MILITARY SEALIFT COMMAND

11 JUNE 2020

LUBRICANTS AND THEIR PROPERTIES

WHY LUBRICATE?

• Minimize Wear• Separate moving surfaces

• through a suitable lubricant film• mainly during start-up

• Avoid metal to metal contact• Minimize Friction• Sealing

• Filling the gaps between • pistons and liners • piston rings and piston grooves• vanes and pump case

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WHY LUBRICATE?

• Cooling• Good thermal conductivity• Provide for high oil flow rate

• Keep the machine clean• Hold contaminants in

suspension• Prevents corrosion and rust

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BASE OILS

BASE OIL GROUPS• GROUP I (Solvent Refined)

• >90% Saturates• >0.03% Sulfur• VI 80-120

• GROUP II (Hydrogenation-Hydrogen Gas)• >90% Saturates• <0.03% Sulfur• VI 80-120• Better Anti-oxidation Properties

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BASE OILS

• GROUP III (Hydro-cracked higher pressure/temp)• >90% Saturates• <0.03% Sulfur• VI >120• Very pure base oil

• GROUP IV (SYNTHETIC)• Polyalphaolefin (PAO)• Polyolefin (POE)

• GROUP V• Base oil and synthetic combinations, Polyalkylene

Gylcol (PAG), Diester, Phosphate Esters

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HOW A LUBRICANT WORKS

• Petroleum-based products are ideal choices as lubricants due to their ability to wet metal surfaces

• Lubricant is able to get in between two metal surfaces and form a barrier

• Viscosity is key measure of lubricant effectiveness

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WHAT IS VISCOSITY?

• The measurement of a fluid’s resistance to flow

• Viscosity is dependent on temperature and pressure

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HOW A LUBRICANT WORKS

• High viscosity good for:• High temperatures• High loads• Low speed rotation

• Low viscosity better for:• Low temperatures• High speed rotation

• The less viscosity variation with temperature, the greater the Viscosity Index (VI)

• High VI - little variation good• Low VI - lots of variation bad

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VISCOSITY INDEX IMPROVERS

• Polymers are added to lubes to increase VI• At low temperature they form balls allowing

improved flow• At higher temperatures they inter-twine and

decrease flow• Polymer chains can be broken in areas of

high shear, e.g. in bearings which results in drop of VI and viscosity

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LUBRICATION REGIMES

• There are four major lubrication modes, or regimes:

• Boundary• Mixed• Hydrodynamic• Elasto-hydrodynamic (EHL)

• Increasing film thickness

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LUBRICATION REGIMES- BOUNDRY/MIX

• Boundary lubrication occurs due to:• Viscosity is too low• Speed is too low• Contact area is too small

SOLID FRICTION

STATIONARY

SLIDING

WELDING (WEAR)

BOUNDARY LUBRICATION

SLIDING

EXTREME PRESSURE

STATIONARY

ADDITIVE

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LUBRICATION REGIMES- HYDRODYNAMIC

• Hydrodynamic pressure is generated by:• Sliding of layers• Equipment design• Adequate oil supply• Oil viscosity

• Hydrodynamic is the desired regime

HYDRODYNAMIC PRESSURE

FLUIDPRESSURE BUILD UP

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LUBRICATION REGIMES- EHL• EHL is characterised by

• Elastic deformation of surfaces• Large increase in pressure and viscosity

• Typically found in anti-friction bearings (ball, roller bearings)

PRESSURECURVE

FLUIDBALL BEARING

OUTER RACE

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LUBRICATED PARTS-BEARINGS

• Illustration

FULL OIL PRESSUREOIL SUPPLY

RUNNING

HYDRODYNAMICLUBRICATION

NO OIL PRESSURE LOW OIL PRESSURE

LOAD OIL PRESSURE

MIXEDLUBRICATION

BOUNDARYLUBRICATION

START UP

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OIL BASE STOCK PROPERTIES

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GREASE

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GREASE COMPATIBILITY

DIESEL ENGINE OILS• HIGH SPEED DIESEL ENGINES

• MOBILGARD 312• MOBIL DELVAC 1300 SUPER 15W40 • MOBIL DELVAC 1 ESP 5W40 (SYNTHETIC)• MOBILGARD HSD+ 15W40

• MEDIUM SPEED DIESEL ENGINES• MOBILGARD 412• MOBIL DELVAC 1630 OR 1640• MOBILGARD ADL 40 OR ADL 30• MOBILGARD 410 OR 450 (ZINC FREE)

ExxonMobil Lubricants

DIESEL ENGINE OILS• LOW SPEED DIESEL ENGINES

• MOBILGARD 300C (TRUCK OIL)• MOBILGARD 570C (CYLINDER OIL-RESIDUE FUELS)• MOBILGARD 525 (CYLINDER OIL-DISTILLATE FUELS)

ExxonMobil Lubricants

ExxonMobil Lubricants

TURBINE OILS• MARINE TURBINE OILS

• MOBIL DTE MEDIUM (ISO-46)• MOBIL DTE HEAVY MEDIUM (ISO-68)• MOBIL DTE HEAVY (ISO-100)

• MARINE GAS TURBINE OILS• MOBIL JET OIL II (LM2500 NAVY)• MOBIL JET OIL 254 (LM-2500 COMMERCIAL)

GEARS• MAIN AND AUXILIARY GEARS (MINERAL OILS)

• MOBILGEAR 600 XP 68• MOBILGEAR 600 XP 100• MOBILGEAR 600 XP 150• MOBILGEAR 600 XP 220• MOBILGEAR 600 XP 320• MOBILGEAR 600 XP 460• MOBILGEAR 600 XP 680

ExxonMobil Lubricants

• MAIN AND AUXILIARY GEARS (SYNTHETIC OILS)• MOBILGEAR SHC MT 68* (FUTURE CONTRACT MOD)• MOBIL SHC 629• MOBIL SHC 630• MOBIL SHC 632• MOBIL SHC 634

• TRANSMISSION/GEAR OILS (AUXILIARY EQUIPMENT)• MOBIL ATF DM• MOBIL ATF 220• MOBILFLUID 424• MOBILUBE HD PLUS 80W90• MOBILUBE HD PLUS 85W140

ExxonMobil LubricantsGEARS

• HYDRAULIC FLUIDS• MOBIL DTE 10 EXCEL 15• MOBIL DTE 10 EXCEL 32• MOBIL DTE 10 EXCEL 46• MOBIL DTE 10 EXCEL 68• MOBIL DTE 10 EXCEL 100• MOBIL DTE 10 EXCEL 46 (ZINC FREE)• MOBIL DTE 10 EXCEL 68 (ZINC FREE)

ExxonMobil Lubricants

HYDRAULICS

• REFRIGERATION COMPRESSOR OILS (POE)• MOBIL EAL ARCTIC 32• MOBIL EAL ARCTIC 46• MOBIL EAL ARCTIC 68• MOBIL EAL ARCTIC 100 * (FUTURE CONTRACT MOD)• MOBIL EAL ARCTIC 220 * (FUTURE CONTRACT MOD)

REFRIGERATION

ExxonMobil Lubricants

• COMPRESSOR OILS• MOBIL RARUS 427 (MINERAL-RECIPROCATING)• MOBIL RARUS 429 (MINERAL-SCBA)• MOBIL RARUS SHC 827 (SYNTHETIC-RECIPROCATING)• MOBIL RARUS SHC 1025 (SYNTHETIC-ROTARY)• MOBIL RARUS SHC 1026 (SAME SHC RARUS 68) AAB-TURBO• MOBIL SHC RARUS 68 (SYNTHETIC-ROTARY SCREW AND VANE)

ExxonMobil Lubricants

COMPRESSED AIR

• GREASES• MOBILGREASE 28 (SYNTHETIC-CLAY)• MOBILGREASE XHP 220 (EP0-LITHIUM COMPLEX)• MOBILGREASE XHP 221 (EP1-LITHIUM COMPLEX)• MOBILGREASE XHP 222 (EP2-LITHIUM COMPLEX)• MOBIL UNIREX N2 (MULTI-PURPOSE BEARING- LITHIUM)• MOBILITH SHC 100/220/460 (SYNTHETIC-LITHIUM)• MOBILTAC 375 NC (NON-CHLORINATED) CALCIUM• MOBILGREASE XTC (NGLI-1 LITHIUM) COUPLING GREASE• MOBILARMA 798 ( CALCIUM-WIRE ROPE GREASE )• MOBIL POLYREX EM (POLYUREA- MOTOR BEARING)

ExxonMobil LubricantsOTHER LUBRICATION REQUIREMENTS

QUESTIONS?

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