All tanker required equipped inert gas system that serves to safeguard the existing air cavity in the tank in order to have the maximum amount of oxygen is 8%. K.M.Gandini has a capacity of loading unloading capacity m3 42.875 payload of 1,200 m3/h. Inert gas system used is a Daewoo Heavy IND. Ltd. with Nozzle size m14, fuel consumption 20 US gal/h. The purpose of this research is to know the working ability of the inert gas system in generating inert gas to fill the cavity of the tank of K.M.Gandini. The methods used library research with a descriptive exploratory approach. The results showed that the capacity of the inert gas produced is 1.505, 3 m3/h. with 7.8% oxygen levels, so that the inert gas system is quite operated 80% of its normal capacity.