NPS 14 Pipe Dimensions
Outside diameter 14.000 in (355.6 mm) — fixed across every schedule. 13 wall thicknesses from ASME B36.10M, with bore, plain-end weight and flow area for each.
- Nominal size
- NPS 14
- Metric designator
- DN 350
- Outside diameter
- 14.000 in (355.6 mm)
- Schedules listed
- 13
- Standard weight wall
- 0.375 in (9.5 mm)
- Extra strong wall
- 0.500 in (12.7 mm)
Every schedule in NPS 14
Dimensions are given in inches, with the millimetre equivalent beneath in grey.
| Schedule | Wall thickness | Inside diameter | Weight, empty | Flow area (in²) | Water (US gal/ft) |
|---|---|---|---|---|---|
| Sch 5 | 0.1563.96 mm | 13.688347.68 mm | 23.0734.33 kg/m | 147.15 | 7.644 |
| Sch 10 | 0.1884.78 mm | 13.624346.05 mm | 27.7341.27 kg/m | 145.78 | 7.573 |
| Sch 20 | 0.3127.92 mm | 13.376339.75 mm | 45.6167.88 kg/m | 140.52 | 7.300 |
| Sch 30 | 0.3759.52 mm | 13.250336.55 mm | 54.5781.21 kg/m | 137.89 | 7.163 |
| Sch 40 | 0.43811.13 mm | 13.124333.35 mm | 63.4494.41 kg/m | 135.28 | 7.027 |
| STD | 0.3759.52 mm | 13.250336.55 mm | 54.5781.21 kg/m | 137.89 | 7.163 |
| Sch 60 | 0.59415.09 mm | 12.812325.42 mm | 85.05126.57 kg/m | 128.92 | 6.697 |
| Sch 80 | 0.75019.05 mm | 12.500317.50 mm | 106.13157.95 kg/m | 122.72 | 6.375 |
| XS | 0.50012.70 mm | 13.000330.20 mm | 72.09107.28 kg/m | 132.73 | 6.895 |
| Sch 100 | 0.93823.83 mm | 12.124307.95 mm | 130.86194.73 kg/m | 115.45 | 5.997 |
| Sch 120 | 1.09427.79 mm | 11.812300.02 mm | 150.80224.41 kg/m | 109.58 | 5.693 |
| Sch 140 | 1.25031.75 mm | 11.500292.10 mm | 170.22253.31 kg/m | 103.87 | 5.396 |
| Sch 160 | 1.40635.71 mm | 11.188284.18 mm | 189.12281.43 kg/m | 98.31 | 5.107 |
Weight is calculated for carbon steel as w = 10.6802 × t × (OD − t) lb/ft and is the plain-end weight, excluding coatings, linings and fittings.
Standard weight equals Schedule 30 in this size. Extra strong does not coincide with a numbered schedule here.
This size, schedule by schedule
A page for each combination, with bore, weight, water capacity and the matching flange and fitting data.
This size in a schedule chart
Common questions
What is the outside diameter of NPS 14 pipe?
NPS 14 pipe has an outside diameter of 14.000 in (355.6 mm). That outside diameter is fixed: it is identical in every schedule, and only the wall thickness — and therefore the bore — changes from one schedule to the next.
How much does NPS 14 schedule 40 pipe weigh?
63.44 lb/ft (94.41 kg/m) as plain-end carbon steel, on a wall thickness of 0.438 in (11.1 mm).
What is the metric equivalent of NPS 14?
DN 350. DN is a dimensionless designator, not a measurement — DN 350 pipe does not measure 350 mm anywhere. Its actual outside diameter is 355.6 mm.