石油、石化和天然气工业.防止杂散电流对管道系统的腐蚀

[中文适用范围]： 本文件确立了评估和最小化由交流和直流电干扰引起的埋地或浸没管道系统外表面杂散电流腐蚀影响的一般原则。 本文件未涵盖其他杂散电流影响，例如过热和焊接操作干扰。 提供了交流效应的简要描述、一般原则和一些指南。 注 1：也可能受到杂散电流影响的系统包括埋地或浸没的金属结构，如下所示： a) 管道系统； c) 储罐和容器； e) 混凝土中的钢筋； b) 金属护套电缆； d) 接地系统； f) 钢板桩。 本文件提供了以下方面的指南： - 可能产生杂散电流的阴极保护系统的设计； - 埋地或浸没的、可能受到杂散电流腐蚀的管道系统或管道系统元件的设计；以及 -选择适当的保护或缓解措施。 本文件未详细讨论杂散电流造成的内部腐蚀风险，但本文所述的原则和措施可用于最大限度地减少干扰影响。 注 2：EN 50443、IEC 61140、IEC 60364-4-41、IEC 60479-1、IEC 60364-5-52、IEC/TS 61201 和 IEC/ TR 60479-5。 本文件还可用于石化和天然气行业以外的管道系统以及其他埋地或浸没结构。 注 3 EN 50162 为铁路相关结构提供了指导。 [外文原描述]： This document establishes the general principles for the evaluation and minimization of the effects of stray current corrosion on external surfaces of buried or immersed pipeline systems caused by AC and DC electrical interference. Other stray current effects such as overheating, and interference with welding operations are not covered in this document. A brief description of AC effects, general principles and some guidelines, are provided. NOTE 1 See ISO 18086 for the effects of alternating current on buried or immersed pipelines. Systems that can also be affected by stray currents include buried or immersed metal structures such as the following: a) pipeline systems; b) metal sheathed cables; c) tanks and vessels; d) earthing systems; e) steel reinforcement in concrete; f) sheet steel piling. This document gives guidelines for — the design of cathodic protection systems that might produce stray currents, — the design of pipeline systems, or elements of pipeline systems, which are buried or immersed, and which can be subject to stray current corrosion, and — the selection of appropriate protection or mitigation measures. Internal corrosion risks from stray currents are not dealt with in detail in this document but principles and measures described here can be applicable for minimizing the interference effects. NOTE 2 The impact of electromagnetic interference on above-ground appurtenances of pipeline systems is covered in EN 50443, IEC 61140, IEC 60364-4-41, IEC 60479-1, IEC 60364-5-52, IEC/TS 61201 and IEC/TR 60479-5. This document can also be used for pipeline systems outside of the petrochemical and natural gas industries and other buried or immersed structures. NOTE 3 EN 50162 provides guidance for railway related structures.