Calibrated orifice

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). 

Certain calibrated orifice instruments (Engler-type) provide viscosity measurements at temperature lower than pour point. This is possible because the apparatus agitates the material to the point where large crystals are prevented from forming whereas in other methods, the sample pour point is measured without agitation. 

Viscosity is normally determined by measuring the time required for a fixed volume of a fluid, at a given temperature, to flow through a calibrated orifice or capillary tube. The instmments used to measure the viscosity of a liquid are known as viscosimeters. 

In the SI system, the theoretical unit of v is m2/s or the commonly used Stoke (St) where 1 St = 0.0001 m2/s = 100 cSt = 100 centiStoke. Similarly, 1 centiStoke = 1 cSt = 0.000001 m2/s = 0.01 Stoke = 0.01 st. The specific gravity of water at 20.2°C (68.4°F) is almost 1. The kinematic viscosity of water at 20.2°C (68.4°F) is for all practical purposes equal to 1 cSt. For a liquid, the kinematic viscosity will decrease with higher temperature. For a gas, the kinematic viscosity will increase with higher temperature. Another commonly used kinematic viscosity unit is Saybolt universal seconds (SUS), which is the efflux time required for 60 mL of petroleum product to flow through the calibrated orifice of a Saybolt universal viscometer, as described by ASTM-D88. Therefore, the relationship between dynamic viscosity and kinematic viscosity can be expressed as... 

Saybolt Universal Seconds (SUS) are used to measure viscosity. The efflux time is the SUS required for 60 mL of a petroleum product to flow through the calibrated orifice of a Saybolt Universal viscometer, under carefully controlled temperature and as prescribed by test method ASTM D 88. This method has largely been replaced by the kinematic viscosity method. SUS is also called the SSU number (Seconds Saybolt Universal) or SSF number (Saybolt Seconds Furol). 

The Saybolt universal viscosity (SUS) (ASTM D88) is the time in seconds required for the flow of 60 mL of petroleum from a container, at constant temperature, through a calibrated orifice. The Saybolt furol viscosity (SFS) (ASTM D88) is determined in a similar manner except that a larger orifice is employed. 

Obtain production, ventilation and system design information Clean elutriators Calibrate orifices... 

All eight sampling sites were operated by local residents. Preweighed filters were placed in filter holders at U.C. Davis and shipped via U.P.S. to each site. The local operator would measure the flow before and after sampling with a spirometer calibrated orifice meter, and then return this information with the exposed filters. Upon arrival at U.C.D., filters were post-weighed and prepared for x-ray analysis. 

Feed tank with control valve and gravimetric flow the desired flow rate is ensured by the appropriate opening of the valve, that is, the actuator of a control loop using the weight of the reactor or of the feed tank, the level in the feed tank, or a flow meter as input. The maximal feed rate can be limited by the clearance of the valve or by a calibrated orifice. 

Dirt and moisture are the worst enemies of the performance of all PD gas meters, so inlet filtering should be used when indicated. Pressure and temperature should either be controlled or compensated. The testing (or proving, as it is called in the gas utility industry) of gas meters is usually done by an accurately calibrated "bell" of cylindrical shape that is sealed in a tank by a suitable liquid. The lowering of the bell discharges a known volume of air through the meter under test. Other standards used to calibrate gas meters are calibrated orifices and critical flow nozzles. These devices compare rates of flow rather than fixed volumes. 

In the pour test [43] foam is obtained by pouring the solution tested through a calibrated orifice from a definite height on the surface of the same solution (Fig. 1.5). This method has been studied in details and has been adopted in several countries as a standard one for estimation of foaming ability of a solution (for example, solutions of detergents). This method has various modifications [5,6,8],... 

Saybolt viscosity measurement was designed for petroleum products measured at temperatures between 21 and 99°C. The efflux hme in seconds of 60 ml samples, through a calibrated orifice, is measured. Cylindrical viscometer is immersed in thermostating bath. Measured liquid flows from viscometer into receiving flask graduated for 60 ml. The measured hme in seconds is multiplied by a correchon factor obtained from a measurement of viscosity standard. The result is in a Saybolt viscosity imits. 

The Saybolt viscometer was developed for petroleum products. A sample of 60 ml flows through a calibrated orifice and the time of flow is measured at a controlled tempera-... 

Saybolt universal viscosity n. Efflux time in seconds for 60 ml or fluid to flow through a calibrated orifice under specified conditions. 

Viscosity is often expressed in terms of Saybolt Universal Seconds (SUS) it is measured as the time it takes 60 mL of oil to flow through a calibrated orifice at a given tempemture. 

It should be stressed that, because the accuracy of the measurements in this investigation was poor compared with that used for calibrating orifices with cold water ( i 0.5 per cent), the orifice coefficients reported here should not be used for design purposes. However, the results indicate... 

A single-stage liquid-oxygen turbo pump circulates liquid from the sump to the top tray via a vessel fitted with liquid level indicator and calibrated orifice at the base. This enables the liquid actually entering the top tray to be metered. 

B ause its calibrated orifices for distribution are on the trough walls this construction is less sensitive to susceptible to plugging. The multiple-stage version is able to handle broad liquid loading ranges, up to 10 1. 

Flow transmitters. Flow measurements are made in high-pressure lines by sensing the pressure drop across a calibrated orifice or venturi, or by the transmitting variable-area type of flowmeter. The latter meter resembles a Rotameter with float position transmitted electrically. It has the advantage of being an in-line element but is not readily applicable to large flows. 

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