ANSI Flange Dimensions
The most common flange standard in the oil and gas industry is arguably American National Standards Institute (ANSI) B16.5.
Other standards are used, e.g.
- British Imperial flanges BS 10,
- Metric flanges SABS 1123, BS 4504, DIN 2501,
- Japanese and Korean flanges JIS-B-2212, JIS-B-2214 & KS-B-1503
ANSI B16.5. Flange Dimensions
The following tables provide flange dimensions, diameters and drillings for the most common sizes and ratings.