Abstract: The common seal weld defect types and causes of titanium tubesheet in the service of condensers are classified and summarized, based on which the corresponding repair solutions are proposed including manual welding, automatic self-fusion welding, automatic wire filling welding and tube blocking, etc. According to the actual situation of defects, the specific welding repair process and implementation steps are taken, and the quality control measures and quality acceptance requirements are clarified, which is regarded as the reference for onsite repairs and quality control of seal welds of titanium tube plates of condensers, and effectively guarantees the safe operation of condensers.