Foreword
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB/T 24187-2009 Cold-drawn precision single welded steel tubes. In addition to structural adjustments and editorial changes, the following main technical changes have been made with respect to GB/T 24187-2009:
a) the types of surface states of steel tubes have been added (see 4.3);
b) the dimensional precision has been deleted from the order contents (see Clause 4 of Edition 2009);
c) the allowable deviation of outer diameter has been changed, and the requirement of delivery according to ordinary precision for allowable deviation of outer diameter has been added (see 6.1.2 hereof; 5.1.2 of Edition 2009);
d) the allowable deviation for wall thickness has been modified (see 6.1.3 hereof; 5.1.3 of Edition 2009);
e) the requirements for mechanical property of steel tapes have been deleted (see 6.1.2 of Edition 2009);
f) the requirements for manufacturing method of steel tubes have been modified (see 7.2 hereof; 6.2 of Edition 2009);
g) the requirements for mechanical property of steel tubes have been modified (see 7.3 hereof; 6.3 of Edition 2009);
h) the requirements for drift expanding test have been modified (see 7.4.2 hereof; 6.4.2 of Edition 2009);
i) the requirements for air tightness test have been modified (see 7.6 hereof; 6.6 of Edition 2009);
j) the seal pressure for nitrogen filling has been modified (see 7.7 hereof; 6.7 of Edition 2009);
k) the requirements for surface quality have been modified, and the requirements for surface quality of HPPP and HPPA steel tubes have been added (see 7.8 hereof, 6.8 of Edition 2009);
l) the sampling method and test method for the inspection items have been modified (see 8.6 hereof; 7.6 of Edition 2009);
Cold-drawn precision single welded steel tubes
1 Scope
This document specifies the classification and designation, dimensions, appearance, weight and allowable deviation, technical requirements, test methods, inspection rules, packaging, marking and quality certification for cold-drawn precision single welded steel tubes.
This document is applicable to the cold-drawn precision single welded steel tubes (hereinafter referred to as "steel tubes") for manufacture of condensers, evaporators, fuel tubes, lubricating oil tubes, electric heating tubes, cooler tubes and general tubes in refrigeration, automobile, electric heating appliances and other industries.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions 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 furnace
GB/T 223.86 Steel and iron - Determination of total carbon content - Infrared absorption method after combustion in an induction furnace
GB/T 228.1-2021 Metallic materials - Tensile testing - Part 1: Method of test at room temperature
GB/T 241 Metal materials - Tube - Hydrostatic pressure test
GB/T 242 Metal materials - Tube - Drift-expanding test
GB/T 244 Metallic materials - Tube - Bend test method
GB/T 246 Metallic materials - Tube - Flattening test
GB/T 2102 Acceptance, packaging, marking and quality certification for steel tubular products
GB/T 2423.22 Environmental testing - Part 2: Tests methods - Test N: Change of temperature
GB/T 2975 Steel and steel products - Location and preparation of samples and test pieces for mechanical testing
GB/T 4336 Carbon and low-alloy steel - Determination of multi-element contents - Spark discharge atomic emission spectrometric method (routine method)
GB/T 7141 Plastics - Methods of heat aging
GB/T 10125 Corrosion tests in artificial atmospheres - Salt spray tests
GB/T 11547 Plastic - Methods of test for the determination of the effects of immersion in liquid chemicals
GB/T 11605 Methods of humidity measurement
GB/T 16422.3 Plastics - Methods of exposure to laboratory light sources - Part 3: Fluorescent UV lamps
GB/T 20066 Steel and iron - Sampling and preparation of samples for the determination of chemical composition
GB/T 20123 Steel and iron - Determination of total carbon and sulfur content - Infrared absorption method after combustion in an induction furnace (routine method)
GB/T 20126 Unalloyed steel - Determination of low carbon content - Part 2: Infrared absorption method after combustion in an induction furnace (with preheating)
GB/T 30062 Terminology of steel pipes and tubes
HJ 637 Water quality - Determination of petroleum oils and animal and vegetable oils - Infrared spectrophotometry
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 30062 apply.
4 Classification and code
4.1 Dimensional precision
Tubes classified by dimensional precision and the corresponding codes are as follows:
a) tubes with ordinary precision, with a code of PA;
b) tubes with high precision, with a code of PC.
4.2 Mechanical properties
Tubes classified by mechanical properties and the corresponding codes are as follows:
a) ordinary steel tubes, with a code of MA;
b) soft steel tubes, with a code of MB.
4.3 Surface state
See Table 1 for the classification and code of steel tubes classified by surface state.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Classification and code
5 Order contents
6 Dimension, appearance, weight and allowable deviation
7 Technical requirements
8 Test methods
9 Inspection rules
10 Packaging, marking and quality certification
Annex A (Normative) Drift expanding test of automobile steel tubes
Annex B (Normative) Requirements and test method for inner surfaces of high-cleanliness steel tubes for refrigeration
Annex C (Normative) Requirements and test method for outer plating and coating of steel tubes
Annex D (Normative) Residue inspection method
