INDUSTRY STANDARD FLANGES Class 350 – Slip-on and Blind Flanges

Nominal
Size
NPS
Outside
Diameter
of
Flange
Diameter Of Hub At Base Outside
Diameter
of
Flange
Diameter Of Hub At Base Thickness
of
Flange
Length
thru
Hub
Diameter Of Raised
Face
Diameter
of
Bolt
Circle
Number of
Bolt Holes
Diameter
of
Bolt
Holes
SOF BLIND
O X O X C C C Y R
I.D. VESSELS O.D. VESSELS I.D. VESS. O.D. VESS. I.D. VESS. O.D. VESS.
26 in. 33.5 28.75 32.75 27.88 2.5 2.5 2.75 4.5 29.5 31.5 30.62 28 1.12
mm 850.9 730.3 831.8 708.2 63.5 63.5 69.8 114.3 749.3 800.1 777.7 28.4
28 in. 35.5 30.75 34.75 29 88 2.5 2.62 2.88 4.5 31.5 33.5 32.62 28 1.12
mm 901.7 781 882 6 759 63.5 66.5 73.2 114.3 800.1 850.9 828.5 28.4
30 in. 37.75 33 37 32.12 2.62 2.88 3 4.75 33.75 35.75 34.88 32 1.12
mm 958.8 838.2 939.8 815.8 66.5 73.2 76.2 120.6 857.3 908 886 28.4
32 in. 39.75 35 39 34.12 2.75 3 3.25 5 35.75 37.75 36.88 36 1.12
mm 1009.7 889 990.6 866.6 69.8 76.2 82.5 127 908 958.8 936.8 28.4
34 in. 42.25 37.5 41 36.12 2.88 3.12 3.38 5.12 37.75 40.25 38.88 40 1.12
mm 1073.1 952.5 1041.4 917.4 73.2 79.2 85.9 130 958.8 1022.3 987.6 28.4
36 in. 44.75 39.5 43.75 38.5 3.12 3.38 3.62 5 62 40.25 42.5 41.5 40 1.25
mm 1136.6 1003.3 1111.3 977.9 79.2 85.9 91 9 142.7 1022.3 1079.5 1054.1 31.8
38 in. 46.75 41.5 45.75 40.5 3.12 3.5 3.75 5.62 42.25 44.5 43.5 40 1.25
mm 1187.5 1054.1 1162.1 1028.7 79.2 88.9 95.3 142.7 1073.1 1130.3 1104.9 31.8
40 in. 48.75 43.5 47.75 42.5 3 25 3.69 4 5.88 44.25 46.5 45.5 44 1.25
mm 1238.3 1104.9 1212.8 1079.5 82.5 93.7 101.6 149.4 1124 1181.1 1155.7 31.8
42 in. 51.25 46 50 44.75 3.5 3.88 4.12 6.12 46.5 49 47.75 48 1.25
mm 1301.8 1168.4 1270 1136.6 88.9 98.6 104.6 155.4 1181.1 1244.6 1212.8 31.8
44 in. 54 48 52.75 46.75 3.75 4 4 38 6.75 48 88 51.5 50.25 44 1.38
mm 1371.6 1219.2 1339.8 1187.5 §5.3 101.6 111.3 171.4 1241.6 1308.1 1276.3 35.1
46 in. 56 50 54.75 48.75 4.25 4.25 4.75 7.25 50.88 53.5 52.25 48 1.38
mm 1422.4 1270 1390.6 1238.3 107.9 107.9 120.6 184.1 1292.4 1358.9 1327.1 35.1
48 in. 58.25 52.25 56.75 50.75 4.25 4.38 4.75 7.25 52.88 55.75 54.25 48 1.38
mm 1479.6 1327.1 1441.4 1^89.1 107.9 111 3 120.6 184.1 1343 2 1416.1 1377.9 35.1

(1) Bore diameter to be specified by purchaser.