Schedule 120 pipe 18 inch (DN450) 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 18 Schedule 120 pipe based on ASME B36.10.
18 Inch Schedule 120 Pipe Dimensions
- Nominal Pipe Size (NPS): 18 inch
- Diameter Nominal (DN): DN450
- Outside Diameter (OD): 457 mm
- Wall Thickness: 34.93 mm
- Inside Diameter (ID): 387.14 mm
- Pipe Weight: 363.58 kg/m
- Pipe Weight Filled With Water: 481.23 kg/m
- Reference Standard: ASME B36.10
- Pipe Type: Steel Pipe
Schedule 120 Pipe 18 Inch Data Table
| Pipe Size | DN | OD (mm) | Wall Thickness (mm) | ID (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 18 inch | 450 | 457 | 34.93 | 387.14 | 363.58 |
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 18 Inch Schedule 120 Pipe
NPS 18 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, structural loading checks, fabrication work, 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 an 18 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.
18 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 18 inch Schedule 120 pipe?
The outside diameter is 457 mm.
What is the wall thickness of DN450 Schedule 120 pipe?
The wall thickness is 34.93 mm.
What is the inside diameter of NPS 18 Schedule 120 pipe?
The inside diameter is 387.14 mm.
How much does 18 inch Schedule 120 pipe weigh?
The approximate weight is 363.58 kg/m.
Which standard covers this pipe size?
This dimension data is based on ASME B36.10 for steel pipe.
Conclusion
Schedule 120 pipe 18 inch (DN450) has an outside diameter of 457 mm, wall thickness of 34.93 mm, inside diameter of 387.14 mm, and a weight of 363.58 kg/m. It is a useful reference for piping design, fabrication, estimating, and heavy-duty industrial engineering work.