Orival Inc. (Englewood, NJ) says its filters protect heat exchangers and prevent clogging of nozzles, tubes, and other narrow passages by removing dirt particles down to micron size, of any specific gravity, from one-through and recirculating cooling water systems. Individual units are available from 10 to 8,100 gpm. The filter is line-pressure powered, cleans itself without external power, and is designed to not interrupt system flow.