Three-piston alternative volumetric pump designed for washing units and industrial systems, with options for direct motor connection or coupling via an elastic joint. The die-cast aluminum alloy body features side covers available closed or with oil level indicators, plus a rear cover equipped with both drain and oil level. Piston motion is driven by a robust connecting-rod/crank system, supported by a high-resistance pressed steel shaft and oversized main bearings. Anti-friction connecting rods in special zinc alloy or die-cast aluminum enhance durability. The unit features full ceramic pistons and a stamped brass pump head, with an optional nickel-plated brass head on request. A double-seal system ensures reliable sealing, while suction and delivery valve plugs facilitate easier maintenance.