Leak detection using chemical markers
US5759857A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 26, 1996 |
| Grant date | Jun 2, 1998 |
| Priority date | — |
| Expiry date | Sep 26, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S44/903
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Leakage in a heat exchanger between two liquids which are in indirect heat exchange relationship is detected by marking one of the two liquids with a colorless chemical marker and detecting it in the second liquid by extraction and conversion to a colored material. The heat exchanger liquids are preferably organic liquids which are immiscible with water. The marker is detected in a heat exchanger liquid by extraction of the marker followed by chemical conversion of the marker to a colored material that can be detected visually. Aminoalkylnaphthalenes are suitable markers which can be extracted by an acidic aqueous solution and converted to a colored material by reaction with a diazotized aromatic amine. Phenylazoalkylphenol derivatives are also suitable markers which can be extracted and simultaneously converted to a colored material with a detection reagent which is comprised of water and a water-soluble amine.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.