Semi-hydraulic four-diaphragm pump, for use in low pressure systems. Parts in contact with pumped liquids in plastic-coated aluminium Rilsan 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. Fitted with air-hydraulic damper for smoother operation and less hammer effect in the delivery circuit. Remote level monitoring sensor on request. Remote oil tank installation kit available on request. Oil drainage stopper. Pistons with a ring for a more efficient “oil cushion” system to protect the diaphragm. Spherical sector profile valves for lower flow resistance and improved volumetric efficiency. Rugged feet secured to pump casing. Mass-produced safety valve and cardan protection. Geomet metal fasteners. Kit for combining two pumps to form a modular unit to supply the sprayer’s various uses.