GB/T 4842-1995 Argon

GB/T 4842-1995 Argon GB/T4842-1995 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Pure argon
Subject content and applicable scope
GB/T 4842--1995
Replaces GB4842-84
GB 4843--84
This standard specifies the technical requirements, inspection methods, acceptance rules, and packaging, marking, storage and transportation of pure chlorine products. This standard applies to gaseous and liquid pure argon extracted from air and synthetic ammonia tail gas by cryogenic method, mainly used for metal welding, smelting, etc. Molecular formula: Ar
Relative molecular mass: 39.948 (according to the international relative atomic mass in 1991) 2 Reference standards
Dangerous goods packaging mark
GB 190
GB5099
Seamless steel gas cylinders
GB/T 5831Www.bzxZ.net
Determination of trace oxygen in gas-Colorimetric method
GB/T 5832. 1
Determination of trace moisture in gas
Electrolytic method
GB/T5832.2Determination of trace moisture in gas-Dew point method GB/T6285Determination of trace oxygen in gas-Electrochemical method GB 7144
Color marking of gas cylinders
GB/T 8981
GB/T 8985
GB/T14852
Technical requirements
Determination of trace hydrogen in gas
Gas chromatography
Determination of total content of carbon monoxide, carbon dioxide and hydrocarbons in gas Determination of trace oxygen in gas
The quality of pure fluorine shall conform to the requirements of Table 1.
Purity, 10-2
Hydrogen content, 10-6
Oxygen content, 10-
Nitrogen content, 10-6
Total carbon content (in terms of methane), 10-6
Water content, 10-6
Approved by the State Administration of Technical Supervision on December 20, 1995 Yellow phosphorus luminescence method
Gas chromatography
Implementation on August 1, 1996
GB/T 4842--1995
Note: () The purity and content in the table are volume fractions (V/V). ② Liquid pure argon does not specify the water content.
4 Inspection method
4.1 Determination of argon purity
This standard uses the subtraction method to calculate the purity by deducting the impurity content. The purity of argon is calculated according to formula (1):
=100-(9+P+++)×10-4
Wherein:
Nitrogen purity (volume fraction), 10-2;
Hydrogen content (volume fraction), 10-°; Oxygen content (volume fraction), 10-6; Nitrogen content (volume fraction), 10-°; 9——Total carbon content (volume fraction), 10-6, 9—Water content (volume fraction), 10~. 4.2 Determination of hydrogen and nitrogen content
4.2.1 Method and principle
Gas chromatography is used, with a thermal conductivity cell as the detector. When the sample enters the thermal conductivity cell after separation by the chromatographic column, due to the change of components and concentration, different heat will be taken away from the thermistor, causing the resistance value of the thermistor to change. Therefore, the corresponding signal is immediately output at the output end of the measuring bridge, thereby determining the content of each component. 4.2.2 Analytical Instruments
A gas chromatograph is used, and the detection limit for hydrogen should be less than 1×10-, and the detection limit for nitrogen should be less than 15×10-6. The concentration of hydrogen and nitrogen impurities in the chromatographic system should be less than 10% of the technical indicators of this standard. The schematic flow chart of the gas chromatograph is shown in Figure 1. Qs
Figure 1 Flow chart of gas chromatograph
1-Carrier gas cylinder, 2-pressure reducing gauge, 3-molecular sieve and drying tube: 4-pressure stabilizing valve? 5-pressure gauge, 6-zirconium aluminum-16 alloy purifier, 7-buffer bottle, 8-thermal conductivity cell; 9-six-way injection valve; 10-quantitative tube: 11-chromatographic column, 12-rotor flowmeter, 13-measuring bridge; 14-recorder; 15-sample gas cylinder or standard gas cylinder: 16-needle valve, 17-water seal bottle; 18-electric furnace 4.2.3 Preparation of purifier and chromatographic column
4.2.3.1 Preparation of purifier
Load about 150g of 250~~400μm zirconium aluminum-16 alloy into the purifier and activate it with pure argon at 750~~800℃ for 2.5h. 150
GB/T 4842—1995
Zirconium-aluminum-16 alloy can be activated multiple times and reused. 4.2.3.2 Preparation of chromatographic column
Put 250~400um 13X molecular sieve or 5A molecular sieve for chromatographic analysis into a stainless steel tube with an inner diameter of 4mm and a length of 1m, and activate it with pure argon at a temperature of 300~~350C for 3~3.5h. 4.2.4 Reference operating conditions
4.2.4.1 Carrier gas flow rate: 20mL/min;
4.2.4.2 Quantitative tube volume: 5mL;
4.2.4.3 Cold resistance of one arm of four-arm thermal conductivity cell: greater than 12002; 4.2.4.4 Working current: 100mA;
4.2.4.5 Purifier working temperature: 400~450℃; 4.2.4.6 Chromatographic column temperature: room temperature;
4.2.4.7 Recorder: 0~1mV automatic balance potentiometer. 4.2.5 Determination steps
4.2.5.1 Instrument start
Open the carrier gas, adjust the carrier gas flow rate to 20mL/min, wait for the carrier gas flow rate to stabilize, connect the thermal conductivity cell power supply, adjust the working current to 100mA, wait for the instrument to stabilize, and connect the standard gas to the instrument through the needle valve and metal sampling tube. 4.2.5.2 Calibration
Open the standard gas cylinder valve, adjust the flow rate with the needle valve, fully replace the needle valve, sampling pipeline and quantitative tube, then switch the six-way valve for sampling, measure the corresponding hydrogen and nitrogen peak areas, repeat twice, and the relative deviation shall not be greater than 10%, and take the average value. The standard gas uses argon as the base gas, and the hydrogen and nitrogen content is similar to the indicators in the technical requirements of this standard. The standard gas used should have the certification mark and number of the State Administration of Technical Supervision. 4.2.5.3 Determination
Open the sample gas cylinder valve, operate according to 4.2.5.2, and take the average value for calculation. 4.2.6 Calculation method
The content of the component to be measured is calculated according to formula (2):
R'·A1
Wherein: 9——the content of the component i to be measured in the sample (volume fraction), 10-6, 9'——the content of the component in the standard gas (volume fraction), 10-6, Ar——the peak area of ​​the component i in the sample gas, mm\; A.-the peak area of ​​the component i in the standard gas, mm\; i——represents the components to be measured, hydrogen and nitrogen, respectively. When the half width remains unchanged, the peak height can be used for quantitative determination. 4.2.7 The determination of hydrogen content is allowed to be carried out in accordance with GB/T8981. 4.3 The determination of oxygen content
is carried out in accordance with GB/T5831 or GB/T6285 or GB/T14852, but the arbitration method is GB/T5831. 4.4 The determination of total carbon content
is carried out in accordance with GB/T8985.
4.5 Determination of moisture content
Perform according to GB/T5832.1 or GB/T5832.2. Both methods have equal validity. 5 Inspection rules
5.1 Pure argon products shall be inspected by the technical supervision department of the manufacturer. It shall be ensured that all pure fluorine leaving the factory meets the requirements of this standard. 451
GB/T 4842-1995
5.2 Bottled pure chlorine shall be randomly sampled and inspected according to the number of bottles specified in Table 2 and accepted in batches. If the inspection result shows that one bottle does not meet the technical requirements of this standard, it shall be re-randomly sampled and inspected with double sampling. If there is still one bottle that does not meet the technical requirements of this standard, the batch of products shall be deemed unqualified. Table 2
Product batch, bottle
Sampling quantity, bottle
50~100
5.3 When liquid pure fluorine is shipped by storage tank or tank truck, samples should be taken from each storage and transportation container for inspection. 5.4 Users shall also conduct acceptance in accordance with this standard. 5.5 When users and manufacturers have different opinions on product quality, both parties shall conduct joint inspection or apply for arbitration. 6 Packaging, marking, storage and transportation
6.1 The packaging, storage and transportation of pure argon shall comply with the "Regulations on Safety Supervision of Pressure Vessels", "Regulations on Safety Supervision of Gas Cylinders", "Regulations on the Transportation of Dangerous Goods" and relevant regulations of the transportation department. 6.2 The marking of pure argon gas cylinders shall comply with the provisions of GB190, and the color marking shall comply with the provisions of GB7144. 6.3 The maximum allowable pressure of pure argon gas cylinders shall comply with the provisions of GB5099. 6.4 The filling pressure of bottled pure fluorine is 15.0±0.5MPa at 20℃. 6.5 There shall be no leakage at the threaded connection between the gas cylinder and the gas valve, the gas valve outlet and the valve stem gap. The gas cylinder shall be capped when leaving the factory. 6.6 The pressure of bottled pure argon should be measured after confirming that the gas temperature is close to the ambient temperature. The accuracy of the pressure gauge used for measurement shall not be lower than Class 2.5, and the range shall be 0-25.0MPa.
6.7 The residual pressure in the empty bottles returned to the manufacturer shall not be lower than 0.2MPa. Gas cylinders without residual gas and gas cylinders that have passed the water pressure test must be treated before filling. 6.8 The volume of bottled pure fluorine shall be calculated in accordance with Appendix A (Supplement) of GB/T4842.2. 6.9 When liquid pure argon is transported in storage tanks or tank trucks, it shall comply with the provisions of 6.1 of this standard. 6.10 The mass of liquid pure argon is converted to the volume of gaseous pure argon at 20℃ and 0.1013MPa according to formula (3). V = m/1. 662
Wherein: V-
The volume of liquid pure fluorine converted into gaseous pure argon, m\; The mass of liquid pure fluorine, kg;
The density of pure fluorine, kg/m2.
6.11 Pure fluorine should be accompanied by a quality certificate when leaving the factory, and its contents should include: a.
Product name;
Manufacturer name;
Production date or batch number;
The volume (m\), pressure (MPa)) or mass (kg) of pure fluorine; This standard number.
Additional remarks:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the technical jurisdiction of the Southwest Research Institute of Chemical Industry of the Ministry of Chemical Industry. This standard was drafted by Shanghai Biosi Gas Industry Co., Ltd. and Southwest Research Institute of Chemical Industry. The main drafters of this standard are Li Zongji and Yan Boju. 12
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