GB/T 46424-2025Failure analysis method for oil and gas transportation pipeline girth welds (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part

1.Structure and Drafting Rules of Standardization Documents". Drafting. Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents. This document was proposed and is under the jurisdiction of the National Technical Committee on Standardization of Petroleum and Natural Gas (SAC/TC355). This document was drafted by: China Oil & Gas Pipeline Network Corporation, and the Science and Technology Department of China Oil & Gas Pipeline Network Corporation. Research Institute Branch, China Special Equipment Inspection and Research Institute, Anke Engineering Technology Research Institute (Beijing) Co., Ltd., China National Petroleum Corporation Pipeline Dao Science Research Institute Co., Ltd., Tianjin University, Beijing University of Aeronautics and Astronautics, China Petroleum Engineering Materials Research Institute Co., Ltd., and the State Administration of Science, Technology and Industry for National Utility Models. Pipeline Group Storage and Transportation Technology Development Co., Ltd., Beijing Zhiwang Digital Technology Co., Ltd., National Pipeline Group Engineering Technology Innovation Co., Ltd., and other companies. China Pipeline Network Group Southwest Pipeline Co., Ltd., China Pipeline Network Group Western Pipeline Co., Ltd., and China Oil & Gas Pipeline Network Group Co., Ltd. Limited Company West-East Gas Pipeline Branch, National Pipeline Group Beijing Pipeline Co., Ltd., Pipeline Group (Xuzhou) Pipeline Inspection and Testing Co., Ltd. The main drafters of this document are. Dai Lianshuang, Lei Zhengqiang, Feng Qingshan, Zhang Duihong, Zhu Xiping, Wang Xiuyun, Wang Haitao, Wang Fuxiang, and Fan Yuran. Deng Caiyan, Liu Yu, Wang Hankui, Liu Haichun, Zhang Zheng, Chen Hongyuan, Yan Bingchuan, Wang Ting, Su Xin, Luo Yanlong, Chen Jian, Li Rui, Wang Ailing, Tan Xiao, Zhou Daowu, Zhang Yanhui, Liu Yuting, Li Zhenglong, Yang Hui, Sha Shengyi, Jia Haidong, Guo Lei, Yao Dengzun, Zhang Yinhui, Wang Dongpeng, Huo Xiaotong, Xuan Wenbo Zhao Xiaoli and Zhu Quezhi. Failure Analysis Method for Circumferential Welds in Oil and Gas Pipelines

1 Scope

GB/T 46424-2025 is the Chinese national standard covering working out why a girth weld failed - the site evidence and the sampling, the fractography and the metallography, the weld procedure and the misalignment reconstructed from the joint, the loads including ground movement, and the conclusion that has to hold up in an inquiry. At 21,500 words. Girth weld failures caused several of China's serious pipeline incidents. First edition, in force from 1 May 2026. Issued on 5 October 2025, it has been in force since 1 May 2026.

This document establishes the process for failure analysis of circumferential welds in steel pipelines used for onshore oil and gas transportation, and specifies the procedures for information collection and failure analysis scheme preparation. This includes review, on-site sampling and sample protection, testing and analysis, failure analysis conclusions and reports, and storage of failure analysis samples and remaining samples. This document applies to the failure analysis of circumferential welds in steel pipelines used for onshore oil and gas transportation.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included. For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies. This document.

GB/T 228.1 Metallic materials - Tensile testing - Part

3 Terms and Definitions

The following terms and definitions apply to this document.

3.1 girthweld Circumferential welded butt joint of steel pipe.

Note. This includes the weld metal, fusion line, and heat-affected zone, also known as the weld joint.

3.2 failure The circumferential weld has lost or partially lost the functions specified in the original design, and is completely unable to serve, or can still serve but cannot operate safely and reliably. The state.

Note. Common failure modes of circumferential welds include plastic instability, corrosion, fatigue, and fracture.