Standard practice for calculating viscosity index from. Viscosity index improvers, viis, are comprised of five main classes of polymers. It is targeted for use in industrial applications where shear stability is critical. Viscosity, density, and refractive index of some ester. Viscosity to determine the oils resistance to flow an increase in viscosity may be due to high soot or insoluble content, water contamination, or admixture with higher viscosity fuel or lubricant a decrease in viscosity may be due to water contamination, or admixture with lower viscosity fuel or lubricant. Dont ignore viscosity index when selecting a lubricant. Viscosity improvers are polymer additives that reduce the impact of increasing temperature on the viscosity of lubricants. The vi is calculated from the viscosity of the polymer in oil solution at 40 c and at 100 c. How to understand the technical data we provide on every. Procedure a is applicable to petroleum products of viscosity index up to and including 100. Lubricants and lubrication from the well to the applications by neville w. The calculator on this site is for informative purposes only and we make no claims as to the accuracy, completeness or fitness for any particular purpose of the results produced. Paos have inherently high viscosity indexes vi while maintaining excellent lowtemperature performance. Viscosity index of the solution copolymer polyethylenepropylene of 3.
These new tables are based on astm method d 227074 for calculating viscosity index from kinematic viscosity at 40 and 100c. What is the best oil to choose for machine operating outside. The method was applied in a wide range and for 81 different producersbrands. For liquids, it corresponds to the informal concept of thickness. The viscosity index vi is an arbitrary, unitless measure of a fluids change in viscosity relative. The scale of viscosity index is numerical in nature, with zero being the most susceptible to changes in viscosity. Bioblend biodegradable lubricants make sense in a number of. It also applies to fluids like engine and automatic transmission oils, gear lubricants, and powersteering fluids. Generally speaking, the less it changes, across a range of temperatures, the better. Standard test method for kinematic viscosity of transparent and opaque liquids and calculation of dynamic viscosity1 this standard is issued under the.
Standard practice for calculating viscosity index from kinematic viscosity at 40 and 100c1 this standard is issued under the. However, it was found that the viscosity index does not correlate with the flow activation energy e a, which is the theoretically defined dependence of the viscosity on temperature. Viscosity improvers supplied as solids and liquids. The viscosity index is important both for new oils and for inservice oils. Faqs the importance of considering viscosity index in.
Viscosity is a tensorial quantity that can be decomposed in different ways into two independent components. The vi scale was set up in the 1920s by the society of automotive engineers sae. A high vi can be interpreted as meaning that a polymer increases the viscosity of the fluid without polymer proportionately more at high temperatures than at low temperatures. By removing the paraffin content, the oil can actually flow better at lower temperaturesthereby giving the oil a higher viscosity index. How polymers behave as viscosity index improvers in. A low viscosity index indicates high viscosity changes with temperature. Viscosity index vi the viscosity index is a calculated number according to din iso 2909, which describes the viscosity change of a mineral oil based or a synthetic fluid in dependence of temperature. Such viscosity index data may be considered as suitable for information only and not for specification purposes. Standard practice for calculating viscosity index from kinematic viscosity at 40 and 100c. Those were based on 100 and 210f as reference temperatures. Highquality medical white oils based on gas to liquids. Moreover the instrument is convenient to manipulate.
The viscosity index vi of the candidate oils, analyzed using the specified astm d2270 test procedure is calculated by measuring the viscosity at 40c and 100c 23. Kinematic viscosity is the dynamic viscosity divided by the density typical units m2s, stokes, st. The viscosity index vi allows for comparison of the viscosity behavior of different oils. We analysed ten gum karaya samples stored for about two yearsshowed high viscosityof maximum about 1835cpsand swelling index 66mlmin.
Ethylene contents of ocp vi improvers are normally in the 4060 wt % range 50 70 mole %. From the experimental measurements, the deviations in viscosity, were correlated accurately with the redlich. It stands alone as an independent lubricant performance differentiator. Viscosity index viscosity index vi is an empirical parameter. Pdf a critical approach to viscosity index sylvain verdier. It corresponds roughly to the intuitive notion of a fluids thickness. High speed dissolving of viscosity index improvers in luboils. The greater the viscosity index vi, the smaller the change in fluid viscosity for a given change in. There are two standard procedures to calculate the viscosity index.
The method is reliable for quality controls in regulatory agencies. Additional information on the various types of viscometers and their operation can be found in the physical measurements training manual, navair 1735qal2. One reason is simply because it is poorly understood. Shell tellus s2 v 68 extra protection versatile applications industrial hydraulic fluid for wide temperature range shell tellus s2 v fluids are high performance hydraulic fluids that use shells unique patented technology with excellent viscosity control under both severe mechanical stress and across a wide range of temperatures. The viscosity index is very important in a suspension oil. Method d 227074 was prepared in compliance with worldwide agreements.
Viscosity, swelling index and moisture content in gum karaya. High speed dissolving of viscosity index improvers in luboils us. The viscosity index vi is a useful tool for lubricant users and refiners, since it is a measure of the effect of temperature changes on the viscosity of the oil. Content reg11, coolmike, corbinsimpson, cosmic latte, courcelles. Triiso distributes a wide range of viscosity index improvers vii to produce high quality lubricants. Low temperatures can rob a lubricant of its ability to reach critical parts, while high temperatures can thin and break down an oil, crippling. Quench oils must remove the heat rapidly but evenly from the immersed work piece to allow a perfect hardening process.
It denotes the extent of change in viscosity of the oil over a given temperature range. The lower the vi, the more the viscosity is affected by changes in temperature. Dynamic viscosity, also absolute viscosity, the more usual one typical units pas, poise, p. Viscosity classifications industrial lubricant cassifications iso international standards organisation viscosity classification the iso viscosity classification uses mm2s cst units and relates to viscosity at 40oc. Viscosity 5 viscosity coefficients viscosity coefficients can be defined in two ways.
They must have a low viscosity at high temperatures to ensure smooth and evenly distributed wetting of the metal surface to be hardened. Determination of viscosity index in lubricant oils by. It is mostly used to characterize the viscositytemperature behavior of lubricating oils. Therefore, a fluid that has a high viscosity index can be expected to undergo very little change in viscosity with temperature extremes and is considered to have a stable viscosity. Vi improvers make up around 10% of the content of a typical multigrade luboil, and. Furthermore, the viscosity index and for some applications also the. The viscosity, density, and refractive index of binary mixtures of ethyl formate or ethyl benzoate with oxylene, mxylene, pxylene, and ethylbenzene were determined at 303.
Viscosity index tables astm international pages 1 9. To mitigate these costs, lubricant manufactures may enhance their oils and improve viscosity index performers with the postrefining addition of viscosity index. The effects of four different additive formulations namely 5748, 801, 264 and 261 on the viscosity index of two lubricating oils base oils namely 150n and 500n at two temperatures 400c and c. Some people think the viscosity index is incorporated in the iso viscosity grade, but it is not. Depending on their intended use, viscosity and density are often stated at the temperatures at which the material is used, e.
Quench oils have a rather low viscosity index, often below 100. A number in parentheses indicates the year of last reapproval. Viscosity describes a fluids internal resistance to flow and may be thought of. Viscosity index is a dimensionless number that represents how the viscosity of a hydraulic fluid changes with temperature. This precision is sufficiently good for works control, has been satisfactory for trading, and is within the requirements demanded by efficient lubrication. Viscosity index vi is a scale used to measure how much an oils viscosity, or resistance to flow, changes depending on its temperature. Too often the viscosity index vi is disregarded as a lubricant selection parameter. Higher viscosity index of lubricating oil fraction is obtained by using nmp instead of furfural under the same operating.
Calculator for viscosity index vi according to astm d2270 and iso 2909. Silverson is the world leader in design and manufacture of high shear mixers for rapid dissolving of viscosity index improvers into luboils, ranging from high shear inline mixers to complete solubilizing plants. Lubricants and lubrication from the well to the applications. For instance, honey has a much higher viscosity than water.
The smaller the difference in viscosity at low 40 c and at high 100 c temperatures, the higher the vi number or index obtained. Viscosity index describe how the viscosity changes with temperature. It consists of a series of 18 2viscosity brackets between 1. The viscosity index vi is an arbitrary, unitless measure of a fluids change in viscosity relative to temperature change. Both properties are critical in protecting engines at temperature extremes. The viscosity index of an oil or an oil formulation is an important physical parameter. Viscosity index improver general irgaflo 1100 v is an alkyl methacrylate copolymer in a highly refined mineral oil providing exceptional shear stability even under the severe krl 100 hours test conditions. Kinematic viscosity of silicone oils amazon web services. By measuring the solution viscosity we should be able to get an idea about molecular weight. Viscosity index improvers and thickeners springerlink. While future production will conform to shells specification, variation in these characteristics may occur. The present paper deals with viscosity, swelling index and moisture content studies on gum karaya. This publication is intended to replace the previous viscosity index tables.
Viscosity can be conceptualized as quantifying the internal frictional force that arises between adjacent layers of fluid that are in relative motion. Viscosity is a material property which describes the resistance of a fluid to shearing flows. A low vi means the change in viscosity of the oil with temperature is high. The viscosity of a fluid is a measure of its resistance to deformation at a given rate. Pdf viscosity index improvement of lubricating oil fraction sae. Click to request samples or quotes of viscosity index improvers. These are the current methods for calculating the vi for petroleum products used in civil and military applications. Accurate determination of viscosity index in lubricants by infrared spectroscopy.
Viscosity index vi is a measure of how oil viscosity changes with variations in temperature. The batch size, type of polymer and formulation dictate which machine is most suitable. The data shown for shell ondina x grades are those typical of current production. Content % mm carbon number chain length shell ondina 941. A critical approach to viscosity index sciencedirect. Twenty different oil samples viscosity index lubricant produced from eight. Viscosity index is a measure for the change of kinematic viscosity with temperature. Calculating viscosity index from kinematic viscosity at 40 c and 100 c1 this standard is issued under the. Gum karaya samples of all the three grades i, ii, and iii showed almost the same viscosity pattern.
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