NPS 3/4 Pipe Dimensions
Outside diameter 1.050 in (26.7 mm) — fixed across every schedule. 8 wall thicknesses from ASME B36.10M, with bore, plain-end weight and flow area for each.
- Nominal size
- NPS 3/4
- Metric designator
- DN 20
- Outside diameter
- 1.050 in (26.7 mm)
- Schedules listed
- 8
- Standard weight wall
- 0.113 in (2.9 mm)
- Extra strong wall
- 0.154 in (3.9 mm)
Every schedule in NPS 3/4
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 | 0.0651.65 mm | 0.92023.37 mm | 0.681.02 kg/m | 0.66 | 0.035 |
| Sch 10 | 0.0832.11 mm | 0.88422.45 mm | 0.861.28 kg/m | 0.61 | 0.032 |
| Sch 40 | 0.1132.87 mm | 0.82420.93 mm | 1.131.68 kg/m | 0.53 | 0.028 |
| STD | 0.1132.87 mm | 0.82420.93 mm | 1.131.68 kg/m | 0.53 | 0.028 |
| Sch 80 | 0.1543.91 mm | 0.74218.85 mm | 1.472.19 kg/m | 0.43 | 0.022 |
| XS | 0.1543.91 mm | 0.74218.85 mm | 1.472.19 kg/m | 0.43 | 0.022 |
| Sch 160 | 0.2195.56 mm | 0.61215.54 mm | 1.942.89 kg/m | 0.29 | 0.015 |
| XXS | 0.3087.82 mm | 0.43411.02 mm | 2.443.63 kg/m | 0.15 | 0.008 |
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 40 in this size. Extra strong equals Schedule 80.
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 3/4 pipe?
NPS 3/4 pipe has an outside diameter of 1.050 in (26.7 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 3/4 schedule 40 pipe weigh?
1.13 lb/ft (1.68 kg/m) as plain-end carbon steel, on a wall thickness of 0.113 in (2.9 mm).
What is the metric equivalent of NPS 3/4?
DN 20. DN is a dimensionless designator, not a measurement — DN 20 pipe does not measure 20 mm anywhere. Its actual outside diameter is 26.7 mm.