❶Carbon
seamless steel pipe: The commonly used manufacturing materials are No. 10, No. 20, and 16Mn steel.
❷Low-alloy steel seamless steel pipe: refers to an alloy steel pipe containing a certain proportion of alloying elements. It is usually divided into two types: one is low-alloy steel pipe containing manganese, called ordinary low-alloy steel pipe, such as 16Mn, 15MnV, etc.; the other is low-alloy steel pipe containing chromium, molybdenum and other elements, called chrome-molybdenum steel pipe.
❸Stainless and acid-resistant seamless steel pipe: According to the different contents of chromium, nickel, and titanium, there are many varieties, such as Cr13, 00Cr17Ni14Mo2, 1Cr18Ni12Mo2Ti, 1Cr18Ni9Ti, etc. The most used of these steel grades is 1Cr18Ni9Ti, which is often represented by the simplified material code 18-8 on the construction drawings, and the applicable temperature range is -196～700℃.
❹High-pressure seamless steel pipe: Its manufacturing material is the same as the above-mentioned seamless steel pipe, but the pipe wall is thicker than the medium-low pressure seamless steel pipe, and the thickest pipe wall reaches 40mm. For example, the specifications of high-pressure seamless steel pipes for fertilizer equipment are φ14×4(mm)～273×40(mm), the length of a single pipe is 4～12m, the applicable pressure range is 10～32MPa, and the working temperature is -40～400℃.
❺Low-temperature steel pipe: It is used more in the cold area of imported projects, and its material grades are STPL-39 and STPL-46, and the working temperature can reach -105°C. Low-temperature steel pipes are divided into seamless steel pipes and seamed steel pipes. The nominal diameter of seamless low-temperature steel pipes is 15-400mm, and the wall thickness is the same as that of carbon steel pipes; The standard length of the root canal is 6m.
