LUBRICANTSADDITIVES AND SELECTION OF LUBRICANTSTHEORY 1 Additives for lubricants: The following additives are employed. i)Oiliness carriers vegetable oil & fatty acids. ii)ExtremepressureadditivesOrganicmaterials which contains S, Cl & P iii)Viscosity Polystyrene, polyster. iv)Viscosity index Hexanol. v)Pour point depression Wax, naphthalene. vi)OxidationstabilityimproverAromaticamines, phenols. vii)CorrosionstabilityimproverOrganiccompoundof phosphorus or antimony. viii)Foam preventer glycerol, glycol ix)Anti wear additives tri- cresyl phosphate x)Deposit inhibitors salt of phenol & carboxylic acid. Selection of lubricant Inselectionoflubricantforaparticularjob,theservice conditionrequirementsaretobe relatedtotheproperties of the lubricant. LUBRICANTSADDITIVES AND SELECTION OF LUBRICANTSTHEORY 2 The properties of a properly selected lubricant should not change under service conditions. It the properties of chosen lubricant alters, during service, it may cause certain problems. Selection of a lubricant for a few typical jobs are illustrated below. Type of Machinery Operating Conditions Properties required in lubricant Example 1.Internal combustion engine High temp. Low to high speed. Low to high press. High thermal stability, High V.I., Non corrosive, Good oiliness, oxidation stability, Moderate Viscosity & should act as seal.Petroleum oils blended with above property improvers. 2.RefrigerationLow temp,Low pourNaphtenoic LUBRICANTSADDITIVES AND SELECTION OF LUBRICANTSTHEORY 3 Moderate load point, Low cloud point, moderate viscosity. base oil 3.Circulating system turbine, hydraulic Water or steam contact, high temp. High oxidation resistance, Antifoaming & Anti-rusting character medium viscosity, High V.I. & Minimum emulsification property. Petroleum oils blended with additives. 4.GearsHigh press, high temp, low to high speeds. High oiliness, proper viscosity, high oxidation, resistance, High V.I. Good antifoaming property. No Proper viscosity petroleum oils blended with additives & greases. LUBRICANTSADDITIVES AND SELECTION OF LUBRICANTSTHEORY 4 dissolution effect on rubber seal. 5.Cutting / drilling Very high press, high temp. Low viscosity. High oiliness, Anticorrosive nature, coolant, Extreme press. Additives Cutting oil (Vegetable oil in water with emulsifier) mixed with additive. 6.TransformersInsulation, heat transfer, higher temp in on load condition. Low viscosity, High dielectric property, High oxidation resistance, Good chemical stability. Highly refined Petroleum oil. 7.Tractor roller, lathecrane pulleys Expreme pressHigh temp.Low speed Very high thermal stability, Non-inflammable, 1.Graphite,

2, Soaps in the form of Suspension in LUBRICANTSADDITIVES AND SELECTION OF LUBRICANTSTHEORY 5 Soft, Reactive on metal surface to form inorganic compounds film of soft nature. oil & waters. 2. Petroleum oil with E.P.additive. 8.Delicate instruments Low load, High Speed. Low to moderate viscosity, Nonvolatile, Low pour poing. Vegetable oil, Animal oil, Low viscosity Petroleum oils. 9.Steam engine cylinder Steam contact, high temp, high press High oiliness Less emulsification with water. High V.I.