Compared with other line types, the subway is more testing for the professional ability of rail welding machine and welder.

According to reports, so far, the maximum design speed is 140 kilometers per hour, Line 18 is the fastest subway under construction in Chengdu and even in the southwest region. At the same time, it is also the "most difficult subway line".

Faced with relatively high intensity welding operation and high requirements for exhaust emissions, the Chengdu Rail Transit Line 18 Engineering Rail Project Department of Sinohydro Bureau 5 Co., Ltd (Line 18 Engineering Rail Project Dept.), which is responsible for the construction of this project, has made strict assessment on the welding performance, energy saving, environmental protection and exhaust emissions of the rail welding machine. After that, they choose to cooperate with Kiway Machinery to customize a K922 mobile flash rail welding machine to ensure efficient, stable and safe operation of rail welding on Line 18.

Qu Xuecheng, Project Manager of Track 2 Bid of Line 18 Project, has participated in and been responsible for many international infrastructure projects. For KIWAY K922 rail welding machine, he said: "The welding system is very stable and reliable."