Wall thickness：14mm

Length：167m

Application：Sewage pipe

Project Introduction：The repaired DN1200 pipe needed to cross the entire lake bottom, with a single repair section of 167 m connecting the lake shore and the central island at both ends.

Construction Challenge：

1. One of the two key working wells was located on a central island, some operating equipment was transported to the island via floating boards. The space on the island was limited, which greatly restricted equipment assembly and UV-CIPP liner preprocessing.

2. The pipe was buried 9m deep, and was below the groundwater level, creating an environment where the UV-CIPP liner cannot be completely water-resistant in practical application. Conventional rehabilitation materials were prone to performance degradation and uneven curing in such humid environments, thus placing extremely high demands on the waterproofness and stability of the liner.