At present, there are a lot of kinds of corrosion-proof centrifugal ventilating fan used in transportation and exhaustion of industrial waste gases. Normally they are made of hard polyvinyl chloride, polyester glass fiber reinforced plastic or stainless steel etc. These fans have their insurmountable weaknesses in application. As the strength of the vane is low, the hard polyvinyl chloride fan can only be used in low pressure field, and has short service life because it is easily aged. Due to limitation of processing technologies, the strength of the vane and their air dynamic properties of the polyester glass fiber reinforced plastic fan can hardly meet the requirement of application. For the stainless steel fan, as it requires high construction cost and large investment, it is hardly to be accepted by customers.  With the support of concerned units, our company has researched and manufactured new-type GBF4-72-12 serial centrifugal ventilating fan. Taking quality carbon steel as the frame of the vane, by means of special technological method to combine steel-made vane with polyester into compound product with corrosion-proof and high strength, this fan has not only the corrosion –resisting property what the full polyester glass fiber reinforced fan has, but also the structural strength of the steel-made fan whose air property can reach that of 4-72 fan with plain curve. It has advantages of wide application range, low noise and long service life. After proved by application, it is rather ideal corrosion-proof fan at present