Self-priming diaphragm pumps

• Quick dry self-priming down to 8 m in afew seconds.
• Can run dry indefinetly.
• No rotating part in contact with the liquid: no shaft seal is required.
• High abrasion resistance.
• Large size solids handled. Liquids containing fibres or rags can be pumped.
• Capacity is proportional to speed.
• Simple construction. Weared parts are easily replaceable.

• Marble industry: cutting or dressing water circulation. pumping out settled sludge.
• Food industry: fruit juice, tomato juice, must, wort, wine lees.
• Textile industry: effluent from washing textiles or fibres.
• Paper industry: wood pulp, water containing wood chips.
• Shipbuilding industry: bilge pumping, toilet waste, stripping and cleaning tanks.
• Mechanical industry: circulation of liquids for rolling or picking, grinding, cutting and quenching oils.
• Chemical industry: acid or alkaline sludge, emulsions, water-based colours.
• Water treatment: pumping out neutralized sludge, cleaning cesspools.
• Agriculture and livestock: liquid manure, fertilizers, liquid animal feed, blood.
• Civil engeneering: frainage of excavations, ponds, cleaning manholes, recirculation of betonite and drilling mud.

Libellula pumps are diaphragm pumps with a coupling rod driven by a gear box speed reducer. The flow generated by the movement of the diaphragm is controlled by check valves at the suction and delivery. As the diaphragm rises away from the bottom of the casing it produces a vacuum whitch draws the liquid into the casing through the suction valve. When the diaphragm is on the downstroke, the liquid is expelled through the delivery valve. Libellula pumps are reciprocating positive displacement pumps. The delivery line must therefore have an adequate diameter and be free to discharge the liquid being pumped to avoid pressure build up which can damage the diaphragm or the drive mechanism. The pump should be connected to pipework using sections of flexible hose to avoid transmitting the pulsations of the pump to the rest of the system.