It was learned on August 4 that the National 863 project "key technology of underwater structure repair system based on friction lap welding" undertaken by COOEC in the 12th Five Year Plan has completed the development of underwater friction lap welding principle prototype and entered the preparation stage of engineering prototype development.

"Friction lap welding technology is less affected by water depth," said Yang Fan, a welding engineer. Traditional manual arc welding is affected by deep-water water pressure and water flow, and its stability and welding adhesion will be greatly reduced. If it is careless, there will be welding joint deviation, which will affect the work efficiency and quality of the whole pipeline. The friction stack welding technology uses the principle of consuming plug rod, and the pressure provided by it can directly fill the plug rod into the air hole to complete the welding, so the underwater welding is more efficient and stable. Xu Wei, a welding engineer, said: "the friction lap welding repair system for underwater structures provides a new development idea for China's offshore engineering to go deep water." (correspondent Liu Guangya, Yang Fan, Liu Bin)