Abstract: A filtering system comprises an outer housing into which fluid enters tangentially through a side inlet port to create rotational flow therein. Solid contaminants which clog filtering media are precipitated to the bottom of housing through action of centrifugal force in rotational flow. An inner can, disposed within the housing shrouds a filter cartridge. Unfiltered fluid flows rotationally into the inner can and is filtered through a vertical cylindrical filter cartridge. Filtered fluid flows up through the center of said cartridge to a clean fluid chamber below a domed cover and exists downwardly through a vertical outlet tube extending through the filter cartridge to an outlet port in the bottom of the housing. Gases in the system are collected in the clean fluid chamber and transported by the fluid flow through the outlet tube, thereby automatically purging gases from the filtering system.

Abstract: A filter cartridge (10) for filtering liquid having an internal liquid trap (28). The cartridge (10) has a cylindrical housing (12) having a closed top end (14) and bottom end (16), and a side wall (30) which is perforated to allow liquid to pass through. A tube (22) extends from a liquid inlet (18) at the bottom end (16) of the housing toward the top end (14), where the tube (22) is open to allow the liquid to flow into the housing (12). The cartridge (10) includes a filter media (26) inside the housing spaced apart from the conduit (22) so that the filter media (26), the bottom end (16) and the length of the conduit (22) below where the conduit is open form a trap (28). This trap catches liquid flowing into the housing (12) through the conduit (22) whereby the liquid may escape the cartridge (10) only through the filter media (26) thereby preventing back flow through the conduit (22).