Machine by using the material classification can be divided into several htf exhaust fans, such as steel fan (ordinary fan), FRP fan, plastic fan, fan aluminum, stainless steel, etc. 2. blower fan in the direction of gas flow classification can be divided into centrifugal, axial, mixed flow (Francis) and cross-flow and other types. 3. According to the flow direction of the fan airflow into the impeller into: axial fans, centrifugal fans and mixed flow (Francis) fan. 4. fan use is divided into push-local fan (hereinafter referred to as the push-fan) and flameproof motors placed runner outside or within the flow channel, explosion-proof electric motor placed in the sealed chamber of withdrawable local fan (hereinafter referred to as extraction fan). 5. A fan in the form of pressure can be divided into single-stage, two-stage or multi-stage pressure fan. 4-72 as a single-stage compression, blower fan is a multi-stage pressure blower 6. division can be divided according to use: axial fan, Francis fan, blower, roof fans, air-conditioning fan and so on. 7. Press the pressure can be divided into low pressure blower fan, pressure fan, I produced all kinds of high pressure air dampers, fire dampers, exhaust valves, control valves, etc., series: Round zipper butterfly, butterfly handle row Smoke fan, square zippered butterfly double speed exhaust fan, round flapper valve, flapper valve square, circular valve, square valve, smoke damper remote control, remote control exhaust valves, exhaust fire dampers, exhaust valves, automatic smoke fire FHZ, fire and smoke control valve FYFH-3 FYFH-7, since hanging over plate damper FHF-1 FHF-2 FHY-1, ceiling dampers FHX, fire valve FHT-2 FHT-7, a small fire control valve FHT-4 FHT-5 Beijing heating unit supplied by Air Conditioning Equipment Co., Shandong GREAT fan. Air Conditioning Equipment Co., Ltd. Shandong GREAT fan (www.greatfengji.com) is a leader in Dezhou, fans, ventilation equipment, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customers needs. GREAT leadership in the staff warmly welcome all inquiries negotiations to create a better future GREAT.