This reference page gives a practical dimensional check for Schedule 30 pipe 1 1/4 inch (DN32). Use the listed outside diameter, inside diameter, wall thickness, and weight when reviewing piping layouts, material takeoffs, CAD drawings, and preliminary support loads.
Because NPS and DN are nominal designations, the nominal size should not be treated as the measured outside or inside diameter. For drafting and coordination, use the stated outside diameter and confirm connection, fitting, material, and project requirements before releasing fabrication or procurement documents.
Schedule 30 pipe 1 1/4 inch (DN32) 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 1/4 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 1/4 Inch Schedule 30 Pipe Dimensions
- Nominal Pipe Size (NPS): 1 1/4 inch
- Diameter Nominal (DN): DN32
- Outside Diameter (OD): 42.2 mm
- Wall Thickness: 2.97 mm
- Inside Diameter (ID): 36.26 mm
- Pipe Weight: 2.87 kg/m
- Pipe Weight Including Water: 3.9 kg/m
- Standard: ASME B36.10
Schedule 30 Pipe 1 1/4 Inch Data Table
| NPS | DN | Outside Diameter (OD) | Wall Thickness | Inside Diameter (ID) | Weight |
|---|---|---|---|---|---|
| 1 1/4 inch | DN32 | 42.2 mm | 2.97 mm | 36.26 mm | 2.87 kg/m |
Understanding 1 1/4 Inch Schedule 30 Pipe
1 1/4 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 42.2 mm and a wall thickness of 2.97 mm, this pipe size is suitable for light to medium 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 1/4, Schedule 30 gives a wall thickness of 2.97 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 2.87 kg/m helps with transport estimates, lifting plans, and support loading. If the pipe is filled with water, the total weight increases to 3.9 kg/m, which is useful for operating load calculations and support checks.
Common Uses of DN32 Schedule 30 Pipe
DN32 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 1/4 and DN32
NPS 1 1/4 is the inch-based nominal pipe size designation, while DN32 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 42.2 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 1/4 Inch
- Pipe Size: 1 1/4 inch
- DN: DN32
- OD: 42.2 mm
- ID: 36.26 mm
- Wall Thickness: 2.97 mm
- Weight: 2.87 kg/m
- Weight Including Water: 3.9 kg/m
- Reference Standard: ASME B36.10
Related Pipe Size Pages
Conclusion
Schedule 30 Pipe 1 1/4 Inch (DN32) is an important steel pipe reference for piping design, drafting, estimation, and fabrication work. With its 42.2 mm outside diameter, 2.97 mm wall thickness, and 2.87 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 This Schedule 30 Pipe Reference
The dimensional list and table are useful for different stages of engineering work. The outside diameter supports layout, clearance, sleeve, clamp, and support coordination. The inside diameter is a reference for flow-area review and should be considered alongside the fluid, design conditions, lining, and system requirements.
The wall thickness identifies the pipe’s schedule dimension for this nominal size. It is not, by itself, a complete basis for pressure design, corrosion allowance, allowable stress, or service selection. Those checks require the applicable material specification, design code, operating conditions, and project requirements.
The listed pipe weight can support estimating, transportation review, lifting planning, and preliminary structural coordination. The water-filled value is relevant when considering an operating condition, but actual support reactions and structural effects may also depend on span, insulation, valves, fittings, contents, restraints, and dynamic or thermal loads.
Drafting and Coordination Notes
- Use NPS 1 1/4 and DN32 as the nominal size labels shown on drawings and schedules.
- Use the stated outside diameter when checking physical routing and clearance.
- Check the inside diameter when coordinating flow references, transitions, and connected components.
- Verify that fittings, flanges, valves, supports, and connection details match the selected pipe specification.
- Use the downloadable DWG as a reference resource, then confirm scale, units, layers, and project drafting conventions before incorporating it into a controlled drawing.
For broader design work, this page can be reviewed alongside related pipe schedule references, pipe weight calculations, fitting dimensions, and flange reference pages.
Frequently Asked Questions
What is the outside diameter of Schedule 30 pipe 1 1/4 inch?
The listed outside diameter is 42.2 mm. Use this value for preliminary layout and clearance coordination, subject to the governing project specification.
What is the inside diameter of NPS 1 1/4 Schedule 30 pipe?
The listed inside diameter is 36.26 mm. It is a dimensional reference and should not replace a project-specific hydraulic or process design check.
What does Schedule 30 indicate?
Schedule 30 identifies the wall-thickness series for the nominal pipe size. On this page, the corresponding wall thickness is 2.97 mm.
Are NPS 1 1/4 and DN32 the same pipe size?
They are the inch-based and metric nominal designations used for the same pipe size category in this reference. The actual outside diameter remains the dimensional value used for physical coordination.
What is the listed weight of this pipe?
The listed pipe weight is 2.87 kg/m. The page also gives a water-filled value of 3.9 kg/m for operating-load reference.
Can this data be used for final pipe design?
The data is useful for dimensional reference, drafting, estimating, and preliminary coordination. Final selection and design should also verify material, pressure and temperature requirements, corrosion considerations, applicable codes, connected components, and project specifications.