Asphalt pumps are gear pumps for heat transfer thicken at room temperature, solidification or crystallization temperature, and easy to maintain a certain flow of media and design, such as asphalt, paraffin, liquid rosin, and of a similar nature. Insulation asphalt pump for conveying medium temperature 300 ℃, viscosity of less than 1500mm2 / s, solid particles of bitumen, paraffin and other at room temperature, the material has solidified, and the alpine areas, outdoor installation requirements and process in the heat of the occasion. Can pass into the thermal oil, hot water, steam and other media for heating and heat transfer. 
 Asphalt can be used as high-temperature heat pump gear pumps used for conveying solid particles, the temperature is not higher than 300 ℃ of heavy oil, bitumen, resins, detergents, plastic and other classes are solidified at room temperature, the media, especially for outdoor installation in the alpine region in the medium and process heat needs of the occasion, medium temperature up to 300 ℃, the viscosity range of 5-1500cst. When the transmission medium viscosity is greater than 1500cSt should slow down transmission mode used.