This reference page brings together the dimensional data used to identify 5 inch Schedule 120 pipe in piping layouts, fabrication documents, and engineering estimates. The NPS and DN designations identify the nominal size, while the listed outside diameter, wall thickness, and inside diameter support practical drafting and checking work.
Use the table for quick dimensional lookup, then review the notes below before applying the data to supports, connected components, material takeoffs, or a CAD model. Dimensional reference data should be checked against the project specification and the applicable component requirements before fabrication or installation.
Schedule 120 pipe 5 inch (DN125) is a heavy-wall steel pipe size commonly used in piping design, fabrication, drafting, and engineering estimation work. This page provides the standard dimensions, wall thickness, inside diameter, and weight per meter for NPS 5 Schedule 120 pipe based on ASME B36.10.
5 Inch Schedule 120 Pipe Dimensions
- Nominal Pipe Size (NPS): 5 inch
- Diameter Nominal (DN): DN125
- Outside Diameter (OD): 141.3 mm
- Wall Thickness: 12.7 mm
- Inside Diameter (ID): 115.9 mm
- Pipe Weight: 40.28 kg/m
- Pipe Weight Filled With Water: 50.82 kg/m
- Reference Standard: ASME B36.10
- Pipe Type: Steel Pipe
Schedule 120 Pipe 5 Inch Data Table
| Pipe Size | DN | OD (mm) | Wall Thickness (mm) | ID (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 5 inch | 125 | 141.3 | 12.7 | 115.9 | 40.28 |
What Does Schedule 120 Mean?
Schedule 120 refers to a heavy wall thickness series used for steel pipe under ASME B36.10. For the same nominal pipe size, the outside diameter remains fixed while the wall thickness increases according to the schedule. A thicker wall reduces the inside diameter and significantly increases pipe weight.
Typical Uses of 5 Inch Schedule 120 Pipe
NPS 5 Schedule 120 pipe is commonly referenced for heavy-duty industrial piping systems where high wall thickness is required. It may be used in process piping, plant utility systems, fabrication work, structural loading checks, and engineering applications where pipe strength and wall thickness are more critical than maximum flow area.
Why Pipe Weight Matters
Pipe weight per meter is essential for transport planning, crane lifting studies, support design, structural loading, fabrication estimates, and installation planning. For a 5 inch Schedule 120 pipe, the heavy wall thickness results in much higher installed weight than lighter schedules, so accurate weight data is important for engineering and construction work.
5 Inch Schedule 120 Pipe Calculation Notes
The listed weight is based on standard steel pipe dimensions using the outside diameter and wall thickness of the pipe. Actual product weight may vary slightly depending on manufacturing tolerance, material specification, and supplier standard.
Frequently Asked Questions
What is the outside diameter of 5 inch Schedule 120 pipe?
The outside diameter is 141.3 mm.
What is the wall thickness of DN125 Schedule 120 pipe?
The wall thickness is 12.7 mm.
What is the inside diameter of NPS 5 Schedule 120 pipe?
The inside diameter is 115.9 mm.
How much does 5 inch Schedule 120 pipe weigh?
The approximate weight is 40.28 kg/m.
Which standard covers this pipe size?
This dimension data is based on ASME B36.10 for steel pipe.
Conclusion
Schedule 120 pipe 5 inch (DN125) has an outside diameter of 141.3 mm, wall thickness of 12.7 mm, inside diameter of 115.9 mm, and a weight of 40.28 kg/m. It is a useful reference for piping design, fabrication, estimating, and heavy-duty industrial engineering work.
How to Read the 5 Inch Schedule 120 Data
The nominal size is a designation used to identify the pipe size; it is not the same as a direct measurement across the pipe. For layout and connection work, the outside diameter is generally the key envelope dimension. The wall thickness helps explain the difference between the outside and inside diameters, while the inside diameter is the more relevant dimensional reference when considering the available flow passage.
- Use the outside diameter when checking physical clearance, pipe supports, clamps, insulation space, and the location of connected fittings or flanges.
- Use the wall thickness when reviewing fabrication details, section properties, corrosion allowances, and material descriptions, subject to the project design basis.
- Use the inside diameter as a dimensional reference for flow-area calculations, while recognizing that the effective internal passage can also be affected by manufacturing tolerances, lining, or deposits.
- Use the listed pipe weight for preliminary handling, support, transport, and structural load checks. Confirm the governing material and procurement requirements for final work.
Dry Weight and Filled Weight in Engineering Checks
The page reports both the pipe weight and the weight when the pipe is filled with water. These values serve different planning purposes. The dry pipe value is useful for procurement, lifting, and installation planning; the filled condition is useful when reviewing operating or hydrostatic load cases. Supports and nearby structures may need to be checked for the relevant combination of pipe, contents, insulation, valves, and other attached items.
Using the DWG Reference
The downloadable DWG can support preliminary arrangement and drafting workflows. Before incorporating it into a project drawing, confirm the drawing units, scale, layer conventions, connection details, and required clearances. The CAD file should be treated as a dimensional reference alongside the tabulated data, not as a substitute for the project specification or a verified fabrication drawing.
Related Pipe Reference Topics
This page can be used alongside references on pipe schedules, NPS and DN designations, pipe fittings, flanges, pipe supports, and steel pipe weight calculations. Cross-linking these topics helps readers move from a single pipe dimension to the connected components and design checks needed for a complete piping layout.
Additional Questions About Schedule 120 Pipe
Is the nominal size the same as the measured outside diameter?
No. The nominal size is a standardized identification for the pipe, whereas the outside diameter is the physical dimension used for layout and component coordination.
Does the schedule alone establish a pipe pressure rating?
No. Schedule identifies a wall-thickness series, but pressure suitability also depends on material, temperature, design code, manufacturing requirements, corrosion considerations, and the project design conditions.
Why should the filled-pipe condition be considered?
Water or another process fluid adds load to the piping system. The filled condition can therefore affect support spacing, structural reactions, lifting plans, and operating or testing checks.
Can the DWG file be used directly for fabrication?
It is best used as a drafting reference. Verify units, tolerances, component interfaces, material requirements, and project-specific details before issuing fabrication documents.