The motor starts, driving the oil pump to normal pressure; Valve A activates, causing the small cylinder to rise. Accompanied by the simultaneous rise of three large cylinders, which also extract hydraulic oil from the oil tank, of course, with one-way valves in the intake. When resistance is encountered, Valve B is energized, loading the three large cylinders with oil pressure for bending work. Pressure is controlled by the servo valve. Upon returning, Valves A and B lose power, while Valve C gains power.