Technical Specification for Polyethylene Gas Pipeline Engineering (4)

6 Test and acceptance 6.0.1 The test and acceptance of polyethylene gas pipelines shall comply with the current industry standard “Code for Construction and Acceptance of Urban Gas Transmission and Distribution Engineering” (CJJ33-89), Chapter 7 Section-Regulations. 6.0.2 After the polyethylene gas piping system is installed, after the visual inspection is qualified, the entire system shall be purged in sections. After the purging is qualified, the strength test and air tightness test can be carried out. In the strength test, use detergent or soap liquid to check whether the joints are leaking. After the inspection is completed, rinse off the leaking detergent or soap liquid in time. 6.0.3 Compressed air should be used as the purging and test medium, and its temperature should not exceed 40°C. 6.0.4 A separator and a filter should be installed at the outlet of the compressor to prevent harmful substances from entering the polyethylene gas pipeline. 6.0.5 The strength test pressure of the polyethylene gas pipeline should be 1.5 times the design pressure of the pipeline. The minimum pressure of the medium-pressure pipeline shall not be less than 0.30MPa; the minimum of the low-pressure pipeline shall not be less than 0.05MPa. 6.0.6 During the strength test of the polyethylene gas pipeline, the pressure should be increased slowly, and after reaching the test pressure, the pressure should be stabilized for 1 hour, and the pressure should not be reduced to be qualified. 6.0.7 The air tightness test of polyethylene gas pipeline shall comply with the current industry standard “Code for Construction and Acceptance of Urban Gas Transmission and Distribution Engineering” (cJJ33-89), Chapter 7, Section 3. Appendix A Explanation of terms used in this regulation A.0.1 In order to facilitate different treatment when implementing the provisions of this regulation, the terms with different strictness requirements are explained as follows: (1) It means very strict, so it must be done: positive words use “must” “; The opposite word adopts: “Forbidden”. (2) It means strict, which should be done under normal circumstances: positive words use “should”; negative words use “should” or “not allowed”. (3) It means that a slight choice is allowed, and this should be done first when conditions permit; positive words use “suitable” or “can”; negative words use “not suitable”. A.0. 2 The wording in the clause when it is specified that it must be implemented in accordance with other relevant standards is “should be implemented in accordance with…” or “shall meet the requirements (or regulations) of…”. Additional explanations The editor-in-chief, participating units and main drafters of this regulation. Editor-in-chief: China Academy of Building Technology Participating Unit: Beijing Gas Thermal Engineering Design Institute Shanghai Gas Company Harbin Gasification Engineering Construction Headquarters China Municipal Engineering North China Design Institute The main drafter of the Beijing Institute of Public Utilities Science: Gao Lixin, Cao Yonggen, Zhu Yunwei, Chen Junlun, Zhang Weimin, Wang Junchang, Fang Luoyu, Zhang Fulin, Zhang Linwei, Zhang Ronglin
    Article Description Foreword According to the requirements of the Ministry of Construction Jianbiao [1992] No. 732, the “Technical Regulations for Polyethylene Gas Pipeline Engineering” (CJJ 63 —95), approved by the Ministry of Construction on April 6, 1995 with Jian Biao [1995] No. 189, and has been released. In order to facilitate the relevant personnel of the majority of design, construction, scientific research, schools and other units to correctly understand and implement the provisions when using this regulation, the compilation group of the “Technical Regulations for Polyethylene Gas Pipeline Engineering” has compiled this standard in the order of chapters, sections and articles. The article description is for the reference of domestic users. If you find any defects in this provision during use, please send your opinion letter to China Academy of Building Technology. This “Article Description” is organized and published by the Institute of Standards and Ratings of the Ministry of Construction. 1 General 1.0.1 Compared with steel pipes and cast iron pipes, polyethylene gas pipes have different characteristics in terms of compressive strength, hydraulic properties, connection (welding) and laying. Therefore, in order to guide the design of polyethylene gas pipeline engineering, Construction and acceptance work, to ensure the quality of the project and safe gas supply, formulate this regulation. 1.0.2 This article specifies the scope of application of this regulation in view of the characteristics of gas transmission and distribution projects and the characteristics of polyethylene gas pipelines. The working temperature is -20~40℃. It is considered that the polyethylene gas pipeline is greatly affected by temperature. Too high temperature will cause it to soften and reduce its compressive strength; if the temperature is too low, it will become brittle. When impacted, it is easy to produce cracks. Too high and too low temperature will reduce its pressure-bearing capacity and service life. The United States stipulates: -29(-20F)-38°C (100F), the UK, France, ISO, etc.: -20~40°C. The maximum allowable working pressure is not more than 0.4MPa, considering that the pressure-bearing capacity of polyethylene gas pipelines is worse than that of steel pipes. Internationally, the pressure-bearing capacity of polyethylene gas pipelines is generally calculated as follows: where P-working pressure (MPa); σ-the minimum required long-term hydrostatic strength (MPa), that is: at 20 ℃, use Circumferential stress at 50 years of service life, according to international standards and China’s National Standards for “Buried Polyethylene Pipes for Gas Use” and “Buried Polyethylene Pipe Fittings for Gas Use”, σ≥8.0MPa Fd——design factor (safety factor) . The gas pipe selection range is 2~5, generally Fd=4. 0; SDR-standard size ratio, that is, the ratio of the nominal outer diameter to the wall thickness. SDR 11 and SDR 17.6 are specified in the national standard. Therefore, the maximum allowable working pressure can be obtained from this: For SDR 11 series pipelines, P=2×8.0/4×(11–1)=0.4MPa For SDR l7.6 series pipelines: P=2×8.0/4×( 17.6-1) = 0.24MPa Therefore, the maximum allowable working pressure is 0.4MPa. The maximum allowable working pressure of polyethylene gas pipelines in the world is generally specified as 0.4MPa, such as the United States, Britain, France and so on. 1.0.3 The mechanical strength of polyethylene pipes is low, and the exposed pipes are easy to be damaged by collision, resulting in air leakage. At the same time, they are affected by ultraviolet rays and oxygen in the atmosphere, which will accelerate the aging. The change of temperature and the erosion of oil fume or other chemical agents are also detrimental to polyethylene pipes. Therefore, as an inflammable and explosive gas pipeline, polyethylene pipes should not be used as indoor and above-ground pipes. Internationally, it is generally stipulated that only buried pipes are used. 1.0.4 This entry is specified to emphasize the materials used in polyethylene gas pipeline engineering, that is, pipes and fittings must comply with the current national standards “Buried Polyethylene Pipes for Gas” and “Buried Polyethylene Pipes for Gas” Requirements, so as to ensure the quality of the project and the safe supply of gas. 1.0.5 Urban gas is flammable, explosive and toxic (artificial gas). Moreover, polyethylene gas pipelines have some unique characteristics compared with metal pipelines. Therefore, in order to ensure project quality and safe gas supply, it is necessary to require reasonable engineering design and good construction quality. This requires the design of polyethylene gas pipeline engineering and the construction unit to have certain technical strength. Only after this ability has been approved by the higher-level competent authority and relevant departments can they engage in the design and construction of polyethylene gas pipeline engineering. 1.0.6 This article emphasizes that the design, construction and acceptance of buried polyethylene gas pipeline engineering should be in accordance with the current national standard “Code for Urban Gas Design” (GB 50028-93) and the current industry standard “Code for Construction and Acceptance of Urban Gas Transmission and Distribution Projects” “(CJJ 33-89) is used in conjunction with each other to coordinate and cooperate with each other, and at the same time, it should also meet the requirements of relevant standards to ensure the completion of project construction tasks. 4MPa For SDR l7.6 series pipeline: P=2×8.0/4×(17.6-1)=0.24MPa Therefore, the maximum allowable working pressure is 0.4MPa. The maximum allowable working pressure of polyethylene gas pipelines in the world is generally specified as 0.4MPa, such as the United States, Britain, France, etc. 1.0.3 The mechanical strength of polyethylene pipes is low, and the exposed pipes are easy to be damaged by collision, resulting in air leakage. At the same time, they are affected by ultraviolet rays and oxygen in the atmosphere, which will accelerate the aging. The change of temperature and the erosion of oil fume or other chemical agents are also detrimental to polyethylene pipes. Therefore, as an inflammable and explosive gas pipeline, polyethylene pipes should not be used as indoor and above-ground pipes. Internationally, it is generally stipulated that only buried pipes are used. 1.0.4 This item is specified to emphasize the materials used in polyethylene gas pipeline engineering, that is, pipes and fittings must comply with the current national standards “Buried Polyethylene Pipes for Gas” and “Buried Polyethylene Pipes for Gas” Requirement, so as to ensure the quality of the project and the safe gas supply. 1.0.5 Urban gas is flammable, explosive and toxic (artificial gas). Moreover, polyethylene gas pipelines have some unique characteristics compared with metal pipelines. Therefore, in order to ensure project quality and safe gas supply, it is necessary to require reasonable engineering design and good construction quality. This requires the design of polyethylene gas pipeline engineering and the construction unit to have certain technical strength. Only after this ability has been approved by the higher-level competent authority and relevant departments can they engage in the design and construction of polyethylene gas pipeline engineering. 1.0.6 This article emphasizes that the design, construction and acceptance of buried polyethylene gas pipeline engineering should be in accordance with the current national standard “Code for Design of Urban Gas” (GB 50028-93) and the current industry standard “Code for Construction and Acceptance of Urban Gas Transmission and Distribution Projects” “(CJJ 33-89) is used in conjunction with each other to coordinate and cooperate with each other, and at the same time, it should also meet the requirements of relevant standards to ensure the completion of project construction tasks. 4MPa For SDR l7.6 series pipeline: P=2×8.0/4×(17.6-1)=0.24MPa Therefore, the maximum allowable working pressure is 0.4MPa. The maximum allowable working pressure of polyethylene gas pipelines in the world is generally specified as 0.4MPa, such as the United States, Britain, France, etc. 1.0.3 The mechanical strength of polyethylene pipes is low, and the exposed pipes are easy to be damaged by collision, resulting in air leakage. At the same time, they are affected by ultraviolet rays and oxygen in the atmosphere, which will accelerate the aging. The change of temperature and the erosion of oil fume or other chemical agents are also detrimental to polyethylene pipes. Therefore, as an inflammable and explosive gas pipeline, polyethylene pipes should not be used as indoor and above-ground pipes. Internationally, it is generally stipulated that only buried pipes are used. 1.0.4 This entry is specified to emphasize the materials used in polyethylene gas pipeline engineering, that is, pipes and fittings must comply with the current national standards “Buried Polyethylene Pipes for Gas” and “Buried Polyethylene Pipes for Gas” Requirement, so as to ensure the quality of the project and the safe gas supply. 1.0.5 Urban gas is flammable, explosive and toxic (artificial gas). Moreover, polyethylene gas pipelines have some unique characteristics compared with metal pipelines. Therefore, in order to ensure project quality and safe gas supply, it is necessary to require reasonable engineering design and good construction quality. This requires the design of polyethylene gas pipeline engineering and the construction unit to have certain technical strength. Only after this ability has been approved by the higher-level competent authority and relevant departments can they engage in the design and construction of polyethylene gas pipeline engineering. 1.0.6 This article emphasizes that the design, construction and acceptance of buried polyethylene gas pipeline engineering should be in accordance with the current national standard “Code for Design of Urban Gas” (GB 50028-93) and the current industry standard “Code for Construction and Acceptance of Urban Gas Transmission and Distribution Projects” “(CJJ 33-89) is used in conjunction with each other to coordinate and cooperate with each other, and at the same time, it should also meet the requirements of relevant standards to ensure the completion of project construction tasks. 3 The mechanical strength of polyethylene pipes is low, and the exposed pipes are easily damaged by collisions, resulting in air leakage. At the same time, they are affected by ultraviolet rays and oxygen in the atmosphere, which will accelerate the aging. The change of temperature and the erosion of oil fume or other chemical agents are also detrimental to polyethylene pipes. Therefore, as an inflammable and explosive gas pipeline, polyethylene pipes should not be used as indoor and above-ground pipes. Internationally, it is generally stipulated that only buried pipes are used. 1.0.4 This entry is specified to emphasize the materials used in polyethylene gas pipeline engineering, that is, pipes and fittings must comply with the current national standards “Buried Polyethylene Pipes for Gas” and “Buried Polyethylene Pipes for Gas” Requirement, so as to ensure the quality of the project and the safe gas supply. 1.0.5 Urban gas is flammable, explosive and toxic (artificial gas). Moreover, polyethylene gas pipelines have some unique characteristics compared with metal pipelines. Therefore, in order to ensure project quality and safe gas supply, it is necessary to require reasonable engineering design and good construction quality. This requires the design of polyethylene gas pipeline engineering and the construction unit to have certain technical strength. Only after this ability has been approved by the higher-level competent authority and relevant departments can they engage in the design and construction of polyethylene gas pipeline engineering. 1.0.6 This article emphasizes that the design, construction and acceptance of buried polyethylene gas pipeline engineering should be in accordance with the current national standard “Code for Design of Urban Gas” (GB 50028-93) and the current industry standard “Code for Construction and Acceptance of Urban Gas Transmission and Distribution Projects” “(CJJ 33-89) is used in conjunction with each other to coordinate and cooperate with each other, and at the same time, it should also meet the requirements of relevant standards to ensure the completion of project construction tasks. 3 The mechanical strength of polyethylene pipes is low, and the exposed pipes are easily damaged by collisions, resulting in air leakage. At the same time, they are affected by ultraviolet rays and oxygen in the atmosphere, which will accelerate the aging. The change of temperature and the erosion of oil fume or other chemical agents are also detrimental to polyethylene pipes. Therefore, as an inflammable and explosive gas pipeline, polyethylene pipes should not be used as indoor and above-ground pipes. Internationally, it is generally stipulated that only buried pipes are used. 1.0.4 This entry is specified to emphasize the materials used in polyethylene gas pipeline engineering, that is, pipes and fittings must comply with the current national standards “Buried Polyethylene Pipes for Gas” and “Buried Polyethylene Pipes for Gas” Requirement, so as to ensure the quality of the project and the safe gas supply. 1.0.5 Urban gas is flammable, explosive and toxic (artificial gas). Moreover, polyethylene gas pipelines have some unique characteristics compared with metal pipelines. Therefore, in order to ensure project quality and safe gas supply, it is necessary to require reasonable engineering design and good construction quality. This requires the design of polyethylene gas pipeline engineering and the construction unit to have certain technical strength. Only after this ability has been approved by the higher-level competent authority and relevant departments can they engage in the design and construction of polyethylene gas pipeline engineering. 1.0.6 This article emphasizes that the design, construction and acceptance of buried polyethylene gas pipeline engineering should be in accordance with the current national standard “Code for Design of Urban Gas” (GB 50028-93) and the current industry standard “Code for Construction and Acceptance of Urban Gas Transmission and Distribution Projects” “(CJJ 33-89) is used in conjunction with each other to coordinate and cooperate with each other, and at the same time, it should also meet the requirements of relevant standards to ensure the completion of project construction tasks. 5 Urban gas is flammable, explosive and toxic (artificial gas). Moreover, polyethylene gas pipelines have some unique characteristics compared with metal pipelines. Therefore, in order to ensure project quality and safe gas supply, it is necessary to require reasonable engineering design and good construction quality. This requires the design of polyethylene gas pipeline engineering and the construction unit to have certain technical strength. Only after this ability has been approved by the higher-level competent authority and relevant departments can they engage in the design and construction of polyethylene gas pipeline engineering. 1.0.6 This article emphasizes that the design, construction and acceptance of buried polyethylene gas pipeline engineering should be in accordance with the current national standard “Code for Design of Urban Gas” (GB 50028-93) and the current industry standard “Code for Construction and Acceptance of Urban Gas Transmission and Distribution Projects” “(CJJ 33-89) is used in conjunction with each other to coordinate and cooperate with each other, and at the same time, it should also meet the requirements of relevant standards to ensure the completion of project construction tasks. 5 Urban gas is flammable, explosive and toxic (artificial gas). Moreover, polyethylene gas pipelines have some unique characteristics compared with metal pipelines. Therefore, in order to ensure project quality and safe gas supply, it is necessary to require reasonable engineering design and good construction quality. This requires the design of polyethylene gas pipeline engineering and the construction unit to have certain technical strength. Only after this ability has been approved by the higher-level competent authority and relevant departments can they engage in the design and construction of polyethylene gas pipeline engineering. 1.0.6 This article emphasizes that the design, construction and acceptance of buried polyethylene gas pipeline engineering should be in accordance with the current national standard “Code for Design of Urban Gas” (GB 50028-93) and the current industry standard “Code for Construction and Acceptance of Urban Gas Transmission and Distribution Projects” “(CJJ 33-89) is used in conjunction with each other to coordinate and cooperate with each other, and at the same time, it should also meet the requirements of relevant standards to ensure the completion of project construction tasks.