GB/T 42626-2023 English PDF (GB/T42626-2023)

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GB/T 42626-2023: Periodic inspection and evaluation of fully wrapped fibre reinforced composite gas cylinders of compressed hydrogen gas for automotive vehicles
GB/T 42626-2023
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 23.020.30
CCS J 74
Periodic Inspection and Evaluation of Fully Wrapped Fiber
Reinforced Composite Gas Cylinders of Compressed
Hydrogen Gas for Automotive Vehicles
ISSUED ON: MAY 23, 2023
IMPLEMENTED ON: DECEMBER 1, 2023
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword ... 4
1 Scope ... 5
2 Normative References ... 5
3 Terms and Definitions ... 6
4 Technical Requirements ... 8
4.1 Types and Descriptions of Gas Cylinder ... 8
4.2 Inspection Tools and Devices ... 8
4.3 Inspection Cycle ... 9
4.4 Inspection Items ... 9
5 Inspection Preparation ... 10
5.1 Pre-inspection of Hydrogen Storage System ... 10
5.2 Information Query and Recording ... 11
5.3 Depressurization and Nitrogen Replacement of Gas Cylinders ... 12
5.4 Disassembly and Surface Cleaning of Gas Cylinders and Cylinder Valves ... 12
6 Appearance Inspection and Evaluation ... 13
6.1 Types of Damage ... 13
6.2 Damage Level ... 13
6.3 Inspection and Evaluation of Appearance Damages ... 16
7 Treatment of Outer Surface Damage ... 18
8 Internal Inspection and Evaluation ... 19
8.1 Types of Damage ... 19
8.2 Damage Level ... 19
8.3 Internal Damage Inspection and Evaluation ... 19
9 Cylinder Neck Thread Inspection and Evaluation ... 19
10 Hydrostatic Test ... 20
11 Internal Drying ... 21
11.1 Method and Requirements for Drying ... 21
11.2 Inspection of Drying Condition ... 21
12 Inspection and Assembly of Cylinder Valve ... 21
13 Air-tightness Test ... 22
14 Post-inspection Work ... 23
Appendix A (informative) Depressurization of Gas Cylinders ... 25
Appendix B (informative) Illustrations of Typical Damages to Gas Cylinders ... 26
Appendix C (informative) Illustrations of Surface Damage Treatment Method of Gas
Cylinders ... 35
Appendix D (normative) Reset Installation Inspection of Gas Cylinders ... 39
Appendix E (informative) Periodic Inspection Report of Gas Cylinders ... 41
Bibliography ... 47
Periodic Inspection and Evaluation of Fully Wrapped Fiber
Reinforced Composite Gas Cylinders of Compressed
Hydrogen Gas for Automotive Vehicles
1 Scope
This document specifies the basic method and technical requirements for the periodic
inspection and evaluation of fully wrapped fiber reinforced composite gas cylinders of
compressed hydrogen gas for automotive vehicles (hereinafter referred to as “gas cylinders”).
This document is applicable to gas cylinders designed and manufactured in accordance with
GB/T 35544 and GB/T 42612, whose nominal working pressure does not exceed 70 MPa,
nominal water capacity is not greater than 450 L, and the storage medium is compressed
hydrogen gas, and operating temperature is not lower than 40 C and not higher than 85 C.
This document is not applicable to gas cylinders installed on passenger vehicles with a length
of not more than 8 m and a seating capacity of not more than 19, and cannot be disassembled
for periodic inspection.
The periodic inspection and evaluation of gas cylinders for hydrogen supply, such as: hydrogen
fuel cell urban rail transits, hydrogen energy ships sand hydrogen energy power generation
devices, etc. may take this document as a reference.
2 Normative References
The contents of the following documents constitute indispensable clauses of this document
through the normative references in the text. In terms of references with a specified date, only
versions with a specified date are applicable to this document. In terms of references without a
specified date, the latest version (including all the modifications) is applicable to this document.
GB/T 3464.1 Machine and Hand Taps - Part 1: Plain Parallel Shank Machine and Hand Taps
GB/T 3836.1 Explosive Atmospheres - Part 1: Equipment - General Requirements
GB/T 3934 Specification of Gauges for General Purpose Screw Threads
GB/T 8979 Pure Nitrogen and High Purity Nitrogen and Ultra Pure Nitrogen
GB/T 9251 Methods for Hydrostatic Test of Gas Cylinders
GB/T 13005 Terminology of Gas Cylinders
Resin refers to a material used to bond fibers and transmit loads.
NOTE: it is usually thermoset.
3.8 stress corrosion cracking
Stress corrosion cracking refers to cracks or fractures of composite materials caused by a
combined action of load and harsh environments.
3.9 thermally-activated pressure relief device (TPRD) end plug
Thermally-activated pressure relief device (TPRD) end plug refers to an end plug installed at
one end of the double-port structure gas cylinder, and equipped with a thermally-activated
pressure relief device (TPRD) and the function of blind plugging.
3.10 rejection elastic expansion; REE
Rejection elastic expansion refers to the allowable upper limit of elastic expansion of gas
cylinder specified by the manufacturing organization in the design and finalization stage of each
specification and model of gas cylinder, and it is expressed in milliliters.
3.11 bulge
Bulge refers to visible partial bulging of the gas cylinder.
3.12 buckling
Buckling refers to the failure caused by the plastic liner losing its original regular geometric
shape under the action of compressive stress.
3.13 blister
Blister refers to a local defect in the plastic liner that that looks like a bubble.
3.14 hydrogen storage system
Hydrogen storage system refers to a collection of components related to on-board hydrogen
storage and transmission.
NOTE: it usually consists of gas cylinders (including cylinder valves), valves and connecting
pipelines, etc. For a single gas cylinder, it refers to gas cylinder and cylinder valve; for a
cylinder group consisting of two or more gas cylinders, it refers to gas cylinders (including
cylinder valves), and connecting pipelines and valves within the frame, etc.
4 Technical Requirements
4.1 Types and Descriptions of Gas Cylinder
4.1.1 Type 3 gas cylinder
Fully-wrapped carbon fiber reinforced cylinder with an aluminum alloy liner.
4.1.2 Type 4 gas cylinder
Fully-wrapped carbon fiber reinforced cylinder with a plastic liner.
4.2 Inspection Tools and Devices
The inspection institution shall be equipped with at least the following tools and devices:
a) Explosion-proof lamp: used to inspect the inner and outer surfaces of gas cylinders
and the surface of accessories. The voltage shall not exceed 12 V, and shall satisfy the
requirements of explosion-proof level II class C and group T1 in GB/T 3836.1;
b) Inspectoscope and endoscope: used to inspect the surface of gas cylinder and the inner
surface of gas cylinder (including the inner surface of the neck) that are partially
obscured due to installation. The endoscope shall be in high-definition color and have
the function of storage;
c) Special tools, for example, torque wrench: used for the disassembly and installation
of gas cylinders, cylinder valves or TPRD end plugs;
d) Depth gauge: used to measure the depth of damages, such as: scratches, dents and
abrasions, etc.;
e) Length measurement tools: including rulers, squares and tape measures, which are
used to measure the length of damages, etc.;
f) Hydrostatic test device: used for hydrostatic test of gas cylinders;
g) Air-tightness test device: used for air-tightness test of gas cylinders;
h) Air-tightness helium leak detection device: used for helium leak detection of gas
cylinders;
i) Hydrogen venting / recovery device: used for the discharge or recovery of hydrogen
gas;
j) Cleaning device: used for the cleaning of contaminants and corrosion products on the
inner and outer surfaces of gas cylinders;
k) Portable pumping-type hydrogen leak detection device: used to detect hydrogen
4.4.3 If the results of the pre-inspection satisfy the relevant stipulations of 5.1, the inspection
institution may complete the inspection without disassembling the gas cylinder. The inspection
items without disassembling the gas cylinder are only visual inspection.
4.4.4 If the results of the pre-inspection do not satisfy the relevant stipulations of 5.1, or the
cylinder valve needs to be replaced, then, the gas cylinder shall be disassembled, then, be
inspected for all the items.
4.4.5 For gas cylinders with a nominal working pressure of 35 MPa in GB/T 35544 and Class
A2 gas cylinders in GB/T 42612, during the 2nd, 4th and the subsequent inspections, the gas
cylinders shall be inspected for all the items; the 3rd inspection may adopt the same judgment
mode as the first inspection to determine whether to conduct disassembly inspection. For gas
cylinders with a nominal working pressure of 70 MPa in GB/T 35544 and Class B2 gas
cylinders in GB/T 42612, during the 2nd and the subsequent inspections, the gas cylinders shall
be inspected for all the items.
5 Inspection Preparation
5.1 Pre-inspection of Hydrogen Storage System
5.1.1 Overview
The pre-inspection of the hydrogen storage system includes appearance patrol inspection and
hydrogen leak detection.
5.1.2 Appearance patrol inspection
Before the appearance patrol inspection, it shall be confirmed that the on-board hydrogen
system has been powered off. In the appearance patrol inspection, the gas cylinders, cylinder
valves, connecting pipelines, fixing brackets or fastening belts shall be inspected. If the
following conditions are satisfied, the inspection result is qualified:
a) The fixing bracket or fastening belt of the gas cylinder is intact, and not loosening or
deformed;
b) The cylinder valves and hydrogen pipelines of the cylinder group or a single cylinder
are not loosening or damaged, and there are no obvious signs of gas leakage;
c) There is no abnormality on the surface of the gas cylinder and cylinder valve.
5.1.3 Hydrogen leak detection
5.1.3.1 After the appearance patrol inspection, hydrogen leak detection shall be carried out one
by one on the gas cylinders, cylinder valves / TPRD end plugs, connecting pipeline joints on
the hydrogen storage system and other parts where leaks may occur.
5.1.3.2 The detection pressure of hydrogen leakage shall not be lower than 20% of the nominal
working pressure.
5.1.3.3 A portable pumping-type hydrogen leak detection device shall be used for detection.
The resolution of the instrument shall not be lower than 1 mL/m3, and the minimum detection
concentration shall not be greater than 100 mL/m3.
5.1.3.4 Thoroughly rotate the end of the detection head of the instrument in the site to be
detected to find the maximum leakage point, and read the hydrogen concentration value at that
location. When there may be condensation water dripping from the detection area, it is advisable
to install a detection head shield with a lateral opening on the detection head of the instrument.
5.1.3.5 If leakage is found through detection, the actual measured hydrogen concentration shall
not be greater than 300 mL/m3.
5.1.3.6 The hydrogen leak detection device shall be regularly verified or calibrated, and the
verification or calibration cycle shall comply with the relevant stipulations.
5.2 Information Query and Recording
5.2.1 Before the inspection of the gas cylinder, the following information shall be consulted:
a) Relevant information provided by the gas cylinder manufacturing organization,
including gas cylinder supervision and inspection certificate, instructions for use and
certificate of conformity, etc.;
b) Relevant information provided by the vehicle manufacturing organization (when the
on-board hydrogen system is installed by the vehicle manufacturing organization) or
on-board hydrogen system integration organization (when the on-board hydrogen
system is installed by an organization other than the vehicle manufacturing
organization);
c) Registration certificate for gas cylinders for automotive vehicles;
d) Previous inspection reports;
e) Filling records of gas cylinders after the last inspection, daily maintenance records,
emergency measures and handling records of accidents or abnormal situations, etc.
5.2.2 Check and record the manufacturing mark and inspection mark of gas cylinders. The
recorded content shall at least include license number or organization code of the manufacturing
organization, gas cylinder manufacturing standard, gas cylinder serial No., manufacturing year
and month, nominal working pressure, hydrostatic test pressure, nominal water capacity, design
service life, design cycle times, REE, manufacturing organization and model of cylinder valve
and TPRD end plug (if present, the same below), the date of the last inspection and the name
or code of the inspection institution, etc. For imported gas cylinders, the nationality shall be
recorded.
5.2.3 Gas cylinders manufactured by manufacturing organizations that have not obtained
When it is confirmed that the known chemicals, by which, the gas cylinder is contaminated,
will not cause damage to the gas cylinder, it shall be determined as level 1 damage; spots,
blistering, softening, resin falling-off, fiber breakage or looseness caused by chemical erosion
of the gas cylinder shall be determined as level 3 damage; when the type of chemical cannot be
determined, or the impact on the gas cylinder material cannot be confirmed, it shall also be
determined as level 3 damage.
6.3.5 Ageing
When a gas cylinder is exposed to sunlight and atmospheric environment for a long time, the
glass fiber protective layer on the outer surface of the gas cylinder will be damaged and aged,
which may cause discoloration or degradation of the outer surface material. If only the surface
layer of resin is pulverized, and no fiber in the wrapping layer is broken or loosened, it shall be
determined as level 1 or level 2 damage; otherwise, it shall be determined as level 3 damage.
6.3.6 Impact damage
Impact damage is caused by a strong impact on the surface of the gas cylinder. Impact damage
may cause permanent deformation and dents on the surface of the gas cylinder, and may also
cause delamination of the wrapping l...