General inspection of pipeline components

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General inspection of pipeline components: 1. Pipeline components must be accompanied by a quality certificate or approval document; products without such certificates shall not be used. 　　2. For materials specified in the design documents to have low-temperature impact values, the product quality certificate must include the results of low-temperature impact toughness tests; otherwise, supplementary tests shall be conducted as required. 　　3. The quality certificate of the pipeline used for transporting the **medium shall include the results of ultrasonic testing; otherwise, supplementary tests shall be carried out as specified. 　　4. The quality certificate for pipes shall include the following information: 　　(1) Product standard number 　　(2) Steel grade 　　(3) Furnace/pond number, batch number, condition at delivery, weight, and quantity 　　(4) Product name, specifications, and quality grade 　　(5) Results of various tests specified in the product standards 　　(6) Stamp from the technical supervision department 　　Before using the product, the quality certificate must be carefully checked; if there are any discrepancies in the data listed in it, necessary analyses and inspections should be carried out. 　　Inspection of the outer tube of steel pipes Before use, steel pipes should be inspected for their appearance, and their surface must meet the following requirements. 　　(1) Defects such as cracks, shrinkages, inclusions, folds, and double skins. (2) The depth of rust, dents, and other mechanical damages shall not exceed the allowable negative deviation in wall thickness as specified by the relevant product standards. (3) The machining accuracy and surface roughness of threads and sealing surfaces must meet the design requirements or manufacturing standards. (4) There must be product markings. Physical and chemical testing of steel pipes: 1. The key alloying elements in alloy steel pipes should be rechecked using rapid spectral analysis or other methods, with appropriate labeling to be applied. 　　2. In SHA-class pipelines, for pipes with a design pressure of 10 MPa or higher, their outer surfaces shall be subject to non-destructive testing on a pipe-by-pipe basis using the methods specified below, and no linear defects are allowed. 　　(1) Magnetic particle testing shall be applied to magnetic steel pipes with an outer diameter greater than 6 mm. (2) Penetrant testing shall be used for non-magnetic steel pipes. 3. For pipes in SHA class that transport extremely hazardous media and have a design pressure of less than 10 MPa, 5% of each batch, or at least one pipe, shall be subject to magnetic particle or penetrant testing on their outer surfaces; no linear defects are allowed. 　　Inspection of other pipeline components 　　1. The quality certification documents for pipeline components must be verified, and the following parameters must meet the requirements specified in the design documents: 　　(1) Chemical composition and mechanical properties 　　(2) Microstructural analysis results of alloy steel forgings 　　(3) Heat treatment results and non-destructive testing reports for welds. 　　If there are any discrepancies regarding the data provided in the quality certification documents, it is necessary to contact the manufacturer promptly. Until such discrepancies are resolved, the batch of products in question shall not be used. 　　2. Valves must undergo rapid spectral analysis of their components to ensure they meet the required standards, as well as pressure tests and pressure adjustment tests for safety valves. 　　3. Alloy bolts and nuts used in pipelines must also undergo rapid spectral analysis and hardness testing as required. 　　4. Flange sealing surfaces, metal gaskets, and wound gaskets must not have any radial scratches, looseness, warping, or other defects. 　　In cases where sampling inspections are conducted as per regulations, if even one sample fails the inspection, an additional equal number of samples must be inspected. If those samples also fail, then the entire batch of pipeline components shall not be used; they must be properly marked and isolated.