	40 × Ø47.6	—	—	1499 kg	Spec sheet
44″DN1100	Class 400	1384	139.7	1200	1282.7	32 × Ø54	—	—	—	Spec sheet
44″DN1100	Class 600	1454	177.8	1226	1333.5	32 × Ø66.7	—	—	—	Spec sheet
44″DN1100	Class 900	1648	242.9	1270	1463.5	24 × Ø98.4	—	—	—	Spec sheet
46″DN1150	Class 150	1341	73.2	1235	1284.3	40 × Ø31.8	—	—	828 kg	Spec sheet
46″DN1150	Class 300	1460	128.6	1270	1365.2	36 × Ø50.8	—	—	1708 kg	Spec sheet
46″DN1150	Class 400	1441	146.1	1257	1339.8	36 × Ø54	—	—	—	Spec sheet
46″DN1150	Class 600	1511	185.7	1276	1390.6	32 × Ø66.7	—	—	—	Spec sheet
46″DN1150	Class 900	1734	255.6	1334	1536.7	24 × Ø104.8	—	—	—	Spec sheet
48″DN1200	Class 150	1392	76.2	1289	1335.1	44 × Ø31.8	—	—	928 kg	Spec sheet
48″DN1200	Class 300	1511	133.4	1327	1416	40 × Ø50.8	—	—	1897 kg	Spec sheet
48″DN1200	Class 400	1511	152.4	1308	1403.4	28 × Ø60.3	—	—	—	Spec sheet
48″DN1200	Class 600	1594	195.3	1334	1460.5	32 × Ø73	—	—	—	Spec sheet
48″DN1200	Class 900	1784	263.5	1384	1587.5	24 × Ø104.8	—	—	—	Spec sheet
50″DN1250	Class 150	1443	79.4	1340	1385.9	48 × Ø31.8	—	—	1036 kg	Spec sheet
50″DN1250	Class 300	1562	138.1	1378	1466.8	44 × Ø50.8	—	—	2100 kg	Spec sheet
50″DN1250	Class 400	1568	158.8	1362	1460.5	32 × Ø60.3	—	—	—	Spec sheet
50″DN1250	Class 600	1670	203.2	1384	1524	28 × Ø79.4	—	—	—	Spec sheet
52″DN1300	Class 150	1494	82.6	1391	1436.7	52 × Ø31.8	—	—	1155 kg	Spec sheet
52″DN1300	Class 300	1613	142.5	1429	1517.6	48 × Ø50.8	—	—	2312 kg	Spec sheet
52″DN1300	Class 400	1619	163.5	1413	1511.3	32 × Ø60.3	—	—	—	Spec sheet
52″DN1300	Class 600	1721	209.6	1435	1574.8	32 × Ø79.4	—	—	—	Spec sheet
54″DN1350	Class 150	1549	85.9	1441	1492.2	56 × Ø31.8	—	—	1292 kg	Spec sheet
54″DN1350	Class 300	1673	147.6	1480	1577.8	48 × Ø50.8	—	—	2576 kg	Spec sheet
54″DN1350	Class 400	1702	171.5	1470	1581.2	28 × Ø66.7	—	—	—	Spec sheet
54″DN1350	Class 600	1778	217.5	1492	1632	32 × Ø79.4	—	—	—	Spec sheet
56″DN1400	Class 150	1600	88.9	1492	1543	60 × Ø31.8	—	—	1427 kg	Spec sheet
56″DN1400	Class 300	1765	155.4	1537	1651	36 × Ø60.3	—	—	3013 kg	Spec sheet
56″DN1400	Class 400	1753	176.2	1527	1632	32 × Ø66.7	—	—	—	Spec sheet
56″DN1400	Class 600	1854	225.6	1543	1695.4	32 × Ø85.7	—	—	—	Spec sheet
58″DN1450	Class 150	1675	91.9	1543	1611.3	48 × Ø34.9	—	—	1615 kg	Spec sheet
58″DN1450	Class 300	1827	160.3	1594	1712.9	40 × Ø60.3	—	—	3333 kg	Spec sheet
58″DN1450	Class 400	1803	180.8	1578	1682.8	32 × Ø66.7	—	—	—	Spec sheet
58″DN1450	Class 600	1905	231.6	1600	1746.2	32 × Ø85.7	—	—	—	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.