NPS 16 Extra Strong (XS) Pipe
16.000 in (406.4 mm) outside diameter on a 0.500 in (12.7 mm) wall, giving a 15.000 in (381.0 mm) bore and 82.77 lb/ft (123.18 kg/m) empty. ASME B36.10M.
- Nominal size
- NPS 16 (DN 400)
- Schedule
- Extra Strong (XS)
- Outside diameter
- 16.000 in (406.4 mm)
- Wall thickness
- 0.500 in (12.7 mm)
- Inside diameter
- 15.000 in (381.0 mm)
- Weight, empty
- 82.77 lb/ft (123.18 kg/m)
- Weight, water filled
- 159.38 lb/ft (237.19 kg/m)
- Flow area
- 176.715 in² (114009 mm²)
In NPS 16 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 16
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 | 0.1654.19 mm | 15.670398.02 mm | 27.9041.53 kg/m | 10.018 |
| Sch 10 | 0.1884.78 mm | 15.624396.85 mm | 31.7547.25 kg/m | 9.960 |
| Sch 20 | 0.3127.92 mm | 15.376390.55 mm | 52.2877.79 kg/m | 9.646 |
| Sch 30 | 0.3759.52 mm | 15.250387.35 mm | 62.5893.13 kg/m | 9.489 |
| Sch 40 | 0.50012.70 mm | 15.000381.00 mm | 82.77123.18 kg/m | 9.180 |
| STD | 0.3759.52 mm | 15.250387.35 mm | 62.5893.13 kg/m | 9.489 |
| Sch 60 | 0.65616.66 mm | 14.688373.08 mm | 107.50159.98 kg/m | 8.802 |
| Sch 80 | 0.84421.44 mm | 14.312363.52 mm | 136.62203.31 kg/m | 8.357 |
| XS this page | 0.50012.70 mm | 15.000381.00 mm | 82.77123.18 kg/m | 9.180 |
| Sch 100 | 1.03126.19 mm | 13.938354.03 mm | 164.83245.29 kg/m | 7.926 |
| Sch 120 | 1.21930.96 mm | 13.562344.47 mm | 192.44286.38 kg/m | 7.504 |
| Sch 140 | 1.43836.53 mm | 13.124333.35 mm | 223.65332.82 kg/m | 7.027 |
| Sch 160 | 1.59440.49 mm | 12.812325.42 mm | 245.25364.97 kg/m | 6.697 |
Weight is plain-end carbon steel, w = 10.6802 × t × (OD − t) lb/ft.
Flanges for NPS 16 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 Extra Strong (XS) means 15.000 in (381.0 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 | 23.50596.90 mm | 1.4436.58 mm | 21.25539.75 mm | 16 × 1 in |
| Class 300 | 25.50647.70 mm | 2.2557.15 mm | 22.50571.50 mm | 20 × 1 1/4 in |
| Class 400 | 25.50647.70 mm | 2.5063.50 mm | 22.50571.50 mm | 20 × 1 3/8 in |
| Class 600 | 27.00685.80 mm | 3.0076.20 mm | 23.75603.25 mm | 20 × 1 1/2 in |
| Class 900 | 27.75704.85 mm | 3.5088.90 mm | 24.25615.95 mm | 20 × 1 5/8 in |
| Class 1500 | 32.50825.50 mm | 5.75146.05 mm | 27.75704.85 mm | 16 × 2 1/2 in |
Fittings for NPS 16 pipe
ASME B16.9 dimensions come from NPS alone, so these figures hold for Extra Strong (XS) exactly as they do for every other schedule in the size. Only the wall thickness has to be ordered to match.
| Fitting | Dimension | NPS 16 |
|---|---|---|
| 90° Long Radius Elbow | Centre-to-end A | 24.00609.60 mm |
| 90° Short Radius Elbow | Centre-to-end A | 16.00406.40 mm |
| 45° Long Radius Elbow | Centre-to-end B | 10.00254.00 mm |
| Straight Tee | Centre-to-end C and M | 12.00304.80 mm |
| Reducing Tee | Run centre-to-end C | 12.00304.80 mm |
| Concentric Reducer | End-to-end H | 14.00355.60 mm |
| Eccentric Reducer | End-to-end H | 14.00355.60 mm |
| Cap | Length E | 7.00177.80 mm |
Common questions
What is the inside diameter of NPS 16 extra strong (xs) pipe?
15.000 in (381.0 mm). The outside diameter is fixed at 16.000 in (406.4 mm) by ASME B36.10M, and the 0.500 in (12.7 mm) wall takes 1.000 in off it — 0.500 in from each side — leaving that bore.
How much does NPS 16 extra strong (xs) pipe weigh?
82.77 lb/ft (123.18 kg/m) empty, as plain-end carbon steel. Full of water it comes to 159.38 lb/ft (237.19 kg/m), because the bore holds 9.180 US gallons per foot. One short ton of this pipe is about 24 ft.
Does NPS 16 extra strong (xs) pipe use special flanges or fittings?
No. Flanges and buttweld fittings are dimensioned from NPS, so NPS 16 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 15.000 in (381.0 mm) to match.