LAP JOINT CLASS 2500 (IN INCH)
| FLANGE | Inside | Outside | Bolt Circle (BC) | H | T1 | T2 | RA | Bolt Hole (B) | No. of Bolt Holes |
| NPS | Diameter | Diameter | |||||||
| 1/2″ | 0.90″ | 5.25″ | 3.50″ | 1.69″ | 1.19″ | 1.56″ | .12″ | 0.88″ | 4 |
| 3/4″ | 1.11″ | 5.50″ | 3.75″ | 2.00″ | 1.25″ | 1.69″ | .12″ | 0.88″ | 4 |
| 1″ | 1.38″ | 6.25″ | 4.25″ | 2.25″ | 1.38″ | 1.88″ | .12″ | 1.00″ | 4 |
| 1-1/4″ | 1.72″ | 7.25″ | 5.13″ | 2.88″ | 1.50″ | 2.06″ | .19″ | 1.13″ | 4 |
| 1-1/2″ | 1.97″ | 8.00″ | 5.75″ | 3.13″ | 1.75″ | 2.38″ | .25″ | 1.25″ | 4 |
| 2″ | 2.46″ | 9.25″ | 6.75″ | 3.75″ | 2.00″ | 2.75″ | .31″ | 1.13″ | 8 |
| 2-1/2″ | 2.97″ | 10.50″ | 7.75″ | 4.50″ | 2.25″ | 3.13″ | .31″ | 1.25″ | 8 |
| 3″ | 3.60″ | 12.00″ | 9.00″ | 5.25″ | 2.63″ | 3.63″ | .38″ | 1.38″ | 8 |
| 4″ | 4.60″ | 14.00″ | 10.75″ | 6.50″ | 3.00″ | 4.25″ | .44″ | 1.63″ | 8 |
| 5″ | 5.69″ | 16.50″ | 12.75″ | 8.00″ | 3.63″ | 5.13″ | .44″ | 1.88″ | 8 |
| 6″ | 6.75″ | 19.00″ | 14.50″ | 9.25″ | 4.25″ | 6.00″ | .50″ | 2.13″ | 8 |
| 8″ | 8.75″ | 21.75″ | 17.25″ | 12.00″ | 5.00″ | 7.00″ | .50″ | 2.13″ | 12 |
| 10″ | 10.92″ | 26.50″ | 21.25″ | 14.75″ | 6.50″ | 9.00″ | .50″ | 2.63″ | 12 |
| 12″ | 12.92″ | 30.00″ | 24.38″ | 17.38″ | 7.25″ | 10.00″ | .50″ | 2.88″ | 12 |
For a Class 1500 Lap Joint Flange according to ASME B16.5 standards, and similarly for a Class 2500 Lap Joint Flange, the dimensions in inches for common sizes are as follows:
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 13.50 inches, while the OD of a 24-inch flange is around 63.00 inches.
Bore Diameter (BD): The bore diameter of a lap joint flange matches the inside diameter (ID) of the pipe to which it is attached. It is typically the same as the nominal pipe size (NPS).
Thickness (T): The thickness of the lap joint flange is relatively uniform and typically corresponds to the thickness of the pipe it is used with.
Hub Diameter (HD): The hub diameter of a lap joint flange is typically larger than the OD to allow for easy fitting over the pipe.
Overall Length Through Hub (LTH): This dimension, which is the distance from the face of the flange to the end of the hub, also increases with the size of the flange.
Flange Thickness: The thickness of the flange varies based on the pressure class.
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 lap joint flange size.
