This reference page provides a practical dimensional check for Schedule 30 pipe 3 1/2 inch (DN90). Use the listed outside diameter, inside diameter, wall thickness, and mass values when reviewing piping layouts, CAD drawings, material takeoffs, and preliminary support loads.
Keep the nominal size designation separate from the physical dimensions: NPS 3 1/2 and DN90 identify the pipe size category, while the stated outside diameter controls many layout and clearance checks. The schedule identifies the wall-thickness series for this pipe size.
Schedule 30 pipe 3 1/2 inch (DN90) 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 3 1/2 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.
3 1/2 Inch Schedule 30 Pipe Dimensions
- Nominal Pipe Size (NPS): 3 1/2 inch
- Diameter Nominal (DN): DN90
- Outside Diameter (OD): 101.6 mm
- Wall Thickness: 4.78 mm
- Inside Diameter (ID): 92.04 mm
- Pipe Weight: 11.41 kg/m
- Pipe Weight Including Water: 18.06 kg/m
- Standard: ASME B36.10
Schedule 30 Pipe 3 1/2 Inch Data Table
| NPS | DN | Outside Diameter (OD) | Wall Thickness | Inside Diameter (ID) | Weight |
|---|---|---|---|---|---|
| 3 1/2 inch | DN90 | 101.6 mm | 4.78 mm | 92.04 mm | 11.41 kg/m |
Understanding 3 1/2 Inch Schedule 30 Pipe
3 1/2 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 101.6 mm and a wall thickness of 4.78 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 3 1/2, Schedule 30 gives a wall thickness of 4.78 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 11.41 kg/m helps with transport estimates, lifting plans, and support loading. If the pipe is filled with water, the total weight increases to 18.06 kg/m, which is useful for operating load calculations and support checks.
Common Uses of DN90 Schedule 30 Pipe
DN90 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 3 1/2 and DN90
NPS 3 1/2 is the inch-based nominal pipe size designation, while DN90 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 101.6 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 3 1/2 Inch
- Pipe Size: 3 1/2 inch
- DN: DN90
- OD: 101.6 mm
- ID: 92.04 mm
- Wall Thickness: 4.78 mm
- Weight: 11.41 kg/m
- Weight Including Water: 18.06 kg/m
- Reference Standard: ASME B36.10
Related Pipe Size Pages
Conclusion
Schedule 30 Pipe 3 1/2 Inch (DN90) is an important steel pipe reference for piping design, drafting, estimation, and fabrication work. With its 101.6 mm outside diameter, 4.78 mm wall thickness, and 11.41 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 most useful value depends on the task. Use the outside diameter when checking spatial clearance, pipe routing, sleeve openings, clamps, and connection geometry. Use the inside diameter as a flow-path reference, while recognizing that actual hydraulic design also depends on the fluid, operating conditions, fittings, valves, and other system details.
Wall thickness is primarily a dimensional and fabrication reference in this table. It should not be treated by itself as a pressure rating or as proof that a pipe is adequate for a particular service. Design verification must also consider the applicable material specification, temperature, pressure, joining method, corrosion or erosion allowances, and project requirements.
Using the Weight Values in Design Reviews
The listed pipe weight supports preliminary material estimates, handling reviews, transport planning, and pipe-support load checks. The water-filled value is a separate operating-load reference and should be used only when the relevant line condition calls for water or an equivalent contained load. For a complete support review, include the effects of fittings, valves, insulation, contents, supports, and any applicable dynamic or test conditions.
CAD and Drafting Checks
- Use the stated outside diameter for the pipe envelope and clearance review.
- Use the inside diameter when documenting the internal flow path or comparing bore dimensions.
- Do not assume that nominal size is the same as the measured outside diameter.
- Confirm that fittings, flanges, valves, and connection details use compatible dimensional references.
- Check the project specification before releasing fabrication drawings or procurement documents.
For nearby size comparisons, review the related Schedule 30 Pipe 3 Inch (DN80) and Schedule 30 Pipe 4 Inch (DN100) reference pages.
Frequently Asked Questions
What is the difference between NPS 3 1/2 and DN90?
NPS 3 1/2 is the inch-based nominal pipe size designation, while DN90 is the metric nominal reference used for the same size category on this page. Neither designation should be read as the pipe’s actual outside diameter.
Does Schedule 30 describe the pipe pressure rating?
No. Schedule 30 identifies a wall-thickness series for the pipe size. A pressure or service assessment requires additional information, including material, temperature, design conditions, manufacturing requirements, and the governing project or code criteria.
Which dimension should be used for a CAD clearance check?
Use the stated outside diameter for the basic pipe envelope. Add any required allowance for coatings, insulation, movement, supports, clamps, or adjacent components according to the project design.
What does the water-included weight represent?
It represents the listed pipe weight with the stated water-filled condition included. Actual operating, hydrostatic-test, or process loads may differ and should be established from the applicable line condition.
Can this table replace a piping design review?
No. The table is a dimensional reference. Final selection, pressure integrity, support design, fabrication, and installation should be checked against the applicable engineering specifications and verified by the responsible design team.