Boltex Reference Manual

indstandard

Industry Standard - Welding Neck & Blind Flanges

Class 350

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 No. of Bolt Holes Diameter of Bolt Holes
WNF BLIND
A O C C Y X R
26 in. 32.75 2.50 2.50 5.00 27.88 29.50 30.62 28 1.12
mm. 831.8 63.5 63.5 127.0 708.2 749.3 777.7 28.4
28 in. 34.75 2.50 2.62 5.00 29.88 31.50 32.62 28 1.12
mm. 882.6 63.5 66.5 127.0 759.0 800.1 828.5 28.4
30 in. 37.00 2.62 2.88 5.25 32.12 33.75 34.88 32 1.12
mm. 939.8 66.5 73.2 133.3 815.8 857.3 886.0 28.4
32 in. 39.00 2.75 3.00 5.50 34.12 35.75 36.88 36 1.12
mm. 990.6 69.8 76.2 139.7 866.6 908.0 936.8 28.4
34 in. 41.00 2.88 3.12 5.75 36.12 37.75 38.88 40 1.12
mm. 1041.4 73.2 79.2 146.00 917.4 958.8 987.6 28.4
36 in. 43.75 3.12 3.38 6.12 38.50 40.25 41.50 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 3.50 6.12 40.50 42.25 43.50 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 42.50 44.25 45.50 44 1.25
mm. 1212.8 82.5 93.7 158.8 1079.5 1124.0 1155.7 31.8
42 in. 50.00 3.50 3.88 6.50 44.75 46.50 47.75 48 1.25
mm. 1270.0 88.9 98.6 165.1 1136.6 1181.1 1212.8 31.8
44 in. 52.75 3.75 4.00 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 3.51