A lubricant is a substance introduced to reduce friction between moving surfaces. The moving surfaces are found everywhere- in an engine, gear, brakes, turbine, compressors, hydraulics, rolling etc. Friction generated due to this movement causes a build-up of heat and eventually leads to wear. The combination of heat and wear debris can lead to many problems in systems, including sludge, varnish deposits, shortened lubricant life and eventual equipment failure. In addition, friction wastes energy. It is estimated that more than 30% of the world’s energy production is consumed in overcoming friction. Use of proper lubricants and applying lubrication principles can minimize or prevent most problems associated with modern machines and equipment.
 
Lubricants are broadly classified as Automotive and Industrial Lubricants. Lubricants used by Automotive industry such as Engine Oils, Transmission Oils, Coolants, Brake Fluids, Steering Fluids etc. fall under the scope of Automotive Lubricants, whereas the lubricants used by different industries such as Hydraulic Oils, Gear Oils, Turbine Oils, Compressor Oils etc. constitute Industrial Lubricants.

We are going to discuss about major Industrial Lubricants in this paper. Industrial Lubricants are the Lifeline of any manufacturing or services industry as any such industry would have hundreds of machinery with moving parts working non-stop to achieve plant productivity.

Turbine Oils
In a Turbine, more than 100 tons of steel, rotating at 3600 rpm, is supported by plain bearings on a cushion of oil that is thinner than a human hair. In power plants around the world, the same fluid dynamics take place day-in and day-out without much notice. Poor selection and maintenance of turbine oil can result in production losses exceeding Rs. 3 crores per day.
 
Steam, gas and hydro turbines operate on a family of lubricating oils known as R&O oils (Rust & Oxidation inhibited oil). Turbine equipment geometry, operating cycles, maintenance practices, operating temperatures and potential for system contamination present unique lubricating oil demands when compared against other lubricating oils like gasoline and diesel engine applications. Utility steam and gas turbine sump capacities can range in size from 5 to 100 kilolitres, which drives the economic incentive for a long-life lubricating oil. Low turbine oil makeup rates (approximately five percent per year) also contribute to the need for high-quality, long-life lubricants.

Indian Oil has been a pioneer in manufacturing and marketing of Turbine Oils with more than 70% Power Houses in India running on Servoprime oils. Servoprime oils meet most of the national and international OEM specifications and are also endorsed by them.  The reason this oil is most loved by all the users is its excellent service life which spans in some cases to more than 25 years. More than 2,00,000 hrs. have been clocked by one of the thermal power plants with the same oil and the oil as well as system condition is still absolutely healthy. Recently, Servoprime 32 XL has been approved by MHI Japan having the most stringent specifications as far as sludge generation tendency is concerned.

	Turbine Oils
	Servoprime series	Most popular Turbine oils recommended for lubrication of any type of Turbine due to its exceptional thermal and oxidation stability, excellent demulsibility, air release property and resistance to  foaming. These oils meet IS:1012-2002, BS 489, L-TSA & L-TGA specifications of ISO 8068:2006(E) and BHEL turbine oil requirements.
	Servoprime T oils	These oils have higher FZG ratings and meet the requirements of geared turbines.
	Servoprime  LP oils	Low-pour Turbine Oils recommended for low temperature applications like Rotoflow expanders and Turbo-compressors used in refrigeration applications.
	Servoprime G oils	Specially designed to satisfy the demanding requirements of modern high output gas turbines including geared units. Exceed the specification requirement of Alstom HTGD 90117, GEK 32568F, BHEL GT10198, Siemens TLV 901304.
	Servoprime XL oils	Specially designed turbine oils meeting Mitsubishi Heavy Industries (MHI) specification MS 04-MA-CL001 (Rev 2) & MS04-MA-CL002 (Rev. 2) for application in heavy duty single to multi-shaft steam and gas turbines. The oil has excellent thermal/oxidation properties with minimal sludge generation tendency.
	Synthetic Turbine Oils
	Servoprime SHC oils	Servoprime SHC Oils are PAO based Turbine oils specifically designed to meet severe industrial gas turbine applications.

Hydraulic Oils
Hydraulics cover a wide range of industrial applications in which mechanical energy is converted to fluid energy and then to mechanical work. Hydraulic systems depend on a fluid medium under pressure to create motion in machine components. Pumps are used to create the combination of flow and pressure in such systems. The type of pump, whether it is a piston pump, vane pump or Gear pump, decides the type of hydraulic fluid.

Hydraulic fluids are used for transmission of pressure and controlled flow. Hydraulic fluids are also responsible for lubrication, heat transfer and contamination control. When choosing a hydraulic fluid, viscosity, viscosity index, oxidation stability and wear resistance are the four critical characteristics to be considered. In case of vane pump, antiwear performance of the oil is of paramount importance whereas in case of piston pump, since it operates under full film lubrication, viscosity becomes the key parameter.

Indian Oil has full range of hydraulic fluids for all critical applications. Servo Hydraulic Oils are endorsed by steel plants, mining, power plants, fertiliser, engineering and different types of industries. Use of one of the hydraulic oils, Servohydrex TH 46 Plus in HEMM at a Steel plant doubled the service life from 2000 to 4000 hours.

	Circulating and Hydraulic Oils (Anti-wear Type)
	Servosystem oils	Recommended for hydraulic and circulation systems of wide variety of equipments.  These oils pass Vickers V-1O4C vane pump test and meet IS:10522-1983 (Reaffirmed 2004) and IPSS 1-09-002 specifications.
	Servosystem HLP oils	These are premium hydraulic oils recommended for high performance electro-hydraulic or numerically controlled systems.  These oils meet DIN 51524 Part 2, Denison HF-O, US Steel 127, Cincinnati Machines P-69 and P-70  and IS:11656-1986 specifications.
	Servosystem XLP oils	The oil has excellent oxidation stability with D943 life of more than 4000 hours. It is recommended for use in hydraulic systems at Plate mill etc. at Steel plants.
	Special Purpose High VI Hydraulic Oils (Anti-wear Type)
	Servosystem HVLP oils	These oils are all-weather high anti-wear hydraulic oils recommended for use in equipments working at high altitudes and under wide ambient temperature variation.  They meet DIN 51524 Part 3 specifications.
	Servohydrex oils	Servohydrex oils are very high viscosity index, anti-wear type hydraulic oils recommended as hydraulic fluid for Heavy Earth moving machinery (HEMMs).
	Foodgrade Hydraulic Oils
	Servosystem FG oils	Specially designed synthetic hydraulic fluids for Food Processing Industry listed by National Sanitary Foundation (NSF) , USA as H1 category food grade lubricants.

Industrial Gear Oils
Today’s gearboxes typically are smaller and made from newer, lighter-weight materials than before. But, these smaller, lighter pieces of equipment are pushed to produce more power and, at the same time, be more durable and reliable than before. In addition, Industrial gear sets work in presence of large quantities of water, as is found in steel mills, or in highly contaminated environment of a mine or quarry. This translates into very severe environment for Industrial gear oils to work.

The goal for handling such increasing demands is to keep the lubricant thermally stable and robust enough to ensure that it lasts longer, protects better and performs more efficiently, while at the same time, keep the system clean and carry away heat and contaminants. This is achieved by proper selection of base fluids and additives. Depending upon the type of gear and operating environment, additives are carefully chosen. Some of the key parameters besides evaluating the Extreme pressure and antiwear properties of the oil are demulsibility, corrosion, foaming and oxidation.

Indian Oil can cater to all the requirements of Industrial Gear oils, be it in steel plants, collieries, wind mills, power plants, engineering industries. With the kind of product portfolio from mineral oil based products to PAO/ PAG based synthetic products, you can bet on Servo Industrial Gear Oils. While Servomesh EE oils are known to give substantial energy savings in the bowl mill of thermal power plants , Servosyngear HVI oils has reduced the oil temperature compared to conventional gear oils in a cooling tower gear box and hence increased life. Servomesh Gold as well as Servosyngear Plus have been approved by Flender as per their latest revision for use in helical, bevel and planetary gera boxes.

	Industrial Gear Oils
	Servomesh SP oils	These oils based on Sulphur-Phosphorous chemistry are recommended for heavy-duty enclosed gear drives with circulation or splash lubrication system. Servomesh SP oils meet US Steel requirement No. 222 and 224 and IPSS:1-09-003 specifications.
	Energy Efficient Industrial Gear Oils
	Servomesh EE oils	Servomesh EE oils are energy efficient gear oils, which provide reduced friction and thereby reduce power consumption.
	Anti Micropitting Gear Oils
	Servomesh XP oils	Servomesh XP 320 is an anti micro pitting oil with higher load bearing capacity (FZG>14) than conventional gear oils. These oils meet the requirement of DIN 51517 CLP ( Part III).
	Servomesh Plus oils	Advanced extreme pressure type industrial gear lubricants specially formulated to protect heavily loaded gears against micropitting.  They meet performance requirement of AGMA 9005-D95, US Steel 224, DIN 51517 CLP ( Part III), David Brown S1.53.101 etc.
	Servomesh Gold oils	These are high performance anti micropitting industrial gear lubricants recommended for lubrication of helical, bevel & planetary type of Gear units. These oils have the technical approval of Siemens for Flender Gear units under Revision 13.
	Synthetic Gear Oils
	Servosyngear oils	Synthetic gear oils made of PAO based fluids and selected additives. Their natural high VI combined with low traction co-efficient reduce power consumption and make them energy efficient gear oils.  They provide long equipment life.
	Servosyngear HVI oils	Polyalkylene  Glycol based synthetic gear lubricants having inherent high viscosity index and excellent thermal and oxidation stability, recommended for worm gear lubrication and in gear boxes in blast furnaces of Steel plants.
	Anti-Micropitting Synthetic Gear Oils
	Servosyngear Plus oils	Synthetic industrial gear lubricants recommended for wind mill gear lubrication and others working under heavy or shock load conditions which may be subjected to micropitting.  Their natural high VI and low pour point make them suitable for continuous all whether applications. Servosyngear Plus are approved by Flender against specification  24/10/2013/Rev.13

Compressor Fluids
Compressors are gas pumps in which a compressible process fluid, typically air, or a host of other gases is squeezed into much smaller volume, resulting in elevated pressures due to which it move from one place to another. This compression also results in high temperatures. Some of the heat of compression is removed by air, water or oil cooling during the compression cycle.

The overwhelming majority of compressors is either the dynamic (axial/centrifugal) or positive displacement (reciprocating and screw-type) type. Centrifugal compressors are primarily used where high air volumes are required as opposed to high pressure. The recommended lubricants are normally R&O and antiwear oils. In case of reciprocating compressors, high outlet temperatures can cause a buildup of carbon-like deposits in the upper cylinder heads. A di-ester or polyol ester based synthetic fluid shall give best performance under such conditions. In a rotary “wet” screw compressor, the incoming air is mixed with lubricating oil. The oil helps cool the compressed air, as well as provide a seal between rotating screws. Oils with excellent oxidation and thermal stability are desirable for such applications.

Servo range of compressor oils cover from mineral oil based products to PAO, PAG, Diester, Polyol ester based fluids. A very high RPVOT compressor fluid, Servopress XL boasts of more than four time service life than conventional compressor fluids in the market. Excellent performance has been observed at various sites of an oil exploration giant for one of the products, Servosynco E 100 which has clocked more than 10000 hrs. service life. In LPG compressor at one of the customer sites, Servocress series has completed 18000 hours and still running satisfactorily. Some of the compressor fluids manufactured and marketed by Indian Oil is given below:

	Compressor Fluids
	Servopress oils	Servopress oils are excellent cylinder lubricants for high performance reciprocating and rotary air compressors and can be used up to 220 deg C air discharge temperature. . These oils meet the requirement of DIN 51506 VD-L group and ISO DlS-6521 specifications for air compressor oil.
	Servopress T oils	Servopress T oils meet the specific requirement of ammonia oxidation and air blow test and are recommended for lubrication of ammonia and syn-gas centrifugal and screw type compressors.
	Servopress XL oils	Servopress XL oils are high performance rotary screw compressor oils specially developed to provide extended drain intervals against conventional compressor fluids. These oils provide improved thermal and oxidation stability over a wide range of temperatures, reduced carbon forming tendency & reduced volatility.
	Synthetic Compressor Fluids
	Servosynco E oils	Specially designed PAO based synthetic; long drain compressor oils for high pressures air/ flare gas compressors. They provide excellent lubricity and low oil consumption rate.
	Servosynco DE oils	Diester based synthetic compressor oils recommended for single and multi-stage air compressors where discharge temperature is limited upto 200°C.  They have built-in detergency properties which results in longer lasting air compressor parts and reduced oil separator varnishing and sticking of air compressor valves.
	Servosynco PE oils	These are Polyol ester based fully synthetic compressor oils designed to lubricate reciprocating air compressors working under severe operating conditions like air discharge temperature exceeding 200°C and rotary compressors.  These oils possess superior oxidation stability, reduced carbon deposits tendency, high flash point and low volatility.
	Speciality Compressor Fluids
	Servocress oils	Servocress oils are fully synthetic compressor oils for lubrication of LPG & other hydrocarbon gas compressors working under sub-zero temperature. These oils possess high viscosity index and anti-wear properties.  These products have special capability to resist dilution with hydrocarbon gases.

Refrigeration Compression Fluids
Today’s industrial refrigeration systems are mostly compression type systems, where cooling is generated based on the evaporation of a refrigerant fluid such as Freon, ammonia or Carbon dioxide. The basic elements of these refrigeration units are compressor, condenser, expansion valve and evaporator.
 
The lubricant selected for a refrigeration system must be suitable for type of compressor (centrifugal/reciprocating/screw) used in the system and also should have appropriate solubility and miscibility characteristics with the refrigerant fluid. With systems not having oil separator, the lubricant carried over from compressor to the evaporator must be sufficiently miscible with the refrigerant fluid at evaporator temperature so that the blend remains in one phase after expansion in the evaporator and at a sufficiently low viscosity to travel through to the compressor.
 
Indian Oil has refrigeration lubricants for all compressor types as well different refrigerants such as Ammonia, Carbon dioxide, CFC, HCFCs, and HFCs.

	Refrigeration Compressor Oils
	Servofriz oils	Servofriz oils are recommended for a wide range of refrigeration compressors using all conventional refrigerants (CFCs)  except sulphur dioxide and are suitable for both reciprocating as well as rotary compressors.  These oils meet IS:4578-1989 specification.
	Servofriz NH oils	Servofriz NH 32 is recommended for cylinder lubrication of refrigeration compressors, with ammonia as refrigerant requiring a low pour anti-wear oil.
	Semi-Synthetic Refrigeration Compressor Oils
	Servofriz S oils	Servofriz S oils are recommended for use with all fluorochlorocarbon refrigerants and with hydrocarbons and ammonia in refrigeration and air conditioning applications where the evaporation temperatures are lower than the pour point of the oil.
	Eco-friendly Synthetic Refrigeration Oils
	Servofriz ECO series	Servofriz ECO oils are polyol ester based refrigeration oils designed specifically for lubrication of refrigeration compressors and  systems using ozone friendly HFC refrigerants.
	Servofriz Car fluids	Servofriz Car oils are environment friendly PAG based synthetic refrigeration fluids for automobile air conditioning compressors using R134a as refrigerant.

The above paper covers only the most common industrial lubricants being used by any industry. There are lubricants for other applications such as Fire resistant hydraulic fluids, Machine tool way oils, Machinery oils, Textile oils, Bearing oils, Vacuum pump oils, Gas Holder oils, Pneumatic tool oils, Sugar mill lubricants, Open gear compounds, Chain lubricants, Greases and many more which are not covered here. In case of specific query related to above lubricants, the author may be approached at nmittal@indianoil.in.