GB 9644-1988 Extraction methods and allowable values ??of lead, tin, pickaxe and mercury from rigid polyvinyl chloride (PVC-U) drinking water pipes and fittings GB9644-1988 Standard download and decompression password: www.bzxz.net

National Standard of the People's Republic of Chinabzxz.net
Rigid polyvinyl chloride (PVC-U) drinking water pipes
and pipe fittings Extraction methods and allowable values ??of lead, tin, cadmium, mercury
||tt| |Unplasticized polyvinyl chloride(PVC-U)pipes and frittingsfor drinking water supply --.Extractability of lead,tin,cadmium and mercury occurring as impurities-Test method and permitted levelsGB 9644—88
This standard adopts the international standard ISO6992 —1986 "Test methods and allowable values ??for extraction of mercury impurities from rigid polyvinyl fluoride (PVC-U) drinking water pipe saws", IS03114 - 1977 "Rigid polyvinyl fluoride pipes for drinking water supply - Extractability of lead and tin - | |tt||Subject content and scope of application
1
This standard specifies the extraction methods and allowable values ??of lead, tin, pickaxe and mercury from rigid polyvinyl chloride (PVC-U) drinking water pipes. This standard applies to rigid polyvinyl chloride (PVC-U) pipes and fittings for conveying drinking water. 2 Principle
-Test method》.
Rinse the sample with drinking water, then fill the sample with carbon dioxide acidified water, leave it for a certain time, and measure the content of lead, tin, and mercury in the liquid.
This standard requires that the measurement results of the analytical test methods used are accurate to: lead is less than 0.01mg/1, tin is less than 0.001mg/1, cadmium is less than 0.005mg/1; mercury is less than 0.0005mg/1. 3 Test Equipment | |tt||3.1 Glass pipe section with a cock or other device with adjustable flow rate. 3.2 Made of materials that have no effect on the test results. 3.3 Ground glass bottle.
4 Preparation of test water
Pour carbon dioxide into distilled water to acidify the water until the pH value is equal to 4.5±0.1. Note: For each test, use newly prepared test water. 5 Preparation of specimens
5.1 Pipes: Cut three pipe sections from the same batch of pipes. Each section is at least 500mm long, and the internal volume is larger than the volume required to determine the content of lead, tin, and mercury.
5.2 Pipe fittings Take three groups of pipe fittings from the extracted samples. The quantity of each group of pipe fittings should be such that the overall internal volume of the pipe fittings is not less than the size required for measurement. Approved by the Ministry of Light Industry of the People's Republic of China on July 8, 1988, in 1989- 02-01 Implementation
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Product.
6 Test steps
6.1 Pipe flushing
GB 9644-88
6.1.1 Close one end of the sample with a plug. A glass tube section with a cock is installed in the center of the plug. 6.1.2 Clamp the specimen vertically with the open end facing upward. 6.1.3 Pour drinking water into the sample until it overflows. Adjust the plug cock so that the flow rate of water in the sample is 3m/min. 6.1.4 After maintaining the water flow for 60 ± 10 minutes, stop the water flow, remove the plug, and rinse the sample with distilled water. 6.2 Flushing of pipe fittings
The flushing of pipe fittings shall be carried out in accordance with the provisions of Article 6.1. If necessary, use a certain length of pipe to connect the sample for flushing. 6.3 Extraction test
6.3.1 Close one end of the rinsed sample. 6.3.2 First extraction: Fill the sample with test water and place it in an environment of 20 ± 2°C for 48 hours. Then pour the water in the sample into three empty bottles. This water is the second extraction liquid. 6.3.3 Second extraction: Fill the sample with test water, place it in an environment of 20±2°C for 48 hours, and then pour the water in the sample into three other empty bottles respectively. This water is the second extraction. Extract. 6.3.4 The third extraction: Repeat the steps of the second extraction, and the resulting solution is the third extraction solution. The above extract is retained for determination of lead, tin, cadmium and mercury content. 7 Test result expression
7.1 Lead
Calculate the arithmetic mean of the lead content in the three water samples extracted for the first and third times respectively. The results are expressed in mg/L, accurate to 0.02mg/L.
7.2 Tin
Calculate the arithmetic mean of the tin content in the three water samples of the third extraction. Results are expressed in mg/L, accurate to 0.004 mg/L. 7.3 Pot
Calculate the arithmetic mean of the content in the three water samples for each extraction. Results are expressed in mg/L, accurate to 0.005 mg/L. 7.4 Mercury
Calculate the arithmetic mean of the mercury content in the three water samples for each extraction. Results are expressed in mg/L, accurate to 0.0005 mg/L. 8 Allowable value
8.1 Lead
The lead content in the first extraction solution shall not exceed 1.0mg/L. The lead content in the third extraction solution shall not exceed 0.3 mg/L. 8.2 Tin
The tin content in the third extraction solution shall not exceed 0.02mg/L. 8.3 Cadmium
The cadmium content in each of the three extraction liquids shall not exceed 0.01mg/L. 8.4 Mercury
The mercury content in each of the three extraction liquids shall not exceed 0.001mg/L. 9 Test report
The test report should include the following content:
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b.
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d.|| tt | | e. | | tt | ||For factors not mentioned in this test method that may affect the test results, conduct a comprehensive identification of the sample to see if it meets the requirements of this standard; test personnel and date.
Additional notes:
This standard is proposed by the National Technical Committee for Standardization of Plastic Products. This standard is under the jurisdiction of the Plastics Processing and Applied Science Research Institute of the Ministry of Light Industry. This standard is drafted by Jilin Plastics Research Institute. The main drafters of this standard are Liu Yuexian, Wang Yuqin and Shi Baoyuan, 159
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