Set for dispensing a flow of liquefied gas from a vessel containing the gas in liquid phase, comprising: - a supporting structure connecting a suction end and a discharge end, and adapted for being fitted tightly to the vessel so that, when the set is in the operation condition, the suction end is submerged in the liquefied gas within the vessel while the discharge end is located at an external surface of the vessel; - a pump maintained by the supporting structure so as to be submerged in the liquefied gas when the set is in operation condition for dispensing the liquefied gas flow, and adapted for driving the flow of liquefied gas from the suction end toward the discharge end; - a removable sealing assembly located at the discharge end of the supporting structure and adapted for sealing an aperture through a wall of the vessel when the set is in operation condition, and the sealing assembly is provided with a liquid outlet arranged on the sealing assembly and connected to a duct for discharging the liquefied gas flow driven by the pump when the set is in operation condition; and - a conditioning system adapted for cooling or warming up the liquefied gas, - the supporting structure and the sealing assembly designed so that the pump is movable within the vessel by means of said supporting structure when said pump is to be extracted from or introduced into said vessel, - the conditioning system and the supporting structure being adapted so that the conditioning system is maintained within the vessel by the supporting structure in addition to the pump, between the suction end and the discharge end when the set is in operation condition, the supporting structure being further adapted so that the conditioning system is also movable within the vessel by means of said supporting structure when said conditioning system is to be extracted from or introduced into said vessel; characterised in that the supporting structure is oriented vertically in the operation condition within the vessel. - a supporting structure connecting a suction end and a discharge end, and adapted for being fitted tightly to the vessel so that, when the set is in the operation condition, the suction end is submerged in the liquefied gas within the vessel while the discharge end is located at an external surface of the vessel; - a pump maintained by the supporting structure so as to be submerged in the liquefied gas when the set is in operation condition for dispensing the liquefied gas flow, and adapted for driving the flow of liquefied gas from the suction end toward the discharge end; - a removable sealing assembly located at the discharge end of the supporting structure and adapted for sealing an aperture through a wall of the vessel when the set is in operation condition, and the sealing assembly is provided with a liquid outlet arranged on the sealing assembly and connected to a duct for discharging the liquefied gas flow driven by the pump when the set is in operation condition; and - a conditioning system adapted for cooling or warming up the liquefied gas, - the supporting structure and the sealing assembly designed so that the pump is movable within the vessel by means of said supporting structure when said pump is to be extracted from or introduced into said vessel, - the conditioning system and the supporting structure being adapted so that the conditioning system is maintained within the vessel by the supporting structure in addition to the pump, between the suction end and the discharge end when the set is in operation condition, the supporting structure being further adapted so that the conditioning system is also movable within the vessel by means of said supporting structure when said conditioning system is to be extracted from or introduced into said vessel;