Use this reference when you need a quick dimensional check for 3/4 inch Schedule 40 pipe, also identified as NPS 3/4 and DN20. The existing data below is organized for engineers, designers, estimators, fabricators, and CAD users who need consistent pipe information during layout and coordination work.
For related comparisons, review the site’s references for 1/2 inch Schedule 40 pipe and 1 inch Schedule 40 pipe. Nearby-size pages can help with preliminary routing reviews, material takeoffs, and checking transitions between connected piping components.
Schedule 40 pipe 3/4 inch (DN20) is a standard steel pipe size commonly used in piping design, fabrication, drafting, and engineering estimation work. This page provides the standard dimensions and weight data for NPS 3/4 Schedule 40 pipe based on ANSI / ASME B36.10, including outside diameter, inside diameter, wall thickness, and weight per meter.
This size is widely used in industrial piping systems, utility services, water lines, and fabrication projects where accurate dimensional data is important for layout, support design, material takeoff, and installation planning.
3/4 Inch Schedule 40 Pipe Dimensions
- Nominal Pipe Size (NPS): 3/4 inch
- Diameter Nominal (DN): DN20
- Pipe Schedule: Schedule 40
- Outside Diameter (OD): 26.7 mm
- Wall Thickness: 2.87 mm
- Inside Diameter (ID): 20.96 mm
- Pipe Weight: 1.69 kg/m
- Pipe Weight Including Water: 2.03 kg/m
- Reference Standard: ANSI / ASME B36.10
Schedule 40 Pipe 3/4 Inch (DN20) Data Table
| NPS | DN | OD (mm) | Wall Thickness (mm) | ID (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 3/4 inch | DN20 | 26.7 | 2.87 | 20.96 | 1.69 |
What Is 3/4 Inch Schedule 40 Pipe Used For?
3/4 inch Schedule 40 pipe is commonly used in industrial and utility piping systems where a standardized steel pipe size is required. Engineers, designers, and fabricators often use this size in water distribution systems, utility piping, compressed air lines, process piping systems, mechanical piping layouts, and fabrication work.
Because this is a practical and widely used pipe size, accurate dimensions and weight data are important for support design, installation work, material estimation, and field coordination.
Why These Dimensions Matter in Engineering
In piping and mechanical design, standard pipe dimensions are important for more than simple identification. The outside diameter is used for supports, clamps, insulation sizing, and equipment connection layouts. The inside diameter affects internal flow area and hydraulic calculations. The wall thickness is important for fabrication, welding preparation, and pipe strength, while the pipe weight per meter is essential for support load calculations and installation planning.
Using the correct DN20 Schedule 40 pipe dimensions helps reduce drafting errors, procurement mistakes, and field fit-up problems during construction and fabrication work.
3/4 Inch DN20 Schedule 40 Pipe for CAD and Drafting Work
For CAD, BIM, and piping drafting work, this size is commonly listed as NPS 3/4 or DN20. The standard OD of 26.7 mm is especially useful for routing clearance, support detailing, and nozzle or equipment connection references in both 2D drawings and 3D models.
This page can be used as a quick reference for 3/4 inch Schedule 40 pipe dimensions, DN20 pipe dimensions, and Schedule 40 steel pipe weight per meter during design, drafting, and estimation work.
Frequently Asked Questions
What is the outside diameter of 3/4 inch Schedule 40 pipe?
The outside diameter of 3/4 inch Schedule 40 pipe is 26.7 mm.
What is the wall thickness of DN20 Schedule 40 pipe?
The wall thickness is 2.87 mm.
What is the inside diameter of Schedule 40 pipe 3/4 inch?
The inside diameter is 20.96 mm.
How much does 3/4 inch Schedule 40 pipe weigh?
The pipe weight is 1.69 kg/m. The weight including water is 2.03 kg/m.
Which standard covers these dimensions?
These dimensions are based on ANSI / ASME B36.10.
Conclusion
Schedule 40 pipe 3/4 inch (DN20) is an important reference size for industrial piping, drafting, fabrication, and engineering calculations. With an OD of 26.7 mm, ID of 20.96 mm, wall thickness of 2.87 mm, and weight of 1.69 kg/m, it is a useful standard pipe size for engineers, designers, and estimators working with steel piping systems.
For more pipe schedule data, compare this size with nearby standard sizes such as 1/2 inch and 1 inch Schedule 40 pipe pages.
How to Read This Pipe Reference
The terms in the data table describe different ways of identifying and applying the same pipe size. NPS is the inch-based nominal designation, while DN is the metric nominal designation. Neither label should be treated as a direct measurement of the pipe’s outside or inside diameter; use the listed dimensional values when preparing drawings, checking clearances, or coordinating connections.
The schedule designation is used with the dimensional series to identify the pipe wall configuration. For fabrication and design review, check the outside diameter, wall thickness, and inside diameter separately rather than relying on the nominal size alone.
Using the Data in Design and Drafting
- Use the outside diameter when coordinating clamps, supports, insulation space, sleeves, and equipment connection layouts.
- Use the inside diameter when a flow-area or hydraulic calculation requires the internal passage dimension.
- Use the wall thickness when reviewing weld preparation, fabrication details, and dimensional fit-up.
- Use the listed mass values for preliminary support-load reviews, installation planning, and material estimation.
For a complete piping check, coordinate this pipe reference with the applicable material specification, connection type, fittings, flanges, corrosion allowance, design conditions, and project requirements. The dimensional data supports drafting and estimation, but it does not replace project-specific engineering verification.
Related PipeSTD References
This page works well with related references for pipe schedules, steel pipe dimensions, pipe fittings, and pipe flanges. CAD and DWG resources can also be useful when the dimensional reference needs to be transferred into a layout or model. Link these related topics where available so readers can move from pipe identification to connection, modeling, and fabrication information without repeating the same search.
Additional Questions About 3/4 Inch Schedule 40 Pipe
Is DN20 the same naming system as NPS 3/4?
DN20 and NPS 3/4 are corresponding nominal designations used to identify this pipe size in metric and inch-based contexts. For drawing and procurement accuracy, retain the full size and schedule designation shown in the reference.
Should nominal size be used as the CAD outside diameter?
No. CAD geometry and clearance checks should use the listed outside diameter rather than the nominal designation. This helps avoid errors when routing pipe, positioning supports, or coordinating equipment connections.
Why are both pipe weight and weight including water shown?
The dry pipe weight supports material and handling estimates, while the value including water provides a different load condition for preliminary support and installation reviews. Select the load case appropriate to the engineering task and verify project assumptions.
Can this page replace a project piping specification?
No. This page is a dimensional reference. Material grade, connection details, pressure-temperature requirements, corrosion allowance, fabrication requirements, and other project controls must be checked separately.