Basic Knowledge
Diaphragm Pump
How Does It Work?
A diaphragm pump (membrane pump) is a positive displacement pump that performs liquid transfer through the back-and-forth movement of a flexible diaphragm. According to the positive displacement principle, the pump transfers a fixed and predictable liquid volume in each stroke cycle; this characteristic provides a critical advantage especially in applications requiring precise dosing and process control. It is widely preferred in dozens of industrial fields such as chemical processing, food production, wastewater treatment, paint transfer, and mining.
Due to pump design, the fluid does not contact mechanical moving parts; it only contacts the diaphragm and pump body. This sealed structure provides superior safety in terms of leakage and prevents cross-contamination of the fluid with the external environment or mechanical parts. This allows abrasive, viscous, solid particle-containing, or chemically aggressive liquids to be safely transported.
The most commonly encountered type in industrial applications is double diaphragm pumps (AODD and EODD), in which two diaphragms move synchronously but in opposite directions on a common shaft. This design provides both a smoother flow profile and longer component life. They are manufactured in a wide range of sizes and capacities, from small single diaphragm models to large industrial double diaphragm types.
Correct selection of body and diaphragm material directly determines the pump's chemical compatibility, service life, and safety. Models with polypropylene (PP) or PVDF bodies offer high resistance to corrosive chemicals, while stainless steel body hygienic models serve sectors with strict hygiene standards such as food, pharmaceutical, and cosmetic industries.
