BLIND CLASS 300 (IN INCH)
Blind flange dimensions class 300 in inches
| FLANGE | Outside | Bolt Circle (BC) | Raised Face (R) | Raised Face (RF) | Raised Face | Flat Face | Bolt Hole (B) | No. of |
| NPS | Diameter | Thickness (T) | Thickness (T2) | Bolt Holes | ||||
| 1/2″ | 3.75″ | 2.62″ | 1.38″ | .063″ | 0.56″ | 0.50″ | 0.62″ | 4 |
| 3/4″ | 4.62″ | 3.25″ | 1.69″ | .063″ | 0.62″ | .056″ | 0.75″ | 4 |
| 1″ | 4.88″ | 3.50″ | 2.00″ | .063″ | 0.69″ | 0.63″ | 0.75″ | 4 |
| 1-1/4″ | 5.25″ | 3.88″ | 2.50″ | .063″ | 0.75″ | 0.69″ | 0.75″ | 4 |
| 1-1/2″ | 6.12″ | 4.50″ | 2.88″ | .063″ | 0.81″ | 0.75″ | 0.88″ | 4 |
| 2″ | 6.50″ | 5.00″ | 3.62″ | .063″ | 0.88″ | 0.82″ | 0.75″ | 8 |
| 2-1/2″ | 7.50″ | 5.88″ | 4.12″ | .063″ | 1.00″ | 0.94″ | 0.88″ | 8 |
| 3″ | 8.25″ | 6.62″ | 5.00″ | .063″ | 1.12″ | 1.06″ | 0.88″ | 8 |
| 3-1/2″ | 9.00″ | 7.25″ | 5.50″ | .063″ | 1.19″ | 1.13″ | 0.88″ | 8 |
| 4″ | 10.00″ | 7.88″ | 6.19″ | .063″ | 1.25″ | 1.19″ | 0.88″ | 8 |
| 5″ | 11.00″ | 9.25″ | 7.31″ | .063″ | 1.38″ | 1.32″ | 0.88″ | 8 |
| 6″ | 12.50″ | 10.62″ | 8.50″ | .063″ | 1.44″ | 1.38″ | 0.88″ | 12 |
| 8″ | 15.00″ | 13.00″ | 10.62″ | .063″ | 1.62″ | 1.56″ | 1.00″ | 12 |
| 10″ | 17.50″ | 15.25″ | 12.75″ | .063″ | 1.88″ | 1.82″ | 1.12″ | 16 |
| 12″ | 20.50″ | 17.75″ | 15.00″ | .063″ | 2.00″ | 1.94″ | 1.25″ | 16 |
| 14″ | 23.00″ | 20.25″ | 16.25″ | .063″ | 2.12″ | 2.06″ | 1.25″ | 20 |
| 16″ | 25.50″ | 22.50″ | 18.50″ | .063″ | 2.25″ | 2.19″ | 1.38″ | 20 |
| 18″ | 28.00″ | 24.75″ | 21.00″ | .063″ | 2.38″ | 2.32″ | 1.38″ | 24 |
| 20″ | 30.50″ | 27.00″ | 23.00″ | .063″ | 2.50″ | 2.44″ | 1.38″ | 24 |
| 22″ | 33.00″ | 29.25″ | 25.25″ | .063″ | 2.63″ | 2.57″ | 1.63″ | 24 |
| 24″ | 36.00″ | 32.00″ | 27.25″ | .063″ | 2.75″ | 2.69″ | 1.62″ | 24 |
For a Class 300 Blind Flange according to ASME B16.5 standards, here are the approximate dimensions in inches for common sizes:
Nominal Pipe Size (NPS): Ranges from 1/2 inch (DN 15) to 24 inches (DN 600) and larger.
Outside Diameter (OD): The OD varies with NPS. For example, the OD of a 1/2-inch flange is approximately 4.25 inches, while the OD of a 24-inch flange is around 35.50 inches.
Thickness (T): The thickness of the blind flange is relatively uniform and typically corresponds to the thickness of the pipe it is used with.
Bolt Circle Diameter (BCD): This dimension is not applicable for blind flanges as they do not have bolt holes.
Number of Bolt Holes: Blind flanges do not have bolt holes, as they are solid discs used to close off the end of a piping system or vessel.
These dimensions are approximate and may vary slightly depending on the manufacturer and specific requirements. It's essential to consult the ASME B16.5 standard or the manufacturer's specifications for precise dimensions for a specific blind flange size.
