IMPROPER FITTING OF THE INERT GAS LINE N/R VALVE :
Is a chemical tanker, the jet fuel oil is about to be discharged at British island nearer to Srilanka (Where U.S. Naval base is present)
Ship’s Inert gas generator was started and all were normal. Chief officer informed E/R, that inert gas was not coming on deck. In E/R inert gas generator checked and found normal, electrically operated v/v in the deck line checked found normal.
On the deck, the lines were checked and the cause was found. During sailing the pump man had overhauled the NRV in the line and fitted it in opposite direction. Same fitted in right way and the problem was solved.