Method and apparatus for detecting hydrocarbon fuel leaks
AssigneeLockheed Corporation
InventorJeffrey G. Wegrzyn
Life of this patent
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Abstract
A method of and apparatus for detecting fuel leaks employing color variable indicators are disclosed. The method comprises the steps of preparing and applying a water soluble nonstaining indicator dye to a test surface, observing color changes indicative of hydrocarbon leaks and removing the indicator dye from the test surface. The apparatus comprises in combination means for preparing the indicator dye, means for applying the indicator dye to the test surface and means for removing the dye from the test surface. The indicator dye comprises a major portion of a dry inert mineral carrier and from about 0.1 to about 5.0 weight percent of a direct dye which is non-staining on painted surfaces and which does not migrate into or penetrate polyurethane or epoxy resin base painted surfaces.
Claims15
A composition of matter suitable for detecting hydrocarbon leaks comprising a dry powder and consisting essentially of from about 0.1 to about 5.0 percent by weight of a dye soluble in water and lower chain alcohols and which is essentially non-staining to painted surfaces, and which does not migrate into or penetrate painted surfaces, said painted surfaces containing a polyurethane or epoxy base resin, and the balance of said composition of matter consisting essentially of dry inert mineral carrier.
A composition of matter suitable for detecting hydrocarbon fluid leaks consisting essentially of a major portion of volatile liquid carrier and from about one to about twenty percent by volume of an inert mineral carrier having absorbed upon its surface a water soluble sodium salt of a sulfonic acid of an azo dye having a concentration of from about 0.1 to about 5.0 percent by weight of said inert mineral carrier, said dye being essentially non-staining on painted surfaces, and which does not migrate into or penetrate painted surfaces, said painted surfaces containing a polyurethane or epoxy resin base.
A method of producing a substance suitable for detecting hydrocarbon fuel leaks comprising the steps of:
- a. preparing a solution containing from about 0.1 to about 5.0 weight percent of a water soluble sodium salt of a sulfonic acid of an azo dye, said sodium salt being essentially non-staining on painted surfaces, and which will not migrate into or penetrate painted surfaces containing a polyurethane or epoxy resin base;
- b. mixing the solution of azo dye sulfonic acid sodium salt with an inert mineral carrier to form a thick slurry;
- c. drying the slurry at a temperature below the melting point of the azo dye sulfonic acid solution salt whereby substantially all solvent is removed from the slurry to form a dyed mineral carrier;
- d. milling the dyed mineral carrier to form a dyed powder having an even color and a uniform particle size.
Dependencies are inferred from the claim text.