1. Technical Drawings for ASME B16.5 Class 300 Flanges

2. Flange and Bolting Dimensions for Class 300

All dimensions are provided in both mm and inch units. The two unit system shall be used respectively and exclusively. The bolting of Class 300 flanges can be furnished by stud bolt with nuts or machine bolt with nuts. Stud bolts can be used for RF or RTJ end facing while machine bolts are only used for RF facing. Dimensions of ASME B16.5 Class 300 flanges in below tables shall be furnished with RF facing. For other facings, please contact us for detailed specification. The same as Class 150, the Class 300 flange has a 2 mm(0.06 inch) raised face which is additional to the minimum flange-thickness.

NPS	O mm inch	To mm inch	T1 mm inch	X mm inch	Ah mm inch	ro mm inch	Do mm inch
1/2	95 3.75	12.7 0.50	14.3 0.56	38 1.50	21.3 0.84	3 0.12	10 0.38
3/4	115 4.62	14.3 0.56	15.9 0.62	48 1.88	26.7 1.05	3 0.12	11 0.44
1	125 4.88	15.9 0.62	17.5 0.69	54 2.12	33.4 1.32	3 0.12	13 0.50
1-1/4	135 5.25	17.5 0.69	19.1 0.75	64 2.50	42.2 1.66	5 0.19	14 0.56
1-1/2	155 6.12	19.1 0.75	20.7 0.81	70 2.75	48.3 1.90	6 0.25	16 0.62
2	165 6.50	20.7 0.81	22.3 0.88	84 3.31	60.3 2.38	8 0.31	17 0.69
2-1/2	190 7.50	23.9 0.94	25.4 1.00	100 3.94	73.0 2.88	8 0.31	19 0.75
3	210 8.25	27.0 1.06	28.6 1.12	117 4.62	88.9 3.50	10 0.38	21 0.81
3-1/2	230 9.00	28.6 1.12	30.2 1.19	133 5.25	101.6 4.00	10 0.38	…
4	255 10.00	30.2 1.19	31.8 1.25	146 5.75	114.3 4.50	11 0.44	…
5	280 11.00	33.4 1.31	35.0 1.38	178 7.00	141.3 5.56	11 0.44	…
6	320 12.50	35.0 1.38	36.6 1.44	206 8.12	168.3 6.63	13 0.50	…
8	380 15.00	39.7 1.56	41.3 1.62	260 10.25	219.3 8.63	13 0.50	…
10	445 17.50	46.1 1.81	47.7 1.88	321 12.62	273.0 10.75	13 0.50	…
12	520 20.50	49.3 1.94	50.8 2.00	375 14.75	323.8 12.75	13 0.50	…
14	585 23.00	52.4 2.06	54.0 2.12	425 16.75	355.6 14.00	13 0.50	…
16	650 25.50	55.6 2.19	57.2 2.25	483 19.00	406.4 16.00	13 0.50	…
18	710 28.00	58.8 2.31	60.4 2.38	533 21.00	457.0 18.00	13 0.50	…
20	775 30.50	62.0 2.44	63.5 2.50	587 23.12	508.0 20.00	13 0.50	…
24	915 36.00	68.3 2.69	69.9 2.75	702 27.62	610.0 24.00	13 0.50	…

*O:outside diameter of flange; T_o:minimum flange thickness of W/N, S/O, Blind, THD, S/W; T₁:minimum thickness of lap joint flange;
*X:diameter at hub; A_h:hub diameter at the beginning of chamfer for W/N; r_o: corner bore radius of lapped flange; D_o:depth of socket.

NPS	Y1 mm inch	Y2 mm inch	Y3 mm inch	Ta mm inch	B1 mm inch	B2 mm inch	B3 mm inch
1/2	51 2.00	21 0.81	22 0.88	16 0.62	15.8 0.62	22.2 0.88	22.9 0.90
3/4	56 2.19	24 0.94	25 1.00	16 0.62	20.9 0.82	27.7 1.09	28.2 1.11
1	60 2.38	25 1.00	27 1.06	18 0.69	26.6 1.05	34.5 1.36	34.9 1.38
1-1/4	64 2.50	25 1.00	27 1.06	21 0.81	35.1 1.38	43.2 1.70	43.7 1.72
1-1/2	67 2.63	29 1.13	30 1.19	23 0.88	40.9 1.61	49.5 1.95	50.0 1.97
2	68 2.69	32 1.25	33 1.31	29 1.12	52.5 2.07	61.9 2.44	62.5 2.46
2-1/2	75 2.94	37 1.44	38 1.50	32 1.25	62.7 2.47	74.6 2.94	75.4 2.97
3	78 3.06	41 1.63	43 1.69	32 1.25	77.9 3.07	90.7 3.57	91.4 3.60
3-1/2	79 3.13	43 1.69	44 1.75	37 1.44	90.1 3.55	103.4 4.07	104.1 4.10
4	84 3.32	46 1.82	48 1.88	37 1.44	102.3 4.03	116.1 4.57	116.8 4.60
5	97 3.82	49 1.94	51 2.00	43 1.69	128.2 5.05	143.8 5.66	144.4 5.69
6	97 3.82	51 2.00	52 2.06	47 1.81	154.1 6.07	170.7 6.72	171.4 6.75
8	110 4.32	60 2.38	62 2.44	51 2.00	202.7 7.98	221.5 8.72	222.2 8.75
10	116 4.56	65 2.56	95 3.75	56 2.19	254.6 10.02	276.2 10.88	277.4 10.92
12	129 5.06	71 2.82	102 4.00	61 2.38	304.8 12.00	327.0 12.88	328.2 12.92
14	141 5.56	75 2.94	111 4.38	64 2.50		359.2 14.14	360.2 14.18
16	144 5.69	81 3.19	121 4.75	69 2.69		410.5 16.16	411.2 16.19
18	157 6.19	87 3.44	130 5.12	70 2.75		461.8 18.18	462.3 18.20
20	160 6.32	94 3.69	140 5.50	74 2.88		513.1 20.20	514.4 20.25
24	167 6.56	105 4.13	152 6.00	83 3.25		616.0 24.25	616.0 24.25

*Y₁:length through hub of welding neck flange; Y₂:length through hub of threaded, S/O and S/W flange; Y₃:length through hub of lapped flange.
*T_a:minimum thread length of threaded flange; B₁:bore diameter of welding neck flange or lower part of socket welding flange.
*B₂:bore diameter of slip on flange or upper part of socket welding flange; B₃:bore diameter of lap joint(lapped) flange.

NPS	W mm inch	R mm inch	d inch	n	do inch	LSRF mm inch	LSRTJ mm inch	LMRF mm inch
1/2	66.7 2.62	34.9 1.38	5/8	4	1/2	65 2.50	75 3.00	55 2.25
3/4	82.6 3.25	42.9 1.69	3/4	4	5/8	75 3.00	90 3.50	65 2.50
1	88.9 3.50	50.8 2.00	3/4	4	5/8	75 3.00	90 3.50	65 2.50
1-1/4	98.4 3.88	63.5 2.50	3/4	4	5/8	85 3.25	95 3.75	70 2.75
1-1/2	114.3 4.50	73.0 2.88	7/8	4	3/4	90 3.50	100 4.00	75 3.00
2	127.0 5.00	92.1 3.62	3/4	8	5/8	90 3.50	100 4.00	75 3.00
2-1/2	149.2 5.88	104.8 4.12	7/8	8	3/4	100 4.00	115 4.50	85 3.25
3	168.3 6.62	127.0 5.00	7/8	8	3/4	110 4.25	120 4.75	90 3.50
3-1/2	184.2 7.25	139.7 5.50	7/8	8	3/4	110 4.25	125 5.00	95 3.75
4	200.0 7.88	157.2 6.19	7/8	8	3/4	115 4.50	125 5.00	95 3.75
5	235.0 9.25	185.7 7.31	7/8	8	3/4	120 4.75	135 5.25	110 4.25
6	269.9 10.62	215.9 8.50	7/8	12	3/4	120 4.75	140 5.50	110 4.25
8	330.2 13.00	269.9 10.62	1	12	7/8	140 5.50	150 6.00	120 4.75
10	387.4 15.25	323.8 12.75	1 1/8	16	1	160 6.25	170 6.75	140 5.50
12	450.8 17.75	381.0 15.00	1 1/4	16	1 1/8	170 6.75	185 7.25	145 5.75
14	514.4 20.25	412.8 16.25	1 1/4	20	1 1/8	180 7.00	190 7.50	160 6.25
16	571.5 22.50	469.9 18.50	1 3/8	20	1 1/4	190 7.50	205 8.00	165 6.50
18	628.6 24.75	533.4 21.00	1 3/8	24	1 1/4	195 7.75	210 8.25	170 6.75
20	685.8 27.00	584.2 23.00	1 3/8	24	1 1/4	205 8.00	220 8.75	185 7.25
24	812.8 32.00	692.2 27.25	1 5/8	24	1 1/2	230 9.00	255 10.00	205 8.00

*W:diameter of bolt circle; d:diameter of bolt holes; n:number of bolts; d_o:diameter of bolts; R:outside diameter of RF.
*L_SRF:length of stud bolts for raised face; L_SRTJ:length of stud bolts for ring joint; L_MRF:length of machine bolts for raised face.