Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.


  1. Advanced Patent Search
Publication numberUS1915965 A
Publication typeGrant
Publication dateJun 27, 1933
Filing dateMay 29, 1931
Priority dateMay 29, 1931
Publication numberUS 1915965 A, US 1915965A, US-A-1915965, US1915965 A, US1915965A
InventorsWilliams Harry M
Original AssigneeFrigidaire Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method and composition for detecting leaks in refrigerating systems
US 1915965 A
Abstract  available in
Previous page
Next page
Claims  available in
Description  (OCR text may contain errors)

. from leaks, even minute ones.


My invention relates to chemistry and more particularly to methods of testing apparatus suspected of leakage. It is especially concerned with methods of testing for leaks in a refrigerating system of the compression type.

In refrigerating apparatus of the compression type, refrigeration is produced by the evaporation of a volatile liquid, the vapors being compressed in a compressor, condensed in a condenser and again permitted to evaporate within the evaporator. A lubricant is used within such apparatus for sealing and/or lubricating the wearing surfaces. In some compression systems, the lubricant is deliberately carried throughout the complete cycle while in other systems, attempts are made to separate the lubricant from the refrigerant by means of an oil separator generally positioned on the high pressure side and designedto substantially prevent the passage of lubricant into the evaporator. Even in this last named system, some lubricant will pass the separator and will be carried along with the refrigerant through the complete cycle. Thus in all compression refrigerating systems, some lubricant will be present in all parts of the system at substantially all times.

It will be appreciated that it is essential for refrigerating apparatus to be quite free Otherwise, either the refrigerant and/or lubricant will gradually escape, or else air will gradually leak into the apparatus. In either event, the apparatus will gradually produce less and less refrigerating effect, although it apparently is working perfectly in every other respect. Consequently, it is necessary that the apparatus be thoroughly subjected to tests which willshow the existence of the smallest leak before such apparatus is installed and occasionally after the installation of such apparatus. It will also be appreciated that such tests must be of a simple nature for use in the field and inexpensive to perform, particularly where apparatus is manufactured under quantity production.

Many refrigerants are, however, quite difficult to detect because they do not react with Application filed May 29, 1931. Serial No. 541,123.

the well known and commercially available reagents: to give either a color, fum1ng,'or

odor test. Examples of such refrigerants are way diluting or otherwise affecting the properties of the refrigerants.

In carrying out my process for testing re-' frigerating apparatus for leaks, make use of the property of basic dyes to permanently. stain certain surfaces. For example, I have foundthat certain basic dyes such as methyl violet base, crystal violet, auramine. B, rhodamine B, etc.-have the property of perma nently staining certain materials .such as titanium oxide,silica,asbestos, mica, zinc oxide, magnesium oxide, frost, aluminum oxide, aluminum palmitate, and salts such as tri-basic calcium phosphate.

Thus, by coating the apparatus with a paint containing one or more of the above or similar substances, it is possible to obtain a permanent stain by permittinga basic dye to escape from the leaking apparatus.

As a specific example of one mode of carrying out my invention in a refrigerating system using CClgFg asthe refrigerant and mineral oil as the lubricant, I dissolve a small amount of basic dye, such as methyl violet base, in the mineral oil. This solution is obtained by first dissolving the methyl violet base in alcohol or other suitable solvent and then mixing and stirring the solution with the mineral oil, or by mixing the methyl violet base directly with the lubricant and stirring the mixture. The refrigerating system is then charged with its usual amount of (301 15 and mineral oil having the methyl violet base dissolved therein.

The refrigerating apparatus, and particularly those parts where leaks are likely to occur, are painted with a paint such as Duco containing titanium oxide, silica or any other I will indicate a leak which is then specifical- 1y detected by the stain.

After the leak has been detected and re-.

paired, the stain may be removed by painting over with the paint.

The other basic dyes may be used by dissolving the dye in the oil in substantially the same manner.

Likewise, other materials. such as those indicated above, may be used for detecting purposes. For example, the entire refrigerating apparatus may be dipped in aluminium pallnitate or the apparatus may be painted where leaks are likely to occur, with paint containing magnesium or aluminium oxide. Also, any of the other halo-fluoro derivatives may be used as the refrigerant and, in fact, any refrigerant which does not have the property of bleaching the color deposited by the basic dye.

It will be apparent, therefore, that I have rovided a very economical and simple test gor leaks in a refrigerating system. By painting or otherwise treating the parts of the apparatus as manufactured or the apparatus as assembled, no additional appa'ratus is necessary for the process.

Basic'dyes as purchased on the market frequently contain dextrine or other substance for standardizing purposes. It is advisable to utilize in my method, a basic dye free of dextrine or other filler.

While I have disclosed various dyes, substances capable of being stained, refrigerants, and lubricants, it should be understood that my invention involves the useof a dye capable ofpermanently staining certain surfaces with any refrigerant that does not destroy the permanent color imparted to the stainable substance.

What is claimed is as follows:

1. In refrigerating apparatus using as a working fluid both a refrigerant and a lubricant, the method of detecting leaks which comprises dissolving a basic dye in the lubricant, treating the apparatus with a material stainable with the basic dye, and staining the material at the point of leakage.

2. In refrigerating apparatus using a halofluoro derivative of an aliphatic hydrocarbon as the refrigerant and an oil, the method of detecting leaks which comprises dissolving a basic dye in the lubricant, treating the apparatus with a material stainable with the basic dye, and staining the material at the leak.

3. A working fluid for refrigerating sy s- J In testimony whereof I hereto aflix my signature.


Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2479743 *Apr 24, 1947Aug 23, 1949Hall Flemmon PLeak indicator for sealed receptacles
US2682510 *Apr 26, 1950Jun 29, 1954Atomic Energy CommissionGamma and X-ray dosimetric method
US2937145 *Dec 22, 1955May 17, 1960Du PontAntifreeze composition
US2937146 *Nov 21, 1956May 17, 1960Du PontAntifreeze composition
US3370013 *Jul 14, 1964Feb 20, 1968Jet Air Products CompanyPressure packaged refrigerant leak detector and method of packaging same
US3915630 *May 11, 1970Oct 28, 1975Pechiney Saint GobainPreparation of organic solvent-soluble dyes
US4063893 *Sep 13, 1976Dec 20, 1977Stoulil Arthur CDye stabilized trisodium phosphate cleaning solution
US4187798 *Apr 17, 1978Feb 12, 1980Nagatanien Honpo Co., Ltd.Method of detecting defective portion of sealing
US4250740 *Aug 10, 1979Feb 17, 1981Deere & CompanyMethod for evaluating effectiveness of track link seals
US4291193 *May 9, 1980Sep 22, 1981The United States Of America As Represented By The United States Department Of EnergySelf-monitoring high voltage transmission line suspension insulator
US4758366 *Feb 25, 1985Jul 19, 1988Widger Chemical CorporationPolyhalogenated hydrocarbon refrigerants and refrigerant oils colored with fluorescent dyes and method for their use as leak detectors
US5149453 *Mar 12, 1991Sep 22, 1992H. B. Fuller Automotive Products, Inc.Method for detecting leakage in a refrigeration system
US5574213 *Mar 13, 1995Nov 12, 1996Shanley; Alfred W.Apparatus and method for detecting leaks
US5650563 *Apr 6, 1995Jul 22, 1997Spectronics CorporationMethod of introducing leak detection dye into an air conditioning or refrigeration system including solid or semi-solid fluorescent dyes
US6009745 *Oct 10, 1997Jan 4, 2000Apv CorporationMethod of leak testing an assembled plate type heat exchanger
US6070454 *Mar 26, 1997Jun 6, 2000Bright Solutions, Inc.Preparing a dye formulation comprising a thioxanthane dye; introducing said dye formulation(paste) into the system, and operating the system to allow the dye to circualate
US6070455 *Feb 5, 1998Jun 6, 2000Bright Solutions, Inc.Leak detection additives
US6101867 *Apr 23, 1998Aug 15, 2000Bright Solutions, Inc.Dye concentrate
US6170320Apr 10, 1998Jan 9, 2001Mainstream Engineering CorporationMethod of introducing an additive into a fluid system, especially useful for leak detection, as well as an apparatus for leak detection and a composition useful for leak detection
US6327897Jun 11, 1998Dec 11, 2001Mainstream Engineering CorporationMethod of introducing an in situant into a vapor compression system, especially useful for leak detection, as well as an apparatus for leak detection and a composition useful for leak detection
US7148066 *Aug 2, 2004Dec 12, 2006Glotell Products, Inc.Using ammonia to detect leaks in illegal drugs by evaporation and staining
US7943380Jun 2, 2004May 17, 2011Bright Solutions, Inc.Leak detection materials and methods
USRE35395 *Aug 25, 1995Dec 10, 1996Bright Solutions, Inc.Leak detection in heating, ventilating and air conditioning systems using an environmentally safe material
USRE36951 *Apr 6, 1995Nov 14, 2000Spectronics CorporationMethod of introducing leak detection dye into an air conditioning or refrigeration system including solid or semi-solid fluorescent dyes
EP2166040A1Sep 22, 2008Mar 24, 2010Radiant Color N.V.Novel lipophilic fluorescent dyes and a process for their production
WO1996007088A1 *Apr 6, 1995Mar 7, 1996B William CooperMethod of introducing leak detection fluid
WO2005032458A2 *Aug 2, 2004Apr 14, 2005Glotell Products IncDye solution and method for detecting anhydrous ammonia
U.S. Classification436/3, 73/40.50R, 436/124, 116/206, 73/40.7, 252/68, 116/214
International ClassificationC10M171/00, C09K5/04, C09K5/00
Cooperative ClassificationC09K5/044, C10M171/008
European ClassificationC09K5/04B4, C10M171/00R