Method and apparatus for use with metal treating solutions

Claim 1

AN ELECTRICAL CONTROL SYSTEM USEFUL IN CONTROLLING THE FLOW OF LIQUID PRIMING AND FLUSHING MEDIA TO CHEMICAL PUMPING APPARATUS WHICH COMPRISES A PRIMARY CIR-CUIT COMPRISING A SOURCE OF DIRECT CURRENT, AN ELECTRICALLY ACTUATED VALUE MEANS CONNECTED IN SERIES WITH THE DIRECT CURRENT SOURCE, SAID VALVE MEANS BEING ACTIVATED FROM ITS NORMALLY CLOSED POSITION TO AN OPEN POSITION BY THE PASSAGE THERETHROUGH OF CURRENT, AN ELECTRICAL VALUE AND STORAGE MEANS DISPOSED BETWEEN THE CURENT SOURCE AND THE ELECTRICALLY ACIVATED VALVE MEANS AND BEING IN SERIES THEREWITH, SAID VALVE AND STORAGE MEANS BEING CHARGED BY THE PASSAGE THERETHROUGH OF CURENT FROM THE CURRENT SOURCE UNTIL THE POTENTIAL THEREOF BECOMES SUBSTANTIALY EQUAL TO THE POTENTIAL OF THE CURENT PASSING THERETHROUGH, WHEREUPON THE FLOW OF CURRENT THERETHROUGH TO THE VALVE MEANS IS INTERRUPTED AND THE VALVE RETURNS TO ITS NORMALLY CLOSED POSITION, A SECONDARY CIRCUIT COMPRISING A RELAY MEMBER WHICH IS OPEN WHEN THE CURRENT IS PASSED FROM THE DIRECT CURRENT SOURCE AND CLOSED WHEN CURRENT FLOW FROM THE CURRENT SOURCE CEASES, SAID SECONDARY CIRCUIT BEING IN SERIES WITH THE ELECTRICALLY ACTIVATED VALVE MEANS AND THE ELECTRICAL VALVE AND STORAGE MEANS AND POSITIONED SO THAT UPON CESSATION OF CURRENT FLOW FROM THE DIRECT CURRENT SOURCE, CURRENT PASSES FROM THE CHARGED