This reference provides the key dimensional and handling data for Schedule 80 pipe in 1 1/4 inch NPS, also identified as DN32. It is intended for engineers, drafters, fabricators, buyers, and maintenance teams who need a consistent dimensional reference before checking fittings, supports, clearances, or installation details.
Use the dimensional list and data table together when reviewing a piping layout. The outside diameter is particularly useful for connection and support coordination, while the inside diameter helps distinguish geometric flow space from the nominal size used for identification. The downloadable DWG reference can support drafting workflows, but project drawings should still be checked against the applicable specification and connection details.
Schedule 80 Pipe 1 1/4 Inch (DN32) is a heavy wall steel pipe commonly used in industrial piping systems that require higher strength and thicker pipe walls than lighter schedules. This pipe size is based on ANSI/ASME B36.10 and is widely used in process piping, utility systems, water treatment plants, and mechanical services. For this size, the standard data shows an outside diameter of 42.2 mm, an inside diameter of 32.5 mm, a wall thickness of 4.85 mm, and a pipe weight of 4.47 kg/m.
Schedule 80 Pipe 1 1/4 Inch (DN32) Dimensions
- Pipe Standard: ANSI/ASME B36.10
- Nominal Pipe Size: 1 1/4 inch
- DN Size: DN32
- Outside Diameter (OD): 42.2 mm
- Inside Diameter (ID): 32.5 mm
- Wall Thickness: 4.85 mm
- Pipe Weight: 4.47 kg/m
- Pipe Weight Including Water: 5.29 kg/m
What Is Schedule 80 Pipe?
Schedule 80 refers to a pipe wall thickness classification. For the same nominal pipe size, a Schedule 80 pipe has a thicker wall and a smaller inside diameter than lower schedule pipes. This makes it a practical choice for systems that need additional pipe strength, durability, and long-term service performance.
Why 1 1/4 Inch DN32 Pipe Dimensions Matter
Knowing the exact dimensions of a 1 1/4 inch Schedule 80 pipe is important for piping design, fabrication, and installation. The outside diameter helps with flange matching, clamps, and supports. The inside diameter affects flow area and system capacity. The wall thickness is important for strength and service conditions, while the pipe weight per meter is useful for transport, lifting plans, and structural support calculations.
Common Uses of Schedule 80 Pipe 1 1/4 Inch (DN32)
This pipe size is often used in industrial and commercial piping systems such as:
- Water treatment and utility piping
- Process and plant piping systems
- Oil and gas applications
- Pump stations and mechanical services
- Heavy-duty industrial pipe networks
1 1/4 Inch Schedule 80 Pipe Data Table
| NPS | DN | OD (mm) | ID (mm) | Wall Thickness (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 1 1/4 inch | 32 | 42.2 | 32.5 | 4.85 | 4.47 |
Additional Information for Engineers and Buyers
Before selecting this pipe size, it is also important to review the material grade, end type, design pressure, corrosion allowance, operating temperature, and project code requirements. While Schedule 80 defines the dimensional wall category, the final pipe selection should always match the actual service condition and engineering specification.
Note: NPS means nominal pipe size in inches, while DN means diameter nominal in millimeters. These are standard reference sizes used for pipe identification.
How to Use This Schedule 80 DN32 Pipe Reference
Pipe size terminology can be confusing because NPS and DN are identification systems rather than direct statements of the measured outside or inside diameter. For that reason, the dimensional values in the source table should be used when coordinating this pipe with fittings, flanges, clamps, sleeves, and supports.
Schedule 80 describes a wall-thickness category for a nominal pipe size. It should not be treated as a complete pressure-rating designation. Material grade, manufacturing specification, temperature, corrosion allowance, joining method, and the governing project code may all affect the final engineering selection. The source content correctly separates dimensional reference data from the design checks needed for an operating piping system.
Design and Drafting Checks
- Connection coordination: Confirm that the mating fitting, flange, valve, or equipment connection uses the same nominal size and compatible end details.
- Clearance coordination: Use the listed outside diameter when reviewing penetrations, clamps, insulation space, supports, and crowded equipment areas.
- Flow review: Use the listed inside diameter as the geometric reference for flow-area checks; final hydraulic performance also depends on the system arrangement and service.
- Support and lifting review: Consider the listed pipe weight together with contents, valves, fittings, insulation, supports, and any project-specific load cases.
- Procurement review: Verify material grade, end type, certification, corrosion requirements, and applicable project specifications before ordering.
Related PipeSTD References
This page works well alongside internal references covering pipe schedules, NPS and DN terminology, pipe fittings, flange dimensions, pipe supports, and CAD/DWG piping resources. Linking those topics from this section can help readers move from dimensional identification to connection selection and drafting coordination without confusing nominal size with a complete design specification.
Frequently Asked Questions
What does 1 1/4 inch DN32 mean?
It identifies the same nominal pipe size using two conventions: NPS in inches and DN as a metric nominal designation. The actual pipe dimensions should be taken from the dimensional data provided on this page.
Does Schedule 80 determine the pipe pressure rating?
No. Schedule 80 identifies a wall-thickness category for the nominal size. Pressure suitability also requires review of material grade, temperature, corrosion allowance, design pressure, joining details, and the governing engineering code.
Why are both outside diameter and inside diameter important?
The outside diameter supports coordination of fittings, clamps, supports, sleeves, and clearances. The inside diameter is used when reviewing flow space and hydraulic calculations. Both should be checked against the project design and connection requirements.
What should be checked before buying this pipe?
Confirm the required material grade, end type, dimensional standard, certification, service conditions, corrosion requirements, and project specification. Also verify whether the required fittings and connected components are compatible.
What is the DWG download used for?
The DWG file is a drafting reference for this pipe size. Review its geometry against the published dimensional data and project requirements before using it in fabrication, construction, or issued-for-design documentation.