Monitoring and prevention of the risk of deposit and varnish formation
Dr. Milan Kambič, univ. dipl. inž., Olma d. o. o., Ljubljana
Ventil 32 (2026) 2 / Review articles / Technical article – 1.04
Abstract:
Varnish deposits represent one of the key, yet often overlooked, causes of reduced reliability in modern hydraulic and lubrication systems. Their impact does not manifest as sudden failures, but rather as a gradual degradation of performance, which can lead to valve sticking, reduced efficiency of control components, and unplanned equipment downtime. The formation of varnish is associated with complex mechanisms of chemical and physical lubricant degradation, while conventional oil analysis parameters often fail to detect the early stages of this phenomenon.
This paper discusses the mechanisms of varnish formation, the limitations of routine oil analysis, and modern diagnostic approaches for monitoring varnish potential, with an emphasis on preventive management of lubrication systems.
Keywords:
varnish deposits, oxidation, MPC, hydraulic system, lubricants
Copyright (c) 2026 Milan Kambič
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