A method for storage and transport of LPG on LPG carriers, in particular two cargoes of different LPG types on same shipment, having reliquefaction units (300, 400) in which vaporized gases are condensed and then returned into at least one cargo tank (100) for the respective LPG cargo type. The method is further comprising: using the reliquefaction units (300, 400), at a minimum one running, as to condense vapour from the first cargo type; passing the condensed vapour through a heat exchanger (500); simultaneously flowing vapour from the second cargo type through the heat exchanger (500) as to condense vapour by means of heat exchanging with the condensed vapour; and returning the condensed vapours leaving the heat exchanger back into the respective cargo types. The present invention is also disclosing a system for storage and transport of LPG on LPG carriers.
