All-season mineral hydraulic oils created on the basis of highly-purified basic oils with a high viscosity index and a zinc-free (low-ash) additive package for the most full compliance with specific operating requirements of modern high-load and heat-stressed precision hydraulic systems, including the ones equipped with servo mechanisms and servo valves used in industrial and mobile equipment for which the manufacturer recommends using “zinc-free” hydraulic oils. They were developed taking into account the requirements for industrial hydraulic systems, mobile and stationary equipment operating in the conditions of high and extra-high loads, pressures, operating temperatures and/or velocities and especially in the conditions of strongly varying temperatures and in when there is a strong possibility or water contamination.
Zinc-free hydraulic oils have the same properties as ordinary ones, but at the same time they have a greater expected life and completely eliminate the formation of clots and “loose deposits” that obstruct filters and disrupt servo motor elements in the conditions of a humid environment and high temperatures. These “loose deposits” are formed through an interaction of zinc-containing additives and water.