... , hydraulicpower supply, electric control system and computer system.In screwing on, thedouble-pump change speed automatically, screwing on ... on inlow speed, not only to improve efficiency, also in line with API standard. Its operation system (including:operation carbinet, ... see table) , one manual instruction, one pressure - torque table. model specificationYNJX-230/20 Application23/8"-27/8"-31/2"-41 ...