自铁道部车辆局辆货发 [1995 ]4 9号文件《关于货车加装三通阀、安全阀防盗装置的工作安排》下发以来 ,大大遏制了铁路制动配件的丢失 ,保证了行车安全。但文件中并未对空重车转换塞门的防盗做出明确的规定 ,一段时期以来空重车转换塞门丢失十分严重。空重车转换塞门安装在制动 Since the issuance of the document “Work Arrangement on Three-way Valves and Safety Valve Anti-theft Devices for Trucks,” issued by the Ministry of Railways Vehicle and Vehicle Dept. [1995] No. 49, greatly deterring the loss of railway brake parts and ensuring traffic safety . However, the document did not make clear the provisions of anti-theft of empty heavy car conversion door, empty car conversion plug has been very serious for some time. Empty and heavy car conversion plug installed in the brake