of the check valve 42 the non return valve 46 effects a spring loaded closure of the connection between the exterior 48 and the fluid line 44 the air volume enclosed for example in the fluid line 44 forms a damper element which likewise relieves the check valve 42 in the closed state and subsequent system parts of the filter against water hammers preferably the filter installation can be mounted upright by base legs 50 above the floor of the hall or deck 52 of the ship the filter 54 in the figure can be connected to a storage bottle 56 which can likewise be mounted upright above the floor or deck 52 and which preferably holds nitrogen gas as the inert gas under high pressure via a pressure reducer 58 and via a solenoid valve 60 which can be triggered from the outside the interior of the storage bottle 56 can be connected via a connecting line 62 to the filter 54 by one free end of the connecting line 62 extending through the sealing cover 12 and thus establishing a connection or fluid communication to the interior of the filter housing 10 furthermore at least for some of the filter elements 22 a sacrificial anode 64 made as a copper rod runs and extends concentrically in their interior and in their longitudinal directions this sacrificial anode 64 is preferably made as a solid rod and is releasably connected via a screw connection not shown to the upper sealing cap 26 of the respective filter elements 22 by permanent release of copper the sacrificial anode 64 is used up so that from time to time a new sacrificial anode 64 must be installed this replacement can optionally take place with replacement of a used filter element 22 as.