Saybolt Viscosity Test Introduction:
The viscosity of a fluid is an important property in the analysis of liquid behavior and fluid motion near solid boundaries. The viscosity is the fluid resistance to shear or flow and is a measure of the adhesive/cohesive or frictional fluid property. The resistance is caused by intermolecular friction exerted when layers of fluids attempt to slide by one another. In simple terms, viscosity is a measure of a fluid's resistance to flow. The knowledge of viscosity is needed for proper design of required temperatures for storage, pumping or inection of fluids. Ther Theree are two two relat related ed measu measures res of flui fluid d visc viscos osity ity ! know known n as dyna dynami micc "or "or abso absolu lute te## and and kinematic viscosity viscosi ty.. This test can be used to determine the $aybolt %niversal &iscosity or $aybolt urol "fuel and road oils# &iscosity and then kinematic viscosity of asphalt emulsions. This covers the empirical procedures for determining the viscosities of petroleum products at specified temperatures between () and **+ . In this test method, the efflux time in seconds of -+ ml sample, flowing through a calibrated orifice, measured under carefully controlled conditions. This time is corrected by an orifice factor and reported as the viscosity of the sample at that temperature. Objectives: •
bective of this test is to determine the $aybolt %niversal &iscosity or $aybolt urol "fuel "fuel and road road oils# oils# &iscos iscosity ity and then kinema kinematic tic viscos viscosity ity of asphal asphaltt emulsio emulsions ns at specified temperatures between () and ** + .
Apparatus:
The following apparatus are required "igure )#. )# $aybolt $aybolt &isc &iscometer ometer and ath "%niversal "%niversal and and urol urol rifice# rifice#
igure ) 0 $aybolt &iscometer and ath
(# 1eceiving lasks 2# ilter funnel 3# Thermometers 4# Timer Procedure:
5reparation of 6pparatus )# 6 %niversal orifice or tip for lubricants was used and distillated with efflux times greater than 2( s to give the desired accuracy. 7iquids with efflux times greater than )+++ s are not conveniently tested with this orifice. (# 6 urol orifice or tip for residual materials with efflux times greater than (4 seconds was used to give desired accuracy. 2# The viscometer was thoroughly cleaned with an appropriate solvent of low toxicity8 then all solvent was removed from the viscometer and its gallery. The receiving flask was cleaned in the same manner. 3# The viscometer was set up and batted in an area where they would not be exposed to drafts or rapid changes in air temperature and dust or vapors that might contaminated a sample. 4# The receiving flask was placed beneath the viscometer so that the graduation mark on the flask was from )++ to )2+ mm below the bottom of the viscometer tube, and so that the stream of oil would ust stroked the neck of the flask. -# The bat was filled to at least - mm above the overflow rim of viscometer with an appropriate bath medium "water or oil#. 9# 6dequate stirring and thermal control for the bath was provided. :id not make viscosity measurements at temperatures below the dew point of the room;s atmosphere. <# or calibration and referee tests, the room temperature was kept between (+ and 2++, and the actual temperature was recorded. Test 5rocedure= )# The bath temperature was established and controlled at the selected test temperature. $tandard test temperatures for measuring $aybolt %niversal viscosities are ().), • 29.<, 43.3 and *<.* + . $tandard test temperatures for measuring $aybolt urol viscosities are (4.+, 29.<, • 4+.+ and *<.* + . ther standard test temperatures in use include -+.+ + and <(.(+ . • (# ork stopper was inserted, having a cord attached for its easy removal, into the air chamber at the bottom of the viscometer. The cork shall fit tightly enough to prevent the escape of air, as evidenced by the absence of oil on the cork when it was withdrawn later as described. 2# If the selected test temperature was above room temperature, the test may be expedited by preheating the sample in its original container to not more than ).9+ above the test temperature. 6ny sample was never preheated to within (< + of its flash point, because volatility losses might alter its composition.
3# The sample was stirred well8 then it was strained trough the >o.)++ wire cloth in the filter funnel directly into the viscometer until the level was above the overflow rim. 4# The viscosities of stream!refined cylinder oils, black lubricating oils, residual fuel oils, and similar waxy products can be affected by their thermal histories. The following pre! heating procedure was used with such products to obtain uniform results at temperatures below *2+ . -# The sample was heated in its original container to about 4++ , with sting and shaking to dissolve and blended waxy materials. The bottom of the container was probed with a stirring rod to be certain that all waxy materials were in solution and mixed well. 9# 6bout )++ ml was poured into a )(4 ml ?rlenmeyer flask. $topper loosely with a cork or rubber stopper. <# The flask was immersed in a bath of boiling water for 2+ min. *# The sample was mixed well and removed from the boiling water bath, the outside of the flask was wiped and dried and the sample was strained through the >o.(++ wire cloth in the filter funnel directly in to the viscometer until the level was above the overflow rim. )+# The sample in the viscometer was stirred with the appropriate viscosity thermometer equipped with the thermometer support. ircular motion at 2+ to 4+ rpm was used in a hori@ontal plane. Ahen the sample temperature was remained constant within +.+2 + of the test temperature during ) min of continuous stirring, the thermometer was removed. ))# The tip of the withdrawal tube was immediately placed in the gallery at one point, and applied suction to remove oil until its level in the gallery was below the overflow rim. :id not touch the overflow rim with the withdrawal tube8 the effective liquid head of the sample would be reduced. )(# The receiving flask was checked to be sure that it was in proper position8 then the cork was snapped from the viscometer using the attached cord, and the timer was started at the same instant. )2# The timer was stopped at the instant the bottom of the oil meniscus reached the graduation mark on the receiving flask. The efflux time was recorded in second to the nearest +.) s. Observation:
Temperature at 4++ . Trail ) 0 The efflux time B -9 sec. Trail ( 0 The efflux time B 4< sec. Calculations and result: •
The efflux time was reported as the $aybolt %niversal or $aybolt urol viscosity of the oil at the temperature at which the test was made.
•
$aybolt %niversal seconds can be converted in to kinematic viscosity by using the conversion tables. Cethod : 334 and : ()9+ are preferred for the determination of kinematic viscosity.
Specimen Calculation:
$aybolt urol viscosity of the oil at the temperature 4+ + "6verage efflux time#
B "-9 D 4<# ( B 62. Sec
!eneral "iscussion:
The viscosity of a fluid is an important property in the analysis of liquid behavior and fluid motion near solid boundaries. The viscosity is the fluid resistance to shear or flow and is a measure of the adhesive/cohesive or frictional fluid property. The resistance is caused by intermolecular friction exerted when layers of fluids attempt to slide by one another. In simple terms, viscosity is a measure of a fluid's resistance to flow. The knowledge of viscosity is needed for proper design of required temperatures for storage, pumping or inection of fluids. There are two related measures of fluid viscosity ! known as dynamic "or absolute# and kinematic viscosity. This test can be used to determine the $aybolt %niversal &iscosity or $aybolt urol "fuel and road oils# &iscosity and then kinematic viscosity of asphalt emulsions. This covers the empirical procedures for determining the viscosities of petroleum products at specified temperatures between () and **+ .
