Patents by Inventor David W. Gandy

David W. Gandy has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20130121868
    Abstract: A method of manufacturing a weld-free apparatus for use in the connection of dissimilar metals includes the steps of providing a mold designed to replicate a reverse of the apparatus, introducing a low alloy, ferritic steel composition atomized powder into a first portion of the mold, introducing a series of atomized powders incrementally into a second portion of the mold to form a transition region between the ferritic steel composition and an austenitic stainless steel composition, and introducing an austenitic stainless steel composition atomized powder into a third portion of the mold. The method further includes the step of consolidating and melting the atomized powders in a high temperature, high pressure inert gas atmosphere to form the apparatus.
    Type: Application
    Filed: May 3, 2012
    Publication date: May 16, 2013
    Applicant: ELECTRIC POWER RESEARCH INSTITUTE, INC.
    Inventors: David W. Gandy, Kent K. Coleman, John Shingledecker
  • Publication number: 20120299288
    Abstract: A method of manufacturing a header assembly having a header section and a tube section includes the steps of providing a reverse mold of the header assembly, forming the header section by filling a header section of the reverse mold with an atomized low alloy steel powder, and forming the tube section. The tube section is formed by filling a first portion of a tube section with an atomized low alloy steel powder, forming a transition region by filling a second portion of the tube section with a series of atomized steel powders incrementally from a low alloy steel to an austenitic stainless steel, and filling a third portion of the tube section with an atomized austenitic stainless steel powder. The method further includes the step of consolidating and melting the atomized powders in a high temperature, high pressure atmosphere.
    Type: Application
    Filed: May 3, 2012
    Publication date: November 29, 2012
    Applicant: ELECTRIC POWER RESEARCH INSTITUTE, INC.
    Inventors: David W. Gandy, John Shingledecker
  • Publication number: 20120301344
    Abstract: A method of manufacturing integral head and tube replacement sections includes the steps of providing a reverse mold of a head and tube replacement section, providing an atomized steel powder, and filling the reverse mold with the atomized steel powder. The method further includes the step of inserting the mold into a hot isostatic processing (HIP) furnace to consolidate and sinter the powder into the shape of the head and tube replacement section.
    Type: Application
    Filed: May 3, 2012
    Publication date: November 29, 2012
    Applicant: ELECTRIC POWER RESEARCH INSTITUTE, INC.
    Inventors: David W. Gandy, Kent K. Coleman, John Shingledecker
  • Patent number: 6145194
    Abstract: A method for repairing a shrink-fitted turbine disc without removing the disc from the shaft. The method is composed of two basic steps: (1) depositing one or more weld layers in a vicinity of a defective region of the disc using a temperbead welding process and (2) heat treating the disc using an induction heating process. In a first embodiment of the method, the heat treating step includes heating a heat-affected zone of the disc in a vicinity of the one or more weld layers to a temperature T.sub.h, heating a rim region of the disc to a temperature T.sub.r and heating a bore region of the disc to a temperature T.sub.b, where T.sub.h, T.sub.r >T.sub.b. In a second embodiment of the method, the heat treating step includes heating a region of the disc in a vicinity of the one or more weld layers using the induction heating process and concurrently cooling a bore region of the disc.
    Type: Grant
    Filed: May 28, 1999
    Date of Patent: November 14, 2000
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Ronald E. Munson, Shane Joseph Findlan, David W. Gandy, Ramaswamy Viswanathan