This reference page helps engineers, designers, fabricators, and drafters interpret the dimensions of 20 inch Schedule 140 pipe, also identified as DN500. Use the authoritative table below when checking outside diameter, wall thickness, inside diameter, and linear weight for layout, estimating, support studies, and CAD documentation.
For broader comparisons, review related resources covering pipe schedules, NPS and DN terminology, and steel pipe dimensions. Those references can help place this heavy-wall size in the context of other pipe selections without replacing project specifications or engineering review.
Schedule 140 pipe 20 inch (DN500) 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 20 Schedule 140 pipe based on ASME B36.10.
20 Inch Schedule 140 Pipe Dimensions
- Nominal Pipe Size (NPS): 20 inch
- Diameter Nominal (DN): DN500
- Outside Diameter (OD): 508 mm
- Wall Thickness: 44.45 mm
- Inside Diameter (ID): 419.1 mm
- Pipe Weight: 508.15 kg/m
- Pipe Weight Filled With Water: 646.03 kg/m
- Reference Standard: ASME B36.10
- Pipe Type: Steel Pipe
Schedule 140 Pipe 20 Inch Data Table
| Pipe Size | DN | OD (mm) | Wall Thickness (mm) | ID (mm) | Weight (kg/m) |
|---|---|---|---|---|---|
| 20 inch | 500 | 508 | 44.45 | 419.1 | 508.15 |
What Does Schedule 140 Mean?
Schedule 140 refers to a very 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 20 Inch Schedule 140 Pipe
NPS 20 Schedule 140 pipe is commonly referenced for heavy-duty industrial piping systems where very 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 a 20 inch Schedule 140 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.
20 Inch Schedule 140 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 20 inch Schedule 140 pipe?
The outside diameter is 508 mm.
What is the wall thickness of DN500 Schedule 140 pipe?
The wall thickness is 44.45 mm.
What is the inside diameter of NPS 20 Schedule 140 pipe?
The inside diameter is 419.1 mm.
How much does 20 inch Schedule 140 pipe weigh?
The approximate weight is 508.15 kg/m.
Which standard covers this pipe size?
This dimension data is based on ASME B36.10 for steel pipe.
Conclusion
Schedule 140 pipe 20 inch (DN500) has an outside diameter of 508 mm, wall thickness of 44.45 mm, inside diameter of 419.1 mm, and a weight of 508.15 kg/m. It is a useful reference for piping design, fabrication, estimating, and heavy-duty industrial engineering work.
How to Use This Schedule 140 Pipe Reference
The listed outside diameter is the fixed dimensional basis for this nominal pipe size, while the schedule identifies the wall-thickness series. The inside diameter is therefore the more useful dimension when checking available flow area, clearances, sleeves, or connections. Because the wall is substantial, the pipe weight should also be carried into support, lifting, transportation, and installation assessments.
Schedule, nominal size, and actual dimensions
NPS 20 and DN500 identify the nominal size; they are not interchangeable with a direct measured diameter. For fabrication and drafting, use the stated outside diameter and wall thickness rather than treating the nominal designation as a measurement. The schedule should be read together with the applicable material, product, and project requirements.
Weight and filled-pipe checks
The dry pipe weight is useful for estimating steel quantities and evaluating permanent loads. The listed filled-with-water value supports preliminary handling and support discussions, but final calculations should use the actual contents, operating condition, insulation, coatings, valves, fittings, and support arrangement where applicable.
CAD and design coordination
The downloadable DWG can support preliminary routing, model coordination, and drafting workflows. Before issuing fabrication or construction documents, confirm connection details, tolerances, material requirements, and the governing project specifications. A schedule designation by itself should not be treated as a complete pressure-design qualification.
Useful related references for this topic include pipe weight calculations, flange dimensions, fitting dimensions, nominal pipe size terminology, and CAD/DWG pipe details. Linking this page to those resources can help readers move from dimensional lookup to practical piping design checks.
Additional Questions About 20 Inch Schedule 140 Pipe
Is DN500 the same nominal size as NPS 20?
Yes. In this reference, DN500 is the metric designation associated with NPS 20. The nominal designation should still be distinguished from the measured outside and inside diameters.
Does Schedule 140 alone establish a pipe pressure rating?
No. Schedule identifies a dimensional wall-thickness series. Pressure suitability also depends on factors such as material specification, temperature, design code, corrosion allowance, manufacturing requirements, and the applicable engineering design calculation.
Why is the inside diameter important?
The inside diameter affects available flow area, hydraulic evaluation, internal clearances, and connection coordination. It is also useful when checking whether the selected pipe aligns with fittings, valves, and other piping components.
What should be checked before using the listed weight for a project?
Confirm the project material, manufacturing tolerances, coating or lining, contents, insulation, fittings, and support configuration. The table is a dimensional reference and should be coordinated with project-specific engineering requirements.