TPi January 2022

a continuous extrusion of the alloy being used. The uniform shape of seamless pipes also comes in handy while reinstalling pipes and adding fittings. Greater strength under load While seamless steel pipes can be more expensive than other alternatives, they are more reliable due to their high load- bearing capabilities. The reliability of seamless steel pipes makes them a viable option in the long run. Load strength is a crucial aspect of piping systems. The pipes must support their own weight and the weight of the material they are transporting as well. Pipeline leaks and pipe failure are usually common in welded pipes. As seamless pipes are not welded, these failures can be avoided. The benefits of seamless steel pipes make them an excellent choice in commercial applications such as oil rigs, shipbuilding, pressure vessels, offshore drilling and other pipeline applications. Types of seamless steel pipes As per the manufacturing process, seamless pipes can be divided into two categories, hot-rolled seamless steel pipes, and cold-rolled seamless steel pipes. Hot-rolled seamless steel pipes The manufacturing process of hot-rolled and cold-drawn seamless pipes is not entirely different. Cold rolling of seamless pipes is achieved below the recrystallisation temperature of rolling, whereas hot rolling is carried out above the recrystallisation temperature. Hot-rolled seamless steel pipes can disrupt the cast microstructure of the steel ingot, refine the crystal grains of steel, and eliminate any defects in the microstructure, thereby improving the mechanical properties of seamless steel pipes. These pipes are further divided into low, medium and high-pressure boiler pipes, alloy steel pipes, stainless steel pipes, geological steel pipes and oil cracking pipes. The diameter of hot-rolled seamless pipe is greater than 32mm and the wall thickness ranges between 2.5 to 75mm. Cold-rolled seamless steel pipes Cold-rolled seamless pipes comprise high accuracy of dimension and better finish of the surface when used for hydraulic and machinery equipment. These pipes not only include boiler steel pipes, alloy pipes, petroleum cracking pipes and steel pipes, but also carbon thin-walled steel pipes and special-shaped steel pipes. The outer diameter of cold-rolled pipes is usually less than 6mm and the wall thickness is lower than 0.25mm. In case of thin-walled pipes, the outer diameter is less than 5mm. As a result, cold-rolled pipes have higher dimensional accuracy than hot-rolled pipes. While manufacturing cold-rolled pipes, the speed of molding and productivity are increased significantly. The pipes can be rolled in different shapes to adapt to various end-uses. In addition, the cold rolling process can enhance plastic deformation in steel, thereby increasing the yield points of steel.

Applications of seamless steel pipes Because of their unique structure, seamless steel pipes are broadly used as a transmission medium for natural gas, oil, coal gas, water and other solid materials. Seamless steel pipes are lightweight, making them applicable in the petroleum drilling process, bicycle frames and auto transmission shafts. Using seamless steel pipes can enhance material utilisation, streamline the manufacturing process and reduce excessive use of material and processing time. According to the cross- sectional area shape, seamless pipes can be divided into circular tubes and special pipes to suit different applications. Prominent application areas include:

• Manufacturing oil & gas lines • Chemical processing plants • Nuclear power plants • Hydraulics

• Water purification plants • Sensitive measuring units • High temperature and pressure units

Trends in the seamless steel pipes industry Carbon steel seamless pipes are gaining manufactures’ and customers’ attention, owing to their durability, cost- effectiveness, and recyclability. Carbon steel comprises a higher concentration of carbon content in total composition, around 2 per cent. These pipes are being widely adopted in chemicals, oil & gas and power generation sectors. However, manufacturers are facing challenges in some regions due to stringent regulations on carbon emissions during the manufacturing process. As a result, seamless steel suppliers are investing in research and development to create and adopt low-emission manufacturing plants for production. Further, China, Japan, and Europe are emerging as lucrative pockets in the seamless steel pipes industry. In China, the abundance of raw material and economically viable products, along with the presence of regional manufacturers, is actively propelling the production of seamless steel pipes. Besides this, Chinese manufacturers are well-equipped with automated manufacturing processes and strong material handling systems. As per Fact.MR’s analysis, the seamless steel pipes market in China is projected to grow at a 7 per cent CAGR through 2031.

Fact.MR – India www.factmr.com

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TUBE PRODUCTS INTERNATIONAL January 2022

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