In-line filtering device

Claim 1

In a pressurized water system for a pool cleaning system operating at substantially 40 pounds pressure, and having a primary filter unit employing a filtering substance selected from the group of sand diatomaceous earth, and which primary filter unit allows minute portions of its filtering substance to escape into the return line for the pool, and a pool cleaning system responsive to the pressurized water for cleaning the pool and having intricate pressurized water responsive plastic mechanical parts subject to malfunction when the filtering substance is trapped in the pressurized water responsive plastic mechanical parts, and which cleaning system is designed for use with a minimum predetermined water pressure, an in-line filter adapted to be placed intermediate the primary filter unit and the pressurized water responsive plastic mechanical parts for removing said filtering substance without a drop in pressure below said predetermined water pressure, said in-line filter unit comprising: a housing member of annular shape defining a central bore and having an input end and an output end and having an inner surface; an input end cap assembly in mating water-tight attachment with said input end of said member and carrying water input means for attaching to one point in the pressurized water system; an output end cap assembly in mating water-tight attachment to said output end of said member and carrying a water output means for attaching to a second point of the pressurized water system and also carrying fused quartz filter element means located within said housing for filtering the fluid flowing in said system for removing the filtering substance inadvertently escaping from the primary filter; said filter element being in spaced relationship at least over a portion of its length from said inner surface of said housing for providing a surface for contacting the water to be filtered and for providing a fluid to filter surface area of contact for reducing the resistance to the water flowing through the filter, and for providing a chamber for collecting the filtering substance inadvertently escaping from the primary filter; said filter element means being adapted for filtering all the water passing through said in-line filter; Fluid diffuser means carried by said filter element and positioned intermediate said water input means and said filter for preventing direct contact with said filter by the direct flow of water entering the in-line filter through said water input means for preventing damage to said filter by said direct water flow, and said fluid diffuser means diverts the direct flow of water away from that portion of said fused quartz filter, which portion is positioned in-line with the flow of water into the filter for preventing erosion of said fused quartz filter.