- American Standards flanges
- British Standard flanges
|
Flange Tolerance
Tolerance of Welding Neck Flanges
| Outside Diameter |
When O.D. is 24" or less |
±1.6mm﹡ |
| Inside Diameter |
10" and smaller |
±0.8mm |
| 12" thru 18" |
±1.6mm |
| 20" and larger |
+3.2mm, -1.6mm |
| Outside Diameter of hub |
5" and smaller |
+2.4mm, -0.8mm﹡ |
| 6" and larger |
+4.0mm, -0.8mm |
| Diameter of contact face |
1/16" rasied face tongue and groove male, female |
±0.8mm |
| 1/4" rasied face tongue and groove male, female |
±0.4mm |
| Diameter of hub at base |
when hub base is 24" or smaller |
±1.6mm﹡ |
| Diameter of hub at point of welding |
5" and smaller |
+2.4mm, -0.8mm |
| 6" and larger |
+4.0mm, -0.8mm |
| Drilling |
Bolt circle |
±1.6mm |
| Bolt hole spacing |
±0.8mm |
| Eccentricity of bolt circle with respect to facing |
2 1/2" and smaller: 0.8mm, max﹡ |
| Eccentricity of bolt circle with respect to bore |
3" and larger: 1.6mm, max﹡ |
| Thickness |
18" and smaller |
+3.2mm, -0mm |
| 20" and larger |
+4.8mm, -0mm |
| Length of thru hub |
10" and smaller |
±1.6mm |
| 12" and larger |
±3.2mm |
Tolerance of Threaded Flanges, Socket Welding Flanges, Slip-On Flanges
Lap Joint Flanges and Blind Flanges
| Outside Diameter |
When O.D. is 24" or less |
±1.6mm﹡ |
| Inside Diameter |
Threaded |
Within limits on boring gauge |
| Socket welding, Slip-on and Lap joint, 10" and smaller |
+0.8mm, -0mm |
| Socket welding, Slip-on and Lap joint, 12" and larger |
+1.6mm, -0mm |
| Outside Diameter of hub |
5" and smaller |
+2.4mm, -0.8mm﹡ |
| 6" and larger |
+4.0mm, -0.8mm |
| Diameter of contact face |
1/16" rasied face tongue and groove male, female |
±0.8mm |
| 1/4" rasied face tongue and groove male, female |
±0.4mm |
| Diameter of counterbore |
same as for inside diameter |
| Drilling |
Bolt circle |
±1.6mm |
| Bolt hole spacing |
±0.8mm |
| Eccentricity of bolt circle with respect to facing |
2 1/2" and smaller: 0.8mm, max﹡ |
| Eccentricity of bolt circle with respect to bore |
3" and larger: 1.6mm, max﹡ |
| Thickness |
18" and smaller |
+3.2mm, -0mm |
| 20" and larger |
+4.8mm, -0mm |
| Length of thru hub |
10" and smaller |
±1.6mm |
| 12" and larger |
±3.2mm |
|
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