This standard specifies the purity requirements for compressed air for diving and oxygen, nitrogen and helium used to prepare diving breathing gas, as well as the maximum allowable values ​​of the main pollutants in the ambient gas of saturated diving chambers. This standard applies to air diving, mixed gas diving and saturation diving. It also applies to the design, manufacture and maintenance of diving systems, diving equipment and diving gear related to diving breathing gas. GB 18435-2001 Diving breathing gas GB18435-2001 standard download decompression password: www.bzxz.net

GB18435—2001
All technical contents of this standard are mandatory. Foreword
This standard refers to BS4001:1981 "Maintenance and maintenance of underwater breathing apparatus Part 1: Recommendations on open-circuit compressed air", DIN3188:1981 "Compressed air for underwater breathing apparatus", BB-A-1034B; 1995 "Compressed air breathing apparatus", JISS7306-1989 "Compressed air standard for SCLBA" and relevant national military standards: GBn256—1985 is revised. In the revision of this standard, the purity index of diving breathing compressed air and the maximum allowable value of the environmental gas pollution components in the saturated diving chamber in the original standard are retained according to the results of on-site measurement and investigation and analysis. The technical indicators of oxygen, nitrogen and nitrogen gas sources are mainly modified. And the detection method of oil mist and particulate matter in compressed air for diving breathing is revised. Appendix A of this standard is the standard appendix, and Appendix 13 and Appendix C are the prompt appendices. This standard was proposed by the Ministry of Transport of the People's Republic of China. This standard was developed by the Maritime Rescue and Salvage Bureau of the Ministry of Transport. The drafting units of this standard are: the Research Institute of the [Hai Hai] Rescue and Salvage Bureau of the Ministry of Transport, and the Shanghai Institute of Underwater Engineering Science. The main drafters of this standard are: Chen Bainian, Ma Hongnian, Sheng Jinghui, Li Shiming, Jin Wei, and Rong Fukang. This standard was first issued in 1985 and revised for the first time in 2001. This standard was interpreted by the Research Institute of the Shanghai Maritime Rescue and Salvage Bureau of the Ministry of Transport. 374
1 Scope
National Standard of the People's Republic of China
Breathing gases for diving
Breathing gases for divcrs
GB184352001
Bn2561083
This standard specifies the purity requirements for oxygen, nitrogen and ammonia for breathing compressed air for diving and for preparing full water breathing gas, as well as the maximum allowable values ​​of the main pollutants in the saturated diving cabin air environment gas. This standard applies to air diving, mixed gas water skiing and other diving. It also applies to the design, manufacture and maintenance of diving systems, diving equipment and water equipment related to diving breathing gas. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard by reference in this standard: When this standard is published, the latest version is valid. All standards will be revised, and the parties using this standard should explore the feasibility of using the latest version of the following standards. GBm263--1987 Test method for the composition of breathing gas for divers GI 4811. 2---1995 Pure ammonia
GB/T 4844.3—1995 High purity oxygen
GB/T 89791996 Pure fluorine
GB89821998 Medical oxygen
3 Technical requirements
Purity requirements for various gas sources for diving breathing Various gas sources for diving breathing must meet the requirements of Table 1. 3.2 Maximum allowable values ​​of the main pollutants in the ambient gas of saturated diving chambers 3.2.1 The maximum allowable values ​​of the main pollutants in the ambient gas of saturated diving chambers shall meet the requirements of Table 2 3.2.2 The influence of pollutants in diving breathing gas on human health and the relationship between diving depth are shown in the Appendix (Reminder ): Purity requirements for various gas sources for diving breathing Gas source name
Compressed air
Volume fraction of oxygen, 102
Volume fraction of carbon dioxide, 10-ibzxZ.net
Volume fraction of carbon dioxide, 140-
Water {dew point
Oil mist and particulate matter-mg/m
Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on 20010903-riKAONiKAca-
No brother taste
2002 - 04 - 01 Implementation
Name of gas source
Class B:
Volume fraction of oxygen, 10·
Water content (dew point) (
Carbon monoxide content
Carbon monoxide content (GB18435-2001) (Table)
Content of gaseous acidic substances and alkaline substances
Ozone and other gaseous oxides
Volume fraction of nitrogen, 10·
Volume fraction of oxygen, 10·
Volume fraction of hydrogen.10
The superior integral fraction of carbon monoxide-10
The chemical volume fraction of oxygen
The volume fraction of methane, 10-
The volume fraction of water, 10-6
The volume fraction of nitrogen. 10
The volume fraction of oxygen: 10)-:
The volume fraction of hydrogen, 10-
The volume fraction of oxygen (hydrogen), 10-
The volume fraction of nitrogen-10:
The volume fraction of oxygen, C
The volume fraction of carbon dioxide, 0
The volume fraction of methyl ether Fraction, 13)-6
Volume fraction of water, 10-
Volume fraction of complex, 10-2
Volume fraction of negative, 10-
Volume fraction of single, 10-i
Volume fraction of single (oxygen), 1C-5
Volume fraction of cooked, 1C
Volume fraction of carbon dioxide, 10-
Volume fraction of methane, 1t
Volume fraction of water,
1) Adopt the technical requirements of CB8082.
2) Adopt the technical requirements of GB/T5979.
3) Adopt the technical requirements of GI4844.2 first-class products. 4: GE/T4844.3 Technical requirements for qualified products 7
According to the provisions of GB8982
According to the provisions of G8952
According to the provisions of GB8982
According to the provisions of GB8982
Special
(GB18435-7001
Table 2 Maximum allowable values ​​of main pollutants or components in the air environment of saturated diving chambers
Condensate (eabo tlioxile)
Carbon dioxide (curbnxice)
Sulfur dioxide (gulf dioxide)
Hydrogen sulfide (lydrrgen sulfide）
nitrogen oxides (nitrgenoxide)
methae
ketones
oenzun
molecule
78, 11
most important
1)mg/m refers to the mg number of pollutants contained in each m2 of the cabin volume. The unit of measurement and its conversion are shown in the Appendix (Recommended Appendix) 3.3 Selection of nitrogen as diving breathing gas
3. 3.1 In the case of conventional deep diving with reoxygenation, the technical requirements of Class A can be used. 3.3.2 In saturated diving, in order to consider the impact of certain pollutants in the gas source on the human body, the gas in the saturated diving chamber should be guaranteed to meet the requirements of 3.2 of this standard. According to the different depths of saturated diving, Class A or Class B nitrogen should be selected as the gas source for preparing diving breathing gas.
4 Testing methods
4.13.1 The "oil mist and particulate matter" index of small compressed air shall be tested according to the method of Appendix A (Appendix of the standard). The remaining indicators shall be tested according to the method of: J3n 265).
4.2 The various indicators of oxygen in 3.1 shall be tested according to the method of GB: B8982. The various indicators of nitrogen in 4.33.1 shall be tested according to GB/T 8979 method to be tested 4.43.1 nitrogen (class A) indicators according to GB1841.2 method: 4.53.1 nitrogen (class Z) indicators according to G/T4842.3 method. 4.63.2 saturated diving chamber environmental gas main pollutant components indicators according to GBm 265 method, a
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A1 method and principle
GB 184352001
Appendix A
【Appendix of the standard）
The detection method of "oil mist and particulate matter" in compressed air for diving breathing is determined by filter membrane sampling and weighing method. Let a certain amount of sample gas pass through the circular trap equipped with filter membrane, and calculate the content of oil mist and particulate matter according to the volume of sample gas passed and the mass change before and after the filter membrane is ventilated. A2 Instruments and materials
A21 Rotor flowmeter and cumulative gas flow meter, A2.2 Circular trap: as shown in Figure A1: Inlet
1-Filter membrane: 2-Measuring membrane box: 3·Conical filter membrane box holder Figure AI Circular trap
A2.3 Filter membrane: ultrafine fiber filter membrane or tight propylene synthetic fiber filter membrane. The gas after the filter membrane should not contain solid matter larger than 1 μm (including 1 μm).
A2.4 Use a plastic tube to connect the gas needle valve. A3 Preparation before sampling and analysis
A3.1 Wash and dry the circular trap.
A3.2 Cut the filter membrane into a circle and put it in a drying cylinder for dehydration for 4 hours. Then weigh it (accurate to 0.1 mg) and put it in a circular filter box. The weighed filter membrane should not absorb secretions and dust. A3.3 Connect the needle valve, the phoenix trap, the rotary flow meter and the cumulative gas flow meter in turn with a plastic tube. A4 Sampling and analysis
44.1 Set the outlet pressure of the air supply hose for divers to 0.1~0.12MPa absolute pressure), and then connect the inlet of the needle valve to the outlet of the air supply hose. With the needle valve closed, install the circular filter membrane box into the cone filter membrane box holder. Open the needle valve and adjust the rotor flowmeter to allow the gas to pass through the cone filter membrane box holder at a flow rate of 10~201./min to stabilize the gas flow. At the same time, turn on the cumulative gas flowmeter for measurement.
A4.2 When the cumulative flow reaches more than 1m, close the needle valve and take out the filter membrane for weighing (accurate to 0.1mg). Before weighing, the filter membrane must be placed in a drying cylinder for dehydration for 4 hours. When the filter membrane is weighed before and after sampling, the difference in relative humidity in the balance room shall not exceed 10%. A5 Result Processing
The content of "oil oligoparticles and particulate matter" in the steam is calculated according to formula (A1): $78
Oil mist and particulate matter content, IIg/in;
Where: -
The mass of the filter membrane before sampling.irg:
The mass of the filter membrane after sampling, mg
GB184352001
Converted to the sampling volume of 0c and 101.3kPa, m. Appendix B
(Prompt Attachment)
The relationship between the impact of pollutants in diving breathing gas on the human body and the diving depth (A1)
The impact of pollutants in breathing gas in high pressure environment on the human body is mainly determined by the partial pressure value of the component, not by its Volume concentration in breathing gas.
When the diving depth increases, if the volume concentration of pollutants in the breathing gas remains unchanged, then their partial pressures will increase with the increase of total pressure. The impact on people will also increase accordingly. Therefore, under different diving depth conditions, the pollutants in the breathing gas should be controlled according to their partial pressure values. That is, as the total pressure of the breathing gas increases, its volume concentration decreases proportionally. The relationship between the concentration, partial pressure and total pressure of a certain gas in the high-pressure environment at different water depths is calculated according to formula (B1): × 10%
C
Volume fraction of a certain gas (x).;
P,——partial pressure of a certain gas (x).Pa;
Total pressure of high-pressure environment gas, Pa.
(Appendix of tips)
Measurement units of pollutants in the cabin environment and their conversion....( B1)
The values ​​(mg/m3) listed in Table 2 of this standard are based on the content of pollutants in the unit cabin volume, rather than the content of pollutants in the unit gas volume, because the cabin volume and the pollutants contained therein are not affected by the change of diving depth. Therefore, the content of pollutants in the unit cabin volume is used as the unit of the maximum allowable value. It reflects the partial pressure of the pollutant, which does not change with the change of diving depth, so there is no need for conversion. It is suitable for various diving depths. In the test of this gas, the volume ratio concentration of the gas is calculated. In order to facilitate comparison, according to Avogadro's law and gas molar volume, the volume ratio concentration and the maximum allowable value listed in Table 2 can be converted. At a temperature of 25. The conversion formula is shown in formula (C1), Cy
Cw X 24.45
Wherein: (-volume fraction of the measured pollutant.final; Cw-content of the measured pollutant in unit cabin volume, mg/m; M
molecular weight of the measured pollutant.
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