Izr. prof. dr. Franc Majdič, univ. dipl. inž., Univerza v Ljubljani, Fakulteta za strojništvo

Ventil 32 (2026) 3 / Review articles / Technical article – 1.04

DOI: https://doi.org/10.5545/Ventil-32-2026-3.27

Abstract​:

In this article on the maintenance of hydraulic equipment, we will discuss the difference between monograde and multigrade hydraulic oils. Hydraulic oil differs from all other lubricants because it must primarily fulfil two main functions: energy transmission and lubrication. In addition, it must prevent foaming, release entrained air bubbles, be thermally, oxidatively, and hydrolytically stable, possess good anti-wear properties, provide good filterability and demulsibility, offer effective corrosion protection, maintain stable viscosity, and ensure an adequate thickness of the lubricating film. All of this is crucial for ensuring a long service life of hydraulic systems.

Key words:
Mono and multigrade hydraulic oils, Energy transmission, Lubrication, Hydraulic system maintenance

Copyright (c) 2026 Franc Majdič

This work is licensed under a
Creative Commons Attribution 4.0 International License.

Except where otherwise noted, articles in
this journal are published under the
Creative Commons Attribution 4.0 International License.