ASME B16.47 Weld Neck Flange

In industrial piping systems,weld neck flanges serve as critical components for achieving reliable connections between pipes and equipment, as well as between pipes themselves. ASME B16.47 weld neck flange, distinguished by their exceptional structural strength, extensive specification coverage, and stringent quality control, have become a vital solution for high-pressure, large-diameter pipe connections in major industrial sectors such as petroleum, chemical, and energy. They provide a solid foundation for the safe operation of piping systems.

ASME B16.47 Standard

The standard, Large Diameter Steel Flanges, applies to large-diameter, high-pressure weld neck flanges. Series A is based on MSS SP-44 for oil and gas, while Series B is based on API 605 with broader applications. Dimensions and pressure ratings differ slightly, but both follow unified requirements for material, design, and quality control.

Type	weld neck flange，blind flange
Sealing Surface	RF, FF, RTJ
Size Range	26″ – 60″ / DN650 – DN1500
Standard	ASME B16.47 A/B

ASME B16.47 Weld Neck Flange

ASME B16.47 weld neck flanges consist of three parts: the flange ring, the tapered neck, and the beveled weld end. The ring has evenly spaced bolt holes to connect flanges and form a sealed joint. The neck, conical or cylindrical, distributes stresses from pipeline pressure and improves load-bearing capacity. The weld end has a standard bevel (37.5° ± 2.5°) for butt welding. Seal faces include raised face (RF), male-female (MFM), tongue-groove (TG), and others.

ASME B16.47 VS. ASME B16.5

Difference	ASME B16.5	ASME B16.47
Applicable Sizes	1/2″–24″ (small to medium pipelines)	26″–60″ (large industrial pipelines)
Pressure Classes	Class 150, 300, 400, 600, 900, 1500, 2500	Series A: 150, 300, 400, 600, 900 Series B: 75, 150, 300, 400, 600, 900
Flange Types	WN, SO, SW, TH, BL, LAPJ (6 types)	WN, BL (2 types)
Standard Origin & Industry	Independently developed; widely used in petroleum, chemical, power, municipal	Series A: based on MSS SP-44, for high-pressure oil & gasSeries B: based on API 605, for chemical & energy industries
Design & Installation	Smaller structure; simple installation for fast connections	Larger size, thicker neck, some with stiffeners; requires larger bolts and stricter torque

ASME B16.47 Flange Dimension

ASME B16.47 flange standard uses nominal size (NPS) and nominal pressure (Class) as core indicators.

B16.47 Series A Class 150 Flange Dimension

Nominal Pipe Size	A	C		D	E	F	G	H	I	J	R
	mm	mm	mm	mm	mm	mm	mm	Holes	mm	mm	mm
22	749.3	45.97	45.97	149.35	558.8	609.6	641.35	20	35.05	692.15	9.65
26	869.95	68.33	68.33	120.65	660.4	676. 15	749.3	24	35.05	806.45	9.65
28	927.1	71.37	71.37	125.48	711.2	726.95	800.1	28	35.05	863.6	11.18
30	984.25	74.68	74.68	136.65	762	781.05	857.25	28	35.05	914.4	11.18
32	1060.5	81.03	81.03	144.53	812.8	831.85	914.4	28	41.15	977.9	11.18
34	1111.3	82.55	82.55	149.35	863.6	882.65	965.2	32	41.15	1028.7	12.70
36	1168.4	90.42	90.42	157.23	914.4	933.45	1022.4	32	41.15	1085.9	12.70
38	1238.3	87.38	87.38	157.23	965.2	990.60	1073.2	32	41.15	1149.4	12.70
40	1289.1	90.42	90.42	163.58	1016	1041.4	1124.0	36	41.15	1200.2	12.70
42	1346.2	96.77	96.77	171.45	1066.8	1092.2	1193.8	36	41.15	1257.3	12.70
44	1403.4	101.6	101.60	177.80	1117.6	1143	1244.6	40	41.15	1314.5	12.70
46	1454.2	103. 12	103.12	185.67	1168.4	1196.9	1295.4	40	41.15	1365.3	12.70
48	1511.3	107.95	107.95	192.02	1219.2	1247.7	1358.9	44	41.15	1422.4	12.70

B16.47 Series A Class 300 Flange Dimension

Nominal Pipe Size	A	C		D	E	F	G	H	I	J	R
	mm	mm	mm	mm	mm	mm	mm	Holes	mm	mm	mm
22	838.20	66.55	66.55	165.1	558.80	641.35	641.35	24	41.15	742.95	9.65
26	971.55	79.25	84.07	184.15	660.40	720.85	749.30	28	44.45	876.30	9.65
28	1035.1	85.85	90.42	196.85	711.20	774.70	800.10	28	44.45	939.80	11. 18
30	1092.2	91.95	95.25	209.55	762.00	827.02	857.25	28	47.75	996.95	11. 18
32	1149.4	98.55	100.08	222.25	812.80	881.13	914.40	28	50.80	1054. 1	11. 18
34	120.50	101.60	104.65	231.65	863.60	936.75	965.20	28	50.80	1104.9	12.70
36	1270.0	104.65	111.25	241.30	914.40	990.60	1022.40	32.00	53.85	1168.40	12.70
38	1168.4	107.95	107.95	180.85	965.20	993.65	1028.70	32.00	41.15	1092.20	12.70
40	1238.3	114.30	114.30	193.55	1016.00	1047.8	1085.90	32.00	44.45	1155.70	12.70
42	1289.1	119.13	119.13	200.15	1066.80	1098.6	1136.70	32.00	44.45	1206.60	12.70
44	1352.6	123.95	123.95	206.25	1117.60	1149.4	1193.80	32.00	47.75	1263.70	12.70
46	1416.1	128.52	128.52	215.90	1168.40	1203.5	1244.00	28.00	50.80	1320.80	12.70
48	1466.9	133.35	133.35	223.77	1219.20	1254.3	1301.80	32.00	50.80	1371.60	12.70

B16.47 Series B Class 150 Flange Dimension

Nominal Pipe Size	A	C		D	E	F	G	H	I	J	R
	mm	mm	mm	mm	mm	mm	mm	Holes	mm	mm	mm
26	785.88	41.15	44.45	88.90	661.92	684.28	711.20	36	22.35	744.47	9.65
28	836.68	44.45	47.75	95.25	712.72	735.08	762.00	40	22.35	795.27	9.65
30	887.48	44.45	50.80	100.08	763.52	787.40	812.80	44	22.35	846.07	9.65
32	941.32	45.97	53.85	107.95	814.32	839.72	863.60	48	22.35	900.18	9.65
34	1004.8	49.28	57.15	110.24	865.12	892.05	920.75	40	25.40	957.33	9.65
36	1057.1	52.32	58.67	117.35	915.92	944.63	971.55	44	25.40	1009.7	9.65
38	1124.0	53.85	63.50	123.95	968.25	996.95	1022.4	40	28.45	1069.8	9.65
40	1174.8	55.63	66.55	128.52	1019.0	1049.3	1079.5	44	28.45	1120.6	9.65
42	1225.6	58.67	68.33	133.35	1069.8	1101.9	1130.3	48	28.45	1171.4	11.18
44	1276.4	60.45	71.37	136.65	1120.6	1152.7	1181.1	52	28.45	1222.2	11.18
46	1341.4	61.98	74.68	144.53	1171.4	1205.0	1234.9	40	31.75	1284.2	11.18
48	1392.2	65.02	77.72	149.35	1222.2	1257.3	1289.1	44	31.75	1335.0	11.18

B16.47 Series B Class 300 Flange Dimension

Nominal Pipe Size	A	C		D	E	F	G	H	I	J	R
	mm	mm	mm	mm	mm	mm	mm	Holes	mm	mm	mm
26	866.65	88.90	88.90	144.53	665.23	701.55	736.60	32	35.05	803.15	14.22
28	920.75	88.90	88.90	149.35	716.03	755.65	787.40	36	35.05	857.25	14.22
30	990.60	93.73	93.73	157.99	768.35	812.80	844.55	36	38.10	920.75	14.22
32	1054.1	103.12	103.12	168. 15	819.15	863.60	901.70	32	41.15	977.90	15.75
34	1107.9	103.12	103.12	172.97	869.95	917.45	952.50	36	41.15	1031.7	15.75
36	1171.4	103.12	103.12	180.85	920.75	965.20	1009.7	32	44.45	1089.2	15.75
38	1222.2	111.25	111.25	192.02	971.55	1016.0	1060.5	36	44.45	1140.0	15.75
40	1273.0	115.82	115.82	198.37	1022.4	1066.8	1114.6	40	44.45	1190.8	15.75
42	1333.5	119.13	119.13	204.72	1074.7	1117.6	1168.4	36	47.75	1244.6	15.75
44	1384.3	127.00	127.00	214.38	1125.5	1173.2	1219.2	40	47.75	1295.4	15.75
46	1460.5	128.52	130.05	222.25	1176.3	1228.9	1270.0	36	50.80	1365.3	15.75
48	1511.3	128.52	134.87	223.77	1227.1	1277.9	1327.2	40	50.80	1416. 1	15.75

Flange Common Material(A105 & A182）

ASTM A105 Chemical Composition

CHEMICAL	LIMITS	C	Mn	P	S	Si	Cu	Ni	Cr	Mo	V
ASTM A105	MIN		0.60			0.10
	MAX	0.35	1.05	0.035	0.040	0.35	0.40	0.40	0.30	0.12	0.08
ASTM A105N	MIN		0.600
	MAX	0.350	1.050	0.040	0.050		0.400		0.300	0.120	0.080

ASTM A182 Chemical Composition

CHEMICAL	LIMITS	C	Mn	P	S	Si	Ni	Cr	Mo	N
ASTM A182 F304	MIN						8.0	18.0
	MAX	0.08	2.00	0.045	0.030	1.00	11.0	20.0		0.10
ASTM A182 F304H	MIN	0.04					8.00	18.00
	MAX	0.10	2.00	0.045	0.030	1.00	11.00	20.00
ASTM A182 F304L	MIN						8.00	18.00
	MAX	0.03	2.00	0.045	0.030	1.00	13.00	20.00		0.10
ASTM A182 F316	MIN						10.0	16.0	2.00
	MAX	0.08	2.00	0.045	0.030	1.00	14.0	18.0	3.00	0.10
ASTM A182 F316L	MIN						10.00	16.0	2.00
	MAX	0.03	2.00	0.045	0.030	1.00	15.00	18.0	3.00	0.10

ASME B16.47 Weld Neck Flange Application

Oil and Gas Industry

Petrochemical Industry

Liquefied Natural Gas Facilities

Power Generation Industry

Large Offshore Platforms and Marine Engineering

Large Chemical and Fertilizer Plants

10 12 月, 2025