About Us
Eastern Steel Manufacturing Co.,Ltd is a leading manufacturer and distributor of seamless steel pipe, welded steel pipe, OCTG products and fittings. We supply first-step processing, semi-finished parts and finished parts to help our clients meet fabrication requirements beyond their capacity or to improve operations by moving forward the pre-production processing.
News
In this column you can find the steel pipe related articles you need, including industry trends, product standards and materials, and some technical guidelines.
Services
Eastern Steel Manufacturing Co.,Ltd not only improve product production and sales services, but also provide additional value-added services. As long as you need, we can complete your specific needs together.
Facility
Eastern Steel Manufacturing Co.,Ltd not only improve product production and sales services, but also provide additional value-added services. As long as you need, we can complete your specific needs together.
Projects
Many years of large-scale project experience in various fields（Oil & Gas, Construction, Power Energy, Marine & Offshore, Water Treatment, Exploration & Drilling Services, Pipeline & Petrochemical etc.）, professional project team is responsible from receiving until the end of the project.
The roughness coefficient of carbon steel pipe refers to the degree of surface irregularity or convexity, and is an important parameter for measuring the resistance to flow within a pipe.
Carbon steel pipe is a commonly used pipe material. Variations in its surface roughness coefficient can affect its transmission performance. Choosing the right pipe can significantly improve transmission efficiency and reduce material loss.
The roughness coefficient of carbon steel pipe refers to the degree of surface irregularity or convexity on the pipe's inner surface. It reflects the surface condition and is often used to describe the resistance to flow of liquids and gases within the pipe. Its value is related to factors such as the pipe wall material, manufacturing process, and operating conditions. It is generally represented by the symbol ε. The smaller the value, the lower the resistance to flow within the pipe and the greater the flow rate.
This method uses metric units. The calculation formula is:
ε = (e/pipe diameter) × 1000
where e is the absolute roughness in meters, the pipe diameter is in meters, and ε is a dimensionless unit.
This method is often used to calculate the relative roughness coefficient of small-diameter carbon steel pipes.
The relative roughness coefficient ranges from 0.0001 to 0.05.
The calculation formula is: ε = (e/pipe diameter) × 1000
where e is the relative roughness coefficient, also in meters.
This method is suitable for carbon steel pipes with newer or smoother walls.
The calculation is based on existing data and empirical formulas.
The absolute roughness (ε) of carbon steel pipes is generally within the following range:
|
Pipe Type |
Condition |
Absolute Roughness ε (mm) |
Relative Roughness ε/D (Typical Value) |
|
New Carbon Steel Pipe (Cold-Drawn/Precision Tube) |
Smooth Inner Wall |
0.015 ~ 0.03 |
0.00005 ~ 0.0002 |
|
Common Commercial Carbon Steel Pipe (Seamless Pipe/Welded Pipe) |
New Pipe |
0.045 ~ 0.15 |
0.0002 ~ 0.001 |
|
New Pipe |
0.15 ~ 0.20 |
0.0005 ~ 0.0015 |
|
|
Carbon Steel Pipe in Service for Several Years |
with Slight Scale/Corrosion |
0.2 ~ 0.5 |
0.001 ~ 0.003 |
|
Old or Severely Scaled Carbon Steel Pipe |
with Uneven Inner Wall |
0.5 ~ 1.5 |
0.003 ~ 0.01 |
The inner surface smoothness of high-precision cold-drawn steel pipe is superior to that of hot-rolled steel pipe.
Welded steel pipe may experience localized increases in roughness at the weld seam.
Over time, the inner surface of the pipe will gradually wear away, increasing irregularities on the inner surface and increasing the roughness coefficient.
The higher the fluid velocity, the greater the resistance encountered during flow within the pipe, increasing friction and the roughness coefficient accordingly.
In humid, high-temperature, or chemically mediated environments, carbon steel pipe is more susceptible to rust and corrosion, which increases carbon steel pipe roughness.
The roughness coefficient of carbon steel pipe is more than just a surface parameter; it directly affects fluid delivery efficiency, energy consumption, and pipeline network operational stability. To improve delivery efficiency and reduce costs, it is crucial to rationally select pipes and maintain a smooth surface.
E-mail: sales@eastern-steels.com
