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The real world of the 1990's places heavy demands on equipment. We expect equipment to operate between -50°C and 150°C without production loss or increased maintenance costs. Lubricants can be considered a vital component of every machine. Notwithstanding extreme temperatures, many machines are heavily loaded, and operate at higher speeds with smaller reservoirs and longer lubricating intervals.
Proper lubrication is vital in any operation and is determined from the "Four R's".
The Original Equipment Manufacturer (OEM) together with your Petro-Canada Lubricants Representative or Technical Services Advisor can assist you in determining the "Four Rights" for your equipment or machinery.
It had been the practice in North America for many years to define the viscosity of industrial lubricating oils in Saybolt Universal Seconds (SUS) at reference temperatures of 100 °F and 210 °F.
However, there is now a world-wide acceptance of the International Organization for Standardization's (ISO) proposal 3448-1975 (E) to establish viscosity measurements in centistokes (cSt) at 40 °C and 100 °C temperatures.
International acceptance benefits customers, manufacturers and marketers. The lubricant grade recommended by the equipment manufacturer is the same as the number in the product name. Conversion from one viscosity measurement to another is virtually eliminated. The number in the product name for most products represents the viscosity of an industrial oil.
Not involved in this new measurement system are all automotive crankcase and gear oils which continue to be designated by the Society of Automotive Engineers (SAE) viscosity classifications. The table below shows the kinematic viscosity limits for each ISO Viscosity Grade. Each viscosity grade is 50% higher in viscosity than the preceding viscosity grade. These limits are set at a 10 percent tolerance level above and below the mid-point of a grade. Any product with a viscosity outside these tolerance levels is not a recognized ISO Viscosity Grade.
|Kinematic Viscosity Limits|
|ISO Viscosity Grade||Mid Point cSt @ 40 °C||Minimum||Maximum|
The American Gear Manufacturers Association (AGMA) has set up a numbering system to define gear oil viscosities required for various speed reducer types and applications. These AGMA Lubricant Numbers are normally stamped on the manufacturer's metal name plate. ISO Viscosity Grade numbers and AGMA numbers can be compared as shown in the table below.
|AGMA #||R & O||ISO VG Grade||Viscosity Range cSt @ 40 °C|
|-||1||46||41.4 - 50.6|
|2 EP||2||68||61 - 75|
|3 EP||3||100||90 - 110|
|4 EP||4||150||135 - 165|
|5 EP||5||220||198 - 242|
|6 EP||6||320||288 - 352|
|7 EP||7A Comp||460||414 - 506|
|8 EP||8 Comp||680||612 - 748|
|8A EP||8A Comp||1000||900 - 1100|
AGMA # EP requirements are met by Ultima EP mild gear oils of proper viscosity. R&O requirements are met with Premium R&O and Harmony AW. The compounded grades designated "COMP" are met with the Senate grades, which contain additional lubricity additives. Automotive gear oils for hypoid gears are designated by SAE for viscosity grades and API for quality levels. These oils may be used in many speed reducers but oils designed to meet AGMA requirements cannot be used in automotive differentials and transmissions.
Viscosities designated by various societies or organizations may be compared as shown in the table opposite.
This is strictly a viscosity comparison and in no circumstance should it be construed as a quality level comparison. To summarize -
|ISO VG||is viscosity measurement in centistokes (cSt) at 40 °C.|
|AGMA||viscosity grades as designated by the American Gear Manufacturers Association.|
|SAE||Society of Automotive Engineers viscosity measurement for automotive engine and gear oils e.g. SAE 30, SAE 90, etc.|
|Saybolt||These units are in S.U.S. and were used by various refiners/blenders to specify viscosity at 100 °F or 210 °F.|
How to use the chart: For instance, if a manufacturer requests a non-detergent SAE 30 oil for a piece of equipment, go to the SAE viscosity column and follow across horizontally to the left to read an ISO VG of 100. Non-detergent suggests that it is not a typical engine oil, as all engine oils contain detergents. In order to recommend the correct product, the end-use application should be determined. For example,
|(Normally At Start-Up)|
|22,000||Probably maximum pouring viscosity.|
|11,000||Probably maximum for splash or bath lubrication.|
|8,600||Barely pumpable by gear or piston pump too heavy to be serviceable.|
|2,200||Upper limit for an automatic oil lubricator.|
|2,200||Upper limit for circulation system (good practice).|
|2,200||Upper limit for an oil constituent of a grease for dispensing.|
|1,000||Ring or rolling element bearings.|
|860||Hydraulic Vane Pumps @ start-up temperature to prevent cavitation and wear.|
|860||Fuel oil for good pumpability and atomizing.|
|220||Oil mist generators without heat at minimum operating temperature.|
|220||Hydraulic-piston pump start-up temperature to prevent wear.|
|54||Hydraulic Systems at operating fluid temperature.|
|(At Operating Temperature)|
|33 F||or gear lubrication.|
|30||For a gear pump.|
|21||Spherical roller bearings.|
|13||Other rolling element bearings.|
|13||Hydraulic systems to prevent excessive pump wear and slippage.|
|4||Minimum viscosity to support a dynamic load.|
The optimum viscosity is the ideal allowable at the operating temperature.
|40||Spur & Helical Gears (e.g. ISO-VG 150 @ 60 °C)|
|75||Worm Gears (e.g. 460 @ 75 °C)|
Petro-Canada's lubricating oils and greases are the result of considerable research work and, after careful manufacture and delivery, are as good for their intended use as we can make them. However, during storage it is important to guard against contamination, which can drastically reduce the performance and life of a lubricant. Numerous studies have shown that both water and dirt can lessen the life of bearings and other components. Preventing contamination during storage has a direct pay-back in terms of optimum lubricant performance, longer lubricant life and reduced maintenance costs.
Lubricants preferably should be stored inside. However, even then there are certain precautions that should be followed:
If outside storage is unavoidable, then the following precautions should be followed:
Lubricating oils and greases are a relatively harmless class of material. Nevertheless, care should be taken to avoid skin contact and inhalation of oil mists during use. Petro-Canada provides Material Safety Data Sheets (MSDS) on all of its products and these are available from your Sales Representative or our Technical Services Department.
Some general guidelines for personnel handling lubricating oils and greases follow: