Synthetic oil case study

The presence of sludge in hydraulic oil can significantly reduce the service life of the oil. For example, with one percent sludge in an inhibited hydraulic oil, service life is reduced by nearly 40%.

From "The Practical Handbook of Machinery Lubrication"

A Canadian company engaged in the operation of several compressors experienced a problem where high temperatures caused the compressor oil to oxidize. The oxidized oil formed carbon deposits in the discharge pipes, which in turn created several discharge pipe hot spots. Conditions became such that a severe explosion occurred and a catastrophic failure resulted.

Compressor oil oxidation problems have been eliminated through the use of a diester-type synthetic compressor lubricant designed to resist high temperatures and deposit formation. [Editors Note: this is one of the many synthetic lubricant case studies in this book.]

Lube-Trivia: Additives Affect Test Results

Test your knowledge and prepare for ICML lubrication and oil analysis certification.

QUESTION: What types of additives might adversely affect the accuracy of Karl Fischer water measurements?

Q & A: What's an RPVOT?

"What is the RPVOT test? How are the results used?"

ASTM D2272, RPVOT (Rotating Pressure Vessel Oxidation Test) is at test that determines the oxidation stability of an oil. RPVOT, as opposed to FTIR, acid number, viscosity, and other tests, measures the actual resistance to oil oxidation (combination of base oil robustness and the concentration of unconsumed antioxidants) whereas these other tests detect oxidation that is already present in the oil. RPVOT is a more proactive approach because you can respond to pending problems before permanent harm is done to the oil or machine. The test is ideal for large oil volumes with low makeup fluid requirements and also severe-duty applications.

Results are reported in minutes and are trended against the RPVOT of the new oil. The new oil base line can be used to convert RPVOT readings to remaining useful life (RUL) as a percentage of the new oil (100%). Typically the caution limit is at 40% RUL and a critical limit at 25% RUL, but this varies by application. It is important to note that it may take a relatively long time to get to the caution limit but take relatively short time from there to reach the critical limit.

To reward the lubrication and reliability community for its participation in the Noria Message Boards, we've started the Post of the Week award. Every week, we award one lucky member $50.

"Sodium is generally from coolant additives, but if it's not a water cooled system like you've said, then consider looking at what content is in the dust around your machine. Take 2 fresh samples and leave one open to the atmosphere for a while, then send both off to your lab. This will give you information on what is typical of your environment your machine is in." See the entire post.