Water Separability of Petroleum Oils

Description

Evaluates the ability of oil to quickly separate from water, preventing the formation of stable water-in-oil emulsions in circulating systems.

Water ingress into a turbine, compressor, or hydraulic system is always an emergency situation. The RENA laboratory conducts a demulsibility test to ensure that your oil can instantly repel water, allowing it to settle in the sump for subsequent drainage. A stable emulsion (a mixture of water and oil) cannot withstand hydrodynamic loads, causes instant corrosion of precision parts, blocks filters, and leads to the emergency shutdown of expensive turbines. Our analysis ensures your lubricant is ready for such challenges. According to the ASTM D1401 methodology, equal parts of the test oil and distilled water (usually 40 ml each) are placed in a graduated cylinder. The cylinder is immersed in a liquid bath with a precisely maintained temperature (54 °C for less viscous oils, 82 °C for viscous oils). Next, a special paddle stirrer is lowered into the cylinder and rotated at 1500 rpm for 5 minutes, creating an aggressive, finely dispersed emulsion. After the stirring stops, the most crucial stage begins: visual monitoring of the fluid separation process over time. The operator records the volumes of three layers: clear oil, free water, and the emulsion layer remaining between them, every 5 minutes. The test is considered complete when the emulsion volume decreases to 3 ml or less, or after 30-60 minutes.