Generally speaking, a diaphragm pump moves fluids using a two-part cycle. In the first part, the diaphragm is pulled away from the input/output valves so that the volume of the chamber increases. This increase in volume results in a decrease in pressure within the chamber relative to the input and output, creating a vacuum effect that draws fluid in. Check valves on the input and output connections ensure that fluid can only enter the chamber through the input connection. A diaphragm pump is a positive displacement pump that uses a flexible membrane to pump fluids. The pump uses a series of check valves to ensure that fluid can only travel in one direction through the chamber. The diaphragm itself can be expanded and contracted using pressurized air or fluids, or motors. 1.advantage 1     small volume2.     superior pressure technology3.     Dry, durable, maintenance free4.      Extreme chemical stability5.     Mini design6.      Bear  greater pressure7.      Long life 2.usage range       Analysers    · Medical / pharmaceutical    · Environmental / water treatment    · Food / toxicology     Laboratory  · Filtration   · Chromatography   Cleaning industry · Cuvette cleaning · Sterilisers · Industrial washing machines  Printing · Ink jet printing· Photographic / film development  Other applications for diaphragm liquid pumps include: fuel cells, hydrogen generators, CD coating, dental technology, textiles and many more. 3. The motor selection:  KA:24VDC brush motor(56mm)          KB:24VDC brushless motor(67mm) KC:12VDC brush motor(56mm)          KD:12VDC brushless motor(67mm) KE:6VDC brush motor(56mm)          KG:24VDC brush motor(82.5mm)        KH:12VDC brush motor(82.5mm) KI:6VDC brush motor(82.5mm)  4 Pump head selection one or two pump heads  5The flow rate   one head pump:800-850ml/min two head pumps:1600-1700ml/min