High pressure fertilizer (HPF) equipment is a type of fertilizer equipment used to produce fertilizer with a high concentration of nitrogen, phosphorus, and potassium. It is widely used in agricultural and horticultural production. In order to ensure the quality of the HPF equipment and its efficiency, the use of seamless steel pipe is essential. Therefore, it is essential to choose the right grade and chemical composition of the seamless steel pipe in order to ensure the highest quality of the HPF equipment.
GB 6479-2000 provides specific guidelines as to the grades and chemical composition of the seamless steel pipe suitable for use in HPF equipment. It defines the requirements for three different grades of seamless steel pipe, designated A, B and C. Grade A is the highest quality of seamless steel pipe and is used for moderate working pressures and temperatures. Grade B is suitable for medium to high pressure and temperature working conditions, and is the most commonly used grade for HPF equipment. Grade C is a lower grade and is suitable for low to moderate working conditions.
In terms of chemical composition, GB 6479-2000 sets out a detailed standard for each grade of seamless steel pipe. Grade A seamless steel pipe must have a carbon content of 0.25%-0.45%, as well as a phosphorus and sulphur content of <0.025%. It must also have a tensile strength of 415 MPa and a yield strength of 235 MPa. Grade B seamless steel pipe must have a carbon content of 0.20%-0.42%, as well as a phosphorus and sulphur content of <0.022%. It must also have a tensile strength of 510 MPa and a yield strength of 345 MPa. Grade C seamless steel pipe must have a carbon content of 0.15%-0.35%, as well as a phosphorus and sulphur content of <0.021%. It must also have a tensile strength of 425 MPa and a yield strength of 254 MPa.
The grades and chemical composition of seamless steel pipe specified by GB 6479-2000 are the minimum requirements for the use of seamless steel pipe in HPF equipment. It should be noted that there are other grades and chemical compositions available that can also be used for specific applications. For example, stainless steel pipe with a higher grade and chemical composition can be used for applications requiring a higher level of corrosion resistance, such as marine applications.
In conclusion, GB 6479-2000 sets out specific requirements for the grade and chemical composition of seamless steel pipe used in HPF equipment. Grade A is suitable for moderate working pressures and temperatures, Grade B is suitable for medium to high pressures and temperatures, and Grade C is suitable for low to moderate working conditions. The tensile strength and yield strength of the pipe must also meet the requirements of the standard. Additionally, other grades and chemical compositions may be used depending on the specific application requirements.
