Why are all the pipes used in industrial boilers seamless steel pipe?

Why are all the pipes used in industrial boilers seamless steel pipe?

Seamless steel pipe boiler with high quality carbon steel, alloy steel and stainless heat resistant steel seamless steel pipe, used for the manufacture of high pressure and above pressure water tube boiler heating surface. These boiler tubes often work under high temperature and high pressure, and under the action of high temperature flue gas and water vapor, the tube will be oxidized and corroded. Therefore, the steel pipe is required to have high durability, high oxidation resistance and good tissue stability.

Industrial boiler tube is mainly seamless steel tube, because the performance index of seamless steel tube can fully meet the requirements of boiler application. Although the cost is high, its security and reliability are high. Low-pressure fluid transmission pipelines within 2Mpa are generally welded steel tubes. High temperature and high pressure equipment such as industrial boilers must use seamless steel pipes, and the thickness of the pipe wall is correspondingly thick.

Nowadays, welded steel pipes are also used in medium and low pressure boilers, benefiting from the rapid improvement of welding technology. For example, the joint microstructure of the pipe butt friction welded steel pipe is the same, and it is difficult to observe the bulk joint traces by the naked eye after the pipe joint is remelted through the butt joint and the Angle joint. The microstructure of its various parts has always been exactly the same.
Common problems in surface treatment and product processing of seamless steel tubes for high pressure boilers:

1. The surface of seamless steel pipe for high pressure boiler is inconsistent: only the weld is pickled and passivated, resulting in uneven surface and affecting the appearance.

2. Scratches on seamless steel pipes for high-pressure boilers are difficult to remove: after pickling passivation, various scratches generated in the processing process cannot be removed, and scratches and welding splashing attached to the surface of stainless steel cannot be removed. Carbon steel, spatter and other impurities. In the presence of corrosive media, causing chemical corrosion or electrochemical corrosion and rust.

3. Weld defects: Weld defects are serious, and manual and mechanical polishing methods are used to make up for them. The wear marks will cause the surface to be uneven and affect the appearance.