AWWA C207 Class B Ring Flange

Technical Drawing

The AWWA C207 Class B steel ring flanges are available in sizes 4″ through 144″. These flanges have the same OD and drilling pattern as Class 125 cast-iron flanges (ASME B16.1). In sizes 24″ and smaller, they also match ASME B16.5 Class 150 drilling for steel flanges.

Dimensions & Masses

NPS	A	B	T
4"	9.00	4.57	0.625
5"	10.00	5.66	0.625
6"	11.00	6.72	0.688
8"	13.50	8.72	0.688
10"	16.00	10.88	0.688
12"	19.00	12.88	0.688
14"	21.00	14.19	0.688
16"	23.50	16.19	0.688
18"	25.00	18.19	0.688
20"	27.50	20.19	0.688
22"	29.50	22.19	0.750
24"	32.00	24.19	0.750
26"	34.25	26.19	0.812
28"	36.50	28.19	0.875
30"	38.75	30.19	0.875
32"	41.75	32.19	0.938
34"	43.75	34.19	0.938
36"	46.00	36.19	1.000
38"	48.75	38.19	1.000
40"	50.75	40.19	1.000
42"	53.00	42.19	1.125
44"	55.25	44.19	1.125
46"	57.25	46.19	1.125
48"	59.50	48.19	1.250
50"	61.75	50.19	1.250
52"	64.00	52.19	1.250
54"	66.25	54.19	1.375
60"	73.00	60.19	1.500
66"	80.00	66.19	1.625
72"	86.50	72.19	1.750
78"	93.00	78.19	2.000
84"	99.75	84.19	2.000
90"	106.50	90.19	2.250
96"	113.25	96.19	2.250
102"	120.00	102.19	2.500
108"	126.75	108.19	2.500
114"	133.50	114.19	2.750
120"	140.25	120.19	2.750
126"	147.00	126.19	3.000
132"	153.75	132.19	3.000
144"	167.25	144.19	3.250

*A: OD of flange; B: ID of flange; T: thickness of flange; All dimensions are in inch unit.
*The purchaser shall specify the ID of the flange, dimension B, for NPS 26″ and larger. The diameter of the flange bore shall not exceed the pipe OD by more than 0.25″.
*Dimensions of AWWA C207 Class B ring flange are the same as that of Class D ring flange except for the thickness of flange, T.

NPS	n	C	d
4"	8	7.50	0.625
5"	8	8.50	0.750
6"	8	9.50	0.750
8"	8	11.75	0.750
10"	12	14.25	0.875
12"	12	17.00	0.875
14"	12	18.75	1.000
16"	16	21.25	1.000
18"	16	22.75	1.125
20"	20	25.00	1.125
22"	20	27.25	1.250
24"	20	29.50	1.250
26"	24	31.75	1.250
28"	28	34.00	1.250
30"	28	36.00	1.250
32"	28	38.50	1.500
34"	32	40.50	1.500
36"	32	42.75	1.500
38"	32	45.25	1.500
40"	36	47.25	1.500
42"	36	49.50	1.500
44"	40	51.75	1.500
46"	40	53.75	1.500
48"	44	56.00	1.500
50"	44	58.25	1.750
52"	44	60.50	1.750
54"	44	62.75	1.750
60"	52	69.25	1.750
66"	52	76.00	1.750
72"	60	82.50	1.750
78"	64	89.00	2.000
84"	64	95.50	2.000
90"	68	102.00	2.250
96"	68	108.50	2.250
102"	72	114.50	2.500
108"	72	120.75	2.500
114"	76	126.75	2.750
120"	76	132.75	2.750
126"	80	139.25	3.000
132"	80	145.75	3.000
144"	84	158.25	3.250

*n: number of bolts; C: diameter of bolt circle; d: diameter of bolts; All dimensions are in inch unit.
*For flanges up to NPS 84″, bolt holes shall be drilled 1/8″ [3.2 mm] larger in diameter than the nominal diameter of the bolt. For flanges larger than 84″, bolt holes shall be drilled 3/16″ [4.8 mm] larger than the nominal bolt diameter.

NPS	Mass
4"	3.51
5"	3.90
6"	4.85
8"	6.96
10"	8.73
12"	12.73
14"	15.60
16"	18.76
18"	18.71
20"	22.06
22"	25.77
24"	30.39
26"	36.24
28"	42.84
30"	47.49
32"	59.98
34"	62.60
36"	72.92
38"	84.22
40"	87.42
42"	106.15
44"	113.00
46"	118.03
48"	139.15
50"	143.89
52"	153.76
54"	180.29
60"	230.86
66"	301.44
72"	364.21
78"	453.90
84"	519.93
90"	637.41
96"	720.39
102"	868.16
108"	970.03
114"	1146.67
120"	1269.34
126"	1476.77
132"	1622.19
144"	2032.27

*The unit of mass: kg.

AWWA C207 Pipe Flange Dimensions & Masses
Ring Flange	Class B | Class D Class E | Class F
Blind Flange	Class B | Class D Class E | Class F
Hub Flange	Class D | Class E

*Click to view more information about AWWA C207 steel flanges.