NPS 11 Standard (STD) Pipe
11.750 in (298.4 mm) outside diameter on a 0.375 in (9.5 mm) wall, giving a 11.000 in (279.4 mm) bore and 45.56 lb/ft (67.80 kg/m) empty. ASME B36.10M.
- Nominal size
- NPS 11 (DN 275)
- Schedule
- Standard (STD)
- Outside diameter
- 11.750 in (298.4 mm)
- Wall thickness
- 0.375 in (9.5 mm)
- Inside diameter
- 11.000 in (279.4 mm)
- Weight, empty
- 45.56 lb/ft (67.80 kg/m)
- Weight, water filled
- 86.76 lb/ft (129.11 kg/m)
- Flow area
- 95.033 in² (61312 mm²)
In NPS 11 this wall thickness is also designated Schedule 40. That is the same pipe under another name, not a different product — but the coincidence is specific to this size and does not hold across the range.
Every schedule in NPS 11
Dimensions are given in inches, with the millimetre equivalent beneath in grey.
| Schedule | Wall thickness | Inside diameter | Weight, empty | Water (US gal/ft) |
|---|---|---|---|---|
| Sch 40 | 0.3759.52 mm | 11.000279.40 mm | 45.5667.80 kg/m | 4.937 |
| STD this page | 0.3759.52 mm | 11.000279.40 mm | 45.5667.80 kg/m | 4.937 |
| Sch 80 | 0.50012.70 mm | 10.750273.05 mm | 60.0889.40 kg/m | 4.715 |
| XS | 0.50012.70 mm | 10.750273.05 mm | 60.0889.40 kg/m | 4.715 |
Weight is plain-end carbon steel, w = 10.6802 × t × (OD − t) lb/ft.
Common questions
What is the inside diameter of NPS 11 standard (std) pipe?
11.000 in (279.4 mm). The outside diameter is fixed at 11.750 in (298.4 mm) by ASME B36.10M, and the 0.375 in (9.5 mm) wall takes 0.750 in off it — 0.375 in from each side — leaving that bore.
How much does NPS 11 standard (std) pipe weigh?
45.56 lb/ft (67.80 kg/m) empty, as plain-end carbon steel. Full of water it comes to 86.76 lb/ft (129.11 kg/m), because the bore holds 4.937 US gallons per foot. One short ton of this pipe is about 44 ft.
Does NPS 11 standard (std) pipe use special flanges or fittings?
No. Flanges and buttweld fittings are dimensioned from NPS, so NPS 11 hardware fits this pipe in any schedule. The one thing that does follow the schedule is the bore of a weld neck flange or a fitting end prep, which has to be 11.000 in (279.4 mm) to match.