Use this page as a practical reference when checking 4 inch Schedule 120 pipe dimensions for piping layouts, material takeoffs, fabrication drawings, and support-load estimates. The table below brings together the nominal size, DN designation, outside diameter, wall thickness, inside diameter, and listed pipe weight for this heavy-wall steel pipe.
For design coordination, compare these dimensions with the selected pipe material specification, fitting dimensions, flange standard, and project requirements. The accompanying DWG resource can also help with drafting and CAD reference work, while the dimensional data remains the controlling reference for this page.
Schedule 120 pipe 4 inch (DN100) 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 4 Schedule 120 pipe based on ASME B36.10.
4 Inch Schedule 120 Pipe Dimensions
- Nominal Pipe Size (NPS): 4 inch
- Diameter Nominal (DN): DN100
- Outside Diameter (OD): 114.3 mm
- Wall Thickness: 11.13 mm
- Inside Diameter (ID): 92.04 mm
- Pipe Weight: 28.32 kg/m
- Pipe Weight Filled With Water: 34.97 kg/m
- Reference Standard: ASME B36.10
- Pipe Type: Steel Pipe
Schedule 120 Pipe 4 Inch Data Table
| Pipe Size | DN | OD (mm) | Wall Thickness (mm) | ID (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 4 inch | 100 | 114.3 | 11.13 | 92.04 | 28.32 |
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 4 Inch Schedule 120 Pipe
NPS 4 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, support design, 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 4 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.
4 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 4 inch Schedule 120 pipe?
The outside diameter is 114.3 mm.
What is the wall thickness of DN100 Schedule 120 pipe?
The wall thickness is 11.13 mm.
What is the inside diameter of NPS 4 Schedule 120 pipe?
The inside diameter is 92.04 mm.
How much does 4 inch Schedule 120 pipe weigh?
The approximate weight is 28.32 kg/m.
Which standard covers this pipe size?
This dimension data is based on ASME B36.10 for steel pipe.
Conclusion
Schedule 120 pipe 4 inch (DN100) has an outside diameter of 114.3 mm, wall thickness of 11.13 mm, inside diameter of 92.04 mm, and a weight of 28.32 kg/m. It is a useful reference for piping design, fabrication, estimating, and heavy-duty industrial engineering work.
How to Read the Schedule 120 Pipe Data
The NPS 4 and DN100 labels identify the same nominal pipe size in inch-based and metric terminology. Nominal size is a designation rather than a direct statement of the measured outside or inside diameter, so the listed OD and ID should be used when coordinating connected components or preparing drawings.
For this size, the outside diameter is established by the nominal pipe size, while the Schedule 120 designation identifies the wall-thickness series. Because the wall occupies more of the cross-section than in a lighter-wall option, the resulting inside diameter is smaller and the pipe weight is greater. This distinction matters when checking clearance, flow-area assumptions, valve and fitting connections, lifting requirements, and support loads.
Design and Drafting Checks
- Use the listed outside diameter when coordinating clamps, supports, sleeves, insulation space, and external clearances.
- Use the listed inside diameter when reviewing bore continuity, internal clearance, and flow-related calculations.
- Use the listed weight per meter for preliminary material estimates and load coordination, then confirm the applicable product and material requirements before final design.
- Check connected fittings, flanges, valves, and branch components against their relevant dimensional references rather than assuming that nominal size alone confirms compatibility.
- Use the water-filled weight shown in the source data when considering the added operating condition represented by a filled pipe; verify project load cases separately.
Related Pipe Reference Topics
This page works well alongside references for pipe schedules, NPS and DN conversion, steel pipe dimensions, pipe weight calculations, flange dimensions, and pipe support design. These related topics help readers move from a dimensional lookup to coordinated drafting, estimating, and engineering review without treating a nominal size as a complete design specification.
Additional Questions About 4 Inch Schedule 120 Pipe
Is Schedule 120 a material grade?
No. Schedule 120 describes a pipe wall-thickness series. The material grade, manufacturing requirements, corrosion allowance, and design conditions must be established separately from the dimensional schedule.
Why are both OD and ID listed?
The outside diameter supports external coordination, while the inside diameter describes the available internal bore. Both are useful because the wall thickness lies between these two dimensions.
Can the listed weight be used as a final procurement value?
It is a reference value for estimating and coordination. Actual supplied weight can vary with manufacturing tolerances, material requirements, and supplier practices, as noted in the source content.
What is the DWG useful for?
The downloadable DWG is useful as a CAD and drafting reference for the pipe size. Confirm project-specific connection, fabrication, and material requirements before using any drawing in a final design package.