Schedule 5 Pipe 18 Inch (DN450) is a large steel pipe size commonly used in industrial piping systems that require high flow capacity with a relatively light wall thickness. This pipe size is often used in utility piping, water transfer systems, low-pressure industrial service, and general steel pipe fabrication work.
This dimension data is based on ANSI/ASME B36.10, which is the standard commonly used for carbon steel pipe dimensions.
18 Inch Schedule 5 Pipe Dimensions
- Pipe Schedule: 5
- Nominal Pipe Size: 18 Inch
- DN Size: DN450
- Outside Diameter (OD): 457 mm
- Inside Diameter (ID): 448.62 mm
- Wall Thickness: 4.19 mm
- Pipe Weight: 46.79 kg/m
- Pipe Weight Including Water: 204.77 kg/m
- Standard: ANSI/ASME B36.10
Schedule 5 Pipe 18 Inch Dimension Table
| Pipe Schedule | NPS (Inch) | DN (mm) | OD (mm) | ID (mm) | Wall Thickness (mm) | Weight (kg/m) |
|---|---|---|---|---|---|---|
| 5 | 18 | 450 | 457 | 448.62 | 4.19 | 46.79 |
What Is 18 Inch Schedule 5 Pipe?
A 18 inch Schedule 5 pipe is a steel pipe with a nominal size of 18 inches and a relatively thin wall thickness compared with heavier schedules. For this size, the outside diameter is fixed at 457 mm, while the inside diameter is 448.62 mm based on a wall thickness of 4.19 mm.
Schedule 5 pipe is often selected when a project needs large flow capacity, reduced pipe weight, and easier handling compared with thicker wall pipes. It is commonly referenced in steel piping design, drafting, fabrication, and material takeoff work.
Where Is Schedule 5 Pipe 18 Inch Used?
This pipe size is commonly used in applications that need large flow capacity with relatively light wall thickness. Typical uses include:
- Water transfer and distribution systems
- Utility and low-pressure industrial piping
- Large process and service lines
- Pipe spool fabrication and layout work
- General steel piping projects
Why Pipe Dimensions Matter
Accurate 18 inch Schedule 5 pipe dimensions are important for piping layout, fabrication, transport planning, support design, and installation work. Engineers and designers often check OD, ID, wall thickness, and weight before selecting supports, fittings, welding details, and handling methods.
The outside diameter is important for matching supports, clamps, and pipe accessories. The inside diameter helps estimate internal flow area and system capacity. The wall thickness affects mechanical strength and specification compliance, while the pipe weight per meter is useful for lifting plans, transport, and structural loading calculations.
18 Inch Schedule 5 Pipe Weight Information
The nominal weight of this pipe size is 46.79 kg/m. When filled with water, the combined weight becomes approximately 204.77 kg/m. This information is useful for pipe support design, structural coordination, and lifting preparation in large piping systems.
Difference Between NPS 18 and DN450
NPS 18 is the inch-based nominal pipe size, while DN450 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 size 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 18 inch Schedule 5 pipe dimensions, DN450 Schedule 5 pipe dimensions, 18 inch pipe weight per meter, DN450 pipe dimensions, or DN450 sch 5 pipe dimensions.
Conclusion
Schedule 5 Pipe 18 Inch (DN450) has an outside diameter of 457 mm, an inside diameter of 448.62 mm, a wall thickness of 4.19 mm, and a weight of 46.79 kg/m. It is a useful 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 18 inch Schedule 5 pipe dimensions and DN450 pipe dimensions in one place.