DRY SUMP LIQUID FILTER

A liquid filter apparatus, for connection to inlet and outlet piping, includes a housing which is integral with the piping and a removable integral filter unit in the housing. The integral filter unit includes bottom and top end caps with a core tube and a concentric outer tube extending between the end caps. A filter element between the core tube and the outer tube stands on ribs extending upward from the bottom end cap and is spaced from the top end cap by similar ribs extending downward from the top end cap, these ribs creating radial flow channels above and below the filter element. The filter element is a wound spiral of filter material and separator forming a plurality of axial flow channels. Some of these axial flow channels are open at the top to receive liquid from the top radial flow channel and closed at the bottom, and some of the axial channels are closed at the top and open at the bottom to discharge liquid into the bottom radial flow channel. Filter action is by way of radial flow, through the filter material, from the open-top channels to the open-bottom channels. The housing cover is removable to remove and replace the filter. Means are provided to vent air from the system and to drain liquid from the system for removal and replacement of the filter without having to clean the housing.