ASME/ANSI B16.5 Class 150 WN

The Welding neck flanges is normally referred to as the high hub flange. It is designed to transfer stresses to the pipe, thereby reducing high stress concentrations at the base of the flange. The welding neck flange is the best designed butt-welded flange of those currently available because of its inherent structural value. It is expensive because of the design.

Nominal Pipe Size	Outside Diameter of Flange	Diameter of Raised Face	Thickness of Flanges Min.	Diameter of Hub	Hub Diameter Beginning of Chamfer	Length Through Hub	Bore	Diameter of Bolt Circle	Diameter of Bolt Holes	Number of Bolts	Approxi-mate Weight kgs
NPS	O	R	tf	X	A	Y	B	W	I	n
1/2	90	34.9	9.6	30	21.3	46	15.8	60.3	15.9	4	0.51
3/4	100	42.9	11.2	38	26.7	51	20.9	69.9	15.9	4	0.76
1	110	50.8	12.7	49	33.4	54	26.6	79.4	15.9	4	1.09
1 1/4	115	63.5	14.3	59	42.2	56	35.1	88.9	15.9	4	1.35
1 1/2	125	73.0	15.9	65	48.3	60	40.9	98.4	15.9	4	1.73
2	150	92.1	17.5	78	60.3	62	52.5	120.7	19.1	4	2.60
2 1/2	180	104.8	20.7	90	70.0	68	62.7	139.7	19.1	4	4.26
3	190	127.0	22.3	108	88.9	68	77.9	152.4	19.1	4	5.08
3 1/2	215	139.7	22.3	122	101.6	70	90.1	177.8	19.1	8	6.27
4	230	157.2	22.3	135	114.3	75	102.3	190.5	19.1	8	7.26
5	255	185.7	22.3	164	141.3	87	128.2	215.9	22.2	8	9.11
6	280	215.9	23.9	192	168.3	87	154.1	241.3	22.2	8	11.15
8	345	269.9	27.0	246	219.1	100	202.7	298.5	22.2	8	18.57
10	405	323.8	28.6	305	273.0	100	254.6	362.0	25.4	12	24.87
12	485	381.0	30.2	365	323.8	113	304.8	431.8	25.4	12	38.86
14	535	412.8	33.4	400	355.6	125	336.5	476.3	28.6	12	50.99
16	595	469.9	35.0	457	406.4	125	387.3	539.8	28.6	16	62.28
18	635	533.4	38.1	505	457.0	138	437.9	577.9	31.8	16	71.45
20	700	584.2	41.3	559	508.0	143	488.9	635.0	31.8	20	88.66
24	815	692.2	46.1	663	610.0	151	590.9	749.3	34.9	20	120.46