This reference explains how to read the dimensional and weight information for 3 1/2 inch Schedule 40 pipe, also identified as DN90. Use the table below when checking piping layouts, preparing material takeoffs, coordinating supports, or developing fabrication drawings. The listed values are the page’s reference data; project specifications and approved manufacturer information should govern procurement and fabrication.
Schedule 40 pipe 3 1/2 inch (DN90) 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 1/2 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 1/2 Inch Schedule 40 Pipe Dimensions
- Nominal Pipe Size (NPS): 3 1/2 inch
- Diameter Nominal (DN): DN90
- Pipe Schedule: Schedule 40
- Outside Diameter (OD): 101.6 mm
- Wall Thickness: 5.74 mm
- Inside Diameter (ID): 90.12 mm
- Pipe Weight: 13.57 kg/m
- Pipe Weight Including Water: 19.94 kg/m
- Reference Standard: ANSI / ASME B36.10
Schedule 40 Pipe 3 1/2 Inch (DN90) Data Table
| NPS | DN | OD (mm) | Wall Thickness (mm) | ID (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 3 1/2 inch | DN90 | 101.6 | 5.74 | 90.12 | 13.57 |
What Is 3 1/2 Inch Schedule 40 Pipe Used For?
3 1/2 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
- Cooling water piping
- Industrial utility lines
- Process piping systems
- Mechanical piping layouts
- Fabrication and spool drawing preparation
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 DN90 Schedule 40 pipe dimensions helps reduce drafting errors, procurement mistakes, and field fit-up problems during construction and fabrication work.
3 1/2 Inch DN90 Schedule 40 Pipe for CAD and Drafting Work
For CAD, BIM, and piping drafting work, this size is commonly listed as NPS 3 1/2 or DN90. The standard OD of 101.6 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 1/2 inch Schedule 40 pipe dimensions, DN90 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 1/2 inch Schedule 40 pipe?
The outside diameter of 3 1/2 inch Schedule 40 pipe is 101.6 mm.
What is the wall thickness of DN90 Schedule 40 pipe?
The wall thickness is 5.74 mm.
What is the inside diameter of Schedule 40 pipe 3 1/2 inch?
The inside diameter is 90.12 mm.
How much does 3 1/2 inch Schedule 40 pipe weigh?
The pipe weight is 13.57 kg/m. The weight including water is 19.94 kg/m.
Which standard covers these dimensions?
These dimensions are based on ANSI / ASME B36.10.
Conclusion
Schedule 40 pipe 3 1/2 inch (DN90) is an important reference size for industrial piping, drafting, fabrication, and engineering calculations. With an OD of 101.6 mm, ID of 90.12 mm, wall thickness of 5.74 mm, and weight of 13.57 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 3 inch and 4 inch Schedule 40 pipe pages.
How to Read the DN90 Schedule 40 Reference
NPS 3 1/2 and DN90 are nominal designations, not direct measurements of the pipe’s outside or inside diameter. For layout and detailing, use the listed outside diameter. For flow-area and hydraulic work, use the listed inside diameter only after confirming that the selected pipe specification and applicable tolerances match the design basis.
What each value supports
- Outside diameter: Use it when coordinating clamps, supports, insulation clearances, penetrations, and equipment connection layouts.
- Wall thickness: Use it when reviewing section details, weld preparation, machining allowances, and compatibility with connected components.
- Inside diameter: Use it as the dimensional input for flow-area and hydraulic checks, subject to the governing design requirements.
- Weight per meter: Use it for preliminary material estimates, support reactions, lifting plans, and installation coordination.
Drafting and Coordination Notes
When creating a CAD or BIM model, keep the nominal designation, outside diameter, wall thickness, and material specification together rather than identifying the item by schedule alone. This helps prevent confusion when the same nominal size is available with other wall selections. It also makes the model easier to coordinate with pipe fittings, flanges, valves, supports, and equipment nozzles.
The listed pipe weight and the value including water represent different coordination conditions. Use the appropriate condition for the task, and do not treat either value as a substitute for a project-specific load case. Support spacing, seismic actions, insulation, fittings, valves, and other attached items may add loads that are not represented by the basic pipe entry.
Related Pipe Reference Topics
For broader piping work, pair this page with the site’s references for pipe schedules, Schedule 40 pipe dimensions, pipe fittings, flange dimensions, and CAD/DWG pipe resources. Comparing the linked 3 inch and 4 inch Schedule 40 references can also help with routing reviews and material takeoffs when a design changes nominal size.
Additional Questions About This Reference
Does Schedule 40 identify the pipe’s actual diameter?
No. The nominal size identifies the general pipe size, while the schedule identifies a standardized wall-thickness selection. The actual outside and inside dimensions should be taken from the applicable dimensional reference.
Should the nominal size be used for CAD clearances?
No. Use the listed outside diameter for physical clearance, support, clamp, penetration, and insulation coordination. Keep the NPS and DN designations as identification fields in the drawing or model.
Can the listed pipe weight be used for a final support design?
It can support preliminary coordination, but a final support design should account for the governing project loads and all relevant attached components. Confirm the pipe specification and design assumptions before issuing calculations or construction documents.
Why is a water-filled weight shown separately?
The water-filled condition represents a different operating or coordination case from the empty pipe weight. Select the condition that matches the design check, and include other applicable loads separately.