石油和天然气行业.管道输送系统中埋置或所用海底管道的外部涂层.第3部分:安装接头涂层

[中文适用范围]： ISO 21809 的本部分规定了 ISO 13623 中定义的石油、石化和天然气工业中使用的管道运输系统的净化和浸没部分的无缝或焊接钢管的现场接头涂层要求。 ISO 21809 的本部分规定了资格通过焊接连接管道和配件（组件）后，对钢表面进行防腐涂层的应用和测试。 ISO 21809 的这一部分不涉及额外的机械保护、隔热或混凝土配重涂层管道的接头填充的要求。 注：按照 ISO 21809 本部分进行涂层的管道和配件的现场接头被认为适合通过阴极保护的方式进行进一步保护， [外文原描述]： ISO 21809-3:2016 specifies requirements for field joint coating of seamless or welded steel pipes for buried and submerged sections of pipeline transportation systems used in the petroleum, petrochemical and natural gas industries as defined in ISO 13623. This part of ISO 21809 specifies the qualification, application and testing of the corrosion protection coatings applied to steel surfaces left bare after the joining of pipes and fittings (components) by welding. ISO 21809-3:2016 defines and codifies in Table 1 the different types of field joint coatings for pipelines. ISO 21809-3:2016 does not address requirements for additional mechanical protection, for thermal insulation or for joint infills of concrete weight-coated pipes. NOTE Field joints of pipes and fittings coated in accordance with this part of ISO 21809 are considered suitable for further protection by means of cathodic protection.