The ASME B16.5 standard covers flanges and flange bolting for pipes, valves, and fittings. Below is a general flange bolting chart based on ASME B16.5, which includes bolt sizes, quantities, and lengths for different flange classes and sizes.
ASME B16.5 Flange Bolting Chart (Partial Reference)
(For standard Class 150, 300, 600, 900, 1500, and 2500 flanges)
| Nominal Pipe Size (NPS) | Flange Class | Bolt Diameter (in) | Number of Bolts | Bolt Circle Diameter (in) | Recommended Bolt Length (in) |
|---|---|---|---|---|---|
| ½" | 150 | ½" | 4 | 3.25 | 2.5 |
| 1" | 300 | ¾" | 4 | 3.75 | 3.0 |
| 2" | 600 | ¾" | 8 | 5.00 | 3.5 |
| 4" | 900 | ⅞" | 8 | 7.00 | 4.5 |
| 6" | 1500 | 1" | 12 | 9.25 | 5.5 |
| 8" | 2500 | 1⅛" | 12 | 11.50 | 7.0 |
Notes:
Bolt Material: Typically ASTM A193 B7 (high-strength alloy steel) or ASTM A307 (carbon steel) depending on service conditions.
Washers: Hardened washers (ASTM F436) are often used under nuts.
Torque Values: Depend on bolt material, lubrication, and flange rating (refer to ASME PCC-1 for bolt tightening procedures).
Full Charts: For a complete listing, refer to ASME B16.5 Table 7 & Table 8 (bolt quantity and size) and Table 1A/1B (flange dimensions).
Example for Class 150 Flanges (Partial Data):
| NPS | Bolt Diameter | No. of Bolts | Bolt Circle (in) |
|---|---|---|---|
| 1" | ½" | 4 | 3.25 |
| 2" | ½" | 4 | 4.75 |
| 4" | ¾" | 8 | 6.00 |
Key References:
ASME B16.5: Pipe Flanges and Flanged Fittings.
ASME PCC-1: Guidelines for Pressure Boundary Bolted Flange Joint Assembly.
For exact bolt lengths, always verify with flange dimensions and gasket thickness. Let me know if you need details for a specific flange class or size!
