GB/T 24187-2023 PDF EnglishUS$260.00 · In stock · Download in 9 seconds
GB/T 24187-2023: Cold-drawn precision single welded steel tubes Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedure Status: Valid GB/T 24187: Historical versions
Similar standardsGB/T 24187-2023: Cold-drawn precision single welded steel tubes---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT24187-2023GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 77.140.75 CCS H 48 Replacing GB/T 24187-2009 Cold-drawn precision single welded steel tubes Issued on. AUGUST 06, 2023 Implemented on. MARCH 01, 2024 Issued by. State Administration for Market Regulation; Standardization Administration of the People's Republic of China. Table of ContentsForeword... 3 1 Scope... 5 2 Normative references... 5 3 Terms and definitions... 7 4 Classification and code... 7 5 Ordering content... 8 6 Size, shape, weight and allowable deviation... 8 7 Technical requirements... 12 8 Test methods... 15 9 Inspection rules... 17 10 Packaging, marking and quality certificate... 18 Annex A (normative) Bell mouth test of automobile steel tube... 19 Annex B (normative) Requirements and test methods for the inner surface of high- cleanliness steel tubes for refrigeration... 21 Annex C (normative) Requirements and test methods for external coating and cladding of steel tubes... 22 Annex D (normative) Inspection methods for residues... 251 ScopeThis document specifies the classification and code, size, shape, weight and allowable deviation, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of cold-drawn precision single welded steel tubes. This document is applicable to cold-drawn precision single welded steel tubes (hereinafter referred to as "steel tubes") used for the manufacture of condensers, evaporators, fuel pipes, lubricating oil pipes, electric heating pipes, cooler pipes and general piping in industries such as refrigeration, automobiles, and electric heating appliances.2 Normative referencesThe following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. GB/T 222, Permissible tolerances for chemical composition of steel products GB/T 223.5, Steel and iron -- Determination of acid-soluble silicon and total silicon content -- Reduced molybdosilicate spectrophotometric method GB/T 223.59, Iron, steel and alloy - Determination of phosphorus content - Bismuth phosphomolybdate blue spectrophotometric method and antimony phosphomolybdate blue spectrophotometric method GB/T 223.63, Iron, steel and alloy - Determination of manganese content - Sodium (potassium) periodate spectrophotometric method GB/T 223.85, Steel and iron -- Determination of sulfur content -- Infrared absorption method after combustion in an induction furnace3 Terms and definitionsFor the purposes of this document, the terms and definitions defined in GB/T 30062 apply.4 Classification and code4.1 Dimensional accuracy Steel tubes are classified and coded according to dimensional accuracy as follows. 4.2 Mechanical properties Steel tubes are classified and coded according to mechanical properties as follows. 4.3 Surface conditions The classification and code of steel tubes according to surface conditions are shown in Table 1.6 Size, shape, weight and allowable deviation6.1 Outside diameter and wall thickness 6.1.1 The nominal outer diameter (D), nominal wall thickness (S) and theoretical weight of uncoated steel tubes shall comply with the requirements of Table 2.Steel tubes with dimensions other than those specified in Table 2 may be supplied upon request of the purchaser and after negotiation between the purchaser and the supplier. 6.1.2 The allowable deviation of the outer diameter of uncoated steel tubes shall comply with the provisions of Table 3. 6.2 Length 6.2.1 The usual length of steel tubes is 1.5 m~4000 m. Steel tubes with a length of no more than 8 m are delivered in strips. Steel tubes with a length of more than 8 m are delivered in coils. 6.4 Weight 6.4.1 Coiled steel tubes are delivered by actual weight. Strip-shaped steel tubes are delivered by actual weight, or by theoretical weight of number of pieces or without coating. 6.4.2 The theoretical weight of uncoated steel tubes shall comply with the requirements of Table 2 or be calculated according to formula (1). 6.4.3 For steel tubes delivered according to theoretical weight, the allowable deviation between the actual weight and the theoretical weight of each batch shall be ±7.5%. 6.5 Marking examples The marking sequence of steel tubes is. (dimensional accuracy) - dimensional specifications - mechanical properties (category) - surface type and coating post- treatment - this document number.7 Technical requirements7.1 Steel strip requirements 7.1.1 The steel strip used to manufacture steel tubes shall be cold-rolled low-carbon steel strip or cold-rolled ultra-low-carbon steel strip. The chemical composition (melting analysis) of the steel strip shall comply with the requirements of Table 6. Table 6 -- Chemical composition of steel strip 7.2 Manufacturing methods Steel tubes shall be manufactured by forming steel strips, welding longitudinal seams, cold drawing and heat treatment. Steel tubes may be manufactured by other methods after consultation between the supplier and the purchaser and specified in the contract. 7.3 Mechanical properties The room temperature longitudinal mechanical properties of the steel tube shall comply with the requirements of Table 7. 7.4 Process performance 7.4.1 Flattening The steel tube shall be subjected to a flattening test. The length of the specimen is 50 mm~100 mm. During the test, the weld shall be located at 90° to the direction of force application. Use a pressure plate to flatten the specimen at a uniform speed until the inner wall fits. After the test, the specimen shall not have cracks, splits or weld cracks. 7.5 Hydraulic test Automobile steel tubes shall be subjected to hydraulic pressure test. The test pressure is calculated according to formula (2). Under the test pressure, the pressure stabilization 7.6 Airtightness The disc-shaped steel tube shall be subjected to underwater air tightness test or active gas air tightness test. For underwater air tightness test, the test pressure shall be not less than 1.8 MPa. The pressure stabilization time shall be not less than 3 min. The steel tube shall not have gas leakage. For active gas air tightness test, the active gas test pressure shall be not less than 0.5 MPa. The pressure stabilization time shall be not less than 10 min. The steel tube shall not have gas leakage. 7.9 Internal surface cleanliness 7.9.1 Steel tubes shall be inspected for internal surface cleanliness residues. The residues shall not exceed 160 mg/m2. 7.9.2 Based on the purchaser’s requirements, after consultation between the supplier and the purchaser and specified in the contract, the high cleanliness of the inner surface of high-cleanliness steel tubes for refrigeration shall comply with the provisions of Annex B. 7.10 Surface coating and cladding 7.10.1 The surface conditions of different types of steel tubes shall comply with the provisions of Table 1.According to the requirements of the purchaser, steel tubes with surface conditions other than those in Table 1 may be supplied after consultation between the purchaser and the supplier.8 Test methods8.1 The chemical composition of the steel tube shall be subject to the quality certificate of the steel strip manufacturer. The sampling for chemical composition analysis shall comply with the provisions of GB/T 20066. 8.3 The surface of the steel tube is to be visually inspected piece by piece (coil) under adequate lighting conditions. 8.4 The supplier shall select one of the following methods for the air tightness test of the steel tube. 8.6 The sampling method and test method of steel tube inspection items shall comply with the provisions of Table 9.9 Inspection rules9.1 Inspection classification The inspection of steel tubes is divided into exit-factory inspection and type inspection. 9.2 Exit-factory inspection The exit-factory inspection and acceptance of steel tubes shall be carried out by the supplier's quality and technical supervision department. The exit-factory inspection items shall comply with the provisions of Table 9. 9.3 Type inspection When any of the following situations occurs, type inspection shall be carried out. Type inspection items shall comply with the provisions of Table 9. 9.4 Batching rules Steel tubes shall be inspected and accepted in batches. Each batch shall consist of steel tubes of the same steel strip category, the same mechanical property category, the same specification, and the same surface condition. The weight of each batch of steel tubes shall not exceed 10,000 kg. 9.5 Sampling quantity The sampling quantity for each inspection of steel tubes shall comply with the provisions of Table 9. 9.6 Reinspection and judgment rules10 Packaging, marking and quality certificate10.1 Strip steel tubes shall be bundled. Wrap them with moisture-proof paper, vapor- phase rust-proof paper or plastic film and then bundle them with protective packaging materials such as plastic woven belts and non-woven fabrics. 10.4 Special packaging methods are determined by negotiation between the supplier and the purchaser. 10.5 The marking and quality certificate of steel tubes shall comply with the provisions of GB/T 2102. ......Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al. Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of English version of GB/T 24187-2023 be delivered?Answer: The full copy PDF of English version of GB/T 24187-2023 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice.Question 2: Can I share the purchased PDF of GB/T 24187-2023_English with my colleagues?Answer: Yes. 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