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GB 28053-2011 (GB/T 28053-2011)
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 23.020.30
J 74
GB 28053-2011
Composite cylinders for breathing apparatus
This standard was changed to Recommended Standard according to the
Notice [2017] No.7 by the Standardization Administration of PRC
ISSUED ON: DECEMBER 30, 2011
IMPLEMENTED ON: DECEMBER 01, 2012
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative references ... 4
3 Terms and definitions, symbols ... 5
4 Types and parameters ... 7
5 Technical requirements ... 8
6 Test methods and qualification criteria ... 12
7 Inspection rules ... 19
8 Marking, packaging, transport, storage ... 21
9 Product certificate and batch inspection quality certificate ... 22
Appendix A (Normative) Valve assembly torque of gas cylinder ... 24
Appendix B (Informative) Calculation method of thread’s shear stress safety
factor ... 25
Appendix C (Informative) Quality certificate for batch inspection of composite
gas cylinders for breathing apparatus ... 29
Composite cylinders for breathing apparatus
1 Scope
This standard specifies the types and parameters, technical requirements, test
methods and qualification standards, inspection rules and markings, packaging,
transportation and storage requirements of fully wrapped carbon-fiber
reinforced aluminum liner composite cylinders for breathing apparatus
(hereinafter referred to as gas cylinders).
This standard applies to the design and manufacture of gas cylinders which
have a nominal working pressure not greater than 30 MPa, a nominal volume
of not greater than 12 L, an ambient temperature of use of -40 °C ~ 60 °C, is
refillable of breathing gas.
2 Normative references
The following documents are essential to the application of this document. For
the dated documents, only the versions with the dates indicated are applicable
to this document; for the undated documents, only the latest version (including
all the amendments) are applicable to this standard.
GB 191 Packaging - Pictorial marking for handling of goods
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
(scales A, B, C, D, E, F, G, H, K, N, T)
GB/T 231.1 Metallic materials - Brinell hardness test - Part 1: Test method
GB/T 1458 Test method for mechanical properties of ring of filament -
Winding reinforced plastics
GB/T 3191 Extrusion rods and bars of aluminum and aluminum alloys
GB/T 3246.1 Inspection method for structure of wrought aluminum and
aluminum alloy products - Part 2: 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 3362 Test methods for tensile properties of carbon-fiber multifilament
GB/T 3880.1 ~ 3880.3 Wrought aluminum and aluminum alloy plates, sheets
and strips for general engineering
GB/T 3934 Specification of gauges for general purpose screw threads
GB/T 4437.1 Aluminum and aluminum alloy extruded tubes - Part 1:
Seamless tubes
GB/T 4612 Plastics - Epoxy compounds - Determination of epoxy equivalent
GB/T 6519 Process for ultrasonic inspection of wrought aluminum alloy
products
GB/T 7690.3 Reinforcements - Test method for yarns - Part 3: Determination
of breaking force and breaking elongation for glass fiber
GB/T 9251 Methods for hydrostatic test of gas cylinders
GB/T 9252 Method for pressure cycling test of gas cylinders
GB/T 12137 Method 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 20975 (all parts) Methods for chemical analysis of aluminum and
aluminum alloys
YS/T 67 Wrought aluminum and aluminum alloy columniform ingots
TSG R7002 Rules for type test of gas cylinder
3 Terms and definitions, symbols
3.1 Terms and definitions
The terms and definitions as established in GB/T 13005 as well as the following
terms and definitions apply to this document.
The testing method shall comply with the provisions of GB/T 20975.
5.1.1.2 The material of the liner shall meet the requirements of the
corresponding standards. The ingot shall be in accordance with YS/T 67; the
extruded bar shall be in accordance with GB/T 3191; the plate shall be in
accordance with GB/T 3880.1 ~ 3880.3; the tube shall be in accordance with
GB/T 4437.1. The grain size of the ingot shall not be lower than the grade 2.
The test method of grain size conforms to the provisions of GB/T 3246.2.
5.1.1.3 The liner material shall have the product quality certificate of the material
manufacturer. It can be used only after passing the re-inspection by the gas
cylinder manufacturer.
5.1.1.4 The chemical composition re-inspection shall be conducted according
to the material’s furnace number. The content of Pb and Bi may be confirmed
according to the data of the product quality certificate.
5.1.1.5 The ingot shall be ultrasonically tested. The ultrasonic testing shall be
carried out according to the ϕ2mm equivalent flat-bottomed hole. The testing
method shall meet the requirements of GB/T 6519.
5.1.2 Liner design
5.1.2.1 Shoulder and bottom shall adopt convex structure.
5.1.2.2 The thickness of the shoulder and bottom shall meet the requirements
of the hydraulic burst test and fatigue test of the gas cylinder.
5.1.2.3 In order to obtain a reasonable stress distribution, the shoulders and
bottom shall use the gradually-changed thickness design; the cylinder and
shoulders, cylinder and bottom shall be smoothly transitioned.
5.1.2.4 The designed wall thickness of the liner shall be verified by stress
analysis.
5.1.2.5 The thickness of the bottleneck shall ensure that it will not deform when
subjected to the additional external force of valve installation. The valve
installation torque shall comply with the provisions of Appendix A.
5.1.2.6 The thread of the bottle opening shall be straight thread and penetrate
through the opening. The thread length shall be not less than 6 pitches; the
safety factor of shear stress under hydraulic test pressure shall be at least 10.
The calculation method of the safety factor of the thread’s shear stress is as
shown in Appendix B.
5.1.3 Manufacturing of liner
5.1.3.1 It shall meet the requirements of design drawings and relevant technical
The strength of the material shall meet the minimum value of the performance
requirements of the gas cylinder manufacturer.
The testing method shall comply with the provisions of GB/T 7690.3.
5.2.1.3 Resin matrix
It shall use epoxy resin or modified epoxy resin. The material shall meet the
requirements of the corresponding standards and have a quality certificate. The
material shall be suitable for the fiber wrapping process and meet the
performance requirements of the gas cylinder manufacturer. The determination
method of epoxy equivalent shall comply with the provisions of GB/T 4612.
5.2.2 Design of gas cylinder
5.2.2.1 The hydraulic test pressure shall be 5/3 times the nominal working
pressure.
5.2.2.2 The minimum burst pressure shall be 3.4 times the nominal working
pressure.
5.2.2.3 The design service life of the gas cylinder is 15 years.
5.2.2.4 Stress analysis shall use finite element technology and establish an
appropriate model, to calculate the maximum stress in the liner and the
wrapping layer and the stress distribution at each point under zero pressure,
working pressure, test pressure and minimum burst pressure after auto-frettage.
It shall consider the material nonlinearity of the liner, the material anisotropy of
the wrapping layer, the geometric nonlinearity of the structure.
5.2.2.5 Stress distribution requirements
a) The compressive stress of the liner barrel part at zero pressure shall be
between 60% and 95% of the measured yield strength of the liner;
b) The maximum tensile stress of the liner under working pressure shall not
exceed 60% of the measured yield strength of the liner;
c) Under the designed burst pressure, the load carried by the glass fiber shall
not exceed 15% of the total pressure load;
d) The maximum stress of carbon-fiber under working pressure shall not
exceed 30% of the carbon-fiber stress under design burst pressure;
e) The maximum stress shall be located in the barrel part.
5.2.3 Manufacturing of gas cylinder
barrel’s roundness measured on the same cross-section shall not exceed
2% of the average diameter of the cross-section;
d) The straightness of the barrel shall not exceed 0.3% of the length of the
barrel.
6.1.2 Inner and outer surfaces
Visual inspection, the inner surface may be inspected by endoscope.
Qualification criteria:
a) There shall be no sharp surface indentations, obvious protrusions,
overlaps, cracks and inclusions visible on the inner and outer surfaces;
the transition between the neck and shoulders shall not have sharp
changes or obvious wrinkles. It may use machining or polishing method
to remove the surface defects. After the defects are removed, the
corresponding locations shall be smooth and the wall thickness shall not
be less than the design wall thickness.
b) The barrel and shoulders, barrel and bottom shall be smoothly transitioned.
6.1.3 Bottle thread
Thread gauges in accordance with GB/T 3934 shall be used for testing.
Qualification criteria:
a) The thread of the bottle mouth shall meet the design requirements; the
thread shape, dimensions and manufacturing tolerances shall comply with
the relevant requirements of GB/T 192, GB/T 196, GB/T 197.
b) The thread pitch, tooth profile angle, tooth crest, tooth bottom, surface
roughness shall meet the requirements of the standard.
c) The effective number of pitches of the thread shall comply with the
standards.
6.1.4 Hardness test
The test method shall comply with the provisions of GB/T 230.1 or GB/T 231.1.
Qualification criteria: The hardness value shall not exceed the range specified
by the gas cylinder manufacturer.
6.1.5 Tensile test
Cut symmetrically two specimens in the axial direction of the liner barrel. The
gauge length of the specimen is not less than 24 times the design wall thickness
Qualification criteria: Under the pressure of the hydrostatic test, the pressure
shall be maintained for 1 min. There shall be no leakage or obvious deformation
of the cylinder, meanwhile the elastic expansion under the hydraulic test
pressure shall not exceed the rejection elastic expansion (REE) of the gas
cylinder.
6.2.4 Air tightness test
It shall perform the air tightness test after the hydrostatic test. The test pressure
shall be the nominal working pressure; the test method shall comply with the
provisions of GB/T 12137.
Qualification criteria: Under the test pressure, hold the pressure for 1 min; there
shall be no leakage.
The air tightness test is limited only to the gas cylinders that exit-factory with a
cylinder valve.
6.2.5 Hydraulic pressure burst test
Increase pressure at a constant speed to the minimum burst pressure. Hold the
pressure for at least 5 s. Then increase pressure until burst. The pressure
increase rate does not exceed 1.37 MPa per second. The test method shall
comply with the provisions of GB/T 15385.
Qualification criteria: The measured burst pressure is not lower than the
minimum burst pressure. The initial position of burst shall be in the cylinder’s
barrel.
6.2.6 Fatigue test
Under normal temperature conditions, follow the requirements of GB/T 9252 to
perform fatigue test. The pressure cycle frequency shall not exceed 10 times
per minute. The pressure shall be held for not less than 1.2 s during the period
of 90% ~ 100% of the maximum pressure.
The test steps are as follows:
a) The gas cylinder shall be subjected to a pressure cycle of at least 10000
times from less than 10% of the nominal working pressure to the nominal
working pressure;
b) Then, perform a pressure cycle for at least 30 times from near zero
pressure to hydrostatic test pressure;
c) After completing the above test, perform the hydraulic pressure blast test
according to 6.2.5.
cycle test for at least 20 times; it is held at each temperature for at least
10 min;
c) After completing the above test, perform the hydraulic burst test according
to 6.2.5.
Qualification criteria: During the pressure cycle test, the gas cylinder shall not
show any visible damage, deformation, or leakage. The remaining burst
pressure shall not be less than 90% of the minimum burst pressure.
6.2.9 Drop test
Drop the unfilled gas cylinder with valve freely from a height of 3 m to the
concrete floor according to the following requirements.
The test steps are as follows:
a) The gas cylinder falls vertically and the bottom of the cylinder touches the
ground;
b) The gas cylinder falls horizontally and the side wall of the cylinder touches
the ground;
c) The gas cylinder falls horizontally onto the edge of a 38 mm × 4.8 mm
angle steel; the two sides of the angle steel are placed at an angle of 45°
to the ground; the impact point is near the middle of the side wall of the
gas cylinder;
d) After the drop test, the gas cylinder shall be pressure cycled at least 1000
times from less than 10% of the nominal working pressure to the nominal
working pressure, the cycle frequency shall not exceed 10 times per
minute; the pressure shall be held for not less than 1.2 s during 90% ~
100% of the maximum cycle pressure. The pressure cycle’s test method
shall meet the requirements of GB/T 9252;
e) After completing the above test, perform the hydraulic pressure burst test
according to 6.2.5.
Qualification criteria: There shall be no visible leaks in the gas cylinder during
the pressure cycle test. The remaining burst pressure shall not be less than 90%
of the minimum burst pressure.
6.2.10 Shooting test
The test steps are as follows:
a) Fill the gas cylinder with air or nitrogen to the nominal working pressure;
7 Inspection rules
7.1 Exit-factory inspection
7.1.1 Inspection one-by-one
The gas cylinders shall be inspected one by one according to the items
specified in Table 3.
7.1.2 Inspection by batch
7.1.2.1 Gas cylinders shall be subject to batch inspection according to the items
specified in Table 3.
7.1.2.2 Sampling
7.1.2.2.1 Liner
Randomly take one from each batch of liners for tensile test and metallographic
test.
If an item fails during batch inspection, it shall be handled according to the
following requirements:
a) If the failure is due to abnormal test operation or measurement error, it
shall carry out the test of the same quantity of specimens. If the retest
result is qualified, the first test is invalid;
b) If it is confirmed that the disqualification is caused by heat treatment, the
batch of liners can be re-heat-treated, but the number of heat treatments
shall not be more than two (excluding the number of simple artificial aging
treatments). This batch of liners after heat treatment again shall be used
as a new batch for batch inspection;
c) If it is confirmed that the disqualification is caused by other reasons, the
entire batch of liners will be rejected.
7.1.2.2.2 Gas cylinder
a) Randomly take 1 gas cylinder from each batch to perform the fatigue test;
b) Randomly take 1 gas cylinder from each batch to perform the hydraulic
burst test. The gas cylinder used for fatigue test can be used for burst test.
If a certain item fails during batch inspection, it may randomly take another 5
gas cylinders for the test. If all 5 gas cylinders pass the test, then this batch of
gas cylinders is qualified. If one of them fails the test, the entire batch of gas
h) Year and month of cylinder manufacturing;
i) Design service life of gas cylinder;
j) Supervision and inspection marking;
k) Manufacturing unit’s license number;
l) Product standards;
m) The rejection elastic expansion (REE) of the hydraulic test.
8.2 Packaging
8.2.1 When the gas cylinder is exit-factory without a valve, the opening of the
cylinder shall be sealed by reliable measures to prevent contamination.
8.2.2 The gas cylinder shall be properly packed to prevent damage during
transportation.
8.2.3 The packaging and transportation marks shall comply with the relevant
requirements of GB 191.
8.3 Transport
8.3.1 The transport of gas cylinders shall comply with the relevant requirements
of the transportation department.
8.3.2 During the transportation and loading/unloading process, it shall prevent
the accessories from being collided, wet, or damaged, especially to prevent
scratches on the wrapping layer.
8.4 Storage
Gas cylinders shall not be stored in environments exposed to sunlight and high
temperatures, humidity, corrosive media.
9 Product certificate and batch inspection quality
certificate
9.1 Product certificate
9.1.1 Each certified gas cylinder shall be accompanied by a product certificate
and instruction manual.
9.1.2 The product certificate shall include the following:
......
(Above excerpt was released on 2020-04-25, modified on 2021-06-07, translated/reviewed by: Wayne Zheng et al.)
Source: https://www.chinesestandard.net/PDF.aspx/GB28053-2011