Abstract: An integrated check valve/strainer-filter assembly that combines a check valve with a strainer-filter assembly in a compact structure is provided. The novel assembly provides the benefits of floor space savings and low maintenance costs. A strainer-filter element may be mounted in a removable strainer-filter housing to provide easy access to the element for cleaning or replacement. The check valve may be installed at one of three desirable positions thus affording additional flexibility of the present invention novel apparatus.

Abstract: A self-cleaning liquid filter and a method for filtering a liquid are disclosed. In the self-cleaning liquid filter, a rotating hollow drum covered with a filter element is mounted in a filter housing and turned by a waste liquid that contains debris or dirt. Filtered or cleaned liquid enters into the hollow drum and is pumped away at one end of the drum while debris or dirt in the waste liquid are trapped on the filter. A spray nozzle is mounted inside the rotating drum and clean water is sprayed out to wash away the debris and dirt carried by the filter element into a debris collector equipped with a second filter. The debris and dirt are trapped by the second filter while a filtered, or clean liquid is drained back into the filter housing. The novel device is self powered by the waste liquid flow and thus no external power is necessary for operating the device.