Use this page as a working reference when checking 1 1/4 inch Schedule 40S pipe dimensions for layouts, material takeoffs, fabrication, and procurement. The page covers the relationship between NPS 1 1/4, DN32, outside diameter, inside diameter, wall thickness, and pipe weight without treating nominal size as a direct measurement.
For related design work, compare this entry with the site’s pipe schedule references, fitting and flange resources, and CAD and DWG downloads. Always check the project specification, material requirements, joining method, and applicable engineering review before using dimensional data for fabrication or design release.
Schedule 40S Pipe 1 1/4 Inch (DN32) 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.
1 1/4 Inch Schedule 40S Pipe Dimensions
- Pipe Schedule: 40S
- Nominal Pipe Size: 1 1/4 Inch
- DN Size: DN32
- Outside Diameter (OD): 42.2 mm
- Inside Diameter (ID): 35.08 mm
- Wall Thickness: 3.56 mm
- Pipe Weight: 3.39 kg/m
- Pipe Weight Including Water: 4.35 kg/m
- Standard: ANSI/ASME B36.19
Schedule 40S Pipe 1 1/4 Inch Dimension Table
| Pipe Schedule | NPS (Inch) | DN (mm) | OD (mm) | ID (mm) | Wall Thickness (mm) | Weight (kg/m) |
|---|---|---|---|---|---|---|
| 40S | 1 1/4 | 32 | 42.2 | 35.08 | 3.56 | 3.39 |
What Is 1 1/4 Inch Schedule 40S Pipe?
A 1 1/4 inch Schedule 40S pipe is a stainless steel pipe with a nominal size of 1 1/4 inches and a wall thickness defined by the 40S schedule. For this size, the outside diameter is fixed at 42.2 mm, while the inside diameter is 35.08 mm based on a wall thickness of 3.56 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 1 1/4 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 branch and service lines
Why Pipe Dimensions Matter
Accurate 1 1/4 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.
1 1/4 Inch Schedule 40S Pipe Weight Information
The nominal weight of this pipe size is 3.39 kg/m. When filled with water, the combined weight becomes approximately 4.35 kg/m. This information is useful for lifting plans, support design, and pipe rack load calculations in industrial projects.
Difference Between NPS 1 1/4 and DN32
NPS 1 1/4 is the inch-based nominal pipe size, while DN32 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 1 1/4 inch Schedule 40S pipe dimensions, DN32 Schedule 40S pipe dimensions, 1 1/4 inch stainless steel pipe weight, DN32 pipe dimensions, or DN32 sch 40s pipe dimensions.
Conclusion
Schedule 40S Pipe 1 1/4 Inch (DN32) has an outside diameter of 42.2 mm, an inside diameter of 35.08 mm, a wall thickness of 3.56 mm, and a weight of 3.39 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 1 1/4 inch Schedule 40S pipe dimensions and DN32 pipe dimensions in one place.
How to Use This Pipe Reference
Start with the nominal identifiers used on the project drawing or purchase description. NPS 1 1/4 and DN32 identify the same nominal pipe size in the source data, while the listed OD, ID, and wall thickness provide the physical dimensions needed for coordination and checking.
Use the OD when coordinating external clearances, clamps, supports, flanges, and fitting connections. Use the ID when reviewing flow-path geometry or checking an opening through which another component must pass. The wall thickness helps confirm that the selected schedule matches the piping specification, but it should not be treated as a complete pressure-design check.
Coordination Checks Before Release
- Confirm that the drawing uses the same NPS, DN, and schedule designation as the material list.
- Check the listed OD against fitting, flange, support, and penetration details.
- Use the listed weight for preliminary handling and support coordination, then verify project load combinations separately.
- Distinguish the pipe’s own weight from the combined filled condition when reviewing support or rack information.
- Confirm material, finish, joining details, tolerances, and service requirements from the project documents.
Related Pipe and Drafting References
This entry is most useful when reviewed alongside references for pipe dimensions, pipe schedules, flanges, and butt-weld and threaded fittings. Those related references can help users move from a dimensional check to a coordinated piping detail without confusing nominal designations with connection dimensions.
Frequently Asked Questions
What does 1 1/4 inch Schedule 40S mean?
It identifies a stainless steel pipe by its nominal pipe size and schedule designation. In this reference, the corresponding metric nominal designation is DN32.
Are NPS 1 1/4 and DN32 the same pipe size?
Yes. The source data uses NPS 1 1/4 and DN32 as two nominal designations for the same pipe size. The actual dimensional checks should use the listed OD, ID, and wall thickness.
Which dimensions should be checked when selecting fittings?
Check the outside diameter, inside diameter, wall thickness, schedule, and the connection details required by the fitting or flange. Nominal size alone is not enough to release a fabrication or procurement item.
Can the listed pipe weight be used for support design?
The listed pipe weight can support preliminary coordination and load takeoff work. Final support design should also account for the applicable filled condition, attached components, operating requirements, and project-specific load criteria.
Is this page a substitute for pressure or code design?
No. It is a dimensional and weight reference. Pressure design, material acceptance, corrosion evaluation, fabrication requirements, and final engineering approval must be checked against the project specification and applicable requirements.