High-pressure boiler tubes are key components used in boiler systems and are subject to high-temperature and high-pressure working environments, so their performance requirements are extremely strict. Among the many types of boiler tubes, seamless steel tubes are widely used in the manufacture of high-pressure boiler tubes due to their excellent mechanical properties, high-temperature and high-pressure resistance. Compared with welded pipes, seamless steel pipes show higher safety and stability under high-temperature and high-pressure conditions, so seamless steel pipes have become the preferred material for high-pressure boiler tubes.
First of all, seamless steel pipes have stronger compressive and tensile strength and corrosion resistance than welded pipes. During the manufacturing process, seamless steel pipes are made into a continuous pipe by heating and extrusion, while welded pipes are welded at both ends of the pipe. This difference in manufacturing methods determines that there is no welded joint inside the seamless steel pipe, so the structure is more uniform and can maintain good mechanical properties in a high-temperature and high-pressure environment. High-pressure boiler tubes often need to withstand changes in steam pressure and temperature in the boiler. If welded pipes with welded joints are used, the strength and toughness of the joints are usually low, which is prone to weld brittle cracking and falling off, thereby increasing safety hazards in boiler operation. The seamless steel pipe can better ensure the stable operation of the boiler and reduce the risk of failure.
Secondly, the wall thickness and size of the seamless steel pipe are more uniform. During the manufacturing process, the outer diameter and wall thickness of the seamless steel pipe are more accurately controlled, and the wall thickness consistency of the pipe can be guaranteed within a larger range. High-pressure boiler tubes usually need to withstand high-temperature and high-pressure fluids in the boiler, and the uniformity of the tube wall has a crucial impact on the bearing capacity of the tube. After heat treatment, the seamless steel pipe can achieve higher strength and hardness, so that it will not have uneven stress distribution when it is under pressure, thereby effectively preventing the boiler tube from deforming and cracking under long-term high-temperature and high-pressure environments.
In addition, the seamless steel pipe also has good corrosion resistance. In high-pressure boilers, steam, water, air and other media interact under high temperature and high pressure, which is easy to corrode the boiler tube, especially at the welded joints, where the corrosion is more serious. Since the seamless steel pipe has no welded joints, its internal structure is more compact, not easily invaded by corrosive liquids, and exhibits better corrosion resistance. The material and surface treatment process of seamless pipes also make them more resistant to oxidation and can maintain a longer service life in high temperature and high pressure environments.
However, although welded pipes are relatively simple and low-cost in the manufacturing process, the strength and pressure resistance of welded joints are relatively weak due to the limitations of welding processes. During boiler operation, due to the constant changes in temperature and pressure, welding parts are often more prone to cracks or fall off, resulting in failure of boiler pipes. Therefore, although welded pipes are used in some low-pressure boilers or other pipes with lower strength requirements, in high-pressure boilers, seamless steel pipes are obviously more advantageous due to higher safety requirements.
In summary, the use of seamless steel pipes instead of welded pipes for high-pressure boiler pipes is mainly due to the fact that seamless steel pipes have better mechanical properties, more uniform wall thickness, stronger corrosion resistance and higher safety. The use of seamless steel pipes can effectively ensure the stability and safety of the boiler system and avoid the hidden dangers that may be caused by welded joints. Therefore, in the production and use of high-pressure boiler pipes, seamless steel pipes are almost irreplaceable and preferred materials.
