To weld transformer oil tanks the Chinese company Shandong Mingrun relies on the know-how and the expertise of Carl Cloos Schweisstechnik GmbH. The new welding system is nearly 40 m long and consists of three stations and two 7-axis robots, type QIROX QRC-410-E. It allows a flexible processing of the different component types. The robot system is programmed offline with the RoboPlan software by CLOOS. This increases the efficiency and the quality of the hall production many times over.