When Maffia learned about Dynavis technology for hydraulic fluids, he contacted Evonik Industries to find out if this could be a practical way to reduce his company’s fuel costs. After a brief phone call, Dynavis team members met with Maffia and his colleagues in northern Italy to put Dynavis to the test.
A project representative of Ghizzoni’s expertise in pipe laying excavation was the construction of the Poggio Rentico-Cremona pipeline, which involved laying of a 48-in. pipeline spanning 114 km (71 miles) across Italy’s Padan plain. A fleet of 14 New Holland crawler excavators was charged with the task of restoring the topsoil once the pipe laying was completed. For both Maffia and the Dynavis team, the question became, “How much fuel can be saved in a scenario like this?”
Viscosity and Viscosity Index
Dynavis technology is a chemical-additive package incorporated into any of several hydraulic oil base stocks by fluid suppliers to increase the fluid’s viscosity index (VI). Viscosity is probably the single most important characteristic of hydraulic fluid, or just about any other lubricant. If a fluid’s viscosity is too high, it may not achieve full-film lubrication, which could result in rapid wear from metal-to-metal contact between moving parts. Hydraulic equipment operating in cold environments or during cold startup is prone to this condition because base oils tend to become more viscous (thicker) at lower temperatures.
On the other hand, if a fluid’s viscosity is too low, the thin fluid will be unable to keep moving parts separated under load. The result will be the same—rapid wear from metal-to-metal contact. This often occurs when hydraulic systems operate in hot environments or when heavy loading heats up the fluid. Temperature, again, is the culprit because just as hydraulic base oil tends to become thicker at lower temperatures, it tends to become thinner at higher temperatures.
Fluid suppliers circumvent this problem to some extent by adding VI improvers to base oil. The higher a fluid’s viscosity index, the less the fluid’s viscosity is affected by temperature. So a fluid with a high VI will be less prone to thickening at low temperatures and thinning at high temperatures than a fluid with a low VI.