13:55 Feb 25, 2011 

'damper' is potentially ambiguous in the context of a printing machine, please can you see if there are any other clues in your text that might help; in particualr, any further mentions of either this particular 'damper', or this 'main filter' that seems to be associated with it in some way?
Gilles is perfectly right that in an offset litho machine, we do indeed have a 'daper (roller)' — but in the tiny snippet of context we have, this seems not to be a roller at all, but something that one might be able to "replace with in-line fittings".