Lap joint flanges are reviewed together with stub-end requirements, class rating, material, size and facing details.
| Standard / Type | Product | Typical scope |
|---|---|---|
| Type | Lap joint flange | Used with stub end |
| Class rating | 150 to 2500 | By ASME B16.5 order scope |
| Documents | Material certificate | By order requirement |
| NPS | OD in | Thickness in | Bolt circle in | Holes | Hole dia. in | Approx. lb |
|---|---|---|---|---|---|---|
| 1/2" | 3.5 | 0.44 | 2.38 | 4 | 0.62 | 1 |
| 3/4" | 3.88 | 0.5 | 2.75 | 4 | 0.62 | 2 |
| 1" | 4.25 | 0.56 | 3.12 | 4 | 0.62 | 2 |
| 1 1/2" | 5 | 0.69 | 3.88 | 4 | 0.62 | 3 |
| 2" | 6 | 0.75 | 4.75 | 4 | 0.75 | 5 |
| 3" | 7.5 | 0.94 | 6 | 4 | 0.75 | 8 |
| 4" | 9 | 0.94 | 7.5 | 8 | 0.75 | 13 |
| 6" | 11 | 1 | 9.5 | 8 | 0.88 | 19 |
| 8" | 13.5 | 1.12 | 11.75 | 8 | 0.88 | 30 |
| 10" | 16 | 1.19 | 14.25 | 12 | 1 | 43 |
| 12" | 19 | 1.25 | 17 | 12 | 1 | 64 |
| 16" | 23.5 | 1.44 | 21.25 | 16 | 1.12 | 140 |
| 20" | 27.5 | 1.69 | 25 | 20 | 1.25 | 195 |
| 24" | 32 | 1.88 | 29.5 | 20 | 1.38 | 275 |
| NPS | OD in | Thickness in | Bolt circle in | Holes | Hole dia. in | Approx. lb |
|---|---|---|---|---|---|---|
| 1/2" | 3.75 | 0.56 | 2.62 | 4 | 0.62 | 2 |
| 3/4" | 4.62 | 0.62 | 3.25 | 4 | 0.75 | 3 |
| 1" | 4.88 | 0.69 | 3.5 | 4 | 0.75 | 3 |
| 1 1/2" | 6.12 | 0.81 | 4.5 | 4 | 0.88 | 6 |
| 2" | 6.5 | 0.88 | 5 | 8 | 0.75 | 7 |
| 3" | 8.25 | 1.12 | 6.62 | 8 | 0.88 | 13 |
| 4" | 10 | 1.25 | 7.88 | 8 | 0.88 | 22 |
| 6" | 12.5 | 1.44 | 10.62 | 12 | 0.88 | 39 |
| 8" | 15 | 1.62 | 13 | 12 | 1 | 58 |
| 10" | 17.5 | 1.88 | 15.25 | 16 | 1.12 | 91 |
| 12" | 20.5 | 2 | 17.75 | 16 | 1.25 | 140 |
| 16" | 25.5 | 2.25 | 22.5 | 20 | 1.38 | 250 |
| 20" | 30.5 | 2.5 | 27 | 24 | 1.38 | 370 |
| 24" | 36 | 2.75 | 32 | 24 | 1.62 | 550 |
| NPS | OD in | Thickness in | Bolt circle in | Holes | Hole dia. in | Approx. lb |
|---|---|---|---|---|---|---|
| 1/2" | 3.75 | 0.56 | 2.62 | 4 | 0.62 | 2 |
| 3/4" | 4.62 | 0.62 | 3.25 | 4 | 0.75 | 3 |
| 1" | 4.88 | 0.69 | 3.5 | 4 | 0.75 | 4 |
| 1 1/2" | 6.12 | 0.88 | 4.5 | 4 | 0.88 | 7 |
| 2" | 6.5 | 1 | 5 | 8 | 0.75 | 9 |
| 3" | 8.25 | 1.25 | 6.62 | 8 | 0.88 | 15 |
| 4" | 10.75 | 1.5 | 8.5 | 8 | 1 | 36 |
| 6" | 14 | 1.88 | 11.5 | 12 | 1.12 | 78 |
| 8" | 16.5 | 2.19 | 13.75 | 12 | 1.25 | 110 |
| 10" | 20 | 2.5 | 17 | 16 | 1.38 | 170 |
| 12" | 22 | 2.62 | 19.25 | 20 | 1.38 | 200 |
| 16" | 27 | 3 | 23.75 | 20 | 1.62 | 365 |
| 20" | 32 | 3.5 | 28.5 | 24 | 1.75 | 570 |
| 24" | 37 | 4 | 33 | 24 | 2 | 810 |
Use these tables for RFQ preparation. Final production should be confirmed against the required standard edition, drawing, material grade and certificate requirement.
Provide NPS size, class, material, stub-end details if available, quantity and certificate requirements.
Because lap joint assemblies can vary by stub-end design, drawings or previous purchase records are useful for confirmation.
Our technical team compares the requested standard edition and project drawing, then releases the applicable dimensions to production.
We record the Class, RF, FF or RTJ facing, bore or pipe schedule and tolerance notes on each ASME quotation line.
Flange type, sealing face, drilling, thickness and machining details are checked together so production and inspection use the same specification.
Our order file carries the agreed EN 10204 3.1, PED, AD 2000, UKCA, PMI, NDT and third-party inspection scope through to shipment.
Send the ASME B16.5 flange type, NPS, Class, facing, bore or pipe schedule, material grade, quantity and certificate requirement.
