Semi-hydraulic three-diaphragm pump, for use in low pressure systems. Parts in contact with pumped liquids in reinforced polypropylene and AISI 303/304. Diaphragms in NBR. Seals in NBR. Die-cast casing with oil-immersed mechanism and clear plastic tank for visual level checking. Remote oil tank installation kit available on request. Oil drainage stopper. Pistons with ring for a more efficient “oil cushion” system to protect the diaphragm. New-design diaphragm cut-out system to prevent contact tearing even in heavy-duty operating conditions. Spherical sector profile valves for lower flow resistance and improved volumetric efficiency. Rugged feet secured to pump casing. Complete with drive shaft guard. Geomet metal fasteners. Available with reduction gearbox for electric motors or internal combustion engines, pulley fixtures or flanges for hydraulic motors.