Definition - What does Diaphragm Pump mean?
A diaphragm pump is a hydraulically or mechanically actuated positive displacement pump that uses a combination of reciprocating action and either a flapper valve or a ball valve to transfer liquids.
Diaphragm pumps are self priming and are ideal for viscous liquids. Virtually all major industries utilize diaphragm pumps. They are commonly used to move abrasive fluids, including concrete, or acids and chemicals. They are also common in automobiles and aircraft.
A diaphragm pump is also known as a membrane pump, air operated double diaphragm pump (AODD) or pneumatic diaphragm pump.
Corrosionpedia explains Diaphragm Pump
Diaphragm pumps use the up-and-down movement of a cupped, elastic surface to generate liquid flow. This surface, found within the pump, is typically made from polytetrafluoroethylene (PTFE), Teflon, synthetic rubber or a similar material. When the surface is pushed into the liquid, it adds pressure and displaces a certain amount of fluid. When it is pulled back from the liquid, it draws in more fluid. The diaphragm pump uses check-valves to prevent the backflow of fluid through the entry valve.
Diaphragm pumps can be used to meter, dose and transfer liquids. They are suitable for either corrosive or non-corrosive liquids. The diaphragm design means there is no tubing to fatigue or break due to wear or corrosion.
Diaphragm pumps incorporate either hydraulic fluid or pistons to control the movement of the diaphragm. Low-lift, low-pressure pumps are designed to handle thick, viscous liquids, such as slurries or heavy oils, while others are engineered for high-flow applications and high pressures. Teflon diaphragm pumps, for instance, are used for high-precision, high-pressure industrial applications.
They have the ability to run dry for prolonged periods without incurring damage. Most wear is caused by the transported fluid rather than the action of the pump. Heavy duty pumps are designed to withstand extremely thick, sometimes corrosive liquids, although the proper housing material is required for such uses.