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Process performance of seamless steel pipes for high-pressure chemical fertilizer equipment (GB 6479-2000)
In general, seamless steel pipes for high pressure fertilizer equipment are used for pressure pipelines for transport of media such as oil, gas, water and steam. The requirements for seamless steel pipes are very strict. Therefore, Chinas standards and specifications of seamless steel pipes are different from those of blueprints and specifications, and the parameters and performance indexes of seamless steel pipes have to be precisely established. GB 6479-2000 is the standard China has established for seamless steel pipes. This standard specifies the parameters and performance indexes that seamless steel pipes used for high-pressure fertilizer equipment should meet. It also includes requirements for materials, manufacturing processes, inspection, testing and marking of seamless steel pipes.
Seamless steel pipes for high pressure fertilizer equipment are required to have a welded seam, as resistant to leakage and pressure as required. They must also meet a number of other requirements, such as for size, weight and pressure limits. Specifically, the seamless steel pipes must meet the following requirements:
The size of the seamless steel pipe must be accurately controlled according to the corresponding standard. The diameter, wall thickness and length of the seamless steel pipe must meet the specified requirements. Generally, the wall thickness of the seamless steel pipe for high pressure fertilizer equipment should be as thin as possible, and the allowable deviation of the wall thickness shall not exceed 10%. The length of the seamless steel pipe should meet the requirements of the standard, generally no more than 12 meters.
The chemical composition of the seamless steel pipe must meet the requirements of the related standards. The chemical composition of the various seamless steel pipes used in high pressure fertilizer equipment is not the same. Therefore, different grades of seamless steel pipes must meet the corresponding standardized requirements. In addition, the quality of the seamless steel pipe should be guaranteed, and the surface of each seamless steel pipe should be clean and free of oxidized skin.
The steel pipe must comply with the technical requirements of the process. The different manufacturing processes employed in the production of the seamless steel pipes may result in different performances. Therefore, the manufacturers need to check the technicability of the steel pipes in order to guarantee the product’s quality and performance.
The performance of seamless steel pipes is an important technical indicator of their quality (pressure, tension, impact, etc). Generally, the performance of the steel pipes should meet the requirements of the standard and should be able to withstand the working pressure and internal pressure of the pipeline.
The corrosion properties of seamless steel pipes must also meet the requirements of the related standard. The seamless steel pipes should have a certain corrosion resistance in order to meet the requirements of the environment they are used in.
Finally, the inspection and testing of the seamless steel pipes are very important to guarantee the quality of the products. The pressure tests, tensile tests, metallography and hydrocarbon tests should be carried out in accordance with the specified requirements.
From the above discussion, it can be concluded that the performance requirements for seamless steel pipes for high pressure fertilizer equipment are very strict and the quality of the pipes must meet the requirements of the corresponding standards. Only then can the seamless steel pipes be provided for use in high pressure fertilizer equipment.
Table 1:The parameters and performance indexes of seamless steel pipes for high pressure fertilizer equipment
| Dimensions | Seamless steel pipes must meet the corresponding standard requirements |
|--|--|
| Chemical composition | The information of chemical composition should meet the corresponding standard requirements |
| Processing technology|Must meet the technical requirements and mechanical properties of process requirements |
| Performance | The performance of seamless steel pipes should meet the corresponding standard requirements |
| Corrosion resistance | The corrosion resistance should meet the corresponding standard requirements |
| Inspection and testing | The inspection and testing of the seamless steel pipes should be carried out in accordance with the specified requirements |
References
1.《GB 6479-2000》. Seamless steel pipes for high-pressure fertilizer equipment.
2. China National Standard: GB/T 8162-1999, Seamless Steel Tubes for Structural Purposes.
3. American Standard: ASTM A106/A106M-2015, Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service.
4. ASTM A312/A312M-2015, Standard Specification for Seamless and Welded Austenitic Stainless Steel Pipes.
5. GB/T 3087-2008, Seamless Steel Tubes for Low and Medium Pressure Boilers.
