1. Uranium Corporation of
India Ltd.
A CASE STUDY IN
PINAKI ROY

2. A BRIEF RE-CAP of
MAINTENANCE
MAINTENANCE is the act of maintaining
or the state of being maintained.
It denotes the work undertaken for keeping
something in proper condition i.e. upkeep.
It can be machines, household goods or even
yourself !!

3. Basics of Maintenance
Maintenance technology comprises of technical
knowledge plus experience and their application
in identifying and implementing the best possible
maintenance and repair techniques for all
maintainable items, in line with organizational
policy.
• It provides a means to maintain the plant and
equipment in a high state of operating efficiency
and enhance its productivity.

4. Two Keywords of
Maintenance
• CLEANING
&
• LUBRICATION
• CLEANING PHILOSOPHY:
• IF YOU CAN’T SEE IT,
• YOU CAN’T FIX IT
• So use:
• High pressure water jets
• Anti-Rust & Grease removal
compounds
• Scrape, clean & re-paint regularly

5. LUBRICATION
• Dictionary defines lubrication
as the application of some oily
or greasy substance in order to
diminish friction. Though a
valid definition, it fails to realize
all that lubrication actually
achieves.
• Many different substances can
be used to lubricate a surface.
Oil and grease are the most
common. Grease is composed
of oil and a thickening agent to
obtain its consistency, while the
oil is what actually lubricates.
The application determines
which oil, commonly referred to
as the base oil, should be used.

6. STATUS of GREASE
- General Perceptions
Isn’t it true that of all types of lubricants in use, only
Grease is looked down upon & treated with disdain.
While pouring engine oil in your car is considered
normal, greasing is generally given to the mechanic or
his assistant, as its supposed to be a menial & dirty
job.
LETS UNDERSTAND GREASE & GIVE ITS DUE

7. Grease – A Case Study in
UCIL
• UCIL stands for Uranium Corporation of India Ltd, a modern
Indian Public Sector Undertaking, involved in mining &
processing of Uranium Ore. A few years back, a sudden
spurt in equipment breakdowns made us go in for a
detailed root cause analysis to study the failures. Many
factors surfaced but what was shocking was that in most
cases the lack or improper method of greasing was the
culprit.
• This presentation highlights the steps taken to address the
problem and also makes an effort to educate the viewers on
the importance of Greasing by explaining its various facets.

8. TRAINING – The key to change
The analysis highlighted that most workmen (even
some engineers) hardly had any knowledge of
lubrication and greasing. So the first challenge was
to impart training in this domain.
While this challenge involved imparting technical
awareness regarding Lubrication, it was also an
exercise in changing sleepy and often rigid Mind
Sets.

9. Evolutionary Change –
The Model Adopted
• A team of related engineers were selected & sent for a
lubrication training course which involved both theoretical
and practical training. On return they were assigned the
following responsibilities:
• Create a broad based site specific pictorial awareness
manual on lubrication in english and the local language
as a handbook for the workforce
• Evolve a mechanism to train identified personnel
• Demonstrate and bring pride to the persons involved in
lubrication and greasing

10. Evolutionary Change –
The Line of Action
• A list of personnel from various maintenance
sections was prepared by taking their education,
age & experience.
• A short objective test of such personnel was
conducted in order to asses their basic I.Q. &
grasping potential.
• The top eight were short listed & trained in house
on the basics of lubrication by theoretical and
practical on equipment coaching and thereafter
assigned exclusive lubrication responsibilities

11. Training Content
• In order to provide training relevant to the
Equipment in use & the grasping
power/education levels of those persons,
course material was formulated.
• A broad scheme of the training material
which became the foundation for
understanding lubrication in general &
grease in particular, is given in
thefollowing slides:

12. A Layman's DEFINITION of
LUBRICATION
““To make smooth or slipperyTo make smooth or slippery
with oil, or other matter towith oil, or other matter to
overcome friction”.overcome friction”.

13. TECHNICAL DEFINITION OF
LUBRICATION
• LubricationLubrication
– any procedure that reduces friction
between two moving surfaces.
• LubricantLubricant
– Any material that reduces friction.
– The main function of a lubricant is to
separate two moving surfaces and make
their relative movement easier.
– Liquids used as lubricants achieve this by
substituting low fluid friction in place of
high solid-to-solid friction.

14. FRICTION
• Always exists where there is sliding contact
between two surfaces
• Always consumes power
• Always produces heat
• Is independent of contact area and sliding
speed
• Is dependent on surface roughness and contact
pressure
• Represented by COEFFICIENT OF
FRICTION

15. TYPES OF FRICTION
SLIDING FRICTION
(most)
ROLLING FRICTION
FLUID FRICTION
(least)

16. LUBRICATION, FRICTION AND WEAR
SIMPLE REPRESENTATION
UNLUBRICATED
METAL SURFACES
PRESSURE AND
SLIDING MOTION
FRICTION AND
HEAT
(ENERGY LOSS)
CATASTROPHIC
FAILURE
SEIZURE

17. LUBRICATION, FRICTION AND WEAR
LUBRICATION: “MAKES SURFACES SLIPPERY”
LUBRICATED
METAL SURFACES
PRESSURE AND
SLIDING MOTION
OIL FILM
PREVENTS CONTACT
FLUID VISCOSITY: “RESISTANCE TO FLOW”FLUID VISCOSITY: “RESISTANCE TO FLOW”
or “INTERNAL FRICTION”or “INTERNAL FRICTION”
FULL FILM, orFULL FILM, or HYDRODYNAMICHYDRODYNAMIC LUBRICATIONLUBRICATION

18. FRICTION
• Always exists where there is sliding contact
between two surfaces
• Always consumes power
• Always produces heat
• Is independent of contact area and sliding
speed
• Is dependent on surface roughness and contact
pressure
Represented by COEFFICIENT OF FRICTION

19. THE LAWS OF FRICTION
There are two laws of physics that govern sliding
friction:
1. The friction between two solid bodies is independent
of the area of contact.
2. The friction between two solid surfaces is
proportional to the load by one surface on another.
COEFFICIENT OF FRICTION
µ = F / W
where F = frictional force opposing motion
And W = the load

20. Frictional Conditions CoF (µ)
Fluid Friction 0.001 - 0.005
Rolling Friction
• Ball 0.002
• Roller 0.004
Sliding Friction
• Mixed Film 0.02 - 0.08
• Boundary 0.08 - 0.10
• Dry 0.15 - 0.40
LUBRICATION CONDITIONSLUBRICATION CONDITIONS

21. CONDITIONS LEADING TO
BOUNDARY LUBRICATION
• STATIC LOAD
• SLOW SPEEDS
• HIGH LOADS
• ROUGH SURFACE FINISH
• SMALL CLEARANCES
• SHOCK LOADING

22. µ
µ
region of boundary lubrication
partial fluid film lubrication
full fluid film lubrication
TYPES OF OF FRICTIONTYPES OF OF FRICTION

23. • Modes of lubrication
• Hydrostatic
• Hydrodynamic
• Elasto-hydrodynamic
• Boundary
• Regime depends upon
• Design
• Speed
• Load
• Materials
• Viscosity
• Operating conditions etc.
LUBRICATION CONDITIONSLUBRICATION CONDITIONS

24. A solid to semi-fluid product of
dispersion of a thickening agent in
a liquid lubricant.
Greases consist of the following:
1. Additives
2. Thickener
3. Base oils

25. COMPONENTS OF GREASE
• LUBRICATING FLUID
• THICKNER SYSTEM
• ADDITIVES
LUBRICATING OIL(Pet./SYN. 4-20%)
+THICKNER(SOAP/NON-SOAP 75-96%)
+ADDITIVES(0-5%)
= GREASE

26. Mineral Oils
( Paraffinic or Naphthenic Hydrocarbon Based)
Synthetic Oils
(Chemically Synthesised Oils and Esters)
Silicone Oils
(Polymerised product of Silicon Oxide)
LUBRICATING FLUIDS

27. Soap based thickener system
( Product of reaction between fats and
alkalis)
Non-soap thickener systems
THICKENING SYSTEMS

28. Anti-oxidants
Antirust
Antiwear
Extreme Pressure
Tackifiers
Solid Lubricants
Friction Modifiers
Structure Modifiers
Metal Deactivators
ADDITIVES

29. GREASE- CLASSIFICATION
THICKENERS
SOAP
SIMPLE SOAP COMPLEX SOAP
LITHIUM LITHIUM COMPLEX
CALCIUM CALCIUM COMPLEX
ALUMINIUM ALUMINIUM COMPLEX
BARIUM BARIUM COMPLEX
SODIUM TITANIUM COMPLEX
STRONTIUM
MIXED SOAP
NON SOAP
INORGANIC ORGANIC
ORGANOPHYLIC CLAY POLY UREA, etc
Silica Based, etc

30.  The interactions between thickenerThe interactions between thickener
and lubricant (Base oil +Additive)and lubricant (Base oil +Additive)
together with the manufacturingtogether with the manufacturing
process constitute the major part ofprocess constitute the major part of
grease performancegrease performance

31. PROPER GREASE SELECTIONPROPER GREASE SELECTION
 Due to the lack of specificity in most grease recommendations, it isDue to the lack of specificity in most grease recommendations, it is
important to learn how to properly select greases for eachimportant to learn how to properly select greases for each
application in the plant or equipment.application in the plant or equipment.
 Proper grease specification requires all the components of oilProper grease specification requires all the components of oil
selection and more. Other special considerations for greaseselection and more. Other special considerations for grease
selection include thickener type and concentration, consistency,selection include thickener type and concentration, consistency,
dropping point and operating temperature range, worked stability,dropping point and operating temperature range, worked stability,
oxidation stability, wear resistance, etc.oxidation stability, wear resistance, etc.
 Understanding the need and the methods for appropriate greaseUnderstanding the need and the methods for appropriate grease
selection will go a long way toward improving lubrication programsselection will go a long way toward improving lubrication programs
and the reliability of lubricated machinery.and the reliability of lubricated machinery.
 Let’s go through the grease selection process step by step, startingLet’s go through the grease selection process step by step, starting
with the most importantwith the most important

32. Additives and Base Oil TypeAdditives and Base Oil Type
 The additive and base oil types are otherThe additive and base oil types are other
components of grease that should be selected incomponents of grease that should be selected in
a fashion similar to that used for oil-lubricateda fashion similar to that used for oil-lubricated
applications.applications.
 Most performance-enhancing additives found inMost performance-enhancing additives found in
lubricating oils are also used in greaselubricating oils are also used in grease
formulation and should be chosen according toformulation and should be chosen according to
the demands of the application. However, therethe demands of the application. However, there
are applications that might benefit from the useare applications that might benefit from the use
of a synthetic base oil. Such applications includeof a synthetic base oil. Such applications include
high or low operating temperatures, a widehigh or low operating temperatures, a wide
ambient temperature range, or any applicationambient temperature range, or any application
where extended re-lubrication intervals arewhere extended re-lubrication intervals are
desired.desired.

33. Base Oil ViscosityBase Oil Viscosity
 The most important property of any lubricant is viscosity.The most important property of any lubricant is viscosity.
 A common mistake when selecting a grease is to confuseA common mistake when selecting a grease is to confuse
the grease consistency with the base oil viscosity.the grease consistency with the base oil viscosity.
 The majority of grease-lubricated applications are elementThe majority of grease-lubricated applications are element
bearings, one should consider viscosity selection for thosebearings, one should consider viscosity selection for those
applications.applications.
 There are several common methods for determiningThere are several common methods for determining
minimum and optimum viscosity requirements for elementminimum and optimum viscosity requirements for element
bearings, most of which use speed factors, commonlybearings, most of which use speed factors, commonly
denoted as DN or NDm.denoted as DN or NDm.
 Speed factors account for the surface speed of the bearingSpeed factors account for the surface speed of the bearing
elements and are determined by the following formulas:elements and are determined by the following formulas:
 DN = (rpm) * (bearing bore)DN = (rpm) * (bearing bore)
NDm =rpm * (bearing bore + outside diameter)/2)NDm =rpm * (bearing bore + outside diameter)/2)

34. Grease Consistency andGrease Consistency and
Thickener TypeThickener Type
Now for that extra step:
• The consistency of grease is controlled by the
thickener concentration, thickener type and the
viscosity of the base oil. Even though base oil
viscosity affects consistency, it is important to
note that a grease can have a high consistency
and a low base oil viscosity or vice versa.
• Higher speed factors require higher consistency
greases. Grade based on speed factor and
operating temperature.

35. Greases stay put
Greases seal out contaminants
Greases do not need circulation systems
Greases decrease dripping, splattering and leakage
Greases suspend solid additives easily
Greases are suitable for intermittent operations
Greases work under extreme operating conditions
Greases seal for life
Greases reduce noise
Greased machinery tends to need less power

36. • REMAINS AT APPLICATION POINT & ADHERES TO SURFACE
• LESS FREQUENT APPLICATION NEEDED
• SEALS OUT CONTAMINANTS
• REDUCES NOISE AND VIBRATION
• MAINTENANCE COSTS REDUCED
• OPERATES OVER WIDE TEMP. RANGE
• WATER RESISTANT
• MORE EFFECTIVE FOR EXTREME CONDITIONS SUCH AS
SHOCK LOADING, REVERSING OPERATIONS, LOW SPEED &
HIGH SPEEDS
HOWEVER BECAUSE OF THE SEMI-SOLID NATURE OF GREASES,
THE COOLING AND CLEANING FUNCTIONS OF A FLUID
LUBRICANT ARE NOT PERFORMED.
ADVANTAGES OF LUB. GREASE OVER OIL

37.  Greases may not reach all placesGreases may not reach all places
in need of lubricationin need of lubrication
 Greases do not have any cleaningGreases do not have any cleaning
effecteffect
 Greases do not work as coolingGreases do not work as cooling
agentagent
 Greases cannot be used at asGreases cannot be used at as
high speeds as liquidshigh speeds as liquids

38. • Viscosity - Know the viscosity of each grease and
the machine requirements
• Grease base - Which greases are compatible with
bearing requirements
• Is heat a problem - Grease life is halved for every
15 degrees C over 70 deg. C
• Question the grease supplied in new equipment .
Standardize with existing equipment
• Location of grease fittings e.g. Center of pillow
block for a W33 style bearing
• Grease path - Does the housing design allow
grease to easily enter the bearing

39.  Removal
 Clean Area
 Inspection of New
Bearings
 Alignment

40.  Never assume the manufacturer has properlyNever assume the manufacturer has properly
lubricated the bearing from factory. The newlubricated the bearing from factory. The new
bearing may have been shipped with a limitedbearing may have been shipped with a limited
amount of lubrication inside. This level may notamount of lubrication inside. This level may not
be enough to form the necessary film betweenbe enough to form the necessary film between
the inner race and rolling elementsthe inner race and rolling elements..
 Determine lubrication level by using soundDetermine lubrication level by using sound
analysis or vibration monitoring methods.analysis or vibration monitoring methods.
Remember, a “dry” or under-lubricated bearingRemember, a “dry” or under-lubricated bearing
will sound louder or “scratchier” than a “quiet” orwill sound louder or “scratchier” than a “quiet” or
“smooth” sounding properly lubricated bearing.“smooth” sounding properly lubricated bearing.

41. • Scoop or Paddle from a Container
• Tube Refills
• Refilling from a Storage Container using
Mechanical or Hydraulic Pumps

42. FAQ’s
In spite of covering most areas, there
were always plenty of questions.
The common ones were:
How much grease to pump?
In Grease, what actually lubricates?
What to do if a grease drum is not
labeled?

43. HOW MUCH GREASE
TO PUMP
Pumping grease into a well-sealed bearing until
you see the grease leaving at the seal often
compromises the seal and assures that you have
too much grease in the bearing.
A reasonable volume model to use is:
V = D*B*.114, where V = Ounces per cycle, D =
Bearing OD” and B = Bearing width”.

44. In Grease,what actually
lubricates?
It is the oil within grease that does the
lubricating, not the thickener. The
thickener is an agent that holds oil like
a reservoir. In many applications it also
allows oil to release slowly as it
becomes required in bearings and
frictional machine surfaces

45. How to Prevent Mixing Greases "Is
there a color and shape code used to
distinguish between different
greases?”
Use tags to identify product type, quantity and interval.
Colors and shapes can be used to tag grease guns and
transfer containers.
Standardize lubricants. Instead of using a poly-urea and
a lithium-based EM grease, consolidate so that all similar
machines receive the same lubricant.
Use different grease fittings for different greases. This is
an effective way of reducing cross contamination.
Training. Training is a most important component in
proper lubrication.

46. IMPROPER SELECTION AND APPLICATION OF
GREASE
Grease lubricated
failures fall in 4 categories
• The selection and
application of the wrong
type of grease
• Incompatibility resulting in
excessive softening
• Contamination resulting
in excessive wear
• Too much or too little
grease applied
Points to remember
• Do not mix greases of
different thickener types.
• Keep similar thickeners in
the same application
• Lack of grease can cause
failure, but too much
grease is the primary
cause of failure since the
excess lubricant causes
high temperatures, which
in turn oxidizes the grease

47. IN CONCLUSION….
• So the next time you hear
someone cursing this
semi solid slimy lubricant
please take a few minutes
and tell him the true story
of Grease.
• Whether he understands
it or not is a different
matter but in future he’ll
think twice before
‘greasing any palms’!