... 3. Metal pump: precision casting. 4. Longer diaphragm life Our air operated diaphragm pump is different from most of other Chinese ... and even can simultaneously convey two different liquids. Longer diaphragm life. Diaphragm material from Dopont, Exxon. Pilot type air valve, ... for well seal, Strengthen the pump structure, produce good diaphragm for long service time.We treasure the opportunity to ...