The seamless steel pipe can be divided into the following five categories.
1.
Seamless carbon steel pipe
Commonly used manufacturing materials are 10, 20, 16Mn steel. The specification of the pipe is as follows:
Hot rolling outer diameter: φ32-630mm.
Cold drawing outer diameter: φ6-200mm.
Single pipe length: 4-12m.
Allowable operating temperature: -40-450℃.
It is widely used to transport non-corrosive media, such as steam, oxygen, compressed air, oil products and oil and gas.
2. Seamless low alloy steel pipe
This pipe refers to alloy steel pipes containing a certain proportion of alloy elements.
There are usually two types of the pipe: One is the low alloy steel pipe containing manganese, which is called a common low alloy steel pipe (e.g. 16Mn, 15MnV.).
The other is the low alloy steel pipe containing chromium, molybdenum and other elements, which is called a chromium-molybdenum steel pipe.
Commonly used materials are 12CrMo, 15CrMo, 12Cr2Mo, 1Cr5Mo steel, etc.
The specification of this pipe is as follows:
Outer diameter: φ10-273mm.
Single pipe length: 4-12m.
Applicable temperature: -40-550℃.
Seamless low alloy steel pipes are mostly used for transporting high-temperature oil products and oil and gas, salt water with low corrosivity, low-concentration organic acids, etc.
3. Acid-resistant stainless steel seamless pipe
According to the different contents of chromium, nickel and titanium, there are many kinds of materials of the steel pipe, such as Cr13, 00Cr17Ni14Mo2, 1Cr18Ni12Mo2Ti and 1Cr18Ni9Ti.
This pipe is used to transport strong corrosive media such as nitric acid, acetic acid and urea in chemical production.
4. Steel high pressure seamless pipe
Its manufacturing materials are basically the same as the seamless steel pipe mentioned above, except that the pipe wall is thicker than that of the medium and low pressure seamless steel pipe, and the thickest pipe wall is 40mm.
The specification of steel high pressure seamless pipes for fertilizer equipment:
Outer diameter: φ14×4-273×40mm.
Single pipe length: 4-12m.
Applicable pressure range: 10-32MPa.
Working temperature: -40-400℃.
The above steel high pressure seamless pipes are used to transport raw gas, hydrogen and nitrogen, syngas, steam, high-pressure condensed water and other media in petrochemical unit.
5. Low temperature steel pipe
Material grades are STPL-39 and STPL-46. The working temperature can reach -105℃.
Low temperature steel pipes are divided into seamless steel pipes and seamed steel pipes. The nominal diameter of low temperature seamless steel pipes is 15-400mm and the wall thickness is the same as that of carbon steel pipes. The nominal diameter of low temperature seamed steel pipes is 400-1100mm, the wall thickness is 6-10mm, and the standard length of a single pipe is 6m. They are suitable for transporting non-corrosive low-temperature media.
