... min,Pressure:490~1800Pa,Voltage:380V/440V,50HZ/60HZ1. 4-72 series centrifugal ventilators or simply the ventilator is capable of ... Small starting torque.Strong resistance against swing,vibration and impact.4. STRUCTURE TYPEThe ventilator is designed and manufactured into a ... manufacturing, and is composed of one professor (part-time), 4 senior engineers, 11 secondary engineers, 2 technicians and 21 ...