NPS 1/4 Schedule 80 Pipe
0.540 in (13.7 mm) outside diameter on a 0.119 in (3.0 mm) wall, giving a 0.302 in (7.7 mm) bore and 0.54 lb/ft (0.80 kg/m) empty. ASME B36.10M.
- Nominal size
- NPS 1/4 (DN 8)
- Schedule
- Schedule 80
- Outside diameter
- 0.540 in (13.7 mm)
- Wall thickness
- 0.119 in (3.0 mm)
- Inside diameter
- 0.302 in (7.7 mm)
- Weight, empty
- 0.54 lb/ft (0.80 kg/m)
- Weight, water filled
- 0.57 lb/ft (0.84 kg/m)
- Flow area
- 0.072 in² (46 mm²)
In NPS 1/4 this wall thickness is also designated Extra Strong (XS). 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 1/4
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 | 0.0491.24 mm | 0.44211.23 mm | 0.260.38 kg/m | 0.008 |
| Sch 10 | 0.0651.65 mm | 0.41010.41 mm | 0.330.49 kg/m | 0.007 |
| Sch 40 | 0.0882.24 mm | 0.3649.25 mm | 0.420.63 kg/m | 0.005 |
| STD | 0.0882.24 mm | 0.3649.25 mm | 0.420.63 kg/m | 0.005 |
| Sch 80 this page | 0.1193.02 mm | 0.3027.67 mm | 0.540.80 kg/m | 0.004 |
| XS | 0.1193.02 mm | 0.3027.67 mm | 0.540.80 kg/m | 0.004 |
Weight is plain-end carbon steel, w = 10.6802 × t × (OD − t) lb/ft.
Common questions
What is the inside diameter of NPS 1/4 schedule 80 pipe?
0.302 in (7.7 mm). The outside diameter is fixed at 0.540 in (13.7 mm) by ASME B36.10M, and the 0.119 in (3.0 mm) wall takes 0.238 in off it — 0.119 in from each side — leaving that bore.
How much does NPS 1/4 schedule 80 pipe weigh?
0.54 lb/ft (0.80 kg/m) empty, as plain-end carbon steel. Full of water it comes to 0.57 lb/ft (0.84 kg/m), because the bore holds 0.004 US gallons per foot. One short ton of this pipe is about 3738 ft.
Does NPS 1/4 schedule 80 pipe use special flanges or fittings?
No. Flanges and buttweld fittings are dimensioned from NPS, so NPS 1/4 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 0.302 in (7.7 mm) to match.