What are the characteristics of fluid steel pipes?

Posted by zora li on January 18th, 2024

What are the characteristics of fluid steel pipes?

Fluid pipelines are pipelines (mostly seamless pipes) specially used to transport media with fluid properties. Media with fluid properties, in addition to liquid media such as water, oil, and solutions, solid media such as cement, grain, and coal powder can also flow under certain conditions. Fluid pipes can be made from non-ferrous metals such as steel, copper, titanium, or even non-metallic materials such as plastic.

Types of fluid steel pipes

The fluid tube must have a hollow section, but can also be square, triangular or any other shape. Some equipment is restricted by conditions and must use rectangular tubes, but most still use round tubes. Circular tubes have the smallest circumference/area ratio of all geometric cross-sections, i.e. the largest internal cross-section can be obtained using the same amount of material. However, round tubes also have certain limitations. For example, under plane bending conditions, the bending strength of round tubes is not as good as square tubes and rectangular tubes.

Warm reminder: With the continuous improvement of current technology, fluid steel pipes are not necessarily seamless pipes. The process is approved for use in low- and medium-pressure boilers and pipelines carrying fluids. When customers order fluid steel pipes, they must indicate in the industrial contract whether they are welded pipes or seamless pipes. Fluid steel pipes include steel pipes of these two processes, and the difference lies in the delivery price.

Manufacturing method of fluid steel pipe

1. The working temperature of general boiler tubes is below 450°C. Domestic pipes mainly use No. 10 and No. 20 carbon structural steel hot-rolled pipes or cold-drawn pipes.

2. High-pressure boiler tubes are often exposed to high-temperature and high-pressure conditions during use. Under the action of high-temperature flue gas and water vapor, the tubes will oxidize and corrode. Steel pipes are required to have high durability, high resistance to oxidation and corrosion, and good structural stability.

When used as a pipeline for transporting fluids, welded steel pipes have different requirements from ordinary steel pipes:

1. No leakage of welds is allowed. For welded pipes with API and other requirements, ultrasonic flaw detection and hydraulic pressure testing are also required for the welds of each welded pipe;

2. To transport corrosive chemical solutions, all steel pipes must undergo anti-corrosion treatment on the inner wall;

3. All fluid pipelines need to remove internal burrs to reduce fluid transportation resistance.