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Tuesday, 12 February 2013

What is Demulsibility in Oil, and why is it important.

Because water is a lubricants worst nightmare Demulsibility in oil is vital.

I’m sure we’ve all encountered a situation where the dimusibility of an oil has been tested to the limit – ever seen the mess in a car’s sump after a blown head gasket? That milky mess, created by the water and anti-freeze in the oil, tells you that the demulsibility in the oil has been exceeded.

Demulsibility in oil is the ability to release water. This is of extreme importance when the equipment is operating in humid conditions or in a plant atmosphere that is
wet or humid. Paper mills, steel mills and food-processing operations have significant exposure to water-based process fluids and hence water contamination.

Because oil is hygroscopic, meaning that it absorbs water, it seems that water is destined to get mixed into the oil.

Water often enters through thermal breathing (hydraulic systems and mechanical systems that heat and cool allowing any moisture to condense); through the high-pressure blast of an operator’s cleaning hose; through the gravity draining of condensate and indirect water spray.

If this water is not separated from the oil, lubricity will be severely compromised. Generally, it will settle out if the reservoir is large enough and the flow cycle is low enough.

How to determine whether demulsibility in the oil has been lost.

When demulsibility in the oil is lost, it will either cloud or foam, and the loaded components in the equipment will wear rapidly.

If the plant operates in the absence of water and is climate controlled, then demulsibility may not be a key factor to consider, however if water is present, then demulsibility must be monitored.

If there is time, a qualified lab can easily run a specific test that can be performed to measure the remaining demulsibility potential of the oil.

Quick test for demulsibility in oil.

For a quick pass/fail test: 
  • Measure an equal amount (500ml) of new lubricant and water, and fill a blender. 
  • Heat to 38 degrees Celsius or whatever temperature closely resembles the operating temperature of the sump. 
  • Thoroughly mix the oil with the water. 
  • Measure the amount of time it takes to separate. 
  • Also measure how much of the mixture does not separate (the emulsion is called the “cuff”). Now repeat the test with the aged lubricant. 
If it takes more than 20 percent longer to separate, then consider having a lab run the test for demulsibility according to the lab procedure.

If the results indicate that the demulsibility capacity is diminished, then consider how to best address the cause of the problem, particularly if the sump is prone to moisture contamination.

Demulsibility in oil is only one of several properties that a quality lubricant needs to meet in order to ensure the integrity of your plant and equipment. Let the professionals at Habot Synthetic Lubricants supply you with an oil that will meet, and even exceed the requirements.