February 7, 2020

RULER: For Extending Drainage Intervals

Oil drain intervals have generally lengthened as the quality of lubricants and additives improve. However, operations managers still face the dilemma of whether to extend replacement time frames to keep equipment productive or to remain conservative to protect their equipment. Overextending the useful life of a lubricant could cause corrosion, wear, and increase safety risk. It is critical to monitor the useful life of lubricants closely in order to effectively manage oil drain intervals.

Monitoring lubricant quality

There are many metrics that can be used to monitor the quality of a lubricant including:

  • Viscosity
  • Corrosivity
  • Oxidation

Oxidative stress, specifically, can have a measurable impact on multiple properties of a lubricant. To mitigate these effects, anti-oxidant (AO) additives called ‘inhibited phenols and amines’ can be added to the lubricant. These additives intercept oxygen and other oxidative molecules (like free radicals and peroxides) to prevent them from causing damage to both the base oil and other additives present in the lubricant. These anti-oxidants are also regenerative, extending the life of the oil even further.

However, when the phenols and amines are oxidized and can no longer be regenerated, the remaining life of the oil will begin to drop. As anti-oxidant additives are depleted through repetitive stress, the lubricant is at much higher risk for failure due to corrosion or wear. 

Remaining Useful Life Evaluation Routine

The way Fluid Life measures how much useful life oil has is through a test method known as Remaining Useful Life Evaluation Routine (i.e. RULER). RULER can be used to measure the relative concentration of these anti-oxidants from new oil and trended over time. Drainage and maintenance can then be predicted and appropriately scheduled at predetermined intervals, alleviating the stress of lost-time incidents or undue wear of valuable assets.

Remaining Useful Life Evaluation Routine

Download the RULER lab test spotlight paper. Highlights include an overview of the test methodology, a practical example, and recommendations for application of the test.

Contact us if you’d like to learn more about the Remaining Useful Life Evaluation Routine. Fluid Life has a full range of laboratory services – from individual tests to industry specific test packages – to support your reliability programs.