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
|
