An apparatus for filtering fluid has a container, a platform positioned in the interior volume of the container in a location above a bottom of the container, and a bag filter extending through a hole in the platform. The bag filter has an inlet and an outlet. The inlet is positioned at or above a top surface of the platform and an outlet positioned below the top surface of the platform such that a fluid passing through the fluid inlet of the container flows into the inlet of the bag filter and outwardly of the outlet of the bag filter so as to flow toward the fluid outlet of the container. A retainer plate is positioned over the platform and has an orifice opening to the inlet of the bag filter.