Hydraulic oil is an essential component of hydraulic systems that play a crucial role in a wide range of industrial applications, including manufacturing, construction, and transportation. It is used to transmit power, lubricate, and cool the hydraulic system’s moving parts. However, with the evolution of technology, standard hydraulic oil has become outdated, and High VI (Viscosity Index) hydraulic oil is rapidly replacing it.
High VI hydraulic oil has a higher viscosity index than standard hydraulic oil. The viscosity index is a measure of an oil’s ability to maintain its viscosity under different temperature conditions. The higher the viscosity index, the less the oil’s viscosity will change with temperature changes. In hydraulic systems, this means that:
- At low operating temperatures a standard VI oil has a higher viscosity than a high VI oil. This negatively affects the mechanical efficiency of the hydraulic system, resulting in reduced system performance, lubricant starvation and pump cavitation. Additionally, possible loss of the lubricating film creates high contact temperatures, excessive wear and ultimately can result in pump seizure.
- At high operating temperatures a standard VI oil has a lower viscosity than a high VI oil. This negatively affects the volumetric efficiency of the hydraulic system as the hydraulic fluid can bypass critical pump clearances. Thus, inadequate viscosity due to high temperatures creates a destructive cycle of rising temperatures, accelerated wear and increased internal leakage.
Advances in VI improver technology mean that mineral hydraulic oils with a shear-stable viscosity index in the 150 to 200 range are commercially available.
While this may be good to know, what does it really mean to a hydraulic equipment owner?
Well, within the allowable extremes of viscosity required to maintain adequate lubricating film thickness for hydraulic components, there’s a narrower viscosity range where power losses are minimized and, therefore, power transfer is maximized. High VI hydraulic oil can maintain its viscosity over a wide range of temperatures, providing this consistency and by maintaining the oil’s viscosity in this optimum range, machine cycle times are faster (productivity is increased) and power consumption (diesel or electricity) is reduced.
So, using a higher VI oil means the hydraulic system will remain in its power transmission “sweet spot” across a wider operating temperature range.
This translates into a fuel efficiency gain shown in field tests to be approximately 5% and a productivity gain in excess of 4%. All this whilst giving better protection to the hydraulic system, particularly the hydraulic pump.
These gains far outweigh the additional cost of the higher VI oil. To find out more or to see how using High VI hydraulic oil could reduce your downtime and save you money contact one of Finol’s Technical and sales team today. Finol stocks a range of High VI hydraulic oils across all three brands TotalEnergies, PetroCanada and Finol and should have the product you need in stock. To find out more on the different products you can visit them below.
