... side roll device, balance device, tuning device, hydraulic system, electricity control system, NC system, lubricate device. 3-2 the main drive device ... hydraulic force. The adjustment of Pistons force controlled hydraulic system pressure values according to the up/down rolls clamping ... tank, pipe and so on. Pressure adjusted by overflow valve, system working pressure 0-19 MPa, normal pressure is 19.5Mpa ...