Abstract: A cartridge filter is provided having a housing body, a sump releasably attached to the housing body, and a filter cartridge within the housing body releasably attached to the housing body by a screw connection. The sump is attached to the housing body by a separate screw connection. The screw connection includes a first screw formation on the sump having a sloped screw surface and, at the leading end, a lug projecting above the sloped screw surface. A second screw formation is also provided on the housing body having a sloped screw surface along which the lug can run. A further projection is positioned on the housing body to engage the leading end of said first screw formation and to deflect the lug so that the first screw formation hooks over the trailing end of the second screw formation, when the connection is fully tightened.

Abstract: A reinforcing member made of unitary construction is described. The reinforcing member has an outer face connected to an inner face by a middle frame. The inner face includes a first flange extending in a first direction from a first portion of the frame and a resiliently flexible second flange extending in an opposite direction from a flexible second portion of the frame. In use, an installer flexes the second flange and second frame portion so that the inner face will pass through the hand hole. Flexation may involve movement of the first flange toward the second flange, rotation of the second flange away from the outer face, or a combination of both. Once flexed, the inner face is inserted through the hand hole and the second flange is allowed to resume its unflexed position.