Introduce AP, BA, EP and MP tubes

AP Pipe - Annealed and Pickled Pipe  - Solid Solution and Acid Washed Pipe

AP refers to acid pickling treatment. It uses acidic solutions such as nitric acid and perfluoric acid to remove the oxide layer from the steel pipe. It is inexpensive and fast, but it is prone to cause intergranular corrosion and the inner and outer surfaces are rough, making it easy for suspended impurities to adhere.

In literal terms, AP means acid-washed surface. In the category of clean-grade products, it means acid-washed surface + oil-free cleaning. 

MP pipe - Mechanically Polished Pipe  Mechanical polishing pipe

MP: This refers to mechanical polishing. It is commonly used to remove the oxide layer, holes, and scratches on the surface of steel pipes. The brightness and effect depend on the type of processing method. Additionally, although mechanically polished, it may reduce corrosion resistance. Therefore, when used in an environment with corrosion, it needs to undergo passivation treatment. Moreover, there is often residual polishing material on the surface of the steel pipe. 

BA pipe - Bright Annealed Pipe - Bright Annealing steel pipe. During the manufacturing process of this type of steel pipe, lubricating oil is necessary for lubrication and the crystal grains will also deform due to processing. To prevent the lubricating oil from remaining in the steel pipe, in addition to cleaning the pipe, it is also possible to use high-temperature bright annealing to eliminate the deformation. By using argon as the atmosphere inside the furnace and combining argon with carbon and oxygen on the surface of the steel pipe for combustion to further clean the surface of the pipe and achieve a shiny effect. Therefore, this method of using pure argon for annealing heating and rapid cooling to brighten the surface is called bright annealing. Although using this method to brighten the surface can ensure that the steel pipe is completely clean and free from any external pollution, the brightness of this surface compared to other polishing methods (mechanical, chemical, electrolytic) will have a matte effect. Of course, the effect also depends on the content of argon and the number of heating cycles. 

EP pipe - ElectroPolished Pipe  Electrolytic polished pipe

EP stands for Electro Polishing. Electrolytic polishing is achieved through an anode treatment method, using the principles of electrochemistry to appropriately adjust voltage, current, acid composition, and polishing time. This not only enables the surface to achieve a bright, smooth, and clean effect, but also enhances the surface's corrosion resistance. Therefore, it is the best method for brightening the surface. Of course, its cost and technology also increase. However, because electrolytic polishing highlights the original state of the pipe surface, if the pipe surface has severe scratches, holes, pickling (Ra ≤ 2.5 μm), mechanical polishing (Ra ≤ 0.4 μm), bright annealing (Ra ≤ 0.3 μm), or electrolytic polishing (Ra ≤ 0.2 μm), then acid washing (Ra ≤ 2.5 μm), mechanical polishing (Ra ≤ 0.4 μm), bright annealing (Ra ≤ 0.3 μm), or electrolytic polishing (Ra ≤ 0.2 μm) should be carried out.