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.
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).
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 methods and technical requirements for periodic inspection and evaluation of fully wrapped fiber reinforced composite gas cylinders of compressed hydrogen gas for automotive vehicles (hereinafter referred to as "cylinders").
This document is applicable to cylinders designed and manufactured according to GB/T 35544 and GB/T 42612, which have a nominal working pressure of not greater than 70MPa, a nominal water capacity of not greater than 450L, a storage medium of compressed hydrogen, and a working temperature of not lower than -40℃ and not higher than 85℃.
This document is not applicable to cylinders installed on passenger vehicles with a length of not greater than 8m and a number of seats of not greater than 19, which cannot be disassembled for periodic inspection.
This document may serve as a reference for the periodic inspection and evaluation of hydrogen supply cylinders for hydrogen fuel cell powered urban rail transit, hydrogen-powered vessels and hydrogen power generating units.
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 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
GB/T 35544 Fully-wrapped carbon fiber reinforced cylinders with an aluminum liner for the on-board storage of compressed hydrogen as a fuel for land vehicles
GB/T 42612 Fully-wrapped carbon fiber reinforced cylinder with a plastic liner for on-board storage of compressed hydrogen for land vehicles
TSG 23 Regulation on safety technology for gas cylinder
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 13005 as well as the following apply.
3.1
abrasion
cylinder damage caused by friction of materials caused by scraping, grinding or vibration
3.2
crazing
opaque, frosty and striated cracking of resin
3.3
delamination
damage caused by separation between wrapping layers
Note: Generally, delamination is caused by excessive load vertically impacting the wrapping layer surface.
3.4
level 1 damage
minor damage during use
Note: The minor damage on the cylinder surface without fiber damage may be judged as level 1 damage. Such damage has no harmful effect on the safety of the cylinder, so the cylinder may be used continuously.
3.5
level 2 damage
damage more serious than level 1 damage, which does not affect the safe use of the cylinder after treatment
3.6
level 3 damage
damage affecting the safe use of cylinders
3.7
resin
material used to bond fibers and transfer loads
Note: Generally, thermosetting resin is adopted.
3.8
stress corrosion cracking
cracking or fracture of composite materials caused by the combined action of load and harsh environment
3.9
thermally-activated pressure relief device (TPRD) end plug
end plug installed at one end of a cylinder having a structure with openings on both ends, which is equipped with a thermally-activated pressure relief device (TPRD) and blind flange function
3.10
rejection elastic expansion; REE
the allowable upper limit for the elastic expansion of cylinder specified by the manufacturer in the design finalization stage of each specification/model of cylinder, expressed in milliliters (mL)
3.11
bulge
visible partial bulge of a cylinder
3.12
buckling
failure caused by losing of original regular geometry of plastic liner under the action of compressive stress
3.13
blister
local defect in a plastic liner that looks like a bubble
3.14
hydrogen storage system
assembly of components related to on-board hydrogen storage and transportation
Note: It is usually composed of cylinder (including cylinder valve), valve and connecting pipelines. For a single cylinder, it refers to the cylinder and cylinder valve; for a cylinder set consisting of two or more cylinders, it refers to cylinders (including cylinder valves), connecting pipelines and valves within the frame, etc.
4 Technical requirements
4.1 Types and description of cylinders
4.1.1 Type 3 cylinder
Fully wrapped carbon fiber reinforced gas cylinder with an aluminum alloy liner.
4.1.2 Type 4 cylinder
Fully wrapped carbon fiber reinforced gas cylinder with a plastic liner.
4.2 Inspection tools and devices
The inspection organization shall be equipped with the following tools and devices at least:
a) explosion-proof lamp: lamp used to inspect the inner and outer surfaces of the cylinder and the surfaces of accessories, which shall have a voltage of not exceeding 12V, and meet the requirements of explosion-proof grade IIC and Group T1 in GB/T 3836.1;
b) inspection mirror and endoscope: used to inspect the cylinder surfaces and cylinder inner surfaces (including neck inner surface) partially covered due to installation. The endoscope shall have high-definition color and storage function;
c) special tools such as torque wrench: used to remove and install cylinder, cylinder valve or TPRD end plug;
d) depth gauge: used to measure the depth of damage such as scratch, depression and abrasion;
e) length measuring tools: including ruler, square ruler and tape measure for measuring damage length, etc.;
f) hydrostatic test device: used for hydrostatic test of cylinders;
g) air tightness test device: used for air tightness test of cylinders;
h) airtight helium leakage detector: used for helium leakage detection of cylinders;
i) hydrogen venting/recovery device: used for hydrogen venting or recovery;
j) cleaning device: used for cleaning contaminants and corrosion products on the inner and outer surfaces of cylinders;
k) portable pump-type hydrogen leakage detector: used for detecting hydrogen concentration;
l) thread gauge and tap: used for inspection and repair of cylinder opening thread;
m) hydrogen analyzer: used for analyzing the volume concentration of hydrogen;
n) particulate impurity detection instrument: used for detecting particulate impurities.
4.3 Inspection period
4.3.1 The inspection period of periodic inspection of cylinder shall meet the requirements of TSG 23.
4.3.2 In the process of use, in case of the following conditions, inspection shall be carried out in advance:
a) vehicle fire;
b) vehicle collision;
c) cylinder falling or impact during installation;
d) exposure of the cylinder to an overheated environment for other reasons;
e) damage to the cylinder;
f) abnormal decrease of hydrogen pressure in the cylinder;
g) abnormal sharp noise during use;
h) abnormal taste in use as reflected by the user;
i) if the inspection personnel deem it necessary to carry out the inspection in advance.
4.3.3 Cylinders that are in stock or have been out of service for greater than one inspection period shall be inspected before being put into use.
4.4 Inspection items
4.4.1 Periodic inspection items of cylinders include appearance inspection, internal inspection, cylinder opening thread inspection, hydrostatic test, cylinder valve inspection and assembly, and air tightness test.
4.4.2 The inspection organization shall carry out pre-inspection for the hydrogen storage system before cylinder inspection, so as to make a preliminary judgment on the safety status of the hydrogen storage system. For the cylinders inspected for the first time, the inspection organization may determine whether disassembly inspection shall be carried out according to the service conditions of the cylinder and the pre-inspection result of the hydrogen storage system.
4.4.3 If the pre-inspection result meets the relevant requirements of 5.1, the inspection organization may complete the non-disassembly inspection of the cylinder, covering appearance inspection only.
4.4.4 If the pre-inspection result fails to meet the relevant requirements of 5.1, or if the cylinder valve needs to be replaced, the cylinder shall be subjected to disassembly inspection for all items.
4.4.5 For cylinders with a nominal working pressure of 35MPa in GB/T 35544 and Class A2 cylinders in GB/T 42612, all items of cylinders shall be inspected during the second, fourth and subsequent inspections, and the third inspection may be judged using the method same as the first inspection to determine whether to carry out disassembly inspection. For cylinders with a nominal working pressure of 70MPa in GB/T 35544 and Class B2 cylinders in GB/T 42612, all items shall be inspected for the second and subsequent inspections.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Technical requirements
4.1 Types and description of cylinders
4.2 Inspection tools and devices
4.3 Inspection period
4.4 Inspection items
5 Preparation for inspection
5.1 Pre-inspection of hydrogen storage system
5.2 Information access and recording
5.3 Pressure relief and nitrogen replacement of cylinders
5.4 Disassembly and surface cleaning of cylinders and cylinder valves
6 Appearance inspection and evaluation
6.1 Types of damage
6.2 Damage level
6.3 Inspection and evaluation of appearance damage
7 Treatment of outer surface damage
8 Internal inspection and evaluation
8.1 Types of damage
8.2 Damage level
8.3 Inspection and evaluation of internal damage
9 Inspection and evaluation of cylinder opening thread
10 Hydrostatic test
11 Internal drying
11.1 Drying methods and requirements
11.2 Dryness inspection
12 Inspection and assembly of cylinder valve
13 Air tightness test
14 Work after inspection
Annex A (Informative) Pressure relief of cylinders
Annex B (Informative) Typical damage illustrations of cylinders
Annex C (Informative) Illustrations of treatment methods for surface damage of cylinders
Annex D (Normative) Inspection of cylinder reset and installation
Annex E (Informative) Periodic inspection report of cylinders
Bibliography
