Classification of diaphragm pump diaphragm materials and their performance applications

Thread Content

Diaphragm pumps are mainly divided into pneumatic diaphragm pumps and electric diaphragm pumps. Pneumatic diaphragm pumps are positive displacement pumps that use compressed air as power; the volume change in these pumps is caused by the reciprocating deformation of a diaphragm. Their working principle is similar to that of piston pumps. Due to the characteristics of their operating principle, the diaphragm becomes an important component in pneumatic diaphragm pumps. Additionally, because of the reciprocating movement of the positive displacement chamber, the diaphragm is also considered a wear-prone part. Therefore, it is particularly important to select the appropriate diaphragm material depending on different operating conditions. 　　The materials used for the diaphragms in pneumatic diaphragm pumps include: neoprene, nitrile rubber, fluororubber, ethylene propylene diene monomer rubber, perfluoroethylene propylene, Teflon, and others. Below, we will introduce the properties and applications of each of these materials separately. 　　Neoprene: An excellent diaphragm for general use, suitable for transporting non-corrosive liquids such as those used in sewage treatment, tap water, or seawater. It offers good flexibility, is cost-effective, and durable. 　　Nitrile rubber: An excellent choice for transporting petroleum and oily liquids, such as leaded gasoline, diesel, hydraulic oil, kerosene, and engine oils. This diaphragm is suitable for transporting non-corrosive slurries with high specific gravity and viscosity. 　　Fluororubber: The best choice for pumping fluids at extremely high temperatures, with a maximum temperature tolerance of 176 degrees. It can also transport certain corrosive liquids, such as essences, chlorinated hydrocarbons, as well as highly corrosive acids and bases and other chemical substances. Ethylene propylene diene monomer rubber: the best choice for pumping at extremely low temperatures, capable of operating down to minus 51 degrees; it can also be used for pumping dilute acids or liquids with low corrosivity. Perfluoroethylene propylene: it is more expensive, possesses excellent corrosion resistance, and has better flexibility than polytetrafluoroethylene, making it suitable for use with corrosive media at lower temperatures. 　　Polytetrafluoroethylene: abbreviated as PTFE, it is also known as “Teflon”, “Teflon”, “Teflon” etc. It possesses resistance to acids and alkalis as well as to various organic solvents; it is practically insoluble in all solvents. Non-stick coatings made from this material can be used continuously at 260°C, with a maximum operating temperature of 290–300°C. It features an extremely low coefficient of friction, good wear resistance, and excellent chemical stability. Therefore, polytetrafluoroethylene is the most widely used material in diaphragm pumps. Of course, its price is also the highest among all materials. It is generally used in environments with high temperatures, strong acids and bases, as well as other highly corrosive conditions.