3 inch pipe dimensions: OD and wall thickness by schedule
Deskely Completions team Singapore
A 3 inch pipe, NPS 3 or DN 80, has an outside diameter of 88.9 mm (3.500 inches) in every schedule. The nominal size is a name, not a measurement: the outside diameter is larger than 3 inch. The schedule sets the wall thickness, and with it the inside diameter and the weight.
The table gives every schedule listed for NPS 3 in ASME B36.10M and B36.19M, in mm and inches.
- Outside diameter: 88.9 mm (3.500 in), the same for every schedule.
- Schedule 40: 5.49 mm wall, 77.9 mm inside diameter.
- Schedule 80: 7.62 mm wall, 73.7 mm inside diameter.
- Metric equivalent: DN 80.
3 inch pipe dimensions by schedule
| Schedule | Wall mm (in) | ID mm (in) | kg/m (lb/ft) |
|---|---|---|---|
| Schedule 5S | 2.11 (0.083) | 84.68 (3.334) | 4.52 (3.03) |
| Schedule 10S | 3.05 (0.120) | 82.80 (3.260) | 6.46 (4.34) |
| STD (standard) | 5.49 (0.216) | 77.92 (3.068) | 11.29 (7.59) |
| Schedule 40 | 5.49 (0.216) | 77.92 (3.068) | 11.29 (7.59) |
| XS (extra strong) | 7.62 (0.300) | 73.66 (2.900) | 15.27 (10.26) |
| Schedule 80 | 7.62 (0.300) | 73.66 (2.900) | 15.27 (10.26) |
| Schedule 160 | 11.13 (0.438) | 66.64 (2.624) | 21.35 (14.34) |
| XXS (double extra strong) | 15.24 (0.600) | 58.42 (2.300) | 27.68 (18.60) |
Nominal dimensions. Weights are for plain-end carbon steel; stainless steel is about 2 percent heavier. Mill tolerances apply, and your project pipe specification takes precedence.
3 inch pipe outside diameter
The outside diameter of NPS 3 pipe is 88.9 mm, or 3.500 inches, whatever the schedule, so 3 inch fittings and flanges fit every wall thickness. In metric drawings and specifications the same size is called DN 80.
It is larger than 3 inch because, below NPS 14, the nominal size is a traditional name that once roughly matched the bore, not the outside.
Nearby sizes
- 2-1/2 inch pipe dimensions: OD 73 mm
- 3-1/2 inch pipe dimensions: OD 101.6 mm
Every size and schedule in one table: the pipe schedule chart.
The Deskely products for this
Frequently asked questions
What is the OD of 3 inch pipe?
88.9 mm (3.500 inches), the same for every schedule.
What is the wall thickness of 3 inch schedule 40 pipe?
5.49 mm (0.216 in), giving an inside diameter of 77.9 mm (3.068 in).
What is the wall thickness of 3 inch schedule 80 pipe?
7.62 mm (0.300 in), giving an inside diameter of 73.7 mm (2.900 in).
What is 3 inch pipe in DN?
DN 80.
How much does 3 inch schedule 40 pipe weigh?
11.29 kg/m (7.59 lb/ft) for plain-end carbon steel.
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