Some standard content:
National Standard of the People's Republic of China
Industrial Helium
1 Subject Content and Scope of Application
GB/T 4844.1
Replaces GB4844～484584
This standard specifies the technical requirements, inspection methods, inspection rules, and product packaging, marking, storage, transportation, etc. of industrial ammonia. This standard applies to bottled gaseous nitrogen extracted from natural gas, air or factory relaxation gas by cryogenic method and membrane permeation method. Mainly used for leak detection, filling balloons, nitrogen airships, flying ships, etc. Molecular formula: He.
Relative molecular mass: 4.00260 (according to the international relative atomic mass in 1991). 2 Reference standards
Dangerous goods packaging markWww.bzxZ.net
GB4844.2 Pure ammonia
GB5099 Seamless steel gas cylinders
GB/T5274 Preparation of mixed gases for gas analysis and calibration-Weighing method GB/T5832.1 Determination of trace moisture in gas-Electrolytic method GB/T5832.2 Determination of trace moisture in gas-Dew point method GB7144 Color marking of gas cylinders
GB/T 10627
Gas analysis
GB/T 10628
Gas analysis
3 Technical requirements
Preparation of standard mixed gas-Static volume method
Determination of the composition of standard mixed gas-Comparative method
The quality of industrial nitrogen shall comply with the requirements of Table 1. In the table, "purity" and "content" are both volume fractions (V/V). Table 1 Technical indicators
Nitrogen purity, 102
Total content of (hydrogen), oxygen (), nitrogen, and methane, 10-2Water content, dew point, C
4 Inspection method
4.1 Ammonia purity
Nitrogen purity is expressed in volume fraction and calculated according to formula (1): @= 100 — Φ
Approved by the State Administration of Technical Supervision on December 20, 1995
Implementation on August 1, 1996
Where: Φ——nitrogen purity, 10-2 (V/V); GB/T4844.1-1995
Φ, —total content of impurities such as nitrogen (hydrogen), oxygen (fluorine), nitrogen, and methane (volume fraction), 10-2 (V/V). 4.2 Determination of moisture content
The moisture content in industrial nitrogen shall be determined in accordance with the provisions of GB/T5832.1 or GB/T5832.2. The two methods have equal validity. 4.3 Argon (hydrogen), oxygen (argon), nitrogen, and methane Determination of alkane content 4.3.1 Method summary
Thermal conductivity gas chromatography is used for determination. This method separates the sample under the mobile phase through the chromatographic column and then detects it with a thermal conductivity detector.
4.3.2 Instrument
A gas chromatograph with a thermal conductivity detector is used, and the recorder: 0~1mV. The detection limit (volume fraction) of this instrument for hydrogen (hydrogen), oxygen (argon), nitrogen, and methane should not be greater than 0.1×10-22 (V/V). 4.3.3 Determination conditions
a. Carrier gas: pure nitrogen, in accordance with the requirements of GB4844.2, with a flow rate of about 40mL/min. b. Injection volume: 1~~3 mL.
Chromatographic column: about 2m long, 4mm inner diameter, filled with 0.25~0.40mm 13X or 5A molecular sieve. Column temperature: room temperature. After the column is activated by c.
, it should be able to make the separation degree (R) between the components to be measured greater than 1.4.3.4 Operation steps
4.3.4.1 Turn on the carrier gas, adjust the flow rate to about 40mL/min, turn on the power of the instrument, and wait for the instrument to work stably. 4.3.4.2 Connect the standard mixed gas bottle to the instrument through the pressure reducing valve and the metal sampling tube, open the standard gas bottle valve and the pressure reducing valve, and after fully replacing the sampling pipeline system with standard gas, switch the six-way valve for sampling. Measure and record the retention time and peak height (or peak area) of each component.
The standard mixed gas uses nitrogen as the base gas and hydrogen, oxygen, nitrogen and methane as the component gases. The content should be similar to the component to be measured, according to GB/T 5274, or GB/T10627, or GB/T10628. 4.3.4.3 Send the sample gas into the instrument in the same way as in 4.3.4.2. Measure and record the retention time and peak height (or peak area) of each component.
4.3.5 Result processing
4.3.5.1 The content of each component to be measured is calculated according to formula (2): Φ+H
Where: Φ--the content of component i in the sample gas (volume fraction), 10-2 (V/V); Φ,--the content of component i in the standard gas (volume fraction), 10-2 (V/V); H. The peak height of component i in the sample gas, mm;
H. The peak height of component i in the standard gas, mm;
i represents the components nitrogen (hydrogen), oxygen (argon), nitrogen, and methane. 4.3.5.2 The arithmetic mean of two parallel determinations shall be the determination result, and the relative deviation shall not exceed 5%. 5 Inspection rules
5.1 Industrial nitrogen products shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard to ensure that the products leaving the factory meet the requirements of this standard.
5.2 Industrial nitrogen shall be sampled and inspected in batches. The batch size is the number of ammonia bottles produced in one production shift, or the number of nitrogen bottles delivered each time. Inspection samples shall be randomly selected at 2% of the batch, but the number of samples shall not be less than 2 bottles and a maximum of 5 bottles. 5.3 When any of the inspection results does not meet the requirements of this standard, the same batch of products shall be doubled for re-sampling and re-inspection. If any of the indicators in the re-inspection results still do not meet the requirements of this standard, the batch of products shall be deemed unqualified. 454
GB/T 4844.1-1995
5.4 Users have the right to conduct inspection and acceptance in accordance with the provisions of this standard. 5.5 When the supplier and the buyer have any objection to the product quality, the two parties shall jointly inspect or apply for arbitration. Packaging, marking, storage and transportation
6.1 The packaging, marking, storage and transportation of nitrogen shall comply with the provisions of the "Gas Cylinder Safety Supervision Regulations" and the "Dangerous Goods Transportation Regulations". 6.2 Gas cylinders filled with nitrogen shall comply with the provisions of GB5099, and the color marking of gas cylinders shall comply with the provisions of GB7144. 6.3 Nitrogen shall have a dangerous goods packaging mark when leaving the factory and comply with the provisions of GB190. 6.4 The factory pressure of nitrogen is: 15.0 ± 0.5 MPa at 20°C. The volume of hydrogen is calculated according to formula (3): V = KV2
Wherein: V-
-20°C, 101.3 kPa, the volume of nitrogen, m; V-the water volume of the cylinder, L
K-nitrogen volume conversion coefficient, see Table 2. 6.5 After the gas cools to room temperature, the ammonia pressure in the cylinder is measured with a 2.5-level pressure gauge with a range of 0 to 25.0 MPa. (3)
6.6 The nitrogen cylinder returned to the manufacturer should have a residual pressure of not less than 0.05 MPa. Cylinders without residual pressure, cylinders after water pressure test, new cylinders, modified cylinders, etc. should be treated before filling. 6.7
Before leaving the factory, check the mouth and neck of the ammonia cylinder for leakage, put on the bottle cap, and install the anti-vibration ring. Nitrogen should be accompanied by a quality certificate when leaving the factory, and its contents include: a.
Product name;
Manufacturer name;
Production date;
Ammonia volume and pressure;
Product batch number or bottle number;
Code of this standard.
Table 2 Ammonia volume conversion coefficient
0.1340.139
0.1310.136
0.1180.1230.128
—300.113
25 0. 111
-15 0. 106
0.1160.121
0.1080.112
Force, MPa
0.1260.131| |tt||0.179↓0.184
0.1650.1700.174
200.0940.099
0. 0910. 095
Additional Notes:
GB/T4844.1—1995
Continued Table 2
Force, MPa
0.1230.127
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Southwest Research Institute of Chemical Industry of the Ministry of Chemical Industry. 0.118
0.1440.148
0.1330.138
This standard was drafted by the Southwest Research Institute of Chemical Industry of the Ministry of Chemical Industry and Weiyuan Natural Gas Chemical Plant of Sichuan Petroleum Administration Bureau. The main drafters of this standard are He Daoshan and Dai Qiwen. 456
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