Our products centrifugal steel pipe towers and pure steel pipe towers made according to DL/T5030-1996 “Technical Criterion of Thin Centrifugal Steel Pipe and Concrete Structure” and DL/T646-1998 “Technical Conditions of Steel Pipe Structure for Electrical Power Transmission Lines” issued by Ministry of Electrical Power Industry have passed the tests in Hangzhou Concrete Electrical Pole Quality Testing Center of Ministry of Electrical Power Industry.