Former of Turn Trajectory of Sliding Valve Shaft of Gas Line Vladislav. Yu. Dementyev, Nikolay. V. Gusev, Nikolay. V. Koyain and Sergey. Yu. Shiryaev MATEC Web Conf., 91 (2017) 01038 Published online: 20 December 2016 DOI: 10.1051/matecconf/20179101038