ASME B16.5 Class 300 Blind Flange

Technical Drawing

Dimensions of 300# Blind Flanges

NPS	D	G	K	T
1/2	95	34.9	66.7	12.7
3/4	115	42.9	82.6	14.3
1	125	50.8	88.9	15.9
1-1/4	135	63.5	98.4	17.5
1-1/2	155	73.0	114.3	19.1
2	165	92.1	127.0	20.7
2-1/2	190	104.8	149.2	23.9
3	210	127.0	168.3	27.0
3-1/2	230	139.7	184.2	28.6
4	255	157.2	200.0	30.2
5	280	185.7	235.0	33.4
6	320	215.9	269.9	35.0
8	380	269.9	330.2	39.7
10	445	323.8	387.4	46.1
12	520	381.0	450.8	49.3
14	585	412.8	514.4	52.4
16	650	469.9	571.5	55.6
18	710	533.4	628.6	58.8
20	775	584.2	685.8	62.0
22	840	641.4	743.0	65.1
24	915	692.2	812.8	68.3

*D: outside diameter of blind flange; K: diameter of bolt circle; G: outside diameter of raised face; T: minimum thickness of 300LB blind flange; All units are mm.

NPS	n	d	l	L	Mass
1/2	4	5/8	1/2	65	0.64
3/4	4	3/4	5/8	75	1.11
1	4	3/4	5/8	75	1.39
1-1/4	4	3/4	5/8	85	1.79
1-1/2	4	7/8	3/4	90	2.66
2	8	3/4	5/8	90	3.18
2-1/2	8	7/8	3/4	100	4.85
3	8	7/8	3/4	110	6.81
3-1/2	8	7/8	3/4	110	8.71
4	8	7/8	3/4	115	11.5
5	8	7/8	3/4	120	15.6
6	12	7/8	3/4	120	20.9
8	12	1	7/8	140	34.3
10	16	1-1/8	1	160	53.3
12	16	1-1/4	1-1/8	170	78.8
14	20	1-1/4	1-1/8	180	105
16	20	1-3/8	1-1/4	190	137
18	24	1-3/8	1-1/4	195	175
20	24	1-3/8	1-1/4	205	221
22	24	1-5/8	1-1/2	230	…
24	24	1-5/8	1-1/2	230	339

*n: number of bolts; d: diameter of bolt holes; l: diameter of bolts; L: length of machine bolt or stud bolt; Mass: approximate weights/masses of the flange; For all blind flanges of class 300, t (height of raused face)=2mm. All units are mm except that d and l are provided in inch and mass in kg.

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

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