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This document 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 standard replaces GB/T 11640-2011 Seamless aluminium alloy gas cylinders， and the following main technical changes have been made with respect to GB/T 11640-2011:
——In the applicability of scope, the scope of nominal volume is modified, and the upper limit of volume is adjusted to 150L (see Clause 1; Clause 1 of Edition 2011);
——Aluminum alloy material designation 7032 and 7060 for aluminum cylinders are added (see 5.1.1.1);
——The compatibility requirements are modified (see 5.1.1.3; 5.1.3 of Edition 2011);
——The calculation formula of design of wall thickness is modified (see 5.2.2.3; 5.2.1.3 of Edition 2011);
——The control requirements for heat treatment temperature and time are added (see 5.3.5.2);
——The provision that the volume residual deformation rate can be exempted for aluminum cylinders of 12L and below is added (see 6.2.2);
——The relevant regulations on leak-before-break test of high-strength aluminum cylinders with minimum guaranteed yield strength greater than 380MPa are added (see 6.10);
——The requirement for gases suitable for filling in aluminum cylinders is deleted (see Annex C of Edition 2011).
This document is prepared with reference to ISO 7866: 2012 Gas cylinders—Refillable seamless aluminium alloy gas cylinder—Design, construction and testing, and is not equivalent to ISO 7866: 2012.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This document was proposed by and is under the jurisdiction of the National Technical Committee on Gas Cylinder of Standardization Administration of China (SAC/TC 31).
The previous editions of this standard are as follows:
——It was first issued as GB 11640-1989 in 1989;
——It was first revised to GB/T 11640-2001 in 2001, and second revised in 2011;
——This is the third revision.
Seamless aluminum alloy gas cylinders
1 Scope
This document specifies the terms and definitions, symbols, types and parameters, technical requirements, test methods and conformity indicators, inspection rules, marking, coating, packaging, transportation, storage, product certificate and batch inspection quality certificate of seamless aluminum alloy gas cylinders (hereinafter referred to as "aluminum cylinders").
This document is applicable to the design and manufacture of refillable aluminum cylinders with nominal working pressure not greater than 30MPa, nominal volume not greater than 150L, ambient temperature of -40°C to 60°C and used to contain compressed gas or liquefied gas.
This document is not applicable to cylinder pressure vessels attached to transportation tools and machinery and equipment.
2 Normative references
The following documents contain provisions 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 192 General purpose metric screw threads—Basic profile
GB/T 196 General purpose metric screw threads—Basic dimensions
GB/T 197 General purpose metric screw threads—Tolerances
GB/T 228.1 Metallic materials—Tensile testing—Part 1: Method of test at room temperature
GB/T 230.1 Metallic materials—Rockwell hardness test—Part 1: Test method
GB/T 231.1 Metallic materials—Brinell hardness test—Part 1: Test method
GB/T 232 Metallic materials—Bend test
GB/T 3191 Aluminium and aluminium alloys extruded bars, rods
GB/T 3245.1 Inspection method for structure of wrought aluminum and aluminum alloy products—Part 1: Inspection method for microstructure
GB/T 3246.2 Inspection method for structure of wrought aluminum and aluminum alloy products—Part 2: Inspection method for macrostructure
GB/T 3880.1 Wrought aluminium and aluminium alloy plates, sheets and strips for general engineering—Part 1: Technical conditions of delivery
GB/T 3880.2 Wrought aluminium and aluminium alloy plates, sheets and strips for general engineering—Part 2: Mechanical properties
GB/T 3880.3 Wrought aluminium and aluminium alloy plates, sheets and strips for general engineering—Part 3: Tolerances on forms and dimensions
GB/T 3934 Specification of gauges for general purpose screw threads
GB/T 4437.1 Aluminium and aluminium alloy extruded tubes—Part 1: Seamless tubes
GB/T 6519 Ultrasonic inspection of wrought aluminium and magnesium alloy products
GB/T 7144 Coloured cylinder mark for gases
GB/T 7999 Optical emission spectrometric analysis method of aluminum and aluminum alloys
GB/T 8335 Special threads for gas cylinders
GB/T 8336 Special thread gauges for gas cylinders
GB/T 9251 Methods for hydrostatic test of gas cylinders
GB/T 9252 Method for pressure cycling test of gas cylinders
GB/T 12137 Methods for leakage test of gas cylinders
GB/T 13005 Terminology of gas cylinders
GB/T 15385 Method for hydraulic burst test of gas cylinder
GB/T 15970.6-2007 Corrosion of metals and alloys—Stress corrosion testing—Part 6: Preparation and use of pre-cracked specimens for tests under constant load or constant displacement
GB/T 20975 (All parts) Methods for chemical analysis of aluminium and aluminium alloys
YS/T 67 Wrought aluminium and aluminium alloy columniform ingots
ISO 11114-1 Gas cylinders—Compatibility of cylinder and valve materials with gas contents—Part 1: Metallic materials
3 Terms, definitions and symbols
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 13005 and the following apply.
3.1.1
solution treatment
thermal treatment which consists of heating aluminum cylinder shell to a suitable temperature and holding them at that temperature long enough to allow surplus phase fully dissolved in the solid solution, and then rapidly cooling to obtain supersaturated solid solution
3.1.2
batch
quantity of aluminum cylinders heat treated in the same period according to the same design, the same furnace number, the same manufacturing process and the same heat treatment specification
Note: When the control conditions of quality factors are the same, the products heat treated in different furnaces may consist a batch.
3.1.3
yield stress
value corresponding to the 0.2% non-proportional elongation
3.1.4
design stress factor
ratio of equivalent wall stress at test pressure to the guaranteed minimum yield strength
3.1.5
artificial ageing
heat treatment process of aluminum cylinder shell after solution treatment and heat preservation at proper temperature, in which the solute phase is precipitated to give an increased yield stress and tensile stress
3.2 Symbols
For the purposes of this document, the following symbols apply.
A——percentage elongation after fracture, %;
a——fatigue crack length, mm;
a0——original thickness of tensile specimen, mm;
b0——original width of tensile specimen, mm;
C——circumferential tear width of blasting breach, mm;
Df——diameter of the indenter in bend test, mm;
Di——nominal inner diameter of cylindrical shell, mm;
D0——nominal outer diameter of cylindrical shell, mm;
E——modulus of elasticity;
F——design stress factor;
KIAPP——applied elastic stress stress, MPa·m1/2;
L0——length of artificial defect, mm;
l0——original gauge length of tensile specimen, mm;
pb——actual burst pressure, MPa;
ph——hydraulic test pressure, MPa;
pw——nominal working pressure, MPa;
py——measured yield pressure, MPa;
R——radius of indenter cutting edge for flattening test, mm;
Rc——cutting radius of tools, mm;
R e——minimum guaranteed yield stress of shell material after heat treatment, MPa;
Rea——measured yield stress, MPa;
ReSLC——mean yield stress of two specimens representing SLC specimen prepared from test aluminum cylinders at ambient temperature, MPa;
Rg——minimum guaranteed tensile strength of shell material after heat treatment, MPa;
Rm——measured tensile strength, MPa;
r——inner corner radius of the cylinder, mm;
rc——top angle radius of the tool tip, mm;
r1——inner radius of the cylinder, mm;
S——design wall thickness of cylindrical shell, mm;
Sa——actual wall thickness of cylindrical shell, mm;
Sa0——actual mean wall thickness of cylindrical shell, mm; In: mm;
SLC——Crack under constant load;
S0——Original cross-sectional area of the tensile specimens, mm2. In: mm2;
S——Thickness of cylinder bottom center, mm;
T——Indenter spacing for flattening test, mm;
V——Nominal volume, L;
V1——Crack mouth opening displacement (CMOD), in mm, which refers to the component of mode 1 (also called opening mode) of crack displacement caused by elastic and plastic deformation, which is measured at the crack surface with the largest elastic displacement per unit load.
4 Types and parameters
4.1 Types
Generally, the typical structure of aluminum cylinder shell shall comply with the type shown in Figure 1.
Figure 1 Structural types of aluminum cylinder shell
4.2 Parameters and marks
4.2.1 The tolerance of nominal volume of aluminum cylinders shall meet those specified in Table 1.
Table 1 Tolerance of nominal volume of aluminum cylinders
Nominal volume V /L Tolerance/%
V≤2 +20
0
2
Contents of GB/T 11640-2021
Foreword i
1 Scope
2 Normative references
3 Terms, definitions and symbols
4 Types and parameters
5 Technical requirements
6 Test methods and acceptance criteria
7 Inspection rules
8 Marking, coating, packaging, transportation and storage
9 Product certificate, and quality certificate for batch inspection
Annex A (Informative) Corrosion test
Annex B (Normative) Crack test under constant load
Annex C (Normative) Valve assembly torque of aluminum cylinder
Annex D (Informative) Calculation method for shear stress safety factor of thread
Annex E (Informative) Description and judgment on manufacturing defects of aluminum cylinders
Annex F (Normative) Flattening test method
Annex G (Informative) Quality certificate for batch inspection of seamless aluminum alloy gas cylinder
