Standard Pipe Sizes in mm
Steel Pipe Dimensions (Schedule 40, 80 Pipe)
In piping systems or laying pipelines, it is very essential to understand the standard pipe sizes in mm required for their selection in order to maintain optimum performance. The size of pipes varies based on diameter, wall thickness, and schedule of pipes, and specification of those is available either in imperial or metric systems. This article delivers the insight of standard pipe size in terms of millimeters and their application on the different pipe schedules.
We will also provide you with a guide on essential concepts such as pipe schedule charts, pipe dimensions, and differences between Schedule 40 vs Schedule 80 pipes to help guide your decisions.
Pipe Size Chart In mm and inches
Steel Pipe Dimension 3 elements:
Pipe sizes are typically measured using Nominal Pipe Size (NPS) or Diameter Nominal (DN), which indicate the approximate inside diameter of the pipe in inches or millimeters, respectively. In metric systems, pipe sizes are categorized based on Outer Diameter (OD), Wall Thickness (WT), and Inner Diameter (ID).
Pipe OD Chart In mm
The following table provides a comparison of standard pipe sizes in mm based on Nominal Pipe Size (NPS) and Diameter Nominal (DN):
3. Pipe Wall Thickness: Schedule 40, 80, and More
Pipes are classified into different schedules (SCH) based on their wall thickness, affecting their pressure capacity. The most common schedules are:
- Schedule 40: Standard thickness, widely used for general applications.
- Schedule 80: Thicker walls, suitable for high-pressure applications.
- Schedule 160 & XXS: Extra thick walls for extreme conditions.
Example of Wall Thickness for 2-inch Pipe:
- SCH 40: 2.77 mm
- SCH 80: 3.91 mm
- SCH 160: 7.14 mm
4. Common Pipe Material Standards
Different industries use pipes made of various materials, each governed by specific standards:
| Material | Standard |
| Steel Pipes | ASTM A53, ASTM A106 |
| Stainless Steel | ASTM A312, A213 |
| PVC Pipes | ISO 1452, ASTM D1785 |
| Copper Pipes | BS EN 1057, ASTM B88 |
| Ductile Iron | ISO 2531, AWWA C151 |
5. Pipe Size Conversion: Inches to mm
To convert inches to mm, multiply the inch value by 25.4.
Example:
- 2 inches × 25.4 = 50.8 mm
- 4 inches × 25.4 = 101.6 mm
6. Applications of Different Pipe Sizes
- Small Diameter Pipes (6-50 mm): Used in household plumbing, gas lines, and water distribution.
- Medium Diameter Pipes (50-200 mm): Found in industrial pipelines, HVAC systems, and irrigation.
- Large Diameter Pipes (200+ mm): Used in sewage systems, oil and gas transmission, and structural support.
Piping Schedule Chart and Wall Thickness
The piping schedule chart (or pipe schedule table) classifies wall thickness for a given nominal pipe size. In the past, Schedule 40 pipes were typical since they had a minimum base wall thickness. More recent applications, however, demand thicker or thinner pipes, such as Schedule 80 pipes, based on operating pressure.
The Relationship Between Schedule and Wall Thickness
The greater the schedule, the thicker the walls. For example:
Schedule 40 Pipe Dimensions:
Fairly normal in thickness, adequate for low to medium-pressure systems.
Schedule 80 Pipe Thickness:
Thicker than Schedule 40, for high-pressure use.
Steel Pipe Dimensions Chart ANSI B36.10 & 36.19
Conclusion
The main thing to grasp concerning pipe standard sizes in mm is that this is of great importance for selecting the right pipe type in any given application. This is true whether your work involves steel, PVC, copper, or ductile iron because relaxing on any of the following; nominal size, outer diameter of the pipe, or the wall thickness proximate to that of the pipe project is made to meet safety and performance concerns for that project.
For accurate selection, other applicable standards should be consulted, along with your colleagues, if necessary.
Would you like a more detailed analysis for a specific type of pipe? Let me know!