INDUSTRY STANDARD FLANGES Class 350 – Welding Neck and Blind Flanges

Nominal
Size
NPS
Outside
Diameter
of
Flange
Thickness
of
Flange
Length
thru
Hub
Diameter Of Hub At Base Diameter Of Raised
Face
Diameter
of
Bolt
Circle
Number of
Bolt Holes
Diameter
of
Bolt
Holes
WNF BLIND
A O C C Y X R
26 in. 32.75 2.5 2.5 5 27.88 29.5 30.62 28 1.12
mm 831.8 63.5 63.5 127 708.2 749.3 777.7 28.4
28 in. 34.75 2.5 2.62 5 29.88 31.5 32.62 28 1.12
mm 882.6 63.5 66.5 127 759 800.1 828.5 28.4
30 in. 37 2.62 2.88 5.25 32.12 33.75 34.88 32 1.12
mm 939.8 66.5 73.2 133.3 815.8 857.3 886 28.4
32 in. 39 2.75 3 5.5 34.12 35.75 36.88 36 1.12
mm 990.6 69.8 76.2 139.7 866.6 908 936.8 28.4
34 in. 41 2.88 3.12 5.75 36.12 37.75 38.88 40 1.12
mm 1041.4 73.2 79.2 146 917.4 958.8 987.6 28.4
36 in. 43.75 3.12 3.38 6.12 38.5 40.25 41.5 40 1.25
mm 1111.3 79.2 85.9 155.4 977.9 1022.3 1054 1 31.8
38 in. 45.75 3.12 3.5 6.12 40.5 42.25 43.5 40 1.25
mm 1162.1 79.2 88.9 155.4 1028.7 1073.1 1104.9 31.8
40 in. 47.75 3.25 3.69 6.25 42.5 44.25 45.5 44 1.25
mm 1212.8 82.5 93.7 158.8 1079.5 1124 1155.7 31.8
42 in. 50 3.5 3.88 6.5 44.75 46.5 47.75 48 1.25
mm 1270 88.9 98.6 165.1 1136.6 1181.1 1212.8 31.8
44 in. 52.75 3.75 4 6.75 46.75 48.88 50.25 44 1.38
mm 1339.8 95.3 101.6 171.4 1187.5 1241.6 1276.3 35.1
46 in. 54.75 4.25 4.25 7.25 48.75 50.88 52.25 48 1.38
mm 1390.6 107.9 107.9 184.1 1238.3 1292.4 1327.1 35.1
48 in. 56.75 4.25 4.38 7.25 50.75 52 88 54.25 48 1.38
mm 1441 4 107.9 111.3 184.1 1289.1 1343.2 1377.9 35.1

(1) bore diameter to be specified by purchaser.