Socket Weld Flange Dimensions: ASME B16.5

Socket Weld flanges are similar in dimensions to slip-on flanges but instead of the plain bore, it is the recessed area inside the bore. This extra shoulder serves as a guide and it matches to connecting pipe’s inside diameter. It was designed for small diameter high-pressure lines where there is a minimum void between flanged connections.

Only CL150 comes in sizes 1/2 NPS to 24 NPS. CL300 and above come in a maximum of 3 NPS. I also won’t recommend using threaded flanges larger than 3 NPS for any class.

This page will cover key dimensions for ASME B16.5 Socket Weld Flanges From 1/2 NPS to 3 NPS with Pressure rating classes 150, 300, 400, 600, & 1500.

Please click on blow link for more information about:

ASME B16.5 Dimensional Tolerances & Welding Bevel Standards
ASME B16.5 Bolt & Stud Dimensions
ASME B16.47 A/B Large Diameter Flange Dimension from 26 NPS to 60 NPS

Bore* – bore will be specified by the customer to match the ID of connecting pipe. It mostly depends on the schedule of pipe/pipe wall thickness.

Socket Weld Flange Dimension — SW Flange CL150

Socket Weld Flange Class 150: ASME B16.5

wdt_ID	Nom. Pipe Size	O	T	R	X	# - Bolt Hole	B.C.D	B	Bore	L	D
1	½	3.50	0.38	1.38	1.19	4-0.62	2.38	0.88	0.62	0.56	0.38
2	¾	3.88	0.44	1.69	1.50	4-0.62	2.75	1.09	0.82	0.56	0.44
3	1	4.25	0.50	2.00	1.94	4-0.62	3.12	1.36	1.05	0.62	0.50
4	1¼	4.62	0.56	2.50	2.31	4-0.62	3.50	1.70	1.38	0.75	0.56
5	1½	5.00	0.62	2.88	2.56	4-0.62	3.88	1.95	1.61	0.81	0.62
6	2	6.00	0.69	3.62	3.06	4-0.75	4.75	2.44	2.07	0.94	0.69
7	2½	7.00	0.81	4.12	3.56	4-0.75	5.50	2.94	2.47	1.06	0.75
8	3	7.50	0.88	5.00	4.25	4-0.75	6.00	3.57	3.07	1.12	0.81
9	3½	8.50	0.88	5.50	4.81	8-0.75	7.00	4.07	3.55	1.19	0.88
10	4	9.00	0.88	6.19	5.31	8-0.75	7.50	4.57	4.03	1.25	0.94
11	5	10.00	0.88	7.31	6.44	8-0.88	8.50	5.66	5.05	1.38	0.94
12	6	11.00	0.94	8.50	7.56	8-0.88	9.50	6.72	6.07	1.50	1.06
13	8	13.50	1.06	10.62	9.69	8-0.88	11.75	8.72	7.98	1.69	1.25
14	10	16.00	1.12	12.75	12.00	12-1.00	14.25	10.88	10.02	1.88	1.31
15	12	19.00	1.19	15.00	14.38	12-1.00	17.00	12.88	12.00	2.12	1.56
16	14	21.00	1.31	16.25	15.75	12-1.12	18.75	14.14	13.25	2.19	1.63
17	16	23.50	1.38	18.50	18.00	16-1.12	21.25	16.16	15.25	2.44	1.75
18	18	25.00	1.50	21.00	19.88	16-1.25	22.75	18.18	17.25	2.62	1.94
19	20	27.50	1.62	23.00	22.00	20-1.25	25.00	20.20	19.25	2.81	2.13
20	22	29.50	1.75	25.25	24.25	20-1.38	27.25	22.22	21.25	3.07	2.38
21	24	32.00	1.81	27.25	26.12	20-1.38	29.50	24.25	23.25	3.19	2.50
	Nom. Pipe Size	O	T	R	X	# - Bolt Hole	B.C.D	B	Bore	L	D

Socket Weld Flange Class 300: ASME B16.5

wdt_ID	Nom. Pipe Size	O	T	R	X	# - Bolt Hole	B.C.D	B	Bore	L	D
1	½	3.75	0.50	1.38	1.50	4-0.63	2.62	0.88	0.62	0.81	0.38
2	¾	4.62	0.56	1.69	1.88	4-0.75	3.25	1.09	0.82	0.94	0.44
3	1	4.88	0.62	2.00	2.12	4-0.75	3.50	1.36	1.05	1.00	0.50
4	1¼	5.25	0.69	2.50	2.50	4-0.75	3.88	1.70	1.38	1.00	0.56
5	1½	6.12	0.75	2.88	2.75	4-0.88	4.50	1.95	1.61	1.13	0.62
6	2	6.50	0.81	3.62	3.31	8-0.75	5.00	2.44	2.07	1.25	0.69
7	2½	7.50	0.94	4.12	3.94	8-0.88	5.88	2.94	2.47	1.44	0.75
8	3	8.25	1.06	5.00	4.62	8-0.88	6.62	3.57	3.07	1.63	0.81
	Nom. Pipe Size	O	T	R	X	# - Bolt Hole	B.C.D	B	Bore	L	D

Socket Weld Flange Class 400: ASME B16.5

wdt_ID	Nom. Pipe Size	O	T	R	X	# - Bolt Hole	B.C.D	B	Bore	L	D
1	½	3.75	0.56	1.38	1.50	4-0.63	2.62	0.88	0.00	0.88	0.38
2	¾	4.62	0.62	1.69	1.88	4-0.75	3.25	1.09	0.00	1.00	0.44
3	1	4.88	0.69	2.00	2.12	4- 75	3.50	1.36	0.00	1.06	0.50
4	1¼	5.25	0.81	2.50	2.50	4-0.75	3.88	1.70	0.00	1.12	0.56
5	1½	6.12	0.88	2.88	2.75	4-0.88	4.50	1.95	0.00	1.25	0.62
6	2	6.50	1.00	3.62	3.31	8-0.75	5.00	2.44	0.00	1.44	0.69
7	2½	7.50	1.12	4.12	3.94	8-0.88	5.88	2.94	0.00	1.62	0.75
8	3	8.25	1.25	5.00	4.62	8-0.88	6.62	3.57	0.00	1.81	0.81
	Nom. Pipe Size	O	T	R	X	# - Bolt Hole	B.C.D	B	Bore	L	D

Socket Weld Flange Class 600: ASME B16.5

wdt_ID	Nom. Pipe Size	O	T	R	X	# - Bolt Hole	B.C.D	B	Bore	L	D
1	½	3.75	0.56	1.38	1.50	4-0.63	2.62	0.88	0.00	0.88	0.38
2	¾	4.62	0.62	1.69	1.88	4-0.75	3.25	1.09	0.00	1.00	0.44
3	1	4.88	0.69	2.00	2.12	4-0.75	3.50	1.36	0.00	1.06	0.50
4	1¼	5.25	0.81	2.50	2.50	4-0.75	3.88	1.70	0.00	1.12	0.56
5	1½	6.12	0.88	2.88	2.75	4-0.88	4.50	1.95	0.00	1.25	0.62
6	2	6.50	1.00	3.62	3.31	8-0.75	5.00	2.44	0.00	1.44	0.69
7	2½	7.50	1.12	4.12	3.94	8-0.88	5.88	2.94	0.00	1.62	0.75
8	3	8.25	1.25	5.00	4.62	8-0.88	6.62	3.57	0.00	1.81	0.81
	Nom. Pipe Size	O	T	R	X	# - Bolt Hole	B.C.D	B	Bore	L	D

Socket Weld Flange Class 1500: ASME B16.5

wdt_ID	Nom. Pipe Size	O	T	R	X	# - Bolt Hole	B.C.D	B	Bore	L	D
1	½	4.75	0.88	1.38	1.50	4-0.88	3.25	0.88	0.00	1.25	0.38
2	¾	5.12	1.00	1.69	1.75	4-0.88	3.50	1.09	0.00	1.38	0.44
3	1	5.88	1.12	2.00	2.06	4-1.00	4.00	1.36	0.00	1.62	0.50
4	1¼	6.25	1.12	2.50	2.50	4-1.00	4.38	1.70	0.00	1.62	0.56
5	1½	7.00	1.25	2.88	2.75	4-1.12	4.88	1.95	0.00	1.75	0.62
6	2	8.50	1.50	3.63	4.12	8-1.00	6.50	2.44	0.00	2.25	0.69
7	2½	9.62	1.62	4.13	4.88	8-1.12	7.50	2.94	0.00	2.50	0.75
	Nom. Pipe Size	O	T	R	X	# - Bolt Hole	B.C.D	B	Bore	L	D