2. Introduction
1. The proper selection and use of lubricants,
as well as the care and operation of
lubricating systems, is an essential part of
any maintenance program.
2. To choose an appropriate lubricant for a
particular application and to maintain the
lubricant’s effectiveness, a basic
understanding of lubrication theory and the
characteristics of lubricants can be very
beneficial.
3. Fundamentals of lubrication
The basic purpose of a lubricant is to
reduce friction and wear between
two surfaces moving relative to one
another.
In most cases, a lubricant also
dissipates heat, prevents rust or
corrosion, acts as a seal to outside
contaminants, and flushes
contaminants away from bearing
surfaces.
5. Lubricant oil
1. A lubricating oil is composed of a
base stock blended with various
additives to enhance performance
and maintain quality.
2. The base stock may be
a petroleum oil,
a synthetic oil,
or in rare specialized instances,
vegetable oil.
6. Lubricant oil characteristics
Viscosity
Viscosity index
Pour point
Flash point
Fire point
Neutralization number
7. Additive in lubricant
1. Additives present in a lubricant
improve and strengthen the
performance characteristics.
2. Chemically active additives are able
to interact with metals and form a
protective film with the metallic
components present in the
machinery.
11. Grease
1. Lubricating grease is a mixture of a
lubricating fluid, a thickening agent, and
additives.
2. Petroleum oils mixed with a soap thickening
agent make up most of the grease in use
today.
3. The soaps are formed by the reaction of
animal or vegetable fats or fatty acids with
strong alkalies such as calcium or sodium.
4. Non-soap thickening agents, such as
modified clays and poly ureas, are also used
in some instances.
12.
13. Characteristic of a steam turbine oil
Seven essential characteristics of a turbine oil enable
it to perform its critical functions so that a turbine
generator unit will operate reliably for long periods.
(1) Maintain viscosity .
(2) Minimize friction and protect against wear .
(3) Transfer heat from the journals, bearing,
(4) Resist oxidation and degradation due to exposure
to air (oxygen), water, and hydrogen ,
(5) Resist foaming and air entrainment
(6) Protect other components from corrosion
(7) Separate rapidly from water
14. Additive in Steam turbine oil
Present-day turbine oils are formulated with a highly
refined mineral oil base and a varying number of
additives which enhance or impart a specific oil
property.
As a minimum, steam turbine oils contain an
antioxidant to retard oxidative attack and a rust
inhibitor to protect iron-base metals. In addition, an
antifoam agent and a metal deactivator may be
present.
Depending on the properties of the mineral oil base,
other functional additives may be used to achieve the
required performance characteristics.
15. Oil Specification-
KWU –BHEL Turbine 500 MW
Oil of viscosity
class ISO VG 46
shall be used.
The oil shall be a
petroleum product
with or without
additives to meet
the requirement of
this standard.
OIL SUPPLIER BRAND
IOC SERVO PRIME 46
GULF OIL INDIA
LTD
GULF CREST 46
CALTEX REGEL R&O 46
CASTROL Castrol prefecto t-
46 super clean
Indo mobil ltd Mobil DTE
medium/DTE
798
16. FRF oil for turbine control system
Fire Resistant Fluids (FRF) oil
recommended for BHEL make steam
turbine control system in 500 MW .
According to ISO 6743/4, FRF is a
fluid based on triarylphosphate ester
marked ISO-L-HFDR.
