Tools and Machinery
| Wed 11 Mar 2026
Beijing, March 11 -- China Oilfield Services has submitted a patent application for Engine Valve Grinding Tool. This invention was developed by Yan Xuelin, Xing Chengjun, Chen Jun, Wang Shouquan, Wang Jianfu, Liu Zisheng, Yu Zhaosheng, Chen Changqiu, Zhang Zhiwei, Ping Yuan, Jin Hao, Song Liqiang, Fang Chuanfeng and Zhang Tianha..