Saybolt

Flash point, Cleveland Neutralization index Saybolt color Aromatics... 

The viscosity is determined by measuring the time it takes for a crude to flow through a capillary tube of a given length at a precise temperature. This is called the kinematic viscosity, expressed in mm /s. It is defined by the standards, NF T 60-100 or ASTM D 445. Viscosity can also be determined by measuring the time it takes for the oil to flow through a calibrated orifice standard ASTM D 88. It is expressed in Saybolt seconds (SSU). 

Saybolt color NF M 07-003 ASTM D 156 standard Height of liquid column for equality with colored glass... 

TABLE 2.13 Viscosity Conversion Table Centistokes to Saybolt, Redwood, and Engler units. 

The values of Saybolt Universal Viscosity at 100°F and at 210°F are taken directly from the comprehensive ASTM Viscosity Table, Special Technical Publication No. 43A (1953) by permission of the publishers, American Society for Testing Materials, 1916 Race St., Philadelphia 3, Pa. 

Saybolt Universal Viscosity at Redwood Seconds at Engler Degrees at all Temps. 

To obtain the Saybolt Universal viscosity equivalent to a kinematic viscosity determined at FF., multiply the equivalent Saybolt Universal viscosity at lOOT. by 1 + (t — 100) 0.000064 e.g., 10 centistokes at 210T are equivalent to 58.91 X 1.0070, or 59.32 Saybolt Universal Viscosity at 210°F. 

PVC poly(vinyl chloride) SFs Saybolt Furol seconds... 

SUs Saybolt Universal seconds USDA United States Department... 

Color. Colors of hydrocarbon resins are routinely deterrnined on the Gardner scale (ASTM D154) or on the Saybolt scale (ASTM D156). 

The viscosity of the spray oil, as measured by the Saybolt test, also determines its safety on plants. Other properties being equal, oils of low viscosity ate safer to use on foHage than those of high viscosity. For dormant sprays on deciduous trees, oils with viscosities between 100 and 200 Saybolt universal seconds (SUs) at 37.8°C are considered satisfactory. A lower range is often used in colder and a higher range in warmer areas. 

A number of arbitrary viscosity units have also been used. The most common has been the Saybolt Universal second (SUs) which is simply the time in seconds required for 60 mL of oil to empty out of the cup in a Saybolt viscometer through a carefully specified opening. Detailed conversion tables appear in ASTM D2161, approximation of kinematic viscosity V in mm /s(= cSt) can be made from the relation shown in equation 8 ... 

Orifice. Orifice viscometers, also called efflux or cup viscometers, are commonly used to measure and control flow properties in the manufacture, processing, and appHcation of inks, paints, adhesives, and lubricating oils. Their design answered the need for simple, easy-to-operate viscometers in areas where precision and accuracy are not particularly important. In these situations knowledge of a tme viscosity is uimecessary, and the efflux time of a fixed volume of Hquid is a sufficient indication of the fluidity of the material. Examples of orifice viscometers include the Ford, Zahn, and Shell cups used for paints and inks and the Saybolt Universal and Furol instmments used for oils (Table 5). 

Viscosity. Although traditionally of Httle importance in the evaluation of vegetable and insect waxes, viscosity is an important test for mineral and synthetic waxes. One of the most frequently used tests, ASTM D88, is used to measure the time in seconds required for a specified quantity of wax at a specified temperature to flow by gravity through an orifice of specified dimensions. This viscosity is expressed in Saybolt Universal Seconds (SUS) at the temperature of the test. The SI unit for kinematic viscosity is mm /s (=cSt). 

A dry sump design should be employed. The gear unit for a train with a central lube oil system should be designed for the turbine grade oils of the system. Typically, 150 Saybolt Seconds Universal (SSU) oils at 100°F (ISO 32) with an inlet temperature of 110°F to 120°F are adequate. 

Figure 15. Viscosity at operating temperature - Second Saybolt Universal (ssu).

Not less than 90 Not more than 375 F Not more than classification 1 Not less than plus 25 (Saybolt) Negative, sweet ... 

U = dscosity flowing temperature, Saybolt Universal Seconds (See Appendix A-12 and A-13)... 

U = viscosity at the flowing temperature, in Saybolt Universal seconds. 

In decreasing order of exactness, methods of defining viscosity include absolute (poise) viscosity kinematic viscosity in centistokes relative viscosity in Saybolt universal seconds (SUS) and SAE numbers. 

For most practical purposes, it will serve to know the relative viscosity of the fluid. Relative viscosity is determined by timing the flow of a given quantity of the hydraulic fluid through a standard orifice at a given temperature. There are several methods in use. The most acceptable method in the United States is the Saybolt viscosimeter. Figure 40.17. 

The time it takes for the measured quantity of liquid to flow through the orifice is measured with a stopwatch. The viscosity in Saybolt universal seconds (SUS) equals the elapsed time. 

The following formulas may be used to convert centis-tokes (cSt units) to approximate Saybolt universal seconds (SUS units). For SUS values between 32 and 100 ... 

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