GB 16918-1997 Technical requirements for bursting discs for gas cylinders
Some standard content:
GB16918—1997
This standard adopts the content of the first part of the pressure relief device standard of the American Compressed Gas Association CCAS-1.1 (Pressure-relief Device Standards-Part 1: Cylinders for Compressed Gases) in a non-equivalent manner. Appendix A, Appendix B and Appendix C of this standard are appendices to the standard. Appendix D, Appendix E and Appendix F of this standard are indicative appendices. This standard is proposed by the Ministry of Labor of the People's Republic of China. This standard is technically managed by the National Technical Committee for Standardization of Gas Cylinders. The drafting units of this standard are: Dalian Boiler and Pressure Vessel Inspection Institute; Dalian University of Technology Safety Equipment Factory. The main drafters of this standard are: Ma Yuan, Hu Jun, Wang Shulan, Ding Xinwei, Zheng Ning. 436
1 Scope
National Standard of the People's Republic of China
Technical conditions for bursting discs for gas cylinders
Bursting discs specification for gas cylinder This standard specifies the terminology, technical requirements and test methods for bursting discs for gas cylinders to prevent overpressure. This standard applies to bursting discs for gas cylinders containing permanent gases and liquefied gases under compression. 2 Definitions
This standard adopts the following definitions.
2.1 Bursting disc
GB 16918—1997
When the pressure of a gas cylinder increases due to an abnormal increase in ambient temperature, it can quickly actuate (break or fall off) due to overpressure to release the overpressure medium in the cylinder.
2.2 Bursting disc device
A pressure relief device composed of a bursting disc, a clamping ring, a gland and a cock. The device is closed when the gas cylinder is working normally, and releases pressure due to the action (break or fall off) of the bursting disc when the gas cylinder is overpressured. The device cannot be closed and used repeatedly. 2.3 Positive arch bursting disc
The pressure sensitive element is positive arched. When installed, the convex surface of the arch faces the release side. When it actuates, the element undergoes tensile rupture. 2.4 Reverse arched bursting disc
The pressure sensitive element is in the shape of a reverse arch. When installed, the concave surface of the arch faces the discharge side. When it is actuated, the element flips over due to compression instability and causes rupture or fall off.
2.5 Grooved bursting disc
A bursting disc with weakening grooves engraved on the surface of the pressure sensitive element. 2.6 Clamping ring
In the bursting disc device, it has a discharge caliber given by design, which is used to fix the position of the bursting disc and ensure the accurate action of the bursting disc. 2.7 Bad disc
A bad metal disc punched out from a metal strip or sheet before it is made into an arched bursting disc. 2.8 Burst pressure
The pressure difference on both sides of the bursting disc when it is actuated. 2.9 Burst temperature
The wall temperature of the bursting disc corresponding to the burst pressure. 2.10 Pressure test pressure
refers to the hydraulic test pressure of the gas cylinder, but for gas cylinders that cannot be subjected to hydraulic test, it refers to the gas pressure test pressure of the gas cylinder. 2.11 Design bursting pressure
When designing a bursting disc, the bursting pressure corresponding to a certain temperature is determined according to the pressure test pressure of the gas cylinder. 2.12 Test bursting pressure
Approved by the State Administration of Technical Supervision on July 22, 1997, and implemented on March 1, 1998
GB16918--1997
The actual bursting pressure measured at the moment of bursting of the bursting disc at the specified test temperature, 2.13 Calibrated bursting pressure
The bursting pressure value marked on the bursting disc, which is the arithmetic mean of the test bursting pressures of the specified number of samples of the batch of bursting discs. 2.14 Discharge area
The smallest geometric flow area on the bursting disc device. 2.15 Release volume
The pressure flow that can be released through the release area after the bursting disc explodes. 2.16 Batch
A group of bursting discs with the same type, specification, calibrated bursting pressure and bursting temperature, and whose materials (brand, performance) and manufacturing processes are exactly the same is a batch.
3 Technical requirements
3.1 See Appendix A (Appendix to the standard) for the applicable media of gas cylinder bursting discs. 3.2 Bursting disc materials
3.2.1 The metal materials used to manufacture bursting discs, clamping rings and cocks should comply with national standards, professional standards or relevant standards. 3.2.2 The bursting disc materials must have quality certificates and certificates of conformity. 3.2.3 The bursting disc materials must be annealed before molding to make them soft. 3.2.4 For the same batch of bursting discs, the thickness deviation of the bad discs shall meet the following conditions: a) When the material thickness is less than or equal to 0.10mm, the allowable deviation shall not exceed 0.003mm; b) When the material thickness is greater than 0.10mm, the allowable deviation shall not exceed 3% of the thickness. 3.3 Bursting disc discharge volume
The discharge volume and discharge area of the gas cylinder bursting disc shall be designed and calculated in accordance with Appendix B (Appendix of the standard). 3.4 Bursting disc surface quality
The appearance shape and size of the bursting disc shall comply with the provisions of the design drawings. The inner and outer surfaces of the bursting disc shall be free of defects such as cracks, rust, micropores or scratches.
3.5 Design bursting disc pressure
When the bursting temperature is specified to be 20C, the design bursting pressure of the bursting disc is equal to the pressure test pressure of the gas cylinder. 3.6 Performance test of bursting disc
3.6.1 When determining the material, type and manufacturing process of the gas cylinder bursting disc, fatigue performance test can be carried out after consultation between the supply and demand parties. The fatigue test method and requirements are shown in Appendix D (suggestive Appendix). 3.6.2 When determining the material, type and manufacturing process of the gas cylinder bursting disc, aging performance test can be carried out after consultation between the supply and demand parties. The aging test method and requirements are shown in Appendix E (suggestive Appendix). 3.7 Installation, use and maintenance of bursting disc
The installation, use and maintenance requirements of bursting discs are shown in Appendix C (Standard Appendix). 4 Inspection of bursting disc products
4.1 Product appearance inspection
4.1.1 The surface quality of bursting disc products shall comply with the provisions of Article 3.4. 4.1.2 When the material thickness is less than 0.2mm, the bursting disc products shall be light-transmitted for each piece, with an illumination of 50001m/m2, and those that are light-transmitting shall be eliminated.
4.2 Sampling Burst Test
The final assessment of whether the burst pressure of the bursting disc meets the design requirements depends on the results of the sampling burst test. 4.2.1 The number of bursting disc products in each batch shall not exceed 3,000. The number of samples of the same batch of bursting disc products for burst test shall be specified in Table 438
GB16918-1997
1. When the number of samples exceeds the number in the table, it shall be determined by negotiation between the supply and demand parties. The test samples shall be randomly selected from the same batch of bursting discs with qualified surface quality.
Table 1 Sampling quantity for bursting test
Total number of finished bursting discs of the same batch
>500～~1 000
>1 000～~3 000
Sampling quantity for bursting test
4.2.2 When sampling and testing bursting discs for refillable gas cylinders, the maximum value of the test bursting pressure of the products of the same batch shall not exceed the design bursting pressure, and the minimum value of the test bursting pressure shall not be less than 85% of the design bursting pressure. 4.2.3 When sampling and testing bursting discs for non-refillable gas cylinders, the maximum value of the test bursting pressure of the products of the same batch shall not exceed 105% of the design bursting pressure, and the minimum value of the test bursting pressure shall not be less than 90% of the design bursting pressure. 4.2.4 The burst test system should include:
a) pressure medium source;
b) burst pressure measurement system;
c) temperature measurement system;
d) medium discharge channel after burst;
e) pressure medium reflux or venting system; f) safety protection measures.
4.2.5 The discharge port diameter and orifice structure of the clamping ring used for the burst test should be exactly the same as those of the clamping ring actually used. 4.2.6 The pressure medium of the burst test is air, nitrogen or non-toxic gas. The entire test system should be equipped with at least two pressure instruments for measuring the burst pressure. 4.2.7
4.2.8 The accuracy of the spring tube pressure gauge for measuring the burst pressure should not be lower than that specified in Table 2. The maximum range of the pressure gauge should be 1.5 to 3 times the designed burst pressure. The pressure gauge should be used within the valid calibration period. Table 2 Bourdon tube pressure gauge for measuring bursting pressure Grade Burst pressure, MPa
Accuracy grade
4.2.9 Burst pressure rise rate: The test pressure rises to 85% of the rated burst pressure in no less than 3 seconds, and is maintained at this pressure for at least 30 seconds, and then the pressure is increased at a rate not exceeding 1% of the design burst pressure per second until the bursting disc ruptures. 4.2.10 During the sampling burst test, the test medium temperature is controlled at 20°C ± 5°C. 4.2.11 The blasting test results should have a formal test report. The blasting test report is the basis for the quality certification document of the finished blasting disc, and should include the following contents: a) test date, blasting disc model, production batch number and batch size, etc.; b) basic structure of the blasting disc, discharge diameter, material, design blasting pressure and blasting temperature; c) number of sampled blasting discs, test medium, medium temperature and ambient temperature, test instruments, etc.; d) number of sampled blasting discs and corresponding test blasting pressure, test blasting temperature, calibrated blasting pressure, and signatures of test and inspection personnel, etc.
4.3 Each batch of bursting disc products must be accompanied by a quality certificate, which shall include the following contents: a) Batch number;
b) Model;
c) Quantity of this batch;
d) Specification of bursting disc (discharge diameter);
e) Material of bursting disc;
() Applicable cylinder medium;
g) Design bursting pressure, MPa;
h) Rated bursting pressure, MPa;
i) Burst temperature, C;
i) Qualification mark, seal of inspector;
GB16918-1997
i) Name of manufacturer, manufacturing license number, inspection seal of statutory inspection agency; 1) Date of manufacture.
Marking and packaging of bursting disc products
5.1 Before leaving the factory, bursting disc products shall be marked on the discharge side of the bursting disc or the outside of the device. The marking content is: a) manufacturer code;
b) batch number;
c) gas cylinder medium;
d) discharge diameter;
e) designed bursting pressure;
f) bursting temperature
5.2 After passing the inspection, the bursting discs shall be packaged one by one or packed in batches to ensure that the arch surface of the bursting disc is not deformed due to extrusion and to ensure the appearance quality of the bursting disc products.
Gas name
Gas name
Dichlorofluoromethane
Difluorochloromethane
Difluorochlorobromomethane
Chlorotrifluoroethane
Gas name
Nitrogen monoxide
Carbon dioxide
Trifluoromethane
Lanfluorofluoromethane
Trifluorobromomethane
Hexafluoroethane
GB 16918—1997
Appendix A
(Standard Appendix)
Applicable media for gas cylinder bursting discs
Molecular formula
Permanent gas
Low-pressure liquefied gas
Molecular formula
CHCI2F
CHCIF2
CF2CIBr
C2H,CIF3
High-pressure liquefied gas
Molecular formula
CHF:
CBrF:
Gas name
Tetrafluoromethane
Heavy hydrogen
Gas name
Tetrafluorodichloroethane
Pentafluorochloroethane
Hexafluoropropylene
&Chlorotrifluoroethylene
Gas name
Sulfur hexafluoride
Vinylidene fluoride
Molecular formula
Molecular formula
C2Cl2F4
Molecular formula
Note: In addition to the above-mentioned media, if gas cylinders filled with other media need to be installed with bursting discs, they must be reported to the Occupational Safety and Health and Boiler and Pressure Vessel Supervision Bureau of the Ministry of Labor for approval. Appendix B
(Standard Appendix)
Relief area of bursting disc of gas cylinder
B1 Symbol description
Minimum relief area of bursting disc, mm2;
Ws—safe discharge volume of gas cylinder, kg/h,
GB16918—1997
P——-design bursting pressure of bursting disc (absolute pressure), MPa; Po—pressure on the discharge side of bursting disc (absolute pressure), MPa; T——absolute temperature of the discharged medium in the gas cylinder, K; molar mass of the medium in the bottle, kg/kmoL; M
. Gas compressibility factor, obtained from Figure B1;
adiabatic index of gas;
characteristic coefficient of gas, calculated according to the following formula: C
nominal volume of gas cylinder, L;
latent heat of vaporization of liquefied gas under discharge pressure, kJ/kg; heated area of gas cylinder, m2;
A,= 3. 14Do(L+0. 3Do)
outer diameter of gas cylinder, m:
total length of gas cylinder, m;
rated discharge coefficient, A=0.62.
Calculation of safe discharge volume of gas cylinders
B2.1 Liquefied gas cylinders
When the cylinder volume is less than 450L:
Ws = 0.352P. /MV
When the cylinder volume is greater than 450L:
B2.2 Permanent gas cylinders
Burst disc discharge area (gas)
Critical conditions
Subcritical conditions
2.55X105A9.82
Ws - 0.176PMV
7. 6 × 10-2CAP /M/ZT
55.85CAP VM/ZT
（B1）
（B2）
（B3)
（B4）
（B5)
0.2.0. 3 0.4.0. 5
Saturated liquid
0. 2 0.3 0.40. 5
GB16918—1997
Comparative temperature T.
2. 03. 0 4. 0 5. 0
=10.005.00
2.03.0 4.0 5.0
Comparative pressure P
Figure B1 Gas compressibility factor
Appendix C
(Appendix of Standard)
Installation, use and maintenance of bursting discs of gas cylindersC1 Installation of bursting discs of gas cylinders
1 0, 7
C1.1 The bursting disc device for welded gas cylinders generally consists of a bursting disc, a clamping ring, a plug and a pressure cap (Figure C1). The thread of the plug should comply with the provisions of GB8335-87 "Special Thread for Gas Cylinders"; the parallelism tolerance level of the two end faces of the clamping ring should be above level 6, and the surface roughness of the sealing surface should not be less than to ensure that the clamping load can be evenly transmitted, and the edge of the bursting disc will not twitch when it is compressed until it explodes, and the peripheral sealing and no leakage will occur.
C1.2 The bursting discs for non-refillable gas cylinders are generally welded directly to the bottle body (Figure C2). The quality and size of the girth weld should be strictly controlled during welding. The weld should ensure that the periphery of the bursting disc is sealed when it is compressed until it explodes. The weld width deviation is ±0.10mm, and the girth weld mid-diameter deviation is t0.05mm.
Gland-
Clamping ring-
Burst disc
Figure C1 Welded gas cylinder burst disc device
GB16918—1997
Medium:
Medium diameter of ring weld
Burst disc
Figure C2 Installation method of burst disc for non-refillable gas cylinder C1.3 The burst disc for seamless gas cylinder is generally installed at the side channel of the gas cylinder inlet valve. The structural dimensions of the valve body where the burst disc is installed should not affect the bursting performance of the burst disc, and shall be determined by consultation between the valve manufacturer and the bursting disc manufacturer. C1.4 For a combined relief device equipped with a burst disc, the structural dimensions of the burst disc installation should not affect the bursting performance of the burst disc, and shall be determined by consultation between the combined relief device manufacturer and the bursting disc manufacturer. C1.5 The minimum diameter of the entire discharge channel of the bursting disc device (including the pressure-bearing side and the back-pressure side of the bursting disc) shall meet the requirements of the safe discharge volume of the gas cylinder.
C1.6 The bursting discs for welded gas cylinders shall be manufactured, assembled and inspected as a set by the bursting disc manufacturer. C1.7 The complete set of gas cylinder bursting disc devices shipped from the factory shall be subjected to airtightness tests one by one before leaving the factory to ensure the good sealing of the gas cylinder. The requirements for the test system are the same as those for the sampling bursting test. The airtightness test pressure is 1.05 times the working pressure of the gas cylinder, and the pressure is maintained for 2 minutes. C1.8 The bursting disc device that passes the airtightness test shall be sealed with lead or other anti-disassembly measures shall be taken. C2 Use and maintenance of gas cylinder bursting discs
C2.1 When transporting and using gas cylinder bursting disc devices, care should be taken to keep the bursting disc device in good condition to prevent the device from being corroded or blocked by paint, sand and dirt and unable to operate normally. C2.2 The bursting disc device of a gas cylinder should be replaced regularly, and its service life is the interval between the pressure test of the gas cylinder. C2.3 The bursting disc device of a gas cylinder needs to be replaced as a set, and the bursting disc on the bursting disc device must not be adjusted or replaced during use. Appendix D
(Reminder Appendix)
Fatigue test of bursting discs of gas cylinders
D1 Test device and process
D1.1 Basic requirements for test equipment
D1.1.1 The test equipment must have the function of regulating and controlling the cycle pressure, cycle frequency, pressure holding time and continuous pressure cycle. D1.1.2 The test equipment should be able to automatically record the number of pressure cycles and indicate and control the temperature of the test medium. D1.1.3 The air in the test system should be able to be completely discharged. D1.1.4 The pressure-bearing pipeline and its accessories must pass the pressure test. The pressure test pressure should not be less than 2 times the maximum allowable working pressure of the test equipment, and the pressure holding time of the pressure test shall not be less than 3 minutes. D1.1.5 At least two pressure gauges that can correctly display the cycle pressure at the same time should be installed on the test equipment. The accuracy level of the pressure gauge should not be less than Class 1.0, and its range should be 2 to 3 times the cycle pressure of the tested bursting disc. The pressure gauge should be calibrated before each test. D1.2 Process
GB 16918-1997
See Figure D1, which is a schematic diagram of the recommended fatigue test device. A
Figure D1 System diagram of microcomputer-controlled fatigue test device 12
1 Pump: 2- Medium storage tank; 3- Filter; 4 Overflow valve; 5 Three-position four-way electro-hydraulic reversing valve (connected to the control mechanism); 6 Stop valve; 7--- Proportional electromagnetic overflow valve; 8 Current amplifier; 9--D/A digital-to-analog converter; 10-- Microcomputer; 11· Pressure sensor (matched with A/D); 12· A/D analog-to-digital converter; 13- Control, delayed alarm, recording mechanism; 14- Tested bursting disc; 15- Pressure gauge
D2 Test method
D2.1 Cyclic pressure
D2.1.1 The upper limit of the cyclic pressure of the fatigue test can be 80% of the designed bursting pressure of the tested bursting disc. D2.1.2 The lower limit of the cyclic pressure should not exceed 10% of the upper limit of the cyclic pressure. D2.2 Pressure cycle frequency
The pressure cycle frequency is 3 times/min~8 times/min. D2.3 Test operation requirements
D2.3.1 Tightly connect the bursting disc to be tested with the test device. The number of bursting discs to be tested each time shall be determined by the test requirements and the capacity of the test device.
D2.3.2 Increase and decrease the pressure several times at a pressure lower than the nominal working pressure to discharge the air in the test system and check whether the device is normal. D2.3.3 After confirming that there is no leakage in the test system and that the residual air has been exhausted, perform pressure cycle according to the specified cycle pressure and start automatic counting. D2.3.4 During the test, the cycle pressure and pressure cycle waveform shall be checked at any time, and attention shall be paid to whether the displayed values of the two pressure gauges are the same. D3 Fatigue test requirements
D3.1 The number of bursting discs sampled for each group of fatigue tests shall not be less than 6. D3.2 The fatigue life of each sampled bursting disc shall be guaranteed to be more than 4,000 times. Appendix E
(Informative Appendix)
Aging Test for Gas Cylinder Bursting Discs
E1 Aging Method
Use natural aging method: the bursting discs are stored at ambient temperature, and are sampled for bursting test in stages according to the aging time specified in Table E1, with a total aging time of one year.
Number of Sampled Bursting Discs
GB16918
Aging Time
Every 6 bursting discs form a group, and one group of bursting discs is sampled for bursting test in each stage. 3 Bursting Test System
The requirements for the bursting test system and the clamping ring are the same as those for the random bursting test, see the provisions in Article 4.2 of the standard. E4 Time-dependent performance requirements
The time-dependent bursting pressure of the tested bursting disc shall be stable within the range of allowable fluctuation of the sampling bursting test pressure, see Articles 4.2.2 and 4.2.3 of the standard.
Appendix F
(Reminder Appendix)
References
GB567-89 Technical conditions for arched metal bursting discs GB150-89 Steel pressure vessels
GB 16918-1997
Amendment No. 1 to GB16918-1997 Technical conditions for bursting discs for gas cylinders
This amendment was approved by the Standardization Administration of the People's Republic of China on January 8, 2002 in the document No. [2002] 1 of the National Standardization Administration, and will be implemented from April 1, 2002.
Comparison table of standard clause modifications:
（1）P6, row 7 from top
Before modification:
The characteristic coefficient of gas is calculated as follows: Pe+k
C=-i[(section)
After modification:
The characteristic coefficient of gas is calculated as follows: C520
（2）P6, row 1 from bottom
Before modification:
After modification:
55.85C/PM/ZT
55.85CaPVM/ZT
（B5）
（B5）3.
Appendix F
(Informative Appendix)
References
GB567—89 Technical Specifications for Arched Metal Bursting Discs GB150-89 Steel Pressure Vessels
GB 16918-1997
Amendment No. 1 to GB16918-1997 Technical Specifications for Bursting Discs for Gas Cylinders
This amendment was approved by the Standardization Administration of the People’s Republic of China on January 8, 2002 in the document [2002] No. 1 of the Standardization Administration of the People’s Republic of China, and will be implemented from April 1, 2002.
Comparison table of standard clause modifications:
（1）P6, row 7 from top
Before modification:
The characteristic coefficient of gas is calculated as follows: Pe+k
C=-i[(section)
After modification:
The characteristic coefficient of gas is calculated as follows: C520
（2）P6, row 1 from bottom
Before modification:
After modification:
55.85C/PM/ZTbzxZ.net
55.85CaPVM/ZT
（B5）
（B5）3.
Appendix F
(Informative Appendix)
References
GB567—89 Technical Specifications for Arched Metal Bursting Discs GB150-89 Steel Pressure Vessels
GB 16918-1997
Amendment No. 1 to GB16918-1997 Technical Specifications for Bursting Discs for Gas Cylinders
This amendment was approved by the Standardization Administration of the People’s Republic of China on January 8, 2002 in the document [2002] No. 1 of the Standardization Administration of the People’s Republic of China, and will be implemented from April 1, 2002.
Comparison table of standard clause modifications:
（1）P6, row 7 from top
Before modification:
The characteristic coefficient of gas is calculated as follows: Pe+k
C=-i[(section)
After modification:
The characteristic coefficient of gas is calculated as follows: C520
（2）P6, row 1 from bottom
Before modification:
After modification:
55.85C/PM/ZT
55.85CaPVM/ZT
（B5）
（B5）
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