This reference page helps piping engineers, designers, drafters, estimators, and fabricators interpret the dimensional data for NPS 20 Schedule 20 pipe. Use the listed outside diameter when checking routing, clearances, and connection alignment; use the inside diameter for flow-area reference; and use the weight data when preparing estimates or reviewing support loads.
The page also distinguishes the inch-based NPS 20 designation from the metric DN500 reference. Because nominal pipe size is a designation rather than a direct measurement of every pipe dimension, the dimensional table should be used for layout and coordination work.
Schedule 20 pipe 20 inch (DN500) is a standard large-diameter steel pipe size commonly used in piping design, drafting, fabrication, estimation, and industrial layout work. This page provides the standard dimensions, wall thickness, inside diameter, and weight per meter for NPS 20 Schedule 20 pipe based on ASME B36.10.
For engineers, designers, estimators, and CAD users, quick access to accurate pipe data helps improve piping layout, support planning, weight checks, material takeoff, and fabrication coordination during project development.
20 Inch Schedule 20 Pipe Dimensions
- Nominal Pipe Size (NPS): 20 inch
- Diameter Nominal (DN): DN500
- Outside Diameter (OD): 508 mm
- Wall Thickness: 9.53 mm
- Inside Diameter (ID): 488.94 mm
- Pipe Weight: 117.15 kg/m
- Pipe Weight Including Water: 304.81 kg/m
- Standard: ASME B36.10
Schedule 20 Pipe 20 Inch Data Table
| NPS | DN | Outside Diameter (OD) | Wall Thickness | Inside Diameter (ID) | Weight |
|---|---|---|---|---|---|
| 20 inch | DN500 | 508 mm | 9.53 mm | 488.94 mm | 117.15 kg/m |
Understanding 20 Inch Schedule 20 Pipe
20 inch Schedule 20 pipe is a standard steel pipe size used as a reference in industrial piping layouts, water lines, utility systems, process design studies, and CAD drafting. With an outside diameter of 508 mm and a wall thickness of 9.53 mm, this pipe size is useful where a large flow path is needed while keeping the wall lighter than heavier schedules.
What Does Schedule 20 Mean?
Schedule 20 refers to the wall thickness series of the pipe. For NPS 20, Schedule 20 gives a wall thickness of 9.53 mm. The schedule affects the inside diameter, pipe weight, fabrication requirements, and dimensional coordination with fittings, supports, and layout clearances.
Why These Pipe Dimensions Matter
Accurate pipe dimension data is important for piping layouts, spool drawings, support design, structural load review, and material takeoff. Knowing that this pipe weighs 117.15 kg/m helps with transport estimates, lifting plans, and support loading. If the pipe is filled with water, the total weight increases to 304.81 kg/m, which is also useful for operating load calculations.
Common Uses of DN500 Schedule 20 Pipe
DN500 Schedule 20 pipe may be referenced in industrial utility systems, water transfer lines, plant layout studies, process piping documentation, and engineering design work. It is also commonly used by piping designers, CAD users, estimators, and procurement teams who need fast access to standard steel pipe dimensions.
Difference Between NPS 20 and DN500
NPS 20 is the inch-based nominal pipe size designation, while DN500 is the metric nominal diameter reference. Both refer to the same pipe size category on this page. The actual standard outside diameter for this size is 508 mm.
How to Use This Data
You can use this page to quickly check:
- pipe outside diameter for layout and clearance
- inside diameter for flow reference
- wall thickness for schedule comparison
- weight per meter for estimation and transport planning
- water-filled weight for support and structural load review
Quick Reference for Schedule 20 Pipe 20 Inch
- Pipe Size: 20 inch
- DN: DN500
- OD: 508 mm
- ID: 488.94 mm
- Wall Thickness: 9.53 mm
- Weight: 117.15 kg/m
- Weight Including Water: 304.81 kg/m
- Reference Standard: ASME B36.10
Related Pipe Size Pages
Conclusion
Schedule 20 Pipe 20 Inch (DN500) is an important large-diameter steel pipe reference for piping design, drafting, estimation, and fabrication work. With its 508 mm outside diameter, 9.53 mm wall thickness, and 117.15 kg/m pipe weight, it provides useful dimensional data for engineers and designers who need fast and accurate pipe information.
Note: NPS = Nominal Pipe Size, DN = Diameter Nominal. Dimensions and weights shown here are based on ASME B36.10 steel pipe data.
How to Read This Pipe Reference
The outside diameter is the principal envelope dimension for many drafting and layout checks. It helps establish pipe centerline offsets, clearance zones, support locations, insulation allowances, and coordination with fittings or adjacent equipment. The inside diameter is a flow-path reference and may also be useful when comparing hydraulic assumptions or checking transitions.
Schedule identifies a wall-thickness series for a given nominal pipe size. It should not be interpreted as a universal thickness that applies to every NPS. For this pipe size, the listed schedule, wall thickness, inside diameter, and weight belong together and should be reviewed as one dimensional set.
Using the Weight Data in Design Coordination
The dry pipe weight is useful for material takeoffs, handling discussions, transportation estimates, and preliminary support-load reviews. The water-filled value represents a different operating condition and is relevant when considering the additional load from contents. Final support, structural, seismic, thermal, and pressure-related decisions require the applicable project design basis and qualified engineering review.
Drafting and CAD Considerations
When using the supplied DWG reference, confirm the drawing units, insertion scale, layer conventions, centerline assumptions, and connection details before incorporating the file into a project model. The dimensional values on this page remain the controlling reference for coordination, while project-specific fittings, flanges, valves, insulation, and support details may require separate checks.
For comparison with nearby sizes, see the related Schedule 20 Pipe 18 Inch (DN450) and Schedule 20 Pipe 22 Inch (DN550) references.
Frequently Asked Questions
What is the difference between NPS 20 and DN500?
NPS 20 is the inch-based nominal pipe size designation, while DN500 is the metric nominal reference used for the same pipe size category on this page. Neither designation alone replaces the actual dimensional data in the table.
What does Schedule 20 describe?
Schedule 20 identifies the wall-thickness series for this nominal pipe size. The associated wall thickness affects the resulting inside diameter, pipe weight, fabrication coordination, and clearances.
Which diameter should be used for layout?
Use the listed outside diameter when checking the physical pipe envelope, routing, clearances, and coordination with supports or adjacent components. Use the listed inside diameter when an internal flow path is being reviewed.
Why is the water-filled weight listed separately?
A pipe carrying water has a greater operating load than the empty pipe. The water-filled value is therefore useful for preliminary support and structural load review, subject to project-specific engineering checks.
Can this information be used for final pipe design?
The listed dimensions and weights are useful reference data for drafting, estimation, layout, and coordination. Final material selection, pressure design, support design, code compliance, and structural verification must be confirmed against the project requirements by qualified professionals.