Abstract: A closed system for gaining sellable petroleum coke pieces out of solidified petroleum coke in a coke drum unit, comprises a coke drum unit containing solidified petroleum coke; a coke crushing unit for crushing petroleum coke into sellable petroleum coke pieces; a closed slurry pipe leading petroleum coke slurry to a closed slurry pit; a dewatering bin unit for receiving petroleum coke slurry from the slurry pit, for collecting the sellable petroleum coke pieces and for leading filtered water and petroleum coke fines out of it; a closed drain water pit, separate from the slurry pit, for receiving the filtered water and the petroleum coke fines from the dewatering bin unit; a water settling tank receiving the filtered water and the petroleum coke from the drain water pit and for separating the petroleum coke fines from the water such that the petroleum coke fines collect in the bottom part of the water settling tank, and for leading the petroleum coke fines into the slurry pit where they mix with the petroleu