沥青防腐层龟裂原因分析
Analysis on the Chap of asphaltic Coating
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摘要: 沥青玻璃布防腐层是传统的行之有效的防腐结构, 广泛应用于油气管道防腐, 但防腐层处于过高的环境温度下, 会大大降低其使用寿命。中洛线濮阳首站出站管段防腐层, 投用不足3a, 便发生大面积龟裂现象, 经现场观察和东线各站抽样分析化验对比, 并查阅施工时的质量检查记录, 证明濮阳出站段防腐层过早老化龟裂的首要原因是防腐层长期在较高温度条件下使用, 其次是在沉管过程中管道热变形的影响。建议改性沥青的使用温度控制在60C以下为宜, 否则防腐层的使用寿命将会缩短。Abstract: Asphaltic coating which is widely used in corrosion protection of oil and gas pipeline is a conventional and effective' anti-corrosion structure, but the service life of this structural coating would be greatly reduced when it works at excessive high temperature.In the Puyang Initial Pump Station of Zhong-Luo Pipeline, the large scope of chap occured on the coating of outgoing line, which is used in less than three years.Comparing site investigation with sampling analyzing and experimental tests for all pump stations on the eastern Zhong-Luo Pipeline, and refering to the application records of quality control in constructional is proved that the first cause which the as-phaltic coating ages and chaps advancedly in Puyang Initial Pump Station is that the asphaltic coating has been working at a higher temperature, the second cause is the distortion of pipe occured during the pipe settlement is a influence factor.It is suggested that the application temperature of the modified asphalt should be properly controlled below 60 C, otherwise the service life of asphaltic coating will be reduced.