Views:45 Author:Site Editor Publish Time: 2017-09-06 Origin:Site
When finish the installation of pipeline, we must inspect and test the PVC and PPR pipes totally to ensure the installation is qualified. Here the follow are the steps of the pipes' inspection and testing. After you read it, it will definitely help you learn the installation of the pipes.
1.The inspection and test of pipes engineering shall be carried out on the basis of self-inspection by the construction unit. Inspection and test the procedure of PVC piping system, inspection batch or sub-item engineering, and record it at the same time.
2.The weld inspection of all kinds of metal pipes in the clean plant shall meet the following requirements.(1) of highly toxic fluid pipeline welding seam, should be 100% radiographic inspection, the quality level shall not be lower than Ⅱ.(2) the delivery pressure is greater than or equal to 0.5 MPA fluid pipe welds, toxic, flammable fluid should be sampling radiographic inspection, sampling shall be not less than 10%, its quality shall not be lower than Ⅲ level. When the engineering design documents are provided, they shall conform to the requirements of the design documents.(3) radiographic inspection methods and quality grading standards shall conform to the provisions of the current national standard, "on-site equipment, industrial pipeline welding engineering construction and acceptance specifications" GB50236.
3.After the installation of all kinds of metal pipe systems, the pressure test shall be carried out according to the following regulations: (1) the pressure test shall be water as the test medium. When the design pressure of the pipe is less than or equal to 0.8mpa, the gas can also be used as the test medium, but effective safety measures should be taken.(2) in clean plant, various high purity gas pipelines and dry compressed air pipes should be used as test media, and effective safety measures should be taken.(3) in the clean plant, the test media of various high purity material conveying pipes should be purified.(4) the test pressure and test method of the pressure test shall conform to the relevant provisions of the current national standard for construction and acceptance of industrial metal pipe works GB50235.
4.The piping system of liquid gas and high purity gas must be tested for the leakage of highly toxic liquid and poisonous liquid in the clean workshop. The leakage test shall comply with the following requirements: (1) the leakage test shall be carried out after the pressure test is qualified, and the test media shall adopt air or nitrogen or helium. For the leakage test medium for piping high purity gas, it is suitable to use nitrogen or helium gas of > 99.999%.(2) pressure of leakage test shall be design pressure.(3) the leakage test time shall be tested continuously for 24h (nitrogen) or 1h (helium).(4) the leakage test should be combined with the system debugging.(5) leakage test, with an average leakage rate of less than 1% per hour.
5.In the clean plant, the test of all kinds of vacuum piping shall meet the following requirements: (1) the pressure test of the vacuum pipe shall be controlled by air pressure test, and the test pressure shall be 0.2mpa.2) after the pressure test is qualified, the vacuum tube shall be tested in the vacuum degree of 24h according to the design document, and its supercharging rate shall not be greater than 5%.
6.After the test, the inspection qualified, should according to the design requirements for pipeline purging and cleaned and pipe purging and cleaning should comply with the design requirements, when required by the design without, can be reference to the current national standard "industrial metal pipeline engineering construction and acceptance standard" GB50235 provisions.