Use this page as a quick reference when a drawing, material takeoff, or procurement document identifies stainless steel pipe as NPS 3, DN80, or Schedule 40S. The source table provides the controlling dimensional and weight data; the notes below explain how to interpret those terms during layout and coordination.
For related work, compare this reference with the site’s resources on pipe schedules, stainless steel pipe dimensions, pipe fittings, and pipe flanges. Those topics help connect the straight-pipe dimensions shown here with the components and drafting details used in a complete piping assembly.
Schedule 40S Pipe 3 Inch (DN80) is a stainless steel pipe size commonly used in industrial piping systems that require corrosion resistance, dependable wall thickness, and reliable flow capacity. This pipe size is often used in process plants, utility systems, water treatment projects, and stainless steel fabrication work.
This dimension data is based on ANSI/ASME B36.19, which is the standard commonly used for stainless steel pipe dimensions.
3 Inch Schedule 40S Pipe Dimensions
- Pipe Schedule: 40S
- Nominal Pipe Size: 3 Inch
- DN Size: DN80
- Outside Diameter (OD): 88.9 mm
- Inside Diameter (ID): 77.92 mm
- Wall Thickness: 5.49 mm
- Pipe Weight: 11.29 kg/m
- Pipe Weight Including Water: 16.05 kg/m
- Standard: ANSI/ASME B36.19
Schedule 40S Pipe 3 Inch Dimension Table
| Pipe Schedule | NPS (Inch) | DN (mm) | OD (mm) | ID (mm) | Wall Thickness (mm) | Weight (kg/m) |
|---|---|---|---|---|---|---|
| 40S | 3 | 80 | 88.9 | 77.92 | 5.49 | 11.29 |
What Is 3 Inch Schedule 40S Pipe?
A 3 inch Schedule 40S pipe is a stainless steel pipe with a nominal size of 3 inches and a wall thickness defined by the 40S schedule. For this size, the outside diameter is fixed at 88.9 mm, while the inside diameter is 77.92 mm based on a wall thickness of 5.49 mm.
The letter S in 40S is commonly used for stainless steel pipe dimensions under ASME B36.19. This designation is widely used by engineers, fabricators, and procurement teams when selecting stainless steel piping for industrial service.
Where Is Schedule 40S Pipe 3 Inch Used?
This pipe size is commonly used in systems that need both good flow capacity and the corrosion resistance of stainless steel. Typical applications include:
- Process piping in industrial plants
- Water treatment and utility systems
- Food and beverage piping lines
- Chemical service piping
- Stainless steel header and branch piping
Why Pipe Dimensions Matter
Accurate 3 inch Schedule 40S pipe dimensions are important for piping layout, fabrication, support design, transport planning, and material takeoff. Engineers and designers often check OD, ID, wall thickness, and weight before selecting flanges, fittings, supports, and installation methods.
The outside diameter is important for matching clamps, flanges, and pipe supports. The inside diameter helps estimate flow area and system capacity. The wall thickness is important for specification compliance and mechanical strength, while the pipe weight per meter is useful for structural loading, support design, and handling calculations.
3 Inch Schedule 40S Pipe Weight Information
The nominal weight of this pipe size is 11.29 kg/m. When filled with water, the combined weight becomes approximately 16.05 kg/m. This information is useful for lifting plans, support design, and pipe rack load calculations in industrial projects.
Difference Between NPS 3 and DN80
NPS 3 is the inch-based nominal pipe size, while DN80 is the metric designation used in international drawings and specifications. Both terms refer to the same nominal pipe size, and users may search by either inch or DN format depending on project standards.
Common Search Terms for This Pipe Size
Users may also search for this pipe using related keywords such as 3 inch Schedule 40S pipe dimensions, DN80 Schedule 40S pipe dimensions, 3 inch stainless steel pipe weight, DN80 pipe dimensions, or DN80 sch 40s pipe dimensions.
Conclusion
Schedule 40S Pipe 3 Inch (DN80) has an outside diameter of 88.9 mm, an inside diameter of 77.92 mm, a wall thickness of 5.49 mm, and a weight of 11.29 kg/m. It is a useful stainless steel pipe reference size for design, drafting, fabrication, and procurement work.
This page provides a quick reference for engineers, drafters, fabricators, and buyers who need reliable 3 inch Schedule 40S pipe dimensions and DN80 pipe dimensions in one place.
How to Read This Pipe Reference
NPS 3 and DN80 are nominal size designations, not direct measurements of the pipe. The outside diameter, inside diameter, and wall thickness are the dimensions used when coordinating the pipe with fittings, flanges, supports, sleeves, and openings.
The 40S designation identifies the stainless steel dimensional schedule used for this reference. Schedule terminology should not be treated as a complete material or pressure specification. Final selection also requires confirmation of the material grade, service conditions, joining method, applicable project requirements, and the governing design code.
Using the Dimensions in Design and Drafting
- Use the outside diameter when checking physical clearances, support interfaces, clamps, sleeves, and fitting connections.
- Use the inside diameter when reviewing the available flow passage and coordinating hydraulic or process calculations.
- Use wall thickness when checking the specified pipe construction and coordinating fabrication details.
- Use the listed pipe weight for preliminary handling, support, and pipe-rack coordination; include the applicable contents, insulation, valves, fittings, and project loads separately when required.
- Use the downloadable DWG as a drafting aid, then verify project units, layer conventions, connection details, and revision status before incorporating it into a controlled drawing set.
When the line includes elbows, tees, reducers, branch connections, or flanges, the straight-pipe data is only one part of the layout. Related references for pipe fitting dimensions, flange dimensions, and pipe support design can help complete the coordination process without confusing nominal size with every component’s physical envelope.
Important Verification Before Purchase or Fabrication
Confirm that the material description, schedule, end preparation, length, finish, inspection requirements, and applicable specification match the project documents. The dimensions on this page are a reference for the identified pipe size and schedule; they do not replace a project specification, approved material submittal, or engineering review.
Frequently Asked Questions
What does 3 inch Schedule 40S pipe mean?
It identifies stainless steel pipe with the nominal size designation NPS 3 and the 40S dimensional schedule. The corresponding metric nominal designation is DN80.
Are NPS 3 and DN80 the same pipe size?
They are two nominal designations for the same pipe size reference. Always use the listed outside diameter and other dimensional data when checking physical compatibility.
Does Schedule 40S specify the stainless steel grade?
No. The schedule identifies dimensional construction for the pipe reference. The stainless steel grade, corrosion requirements, manufacturing requirements, and certification details must be confirmed separately.
What is the difference between pipe weight and pipe weight including water?
Pipe weight describes the pipe itself. The water-filled value combines the pipe with the water contents identified in the source data. Other contents, insulation, fittings, valves, and supports may add additional load.
Can the listed dimensions be used to select fittings and flanges?
They can support preliminary coordination, especially for outside-diameter checks, but the fitting or flange reference must also match the required size designation, material, pressure class, end connection, and project specification.
Is the downloadable DWG ready for construction?
The DWG is a reference resource for drafting and coordination. Review its units, geometry, connection assumptions, and revision status against the project documents before using it for fabrication or construction.