ASME B16.5 Weld Neck Flange/WN Flange Dimensions

Weld neck flange (also known as a high-hub flange and tapered hub flange) is a type of flange. There are two designs. The regular type is used with pipes. The long type is unsuitable for pipes and is used in process plant.A weld neck flange consists of a circular fitting with a protruding rim around the circumference. Generally machined from a forging, these flanges are typically butt welded to a pipe. The rim has a series of drilled holes that permit the flange to be affixed to another flange with bolts.

ASME B16.5 Welding Neck Flanges Class 150/300LBS Dimensions
ASME B16.5 Welding Neck Flanges Class 150LBS Dimensions
NPS
A
B
I
Holes
C
D
F
E
G
Weight
1/2″
89
15.7
15.7
4
11.2
47.8
30.2
21.3
35.1
0.5
3/4″
99
20.8
15.7
4
12.7
52.3
38.1
26.7
42.9
0.73
1″
108
26.7
15.7
4
14.2
55.6
49.3
33.5
50.8
1.05
1-1/4″
117
35.1
15.7
4
15.7
57.2
58.7
42.2
63.5
1.37
1-1/2″
127
40.9
15.7
4
17.5
62
65
48.3
73.2
1.78
2″
152
52.6
19.1
4
19.1
63.5
77.7
60.5
91.9
2.65
2-1/2″
178
62.7
19.1
4
22.4
69.9
90.4
73.2
104.6
4.25
3″
191
78
19.1
4
23.9
69.9
108
88.9
127
5.1
3-1/2″
216
90.2
    19.1
8
23.9
71.4
122.2
101.6
139.7
6.28
4″
229
102.4
19.1
8
23.9
76.2
134.9
114.3
157.2
7.13
5″
254
128.3
22.4
8
23.9
88.9
163.6
141.2
185.7
8.95
6″
279
154.2
22.4
8
25.4
88.9
192
168.4
215.9
10.97
8″
343
202.7
22.4
8
28.4
101.6
246.1
219.2
269.7
18.18
10″
406
254.5
25.4
12
30.2
101.6
304.8
273.1
323.9
24.92
12?”
483
303.2
25.4
12
31.8
114.3
365.3
323.9
381
39.05
14″
533
333.3
28.4
12
35.1
127
400.1
355.6
412.8
52.27
16″
597
381
28.4
16
36.6
127
457.2
406.4
469.9
66.56
18″
635
428.7
31.8
16
39.6
139.7
505
457.2
533.4
78.03
20″
699
477.8
31.8
20
42.9
144.5
558.8
508
584.2
97.46
24″
813
575
35.1
20
47.8
152.4
663.4
609.6
692.2
136.6

 

ASME B16.5 Welding Neck Flanges Class 300 LBS Dimensions
NPS
A
B
I
Holes
C
D
F
E
G
Weight
1/2″
95
15.7
15.7
4
14.2
52.3
38.1
21.3
35.1
0.77
3/4″
117
20.8
19.1
4
15.7
57.2
47.8
26.7
42.9
1.28
1″
124
26.7
19.1
4
17.5
62
53.8
33.5
50.8
1.64
1-1/4″
133
35.1
19.1
4
19.1
65
63.5
42.2
63.5
2.09
1-1/2″
155
40.9
22.4
4
20.6
68.3
69.9
48.3
73.2
2.96
2″
165
52.6
19.1
8
22.1
69.9
84.1
60.5
91.9
3.51
2-1/2″
191
62.7
22.4
8
25.4
76.2
100.1
73.2
104.6
5.38
3″
210
78
22.4
8
28.4
79.2
117.3
88.9
127
7.14
3-1/2″
229
90.2
22.4
8
30.2
81
133.4
101.6
139.7
8.99
4″
254
102.4
22.4
8
31.8
85.9
146.1
114.3
157.2
11.61
5″
279
128.3
22.4
8
35.1
98.6
177.8
141.2
185.7
15.55
6″
318
154.2
22.4
12
36.6
98.6
206.2
168.4
215.9
19.94
8″
381
202.7
25.4
12
41.1

1

11.3

260.4
219.2
269.7
30.88
10″
445
254.5
28.4
16
47.8
117.3
320.5
273.1
323.9
44.67
12″
521
303.2
31.8
16
50.8
130
374.7
323.9
381
64.76
14″
584
333.3
31.8
20
53.8
142.7
425.5
355.6
412.8
90.8
16″
648
381
35.1
20
57.2
146.1
482.6
406.4
469.9
115.21
18″
711
428.7
35.1
24
60.5
158.8
533.4
457.2
533.4
144.39
20″
775
477.8
35.1
24
63.5
162.1
587.2
508
584.2
175.43
24″
914
575
41.1
24
69.9
168.1
701.5
609.6
692.2
256.96
ASME B16.5 Welding Neck Flanges Class 400-2500 LBS Dimensions
ASME B16.5 Welding Neck Flanges Class 400 LBS Dimensions
NPS
A
B
I
Holes
C
D
F
E
G
Weight
1/2″
95
15.7
16
4
14.2
52.3
38.1
21.3
34.9
0.87
3/4″
117
20.8
19
4
15.7
57.2
47.8
26.7
42.9
1.44
1″
124
26.7
19
4
17.5
62
53.8
33.5
50.8
1.83
1-1/4″
133
35.1
19
4
20.6
66.5
63.5
42.2
63.5
2.46
1-1/2″
155
40.9

</t d>

22
4
22.4
69.9
69.9
48.3
73
3.49
2″
165
52.6
19
8
25.4
73.2
84.1
60.5
92.1
4.33
2-1/2″
191
62.7
22
8
28.4
79.2
100.1
73.2
104.8
6.42
3″
210
78
22
8
31.8
82.6
117.3
88.9
127
8.5
3-1/2″
229
90.2
25
8
35.1
85.9
133.4
101.6
139.7
10.74
4″
254
102.4
25
8
35.1
88.9
146.1
114.3
157.2
13.31
5″
279
128.3
25
8
38.1
101.6
177.8
141.2
185.7
17.47
6″
318
154.2
25
12
41.1
103.1
206.2
168.4
215.9
22.91
8″
381
202.7
29
12
47.8
117.3
260.4
219.2
269.9
35.97
10″
445
254.5
32
16
55.8
124
320.5
273.1
323.8
51.59
12″
521
303.2
35
16
57.2
136.7
374.7
323.9
381
73.21
14″
584
333.3
35
20
60.5
149.4
425.5
355.6
412.8
101.67
16″
648
381
39
20
63.5
152.4
482.6
406.4
469.9
127.34
18″
710
428.7
39
24
66.5
165.1
533.4
457.2
533.4
157.71
20″
775
477.8
42
24
69.9
168.1
587.2
508
584.2
189.97
24″
914
575
48
24
76.2
174.8
701.5
609.6
692.2
277.23

 

ASME B16.5 Welding Neck Flanges Class 600 LBS Dimensions
NPS
A
B
I
Holes
C
D
F
E
G
Weight
1/2″
95
15.7
15.7
4
14.2
52.3
38.1
21.3
35.1
0.87
3/4″
117
20.8
19.1
4
15.7
57.2
47.8
26.7
42.9
1.44
1″
124
26.7
19.1
4
17.5
62
53.8
33.5
50.8
1.82
1-1/4″
133
35.1
19.1
4
20.6
66.5
63.5
42.2
63.5
2.45
1-1/2″
155
40.9
22.4
4
22.4
69.9
69.9
48.3
73.2
3.48
2″
165
52.6
19.1
8
25.4
73.2
84.1
60.5
91.9
4.32
2-1/2″
191
62.7
22.4
8
28.4
79.2
100.1
73.2
104.6
6.39
3″
210
78
22.4
8
31.8
82.6
117.3
88.9
127
8.48
3-1/2″
229
90.2
25.4
8
35.1
85.9
133.4
101.6
139.7
10.7
4″
273
102.4
25.4
8
38.1
101.6
152.4
114.3
157.2
17.25
5″
330
128.3
28.4
8
44.5
114.3
189
141.2
185.7
28.95
6″
356
154.2
28.4
12
47.8
117.3
222.3
168.4
215.9
34.54
8″
419
202.7
31.8
12
55.6
133.4
273.1
219.2
269.7
52.53
10″
508
254.5
35.1
16
63.5
152.4
342.9
273.1
323.9
86.02
12″
559
303.2
35.1
20
66.5
155.4
400.1
323.9
381
103.84
14″
603
333.3
38.1
20
69.9
165.1
431.8
355.6
412.8
124.4
16″
686
381
41.1
20
76.2
177.8
495.3
406.4
469.9
176.38
18″
743
428.4
44.5
20
82.6
184.2
546.1
457.2
533.4
214.12
20″
813
477.8
44.5
24
88.9
190.5
609.6
508
584.2
268.12
24″
940
575
50.8
24
101.6
203.2
717.6
609.6
692.2
382.14

 

ASME B16.5 Welding Neck Flanges Class 900 LBS Dimensions
NPS
A
B
I
Holes
C
D
F
E
G
Weight
1/2″
121
15.7
23
4
22.4
60.5
38.1
21.3
34.9
1.89
3/4″
130
20.8
23
4
25.4
69.9
44.5
26.7
42.9
2.54
1″
149
26.7
26
4
28.4
73.2
52.3
33.5
50.8
3.67
1-1/4″
159
35.1
26
4
28.4
73.2
63.5
42.2
63.5
4.28
1-1/2″
178
40.9
29
4
31.8
82.6
69.9
48.3
73
5.93
2″
216
52.6
26
8
38.1
101.6
104.6
60.5
92.1
10.84
2-1/2″
244
62.7
29
8
41.1
104.6
124
73.2
104.8
14.94
3″
241
78
26
8
38.1
101.6
127
88.9
127
13.51
4″
292
102.4
32
8
44.5
114.3
158.8
114.3
157.2
22.34
5″
349
128.3
35
8
50.8
127
190.5
141.2
185.7
35.82
6″
381
154.2
32
12
55.6
139.7
235
168.4
215.9
47.06
8″
470
202.7
39
12
63.5
162.1
298.5
219.2
269.9
80.24
10″
546
254.5
39
16
69.9
184.2
368.3
273.1
323.8
118.47
12″
610
304.8
39
20
79.2
200.2
419.1
323.9
381
157.18
14″
641
336.6
42
20
85.9
212.9
450.9
355.6
412.8
179.77
16″
705
387.1
45
20
88.9
215.9
508
406.4
469.9
217.21
18″
787
438.2
51
20
101.6
228.6
565.2
457.2
533.4
293
20″
857
489
54
20
108
247.7
622.3
508
584.2
364.13
24″
1041
590.6
67
20
139.7
292.1
749.3
609.6
692.2
666.75

 

ASME B16.5 Welding Neck Flanges Class 1500 LBS Dimensions
NPS
A
B
I
Holes
C
D
F
E
G
Weight
1/2″
121
15.7
23
4
22.4
60.5
38.1
21.3
34.9
1.89
3/4″
130
20.8
23
4
25.4
69.9
44.5
26.7
42.9
2.54
1″
149
26.7
26
4
28.4
73.2
52.3
33.5
50.8
3.67
1-1/4″
159
35.1
26
4
28.4
73.2
63.5
42.2
63.5
4.28
1-1/2″
178
40.9
29
4
31.3
82.6
69.9
48.3
73
5.86
2″
216
52.6
26
8
38.1
101.6
104.6
60.5
92.1
10.84
2-1/2″
244
62.7
29
8
41.1
104.6
124
73.2
104.3
14.93
3″
267
78
32
8
47.3
117.3
133.4
88.9
127
19.73
4″
311
102.4
35
8
53.8
124
162.1
114.3
157.2
29.64
5″
375
128.3
42
8
73.2
155.4
196.9
141.2
185.7
56.52
6″
394
154.2
39
12
82.6
171.5
228.6
168.4
215.9
67.1
8″
483
202.7
45
12
91.9
212.9
292.1
219.2

269.9

114.48
10″
584
254.5
51
12
108
254
368.3
273.1
323.8
199.03
12″
673
304.8
54
16
124
282.4
450.9
323.9
381
297.46
14″
749
336.6
61
16
133.4
298.5
495.3
355.6
412.8
390.41
16″
826
387.1
67
16
146.1
311.2
552.5
406.4
469.9
499.14
18″
914
438.2
74
16
162.1
327.2
596.9
457.2
533.4
646.35
20″
984
489
80
16
177.8
355.6
641.4
508
584.2
790.96
24″
1168
590.6
93
16
203.2
406.4
762
609.6
692.2
1256.08

 

ASME B16.5 Welding Neck Flanges Class 2500 LBS Dimensions
NPS
A
B
I
Holes
C
D
F
E
G
Weight
1/2″
121
15.7
23
4
22.4
60.5
38.1
21.3
34.9
1.89
3/4″
130
20.8
23
4
25.4
69.9
44.5
26.7
42.9
2.54
1″
149
26.7
26
4
28.4
73.2
52.3
33.5
50.8
3.67
1-1/4″
159
35.1
26
4
28.4
73.2
63.5
42.2
63.5
4.28
1-1/2″
178
40.9
29
4
31.3
82.6
69.9
48.3
73
5.86
2″
216
52.6
26
8
38.1
101.6
104.6
60.5
92.1
10.84
2-1/2″
244
62.7
29
8
41.1
104.6
124
73.2
104.3
14.93
3″
267
78
32
8
47.3
117.3
133.4
88.9
127
19.73
4″
311
102.4
35
8
53.8
124
162.1
114.3
157.2
29.64
5″
375
128.3
42
8
73.2
155.4
196.9
141.2
185.7
56.52
6″
394
154.2
39
12
82.6
171.5
228.6
168.4
215.9
67.1
8″
483
202.7
45
12
91.9
212.9
292.1
219.2
269.9
114.48
10″
584
254.5
51
12
108
254
368.3
273.1
323.8
199.03
12″
673
304.8
54
16
124
282.4
450.9
323.9
381
297.46
14″
749
336.6
61
16
133.4
298.5
495.3
355.6
412.8
390.41
16″
826
387.1
67
16
146.1
311.2
552.5
406.4
469.9
499.14
18″
914
438.2
74
16
162.1
327.2
596.9
457.2
533.4
646.35
20″
984
489
80
16
177.8
355.6
641.4
508
584.2
790.96
24″
1168
590.6
93
16
203.2
406.4
762
609.6
692.2
1256.08