This reference provides a quick dimensional check for Schedule 30 Pipe 1 Inch (DN25), including outside diameter, inside diameter, wall thickness, and weight. Use the data when preparing piping layouts, CAD drawings, material takeoffs, support reviews, and preliminary load checks.
Because nominal pipe size is a designation rather than a direct measurement, the NPS and DN labels should be read together with the listed outside diameter and wall thickness. Always coordinate pipe dimensions with the selected fittings, flanges, material specification, joining method, and project requirements before finalizing a design.
Schedule 30 Pipe 1 Inch (DN25) Dimensions and Weight
Schedule 30 pipe 1 inch (DN25) is a standard steel pipe size commonly used in piping design, drafting, fabrication, estimation, and industrial layout work. This page provides the standard dimensions, wall thickness, inside diameter, and weight per meter for NPS 1 Schedule 30 pipe based on ASME B36.10.
For engineers, designers, estimators, and CAD users, quick access to accurate pipe data helps improve piping layout, support planning, weight checks, transport review, and fabrication coordination during project development.
1 Inch Schedule 30 Pipe Dimensions
- Nominal Pipe Size (NPS): 1 inch
- Diameter Nominal (DN): DN25
- Outside Diameter (OD): 33.4 mm
- Wall Thickness: 2.9 mm
- Inside Diameter (ID): 27.6 mm
- Pipe Weight: 2.18 kg/m
- Pipe Weight Including Water: 2.77 kg/m
- Standard: ASME B36.10
Schedule 30 Pipe 1 Inch Data Table
| NPS | DN | Outside Diameter (OD) | Wall Thickness | Inside Diameter (ID) | Weight |
|---|---|---|---|---|---|
| 1 inch | DN25 | 33.4 mm | 2.9 mm | 27.6 mm | 2.18 kg/m |
Understanding 1 Inch Schedule 30 Pipe
1 inch Schedule 30 pipe is a standard steel pipe size used as a reference in industrial piping layouts, utility systems, water lines, process design studies, and CAD drafting. With an outside diameter of 33.4 mm and a wall thickness of 2.9 mm, this pipe size is suitable for light piping applications where designers need a balance between flow capacity and pipe wall strength.
What Does Schedule 30 Mean?
Schedule 30 refers to the wall thickness series of the pipe. For NPS 1, Schedule 30 gives a wall thickness of 2.9 mm. The schedule affects the inside diameter, total pipe weight, fabrication planning, and compatibility with supports, fittings, and structural loading requirements.
Why These Pipe Dimensions Matter
Accurate pipe dimension data is important for piping layouts, spool drawings, support design, structural load review, and material takeoff. Knowing that this pipe weighs 2.18 kg/m helps with transport estimates, lifting plans, and support loading. If the pipe is filled with water, the total weight increases to 2.77 kg/m, which is useful for operating load calculations and support checks.
Common Uses of DN25 Schedule 30 Pipe
DN25 Schedule 30 pipe may be referenced in industrial utility systems, water transfer lines, plant layout studies, process piping documentation, and engineering design work. It is also useful for piping designers, CAD users, estimators, and procurement teams who need standard steel pipe dimensions for piping systems.
Difference Between NPS 1 and DN25
NPS 1 is the inch-based nominal pipe size designation, while DN25 is the metric nominal diameter reference. Both refer to the same pipe size category on this page. The actual standard outside diameter for this size is 33.4 mm.
How to Use This Data
You can use this page to quickly check:
- pipe outside diameter for layout and clearance
- inside diameter for flow reference
- wall thickness for schedule comparison
- weight per meter for estimation and transport planning
- water-filled weight for support and structural load review
Quick Reference for Schedule 30 Pipe 1 Inch
- Pipe Size: 1 inch
- DN: DN25
- OD: 33.4 mm
- ID: 27.6 mm
- Wall Thickness: 2.9 mm
- Weight: 2.18 kg/m
- Weight Including Water: 2.77 kg/m
- Reference Standard: ASME B36.10
Related Pipe Size Pages
Conclusion
Schedule 30 Pipe 1 Inch (DN25) is an important steel pipe reference for piping design, drafting, estimation, and fabrication work. With its 33.4 mm outside diameter, 2.9 mm wall thickness, and 2.18 kg/m pipe weight, it provides useful dimensional data for engineers and designers who need fast and accurate pipe information.
Note: NPS = Nominal Pipe Size, DN = Diameter Nominal. Dimensions and weights shown here are based on ASME B36.10 steel pipe data.
How to Read the Schedule 30 Pipe Data
The table separates the pipe information into four practical dimensions: outside diameter for layout and clearance, wall thickness for section comparison, inside diameter for flow-path reference, and weight for handling and load review. These values serve different purposes and should not be substituted for one another during drafting or engineering calculations.
Outside diameter and inside diameter
The 33.4 mm outside diameter is the key envelope dimension for routing, penetration allowances, clamps, supports, and connections. The listed 27.6 mm inside diameter describes the nominal internal flow passage. Actual system performance also depends on the fluid, temperature, pressure, roughness, fittings, valves, and applicable design requirements.
Wall thickness and schedule
For this NPS, Schedule 30 identifies the pipe wall series shown in the source data. The 2.9 mm wall thickness affects the difference between the outside and inside diameters and contributes to the pipe mass. Schedule selection should be checked against the governing piping specification and design conditions rather than inferred from nominal size alone.
Using the weight values
The listed 2.18 kg/m pipe weight can support preliminary material estimates, lifting discussions, transport planning, and pipe-support load reviews. The 2.77 kg/m water-filled value represents a different operating condition. For a complete support or structural check, include the actual contents, insulation, coating, valves, fittings, supports, and other attached items where applicable.
Using the CAD reference
The downloadable DWG can help CAD users begin a layout or detail reference. Confirm units, insertion scale, layer conventions, connection geometry, and project drafting standards before incorporating the file into issued documentation. A drawing reference does not replace dimensional verification against the project specification.
Design and Procurement Checks
- Confirm that NPS 1 and DN25 match the intended line class and piping specification.
- Use the outside diameter when checking physical clearance and support hardware.
- Use the inside diameter only as a dimensional reference; perform separate hydraulic calculations when required.
- Check whether the listed pipe weight or water-filled weight represents the load case being reviewed.
- Verify fitting, flange, valve, gasket, and connection compatibility before procurement or fabrication.
- Review the governing code, material requirements, corrosion allowance, pressure basis, and temperature conditions through the responsible engineer.
Frequently Asked Questions
What is the outside diameter of 1 inch Schedule 30 pipe?
The listed outside diameter for NPS 1, DN25 Schedule 30 pipe is 33.4 mm.
What is the wall thickness?
The listed wall thickness is 2.9 mm. This is the Schedule 30 wall value shown for the pipe size on this page.
What is the inside diameter?
The listed inside diameter is 27.6 mm. It is a dimensional reference for the internal passage and should not be treated as a complete flow-design result.
How much does the pipe weigh?
The listed pipe weight is 2.18 kg/m. When filled with water, the listed combined value is 2.77 kg/m.
Are NPS 1 and DN25 the same designation?
On this page, NPS 1 is the inch-based nominal size designation and DN25 is the metric nominal reference for the same pipe size category. The actual outside diameter is listed separately.
What standard is referenced for these dimensions?
The source identifies ASME B36.10 as the reference standard for the steel pipe dimensions and weights shown here. Project specifications and applicable design requirements should still be checked before use.