Steel pipe diameters are determined by industry standards and application-specific requirements. Steel pipe is a common metal material that is often used in applications such as oil and gas production, construction, industrial manufacturing, and energy transportation. The choice of pipe diameter has a direct impact on performance, safety and cost.
Pipe Diameters
Steel Pipe Diameters Chart
Tuspipe summarizes the Steel Pipe Diameters Chart 1/2 inch to 24 inch (Inches vs. Millimeters).
Inch Size | Outside Diameter (OD) | Common Use |
1/2” | 0.84 inches (21.3 mm) | Household plumbing |
1” | 1.315 inches (33.4 mm) | Water supply lines |
2” | 2.375 inches (60.3 mm) | Irrigation systems |
4” | 4.5 inches (114.3 mm) | Industrial drainage |
6” | 6.625 inches (168.3 mm) | Oil and gas pipelines |
8” | 8.625 inches (219.1 mm) | Large-scale construction |
12” | 12.75 inches (323.9 mm) | Municipal water mains |
24” | 24 inches (609.6 mm) | Heavy-duty industrial projects |
Standard Steel Pipe Diameters
Steel pipe diameters refers to the outer diameter of a pipe. That is, the diameter of the outer edge of the pipe including the wall thickness of the pipe. General seamless steel pipe, spiral steel pipe is used Ф to identify the specification size, labeled into the outer diameter X wall thickness of the form. Such as: 108X4, said the outer diameter of 108mm, wall thickness of 4mm pipe.
Steel pipe diameters generally follow the following standards.
- Nominal Pipe Diameter (NPS):
- Nominal pipe diameters are labeled with the “inch” approximation, which is a common standard in North America. For example, the actual outside diameter of “2-inch pipe” is not exactly 2 inches.
- The NPS number for large pipe (14“ and larger) is equal to the actual OD, while the NPS number for small pipe (1/8”-12″) approximates the OD.
- Wall Thickness Grade (e.g., Sch 40, Sch 80):
- The larger the number of the wall thickness grade of a steel pipe, the thicker the pipe wall.
- Schedule 40 is one of the most commonly used wall thickness specification grades, which offers economy and strength. While Schedule 80 is more costly and more resistant to high pressure.
- Metric Sizes (mm): Metric sizes are an internationally accepted standard. For example, 6″ steel pipe is approximately 150mm.
How to Measure Steel Pipe Diameters
Measuring pipe diameter can be summarized in three steps.
- Measure the outside diameter (OD):
Measure the outside wall directly with calipers for small pipes, and divide the circumference by 3.14 (π) with a tape measure for large pipes.
- Calculate the inside diameter (ID):
Formula: ID = OD – 2 × wall thickness.
For example, the outside diameter of 6 inches, wall thickness of 0.25 inches of steel pipe, the inner diameter of 5.5 inches.
- Standard size table comparison:
The results will be compared with the steel pipe diameters comparison table, used to determine the nominal size (NPS) or metric specifications.
Steel Pipe Diameters- How to Choose
1/2 inch-36 inch Diameter Steel Pipe
The range of steel pipe diameters is very broad and covers, but is not limited to, 1/2 inch to oversized 36 inch pipes. The applications for different pipe diameters also vary significantly. If the wrong size is selected, leaks, system failures and other serious results can occur. That’s why it’s critical to determine the inside diameter (ID) and outside diameter (OD) for your project needs.
First,
Small Diameter (1/2-inch – 2-inch): suitable for household plumbing, low-pressure gas delivery.
Medium diameter (3-inch-10-inch): mostly used for commercial water supply, heating, ventilation and air conditioning (HVAC) systems.
Large diameter (12 inches-36 inches): common for heavy-duty scenarios such as oil and gas transmission, industrial drainage, etc.
4 Core of Choosing Steel Pipe Diameter
- Flow Requirements: a 10-inch pipe is going to deliver many times more water than a 4-inch pipe. So the larger the diameter of the steel pipe, the higher the fluid throughput.
- Material Type: Carbon steel and stainless steel pipe are available.
- Budget Control: For the same length situation, Sch 40 carbon steel pipe is 30%-50% cheaper than Sch 80 stainless steel pipe.
- Pressure and temperature: Boiler and other high-pressure environment to choose Sch 80 or above thick-walled pipe.
FAQs:
1. What is the general length of steel pipe
The general standard length of steel pipe is 20 or 40 feet (about 6m/12m), but customized cutting service such as 5,10,30 feet etc. is also available.
2. What is the difference between the outside diameter and inside diameter of steel pipe
The outside diameter is the total width of the pipe. The inside diameter is the actual space where the fluid passes through the pipe.
For example, a 2-inch pipe from Sch 40 has an outside diameter of 2.375 inches and an inside diameter of about 2.067 inches.
