Patent ID: 7314547

Claim:
In combination with a printing press of the type having a fountain solution recirculating system comprising a fountain solution recirculation pump for withdrawing fountain solution from a fountain solution tank, for circulating the withdrawn fountain solution through the press, and for returning the fountain solution from the printing press to the fountain solution tank, the improvement comprising an apparatus for maintaining the quality of the fountain solution including: first, a sediment prefilter for removing particulate matter; second, a diatomaceous earth filter for removing sub-micron particles, and third, a zeolite filter for removing ions, and a side stream loop for removing fountain solution from the fountain solution tank independent of the fountain solution recirculating system, for directing the removed fountain solution first through the particulate matter removing prefilter, then through the diatomaceous earth filter, and lastly through the zeolite filter and for thereafter returning the removed fountain solution from the particulate removing matter filter to the fountain solution tank.