Hydraulic Fluids

Abstract

Hydraulic power utilizes hydraulic fluids which may be based on mineral oils, fire‐resistant fluids, high water‐base fluids, water‐in‐oil emulsions, oil‐in‐water emulsions, synthetic fluids, synthetic lubricants, olefin oligimers, alkylated aromatics, polybutenes, cycloaliphatics, diesters, polyol esters, polyglycols, phosphate esters, silicones, silicate esters, or halogenated fluids. These fluids are discussed. Most fluids require additives which act as pour‐point depressants, viscosity index improvers, defoamers, antioxidants, corrosion and rust inhibitors, and/or anti‐wear compounds. Hydraulic fluids basically serve as lubricants to the hydraulic system utilized. Industries employing hydraulic systems include transportation, manufacturing, mining, metal foundries, agriculture, and timber.