DIN EN ISO 21809-5:2019-01
石油和天然气工业-管道运输系统中使用的埋地或水下管道的外部涂层-第5部分:外部混凝土涂层
Petroleum and natural gas industries - External coatings for buried or submerged pipelines used in pipeline transportation systems - Part 5: External concrete coatings (ISO 21809-5:2017); German version EN ISO 21809-5:2017