Pump Three semi Hydraulic membranes for use in low-pressure regime. Parts in contact with the pumped liquid aluminum plasticized Rilsan and AISI 303/304. Membranes BlueFlex ™. Seals in NBR. Carter die with mechanical in oil bath, in a transparent plastic material tank for visual level control. Supplied hydro-pneumatic damper for greater regularity of operation and minor pulsations in the delivery circuit. A request for remote control sensor. A kit required for remote mounting of the oil tank. Oil drain plug. Pistons with segment for a greater protection of the membrane system efficiency to “oil cushion”. Valves with spherical sector profile that oppose less resistance to the passage of the liquid and improve the volumetric efficiency. Feet robust and fixed to the pump casing. Complete with over pressure valve with reset and the cardan shaft protection. Geomet screws.