A filling system has a filling apparatus (200) and a container arrangement inserted into the filling apparatus. A main line includes a feed line (102), connected to a supply container (304), and a trunk line (104), connected linearly downstream of the feed line (102). Outside the trunk line (104), at a branching point (114), a branch line (116) branches from the main line (102) to a compressed-gas source (306), and the main line (102) and the branch line (116), on that side of the branching point (114) which is directed away from the trunk line, pass through a double-valve arrangement (214) having two hose-clamping valves (214a, 214b) controlled oppositely to one another.