NPS 14 Schedule 20 Pipe
14.000 in (355.6 mm) outside diameter on a 0.312 in (7.9 mm) wall, giving a 13.376 in (339.8 mm) bore and 45.61 lb/ft (67.88 kg/m) empty. ASME B36.10M.
- Nominal size
- NPS 14 (DN 350)
- Schedule
- Schedule 20
- Outside diameter
- 14.000 in (355.6 mm)
- Wall thickness
- 0.312 in (7.9 mm)
- Inside diameter
- 13.376 in (339.8 mm)
- Weight, empty
- 45.61 lb/ft (67.88 kg/m)
- Weight, water filled
- 106.53 lb/ft (158.54 kg/m)
- Flow area
- 140.521 in² (90659 mm²)
No other designation in NPS 14 shares this wall thickness, so Schedule 20 is unambiguous in this size.
Every schedule in NPS 14
Dimensions are given in inches, with the millimetre equivalent beneath in grey.
| Schedule | Wall thickness | Inside diameter | Weight, empty | Water (US gal/ft) |
|---|---|---|---|---|
| Sch 5 | 0.1563.96 mm | 13.688347.68 mm | 23.0734.33 kg/m | 7.644 |
| Sch 10 | 0.1884.78 mm | 13.624346.05 mm | 27.7341.27 kg/m | 7.573 |
| Sch 20 this page | 0.3127.92 mm | 13.376339.75 mm | 45.6167.88 kg/m | 7.300 |
| Sch 30 | 0.3759.52 mm | 13.250336.55 mm | 54.5781.21 kg/m | 7.163 |
| Sch 40 | 0.43811.13 mm | 13.124333.35 mm | 63.4494.41 kg/m | 7.027 |
| STD | 0.3759.52 mm | 13.250336.55 mm | 54.5781.21 kg/m | 7.163 |
| Sch 60 | 0.59415.09 mm | 12.812325.42 mm | 85.05126.57 kg/m | 6.697 |
| Sch 80 | 0.75019.05 mm | 12.500317.50 mm | 106.13157.95 kg/m | 6.375 |
| XS | 0.50012.70 mm | 13.000330.20 mm | 72.09107.28 kg/m | 6.895 |
| Sch 100 | 0.93823.83 mm | 12.124307.95 mm | 130.86194.73 kg/m | 5.997 |
| Sch 120 | 1.09427.79 mm | 11.812300.02 mm | 150.80224.41 kg/m | 5.693 |
| Sch 140 | 1.25031.75 mm | 11.500292.10 mm | 170.22253.31 kg/m | 5.396 |
| Sch 160 | 1.40635.71 mm | 11.188284.18 mm | 189.12281.43 kg/m | 5.107 |
Weight is plain-end carbon steel, w = 10.6802 × t × (OD − t) lb/ft.
Flanges for NPS 14 pipe
Flange dimensions are set by NPS and pressure class, not by schedule, so every flange below fits this pipe. The exception is the weld neck: its bore is machined to the pipe it is welded to, which for Schedule 20 means 13.376 in (339.8 mm). Order the flange to the schedule or the bores will not line up at the weld.
| Class | Flange OD | Thickness | Bolt circle | Bolting |
|---|---|---|---|---|
| Class 150 | 21.00533.40 mm | 1.3835.05 mm | 18.75476.25 mm | 12 × 1 in |
| Class 300 | 23.00584.20 mm | 2.1253.85 mm | 20.25514.35 mm | 20 × 1 1/8 in |
| Class 400 | 23.00584.20 mm | 2.3860.45 mm | 20.25514.35 mm | 20 × 1 1/4 in |
| Class 600 | 23.75603.25 mm | 2.7569.85 mm | 20.75527.05 mm | 20 × 1 3/8 in |
| Class 900 | 25.25641.35 mm | 3.3885.85 mm | 22.00558.80 mm | 20 × 1 1/2 in |
| Class 1500 | 29.50749.30 mm | 5.25133.35 mm | 25.00635.00 mm | 16 × 2 1/4 in |
Fittings for NPS 14 pipe
ASME B16.9 dimensions come from NPS alone, so these figures hold for Schedule 20 exactly as they do for every other schedule in the size. Only the wall thickness has to be ordered to match.
| Fitting | Dimension | NPS 14 |
|---|---|---|
| 90° Long Radius Elbow | Centre-to-end A | 21.00533.40 mm |
| 90° Short Radius Elbow | Centre-to-end A | 14.00355.60 mm |
| 45° Long Radius Elbow | Centre-to-end B | 8.75222.25 mm |
| Straight Tee | Centre-to-end C and M | 11.00279.40 mm |
| Reducing Tee | Run centre-to-end C | 11.00279.40 mm |
| Concentric Reducer | End-to-end H | 13.00330.20 mm |
| Eccentric Reducer | End-to-end H | 13.00330.20 mm |
| Cap | Length E | 6.50165.10 mm |
Common questions
What is the inside diameter of NPS 14 schedule 20 pipe?
13.376 in (339.8 mm). The outside diameter is fixed at 14.000 in (355.6 mm) by ASME B36.10M, and the 0.312 in (7.9 mm) wall takes 0.624 in off it — 0.312 in from each side — leaving that bore.
How much does NPS 14 schedule 20 pipe weigh?
45.61 lb/ft (67.88 kg/m) empty, as plain-end carbon steel. Full of water it comes to 106.53 lb/ft (158.54 kg/m), because the bore holds 7.300 US gallons per foot. One short ton of this pipe is about 44 ft.
Does NPS 14 schedule 20 pipe use special flanges or fittings?
No. Flanges and buttweld fittings are dimensioned from NPS, so NPS 14 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 13.376 in (339.8 mm) to match.