ASME B16.5 Class 300 Lap Joint Flange

Technical Drawing

Dimensions of 300# Lap Joint Flanges

NPS	D	B	X	K
1/2	95	22.9	38	66.7
3/4	115	28.2	48	82.6
1	125	34.9	54	88.9
1-1/4	135	43.7	64	98.4
1-1/2	155	50.0	70	114.3
2	165	62.5	84	127.0
2-1/2	190	75.4	100	149.2
3	210	91.4	117	168.3
3-1/2	230	104.1	133	184.2
4	255	116.8	146	200.0
5	280	144.4	178	235.0
6	320	171.4	206	269.9
8	380	222.2	260	330.2
10	445	277.4	321	387.4
12	520	328.2	375	450.8
14	585	360.2	425	514.4
16	650	411.2	483	571.5
18	710	462.3	533	628.6
20	775	514.4	587	685.8
22	840	565.2	640	743.0
24	915	616.0	702	812.8

*D: outside diameter of flange; K: diameter of bolt circle; B: minimum bore diameter; X: diameter of hub at base; All units are mm.

NPS	n	d	l	L
1/2	4	5/8	1/2	-
3/4	4	3/4	5/8	-
1	4	3/4	5/8	-
1-1/4	4	3/4	5/8	-
1-1/2	4	7/8	3/4	-
2	8	3/4	5/8	-
2-1/2	8	7/8	3/4	-
3	8	7/8	3/4	-
3-1/2	8	7/8	3/4	-
4	8	7/8	3/4	-
5	8	7/8	3/4	-
6	12	7/8	3/4	-
8	12	1	7/8	-
10	16	1-1/8	1	-
12	16	1-1/4	1-1/8	-
14	20	1-1/4	1-1/8	-
16	20	1-3/8	1-1/4	-
18	24	1-3/8	1-1/4	-
20	24	1-3/8	1-1/4	-
22	24	1-5/8	1-1/2	-
24	24	1-5/8	1-1/2	-

*n: number of bolts; d: diameter of bolt holes; l: diameter of bolts; L: length of machine bolt or stud bolt, calculated according to Non-mandatory Appendix C; All units are mm except that d and l are provided in inch.

NPS	Y	T	r	Weight
1/2	22	14.3	3	0.62
3/4	25	15.9	3	1.10
1	27	17.5	3	1.33
1-1/4	27	19.1	5	1.65
1-1/2	30	20.7	6	2.44
2	33	22.3	8	2.83
2-1/2	38	25.4	8	4.25
3	43	28.6	10	5.78
3-1/2	44	30.2	10	7.27
4	48	31.8	11	9.55
5	51	35.0	11	12.2
6	52	36.6	13	15.5
8	62	41.3	13	24.1
10	95	47.7	13	34.4
12	102	50.8	13	50.4
14	111	54.0	13	70.9
16	121	57.2	13	89.5
18	130	60.4	13	111
20	140	63.5	13	137
22	145	66.7	13	…
24	152	69.9	13	204

* Y: length through hub;  T: minimum thickness of 300LB lap joint flange; r: corner bore radius of lapped flange and pipe; Weight: approximate weights/masses of the flange; All units are in mm except that weights are in kg.

ASME B16.5 Lap Joint Flanges, Classes
150#	300#	400#	600#
900#	1500#	2500#	-

*Click to view the dimensions and weights of lap joint flanges of each pressure rating.