Neoprene Diaphragm 056L20561for the most low-pressure self-priming diaphragm pump 3" (80mm) :
-LIBELLULA 1-3"(Italy, made by Caffini)
-Dai-Shin 3"(Japan)
-KOSHIN 3" (USA)
powered by Honda and HATZ engines.
 
Features:
Indefinite dry-running capability.
Rapid dry self-priming up to a depth of 7 metres in seconds.
No seal or rotating part in contact with the pumped liquid.
It can be used where there are abrasive or acid fluids.
Wide passage for solid bodies.
Flow rate proportional to number of diaphragm pulses.
Straightforward, occasional maintenance.
 
Characteristic:
• Honda GX160 engine with electronic ignition system and oil alert.
• Diaphragm and valves made of Neoprene.
• New pump design with Die-casted aluminium.
• The connection rod is rigid and self-lubricated.
• Gearbox with helical teeth.
 
Applications:
• Suitable for sandy and muddy water with particles up to 50 mm
• Washing of livestock, barns or agricultural equipment
• Building and public works sector. The capacity to run dry enables the operation to keep the ditch dry even when it contains mud and suspended solids. 
• Pumping water from wells, drainage excavations in repairs of waterworks, sewers, and gas networks. Draining excavations, and cleaning manholes. Pumping bentonite and drilling mud.
• Emergency relief operations following natural calamities. The possibility to operate despite large pieces of waste makes these machines ideal for removing mud or water from cellars or other sites.
• Draining cellars, cleaning wells and manholes.
• Diaphragm pumps are successfully used in the water purification field. They are excellent in flotation equipment applications in the presence of solids, abrasive substances or suspended fatty substances.
• Water treatment industry: Sludge pumping, cleaning septic tanks, dosing lime milk, pumping water from dyeing plants and water cutting(water jet cutting).
• Marble and ceramics industry: great advantages in extraction activities and inactivities linked to the processing of marble. Their structure is designed not to be affected by the abrasiveness of marble dust or similar substances.
• Cutting water pumping and processing, pumping out settled sludge.
• Food industry: ideal for numerous applications, some of which include the pumping of potato pulp and waste, fruit juice, and syrup still containing stones or frozen parts.
• Animal breeding industry: frequently used by companies in the zootechnical and breeding sector for the suction of clean blood or blood with suspended waste and offal of all kinds produced during the processing phases of poultry farming. Pumping blood and slaughterhouse waste, liquid manure, fertilizers, and liquid feed.
• Ship/aircraft industry:  on boats as bilge pumps and for empty tanks. In this application, their total
reliability and capacity not to be affected by all types of waste likely to cause malfunctioning
in other equipment are greatly appreciated. Draining bilges, evacuation of toilet sewage, tank cleaning.
• Mechanical and chemical industry: machinery that is constantly exposed to aggressive substances. Safety and reliability are guaranteed by a wide choice of parts in metal and elastomers, depending on whether they are to be used with acid or base fluids in the presence of abrasives or solid bodies. Pumping acidic or basic liquids, water paints, emulsions, and latex (rubber production).
• Textile industry: the diaphragm pumps equipped with clapet valves thanks to the great passage of solid, are applied to pump wastewater containing fibres, without that the pump will have damage. The wide choice of the parts in contact with liquid and rubber parts also ensures resistance to chemicals present in the liquid. Pumping liquid from the washing of textiles and fibre treatments.
• Paper industry: party and thick liquids, can be easily pumped with diaphragm pumps, which also provide the unique ability to run dry indefinitely. Pieces of wood and dirt contained in the liquid, do not at all hinder the proper functioning. Pumping water containing wood chips, and wood pulp.
 
Working principle:
Diaphragm pumps series Libellula is reciprocating positive displacement pumps.
The membrane is fixed to a connecting rod and mechanically moved by a crank mounted on the speed reducer output. The displacement of liquid in the pump body, generated by the movement of the diaphragm, is controlled in suction and delivery by two check valves. 

In the suction phase, the diaphragm moving upward creates a vacuum that draws the liquid by opening the inlet valve. When the diaphragm moves downwards, the inlet valve is closed by gravity and at the same time, the liquid is expelled through the outlet valve, which opens at this stage.
It is necessary, for this type of pump, that the pressure line is a suitable diameter and free to discharge the pumped liquid, to prevent the discharge pressure exceeds the granted limit, causing breakage of the membrane or mechanical parts damage. To prevent vibrations transmitted in the
pipework from the running pump, it is advisable to connect the plant with a flexible hose.