Overhead return piping system

摘要

An apparatus and method for circulating coolant liquid between machine tools 10 and a coolant filtering unit 23 through an overhead return line 17. A small stream of clean coolant is diverted to a flush tank 38 and the tank 38 is pressurized, e.g., with compressed air. Periodic release of the pressurized liquid from the flush tank 38 through the overhead return line 17 flushes deposited chips and other sediments from the return line 17.