* tmodel t40 axial fan is applicable for the ventilation, air-exchange, warm air radiation reinforcement in the ordinary factory, war ehouse, office, residence and so on. it can be used as free fan after the removal of the casing. it can implement the interval series connecting installation in the long exhaust pipelines in order to enhance the air pressure in the pipelines. this series product adopts external placement of motor belt transmission (the motor is in the casing) in aspect of structural design according to the user’s requirement. the model is kt40. its perfor- mances and parameters are the same as t40 fan.it can also change the rotational speed to fulfill the user’ s required performance according to the user’s gas or moisture-proof gas demands. its max function is to exhaust the high-temperature.