NPS 2 1/2 Double Extra Strong (XXS) Pipe
2.875 in (73.0 mm) outside diameter on a 0.552 in (14.0 mm) wall, giving a 1.771 in (45.0 mm) bore and 13.70 lb/ft (20.38 kg/m) empty. ASME B36.10M.
- Nominal size
- NPS 2 1/2 (DN 65)
- Schedule
- Double Extra Strong (XXS)
- Outside diameter
- 2.875 in (73.0 mm)
- Wall thickness
- 0.552 in (14.0 mm)
- Inside diameter
- 1.771 in (45.0 mm)
- Weight, empty
- 13.70 lb/ft (20.38 kg/m)
- Weight, water filled
- 14.76 lb/ft (21.97 kg/m)
- Flow area
- 2.463 in² (1589 mm²)
No other designation in NPS 2 1/2 shares this wall thickness, so Double Extra Strong (XXS) is unambiguous in this size.
Every schedule in NPS 2 1/2
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 | 0.0832.11 mm | 2.70968.81 mm | 2.473.68 kg/m | 0.299 |
| Sch 10 | 0.1203.05 mm | 2.63566.93 mm | 3.535.25 kg/m | 0.283 |
| Sch 40 | 0.2035.16 mm | 2.46962.71 mm | 5.798.62 kg/m | 0.249 |
| STD | 0.2035.16 mm | 2.46962.71 mm | 5.798.62 kg/m | 0.249 |
| Sch 80 | 0.2767.01 mm | 2.32359.00 mm | 7.6611.40 kg/m | 0.220 |
| XS | 0.2767.01 mm | 2.32359.00 mm | 7.6611.40 kg/m | 0.220 |
| Sch 160 | 0.3759.52 mm | 2.12553.97 mm | 10.0114.90 kg/m | 0.184 |
| XXS this page | 0.55214.02 mm | 1.77144.98 mm | 13.7020.38 kg/m | 0.128 |
Weight is plain-end carbon steel, w = 10.6802 × t × (OD − t) lb/ft.
Flanges for NPS 2 1/2 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 Double Extra Strong (XXS) means 1.771 in (45.0 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 | 7.00177.80 mm | 0.8822.35 mm | 5.50139.70 mm | 4 × 5/8 in |
| Class 300 | 7.50190.50 mm | 1.0025.40 mm | 5.88149.35 mm | 8 × 3/4 in |
| Class 400 | 7.50190.50 mm | 1.1228.45 mm | 5.88149.35 mm | 8 × 3/4 in |
| Class 600 | 7.50190.50 mm | 1.1228.45 mm | 5.88149.35 mm | 8 × 3/4 in |
| Class 900 | 9.62244.35 mm | 1.6241.15 mm | 7.50190.50 mm | 8 × 1 in |
| Class 1500 | 9.62244.35 mm | 1.6241.15 mm | 7.50190.50 mm | 8 × 1 in |
| Class 2500 | 10.50266.70 mm | 2.2557.15 mm | 7.75196.85 mm | 8 × 1 1/8 in |
Fittings for NPS 2 1/2 pipe
ASME B16.9 dimensions come from NPS alone, so these figures hold for Double Extra Strong (XXS) exactly as they do for every other schedule in the size. Only the wall thickness has to be ordered to match.
| Fitting | Dimension | NPS 2 1/2 |
|---|---|---|
| 90° Long Radius Elbow | Centre-to-end A | 3.7595.25 mm |
| 90° Short Radius Elbow | Centre-to-end A | 2.5063.50 mm |
| 45° Long Radius Elbow | Centre-to-end B | 1.7544.45 mm |
| Straight Tee | Centre-to-end C and M | 3.0076.20 mm |
| Reducing Tee | Run centre-to-end C | 3.0076.20 mm |
| Concentric Reducer | End-to-end H | 3.5088.90 mm |
| Eccentric Reducer | End-to-end H | 3.5088.90 mm |
| Cap | Length E | 1.5038.10 mm |
Common questions
What is the inside diameter of NPS 2 1/2 double extra strong (xxs) pipe?
1.771 in (45.0 mm). The outside diameter is fixed at 2.875 in (73.0 mm) by ASME B36.10M, and the 0.552 in (14.0 mm) wall takes 1.104 in off it — 0.552 in from each side — leaving that bore.
How much does NPS 2 1/2 double extra strong (xxs) pipe weigh?
13.70 lb/ft (20.38 kg/m) empty, as plain-end carbon steel. Full of water it comes to 14.76 lb/ft (21.97 kg/m), because the bore holds 0.128 US gallons per foot. One short ton of this pipe is about 146 ft.
Does NPS 2 1/2 double extra strong (xxs) pipe use special flanges or fittings?
No. Flanges and buttweld fittings are dimensioned from NPS, so NPS 2 1/2 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 1.771 in (45.0 mm) to match.