Weld Neck Flange Dimensions: ASME B16.47 Series A & B

Understanding of ASME B16.47 Flange Dimensions:

ASME has incorporated most of the MSS-SP44 specification into B16.47 Series A and API 605 specification into Series B. ASME B16.47 is specifically designed for large-diameter pipe from NPS size 26″ through 60″.

Very important to note that ASME B16.47 only covers the Weld-Neck and Blind Flanges. There is no B16.47 Slip-on flange approved by ASME. But you may find some industry standard flanges that were designed by the manufacturer’s engineers and produced to meet ASME B16.47 standards.

Facts about ASME B16.47 Flanges:

ASME B16.47 offers two different series A & B with pressure classes ranging from 150 to 900.
ASME B16.47 flanges are available from 26 NPS to 60 NPS sizes.
This specification only covers Raised Face flange but you can order Flat Face.
Manufacturers mostly machine the raised face and re-finish the gasket face to ASME standard.
Series A and Series B are not interchangeable. Both have different Bolt Circle Diameters.

This page will cover key dimensions for ASME B16.47 Series A & B Weld Neck Flanges From 26 NPS to 60 NPS with Pressure rating classes 150, 300, 400, 600 & 900.

How to Write Flange Description:

If you would like to order proper Weld Neck flanges or want to add a description in BOM, typically You need to specify the following details:

NPS size for Flange (EX: 30 NPS)
Type of Flange (EX: Weld Neck FF or Weld-neck RF)
Pressure Class (EX: Class 150)
Bore Diameter to Match ID of Pipe or Connecting Pipe Schedule (EX: SCH STD or 0.375W)
Organization Name & Code that covers its specification (EX: ASME B16.47 A or B)
Finally, Material Specification & Code (EX: ASTM A182, 304L, A105)

Please click on the link for more information about:

ASME B16.47 Dimensional Tolerances & Welding Bevel Standards
ASME B16.47 Bolt & Stud Dimensions

Weld Neck Flange Dimension — WELD NECK CL150
*Bore will be specified by Customer*

Weld Neck Flange Class 150: ASME B16.47 Series A

wdt_ID	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE
1	26	34.25	2.63	29.50	26.62	4.69	26.00	31.75	1.38	24
2	28	36.50	2.75	31.50	28.62	4.88	28.00	34.00	1.38	28
3	30	38.75	2.88	33.75	30.75	5.32	30.00	36.00	1.38	28
4	32	41.75	3.13	36.00	32.75	5.63	32.00	38.50	1.62	28
5	34	43.75	3.19	38.00	34.75	5.82	34.00	40.50	1.62	32
6	36	46.00	3.50	40.25	36.75	6.13	36.00	42.75	1.62	32
7	38	48.75	3.38	42.25	39.00	6.13	38.00	45.25	1.62	32
8	40	50.75	3.50	44.25	41.00	6.38	40.00	47.25	1.62	36
9	42	53.00	3.75	47.00	43.00	6.69	42.00	49.50	1.62	36
10	44	55.25	3.94	49.00	45.00	6.94	44.00	51.75	1.62	40
11	46	57.25	4.00	51.00	47.12	7.25	46.00	53.75	1.62	40
12	48	59.50	4.19	53.50	49.12	7.50	48.00	56.00	1.62	44
13	50	61.75	4.32	55.50	51.25	7.94	50.00	58.25	1.88	44
14	52	64.00	4.50	57.50	53.25	8.19	52.00	60.50	1.88	44
15	54	66.25	4.69	59.50	55.25	8.44	54.00	62.75	1.88	44
16	56	68.75	4.82	62.00	57.38	8.94	56.00	65.00	1.88	48
17	58	71.00	5.00	64.00	59.38	9.19	58.00	67.25	1.88	48
18	60	73.00	5.13	66.00	61.38	9.38	60.00	69.25	1.88	52
	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE

Weld Neck Flange Class 300: ASME B16.47 Series A

wdt_ID	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE
1	26	38.25	3.07	29.50	28.38	7.19	26.00	34.50	1.75	28
2	28	40.75	3.32	31.50	30.50	7.69	28.00	37.00	1.75	28
3	30	43.00	3.57	33.75	32.56	8.19	30.00	39.25	1.88	28
4	32	45.25	3.82	36.00	34.69	8.69	32.00	41.50	2	28
5	34	47.50	3.94	38.00	36.88	9.07	34.00	43.50	2	28
6	36	50.00	4.07	40.25	39.00	9.44	36.00	46.00	2.12	32
7	38	46.00	4.19	40.50	39.00	7.06	38.00	43.00	1.62	32
8	40	48.75	4.44	42.75	41.25	7.56	40.00	45.50	1.75	32
9	42	50.75	4.63	44.75	43.25	7.82	42.00	47.50	1.75	32
10	44	53.25	4.82	47.00	45.25	8.06	44.00	49.75	1.88	32
11	46	55.75	5.00	49.00	47.38	8.44	46.00	52.00	2	28
12	48	57.75	5.19	51.25	49.38	8.75	48.00	54.00	2	32
13	50	60.25	5.44	53.50	51.38	9.07	50.00	56.25	2.12	32
14	52	62.25	5.63	55.50	53.38	9.32	52.00	58.25	2.12	32
15	54	65.25	5.94	57.75	55.50	9.88	54.00	61.00	2.38	28
16	56	67.25	6.00	59.75	57.62	10.19	56.00	63.00	2.38	28
17	58	69.25	6.19	62.00	59.62	10.44	58.00	65.00	2.38	32
18	60	71.25	6.38	64.00	61.62	10.69	60.00	67.00	2.38	32
	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE

Weld Neck Flange Class 400: ASME B16.47 Series A

wdt_ID	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE
1	26	38.25	3.50	29.50	28.62	7.62	26.00	34.50	1.88	28
2	28	40.75	3.75	31.50	30.81	8.12	28.00	37.00	2	28
3	30	43.00	4.00	33.75	32.94	8.62	30.00	39.25	2.12	28
4	32	45.25	4.25	36.00	35.00	9.12	32.00	41.50	2.12	28
5	34	47.50	4.38	38.00	37.19	9.50	34.00	43.50	2.12	28
6	36	50.00	4.50	40.25	39.38	9.88	36.00	46.00	2.12	32
7	38	47.50	4.88	40.75	39.50	8.12	38.00	44.00	1.88	32
8	40	50.00	5.12	43.00	41.50	8.50	40.00	46.25	2	32
9	42	52.00	5.25	45.00	43.62	8.81	42.00	48.25	2	32
10	44	54.50	5.50	47.25	45.62	9.18	44.00	50.50	2.12	32
11	46	56.75	5.75	49.50	47.75	10.12	46.00	52.75	2.12	36
12	48	59.50	6.00	51.50	49.88	10.12	48.00	55.25	2.38	28
13	50	61.75	6.19	53.62	52.00	10.56	50.00	57.50	2.38	32
14	52	63.75	6.38	55.62	54.00	10.88	52.00	59.50	2.38	32
15	54	67.00	6.69	57.88	56.12	11.38	54.00	62.25	2.62	28
16	56	69.00	6.88	60.12	58.25	11.75	56.00	64.25	2.62	32
17	58	71.00	7.00	62.12	60.25	12.06	58.00	66.25	2.62	32
19	60	74.25	7.31	64.38	62.38	12.56	60.00	69.00	2.88	32
	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE

Weld Neck Flange Class 600: ASME B16.47 Series A

wdt_ID	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE
1	26	40.00	4.25	29.50	29.44	8.75	26.00	36.00	2	28
2	28	42.25	4.38	31.50	31.62	9.25	28.00	38.00	2.12	28
3	30	44.50	4.50	33.75	33.94	9.75	30.00	40.25	2.12	28
4	32	47.00	4.62	36.00	36.12	10.25	32.00	42.50	2.38	28
5	34	49.00	4.75	38.00	38.31	10.62	34.00	44.50	2.38	28
6	36	51.75	4.88	40.25	40.62	11.12	36.00	47.00	2.62	28
7	38	50.00	6.00	41.50	40.25	10.00	38.00	45.75	2.38	28
8	40	52.00	6.25	43.75	42.25	10.38	40.00	47.75	2.38	32
9	42	55.25	6.62	46.00	44.38	11.00	42.00	50.50	2.62	28
10	44	57.25	6.81	48.25	46.50	11.38	44.00	52.50	2.62	32
11	46	59.50	7.06	50.25	48.62	11.81	46.00	54.75	2.62	32
12	48	62.75	7.44	52.50	50.75	12.44	48.00	57.50	2.88	32
13	50	65.75	7.75	54.50	52.88	12.94	50.00	60.00	3.12	28
14	52	67.75	8.00	56.50	54.88	13.25	52.00	62.00	3.12	32
15	54	70.00	8.25	58.75	57.00	13.75	54.00	64.25	3.12	32
16	56	73.00	8.56	60.75	59.12	14.25	56.00	66.75	3.38	32
17	58	75.00	8.75	63.00	61.12	14.56	58.00	68.75	3.38	32
18	60	78.50	9.19	65.25	63.38	15.31	60.00	71.75	3.62	28
	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE

Weld Neck Flange Class 900: ASME B16.47 Series A

wdt_ID	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE
1	26	42.75	5.50	29.50	30.50	11.25	26.00	37.50	2.88	20
2	28	46.00	5.62	31.50	32.75	11.75	28.00	40.25	3.12	20
3	30	48.50	5.88	33.75	35.00	12.25	30.00	42.75	3.12	20
4	32	51.75	6.25	36.00	37.25	13.00	32.00	45.50	3.38	20
5	34	55.00	6.50	38.00	39.62	13.75	34.00	48.25	3.62	20
6	36	57.50	6.75	40.25	41.88	14.25	36.00	50.75	3.62	20
7	38	57.50	7.50	43.25	42.25	13.88	38.00	50.75	3.62	20
8	40	59.50	7.75	45.75	44.38	14.31	40.00	52.75	3.62	24
9	42	61.50	8.12	47.75	46.31	14.62	42.00	54.75	3.62	24
10	44	64.88	8.44	50.00	48.62	15.38	44.00	57.62	3.88	24
11	46	68.25	8.88	52.50	50.88	16.18	46.00	60.50	4.12	24
12	48	70.25	9.19	54.50	52.88	16.50	48.00	62.50	4.12	24
	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE

Flange Dimensions for ASME B16.47 Series-B

Weld Neck Flange Class 75: ASME B16.47 Series B

wdt_ID	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE
1	26	30.00	1.25	27.75	26.62	2.25	26.06	28.50	0.75	36
2	28	32.00	1.25	29.75	28.62	2.38	28.06	30.50	0.75	40
3	30	34.00	1.25	31.75	30.62	2.50	30.06	32.50	0.75	44
4	32	36.00	1.32	33.75	32.62	2.69	32.06	34.50	0.75	48
5	34	38.00	1.32	35.75	34.62	2.82	34.06	36.50	0.75	52
6	36	40.69	1.38	38.00	36.81	3.32	36.06	39.06	0.88	40
7	38	42.69	1.44	40.00	38.81	3.44	38.06	41.06	0.88	40
8	40	44.69	1.44	42.00	40.81	3.57	40.06	43.06	0.88	44
9	42	46.69	1.50	44.00	42.81	3.69	42.06	45.06	0.88	48
10	44	49.25	1.63	46.25	44.88	4.07	44.06	47.38	1	36
11	46	51.25	1.69	48.25	46.88	4.19	46.06	49.38	1	40
12	48	53.25	1.75	50.25	48.88	4.32	48.06	51.38	1	44
13	50	55.25	1.82	52.25	50.94	4.50	50.06	53.38	1	44
14	52	57.38	1.82	54.25	52.94	4.69	52.06	55.50	1	48
15	54	59.38	1.88	56.25	55.00	4.88	54.06	57.50	1	48
16	56	62.00	1.94	58.50	57.12	5.25	56.06	59.88	1.12	40
17	58	64.00	2.00	60.50	59.12	5.38	58.06	61.88	1.12	44
18	60	66.00	2.13	62.50	61.12	5.63	60.06	63.88	1.12	44
	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE

Weld Neck Flange Class 150: ASME B16.47 Series B

wdt_ID	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE
1	26	30.94	1.57	28.00	26.94	3.44	26.06	29.31	0.88	36
2	28	32.94	1.69	30.00	28.94	3.69	28.06	31.31	0.88	40
3	30	34.94	1.69	32.00	31.00	3.88	30.06	33.31	0.88	44
4	32	37.06	1.75	34.00	33.06	4.19	32.06	35.44	0.88	48
5	34	39.56	1.88	36.25	35.12	4.28	34.06	37.69	1	40
6	36	41.62	2.00	38.25	37.19	4.57	36.06	39.75	1	44
7	38	44.25	2.07	40.25	39.25	4.82	38.12	42.12	1.12	40
8	40	46.25	2.13	42.50	41.31	5.00	40.12	44.12	1.12	44
9	42	48.25	2.25	44.50	43.38	5.19	42.12	46.12	1.12	48
10	44	50.25	2.32	46.50	45.38	5.32	44.12	48.12	1.12	52
11	46	52.81	2.38	48.62	47.44	5.63	46.12	50.56	1.25	40
12	48	54.81	2.50	50.75	49.50	5.82	48.12	52.56	1.25	44
13	50	56.81	2.63	52.75	51.50	6.00	50.12	54.56	1.25	48
14	52	58.81	2.69	54.75	53.56	6.13	52.12	56.56	1.25	52
15	54	61.00	2.75	56.75	55.62	6.32	54.12	58.75	1.25	56
16	56	63.00	2.82	58.75	57.69	6.50	56.12	60.75	1.25	60
17	58	65.94	2.88	60.75	59.69	6.82	58.12	63.44	1.38	48
18	60	67.94	2.94	63.00	61.81	7.00	60.12	65.44	1.38	52
	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE

Weld Neck Flange Class 300: ASME B16.47 Series B

wdt_ID	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE
1	26	34.12	3.44	29.00	27.62	5.63	26.19	31.62	1.38	32
2	28	36.25	3.44	31.00	29.75	5.81	28.19	33.75	1.38	36
3	30	39.00	3.63	33.25	32.00	6.16	30.25	36.25	1.5	36
4	32	41.50	4.00	35.50	34.00	6.56	32.25	38.50	1.62	32
5	34	43.62	4.00	37.50	36.12	6.75	34.25	40.62	1.62	36
6	36	46.12	4.00	39.75	38.00	7.06	36.25	42.88	1.75	32
7	38	48.12	4.31	41.75	40.00	7.50	38.25	44.88	1.75	36
8	40	50.12	4.50	43.88	42.00	7.75	40.25	46.88	1.75	40
9	42	52.50	4.63	46.00	44.00	8.00	42.31	49.00	1.88	36
10	44	54.50	4.94	48.00	46.19	8.38	44.31	51.00	1.88	40
11	46	57.50	5.00	50.00	48.38	8.69	46.31	53.75	2	36
12	48	59.50	5.00	52.25	50.31	8.75	48.31	55.75	2	40
13	50	61.50	5.38	54.25	52.38	9.19	50.31	57.75	2	44
14	52	63.50	5.56	56.25	54.44	9.50	52.31	59.75	2	48
15	54	65.88	5.32	58.25	56.50	9.38	54.31	62.12	2	48
16	56	69.50	6.00	60.50	58.81	10.50	56.31	65.00	2.38	36
17	58	71.94	6.00	62.75	60.94	10.75	58.31	67.44	2.38	40
18	60	73.94	5.88	65.00	62.94	10.63	60.31	96.44	2.38	40
	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE

Weld Neck Flange Class 400: ASME B16.47 Series B

wdt_ID	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE
1	26	33.50	3.50	28.00	27.12	5.88	26.00	30.75	1.5	28
2	28	36.00	3.75	30.00	29.12	6.25	28.00	33.00	1.62	24
3	30	38.25	4.00	32.25	31.25	6.69	30.00	35.25	1.62	28
4	32	40.75	4.25	34.38	33.25	7.06	32.00	37.50	1.75	28
5	34	42.75	4.38	36.50	35.38	7.38	34.00	39.50	1.75	32
6	36	45.50	4.69	38.62	37.50	7.88	36.00	42.00	1.88	28
7	38	47.50	4.88	40.75	39.50	8.12	38.00	44.00	1.88	32
8	40	50.00	5.12	43.00	41.50	8.50	40.00	46.25	2	32
9	42	52.00	5.25	45.00	43.62	8.81	42.00	48.25	2	32
10	44	54.50	5.50	47.25	45.62	9.18	44.00	50.50	2.12	32
11	46	56.75	5.75	49.50	47.75	9.62	46.00	52.75	2.12	36
12	48	59.50	6.00	51.50	49.88	10.12	48.00	55.25	2.38	28
13	50	61.75	6.19	53.62	52.00	10.56	50.00	57.50	2.38	32
14	52	63.75	6.38	55.62	54.00	10.88	52.00	59.50	2.38	32
15	54	67.00	6.69	57.88	56.12	11.38	54.00	62.25	2.62	28
16	56	69.00	6.88	60.12	58.25	11.75	56.00	64.25	2.62	32
17	58	71.00	7.00	62.12	60.25	12.06	58.00	66.25	2.62	32
18	60	74.25	7.31	64.38	62.38	12.56	60.00	69.00	2.88	32
	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE

Weld Neck Flange Class 600: ASME B16.47 Series B

wdt_ID	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE
1	26	35.00	4.38	28.62	27.50	7.12	26.00	31.75	1.75	28
2	28	37.50	4.56	30.88	29.62	7.50	28.00	34.00	1.88	28
3	30	40.25	4.94	33.12	31.75	8.06	30.00	36.50	2	28
4	32	42.75	5.12	35.25	33.88	8.50	32.00	38.75	2.12	28
5	34	45.75	5.56	37.50	36.00	9.19	34.00	41.50	2.38	24
6	36	47.75	5.75	39.75	38.12	9.56	36.00	43.50	2.38	28
7	38	50.00	6.00	41.50	40.25	10.00	38.00	45.75	2.38	28
8	40	52.00	6.25	43.75	42.25	10.38	40.00	47.75	2.38	32
9	42	55.25	6.62	46.00	44.38	11.00	42.00	50.50	2.62	28
10	44	57.25	6.81	48.25	46.50	11.38	44.00	52.50	2.62	32
11	46	59.50	7.06	50.25	48.62	11.81	46.00	54.75	2.62	32
12	48	62.75	7.44	52.50	50.75	12.44	48.00	57.50	2.88	32
13	50	65.75	7.75	54.50	52.88	12.94	50.00	60.00	3.12	28
14	52	67.75	8.00	56.50	54.88	13.25	52.00	62.00	3.12	32
15	54	70.00	8.25	58.75	57.00	13.75	54.00	64.25	3.12	32
16	56	73.00	8.56	60.75	59.12	14.25	56.00	66.75	3.38	32
17	58	75.00	8.75	63.00	61.12	14.56	58.00	68.75	3.38	32
18	60	78.50	9.19	65.25	63.38	15.31	60.00	71.75	3.62	28
	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE

Weld Neck Flange Class 900: ASME B16.47 Series B

wdt_ID	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE
1	26	40.25	5.31	30.00	29.25	10.19	26.00	35.50	2.62	20
2	28	43.50	5.81	32.25	31.38	10.88	28.00	38.25	2.88	20
3	30	46.50	6.12	34.50	33.50	11.38	30.00	40.75	3.12	20
4	32	48.75	6.31	36.50	35.75	11.94	32.00	43.00	3.12	20
5	34	51.75	6.75	39.00	37.88	12.56	34.00	45.50	3.38	20
6	36	53.00	6.81	40.50	40.00	12.81	36.00	47.25	3.12	24
7	38	57.50	7.50	43.25	42.25	13.88	38.00	50.75	3.62	20
8	40	59.50	7.75	45.75	44.38	14.31	40.00	52.75	3.62	24
9	42	61.50	8.12	47.75	46.31	14.62	42.00	54.75	3.62	24
10	44	64.88	8.44	50.00	48.62	15.38	44.00	57.62	3.88	24
11	46	68.25	8.88	52.50	50.88	16.18	46.00	60.50	4.12	24
12	48	70.25	9.19	54.50	52.88	16.50	48.00	62.50	4.12	24
	Nom. Pipe Size	O	T	R	X	L	H	B.C.D	HOLE DIA	#HOLE