Patents Examined by Valiri Fee
  • Corrosion inhibition in chelant solutions
    Patent number: 5171477
    Abstract: The present invention is directed to a method of inhibiting corrosion in aqueous systems which employ amino acid chelants in concentrations which are corrosive to the metal surfaces in contact with the aqueous system. The method comprises adding to the system a corrosion inhibiting amount of 1-hydroxyethane-1,1-diphosphonic acid (HEDPA). The corrosion inhibiting amount is generally in the range of from 0.5% to 10% on the basis of the concentration of amino acid chelant in the system.
    Type: Grant
    Filed: May 31, 1991
    Date of Patent: December 15, 1992
    Assignee: W. R. Grace & Co.-Conn.
    Inventor: Robert P. Kreh