Apparatus for pumping fluid through plural flow lines comprising a pump having an inlet and an outlet for transporting the fluid therethrough, first and second flow lines that are selectively connectable to the pump inlet via a first valve, and third and fourth flow lines that are selectively connectable...http://www.google.fr/patents/US4885001?utm_source=gb-gplus-shareBrevet US4885001 - Pump with plural flow lines
