... 1. Actual dry suction: 4~7m. 2. Plastic pump: Flange connection. 3. Metal pump: precision casting. 4. Longer diaphragm life Our air operated ... diaphragm pump is different from most of other Chinese pump for well mannfactured, well seal and ... the ball is very round for well seal, Strengthen the pump structure, produce good diaphragm for long service time.We treasure ...