Fracture failure analysis of pressure gauge bolt on fuel gas system of offshore platform

•Facture failure analysis of bolt on offshore platform has been performed.•The failure of bolt is caused by stress corrosion cracking of metal materials.•Chloride ions on bolt fracture are derived from seawater droplets.•Poor corrosion resistance of bolt materials is the main cause of the failure. Gas turbine generator unit is the most important equipment on the offshore platform, the reliability of pressure gauge on its fuel gas system affects the operation of the entire platform equipment. In this paper, an abnormal fracture failure of pressure gauge bolt on fuel gas system of offshore platform was investigated. Series experiments of visual examination, chemical analysis, fractography analysis, metallographic analysis, and hardness analysis were conducted on the pressure gauge bolts. Thereafter, the failure mechanism of the pressure gauge bolt was discussed based on the experimental results and bolt service environment. It was concluded that the bolt was fractured due to the stress corrosion cracking, and the poor corrosion resistance of bolt materials is the main cause. Finally, countermeasures were proposed to address similar problems.