Reliability data for R134a and polyolester (POE) refrigerant/oil combination were minimal, and initial testing showed a propensity for the capillary tubes to clog with a variety of contaminants. A test was designed by an industry group to accelerate the process of contamination and capillary plugging. Presents capillary tube stress test data that were developed for this group by its member companies. Investigated the relationship between capillary tube restriction levels and variables including compressor type, oil type, chlorine level, and moisture level. Analysis of the contaminants included a visual description, infrared spectroscopy, scanning electron microscope examination, and measurements of total chlorine content and non-condensable gas content of the refrigerant. Oil samples were measured for moisture level, dissolved iron, and total acid, and an infrared spectral analysis was performed.

Units: Dual

KEYWORDS: year 1997, Refrigerants, replacing, R134a, oils, mixtures, testing, capillary tubes, contaminants, measuring, obstructing, moisture, chlorine compounds, iron, acids, lubricants