超重型电气刚性钢导管

[中文适用范围]： 本文件规定了用于电气安装（包括通信和光纤）的超重型电气刚性钢（EHDERS）导管、耦合器、短接和弯头的技术要求。本文件还规定了这些组件的螺纹要求。 不适用于IEC 60423中规定的导管。 [外文原描述]： IEC 60981:2019 RLV contains both the official IEC International Standard and its Redline version. The Redline version is available in English only and provides you with a quick and easy way to compare all the changes between the official IEC Standard and its previous edition. IEC 60981:2019 specifies requirements for extra heavy-duty electrical rigid steel (EHDERS) conduits, couplings, nipples and elbows for electrical installations, including communications and fibre optics. This document also specifies threads for these components. It is not applicable to the conduits specified in IEC 60423. This third edition cancels and replaces the second edition published in 2004. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the second edition: - addition of provisions for alternative coatings to zinc; - addition of elasticity test for organic coatings; - new Annex B on tests for evaluating alternative exterior coatings applied on extra heavy­duty electrical rigid steel (EHDERS) conduits.