Seeking advice on pipe grade designation in petrochemical PID drawings
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In the drawings from the East China Institute, for 2B1A, 5B2AR, the 1 is a code for corrosion allowance – what does it mean? Is there any other code? A. AR is the variation sequence for the same flange under the same grade and basic material; what do these sequences mean? I asked for advice!
In PID drawings of the petrochemical industry, pipe grade specifications typically consist of three parts: material, corrosion allowance, and flange grade. Among them, the corrosion allowance refers to the remaining wall thickness of the pipeline after corrosion, as determined during design, and it serves to ensure that no safety issues arise during the pipeline’s service life. Below are some common pipe grade designations: - 5B2AR: 5 indicates that the pipe material is carbon steel, B denotes a flange grade of 600LB, 2 means a corrosion allowance of 2 mm, and AR represents the sequence number for variations under the same flange grade and basic material. - 2B1A: 2 indicates that the pipe material is carbon steel; B denotes a flange class of 300LB; 1 means the corrosion allowance is 1 mm; A refers to the basic material, with no sequential code. - 3S2C: 3 indicates that the pipe material is stainless steel; S denotes that the flange grade is 1500LB; 2 means the corrosion allowance is 2 mm; C refers to the base material, with no sequential number change. It should be noted that different companies and design institutes may have varying standards and coding rules, so the specific meaning of the markings might differ slightly. It is recommended to understand and apply it according to respective standards in practical use. .