ASME MFC-22:2007 pdf free download

ASME MFC-22:2007 pdf free download.Measurement of Liquid by Turbine Flowmeters.
ASME MFC-22 describes the criteria for the application of a turbine flowmcter with a rotating blade for the measurement ol liquid flows through closed conduit running full.
The standard discusses the following:
(a) considerations regarding the liquids to be measured
(b) turbine flowmeter system
(C) installation requirements
(d) design specifications
(e) the maintenance, operation, and performance
measurement uncertainties
This Standard does not address the details of the installation of accessory equipment used to measure pressure, temperature, and/or density for the accurate determination of mass or base volumes, or those accessories used to automatically compute mass or base volumes.
2 REFERENCES
The following is a list of publications referenced in this Standard. Unless otherwise specified, the latest edition shall apply.
ANSI/NCSL Z540.2-1997 (R2002), U.S. Guide to Expression of Uncertainty in Measurement
Publisher: NCSL International, 2995 Wilderness Place, Suite 107, Boulder, CO 80301-5404
ASME MFC-1M, Glossary of Terms Used in the Measurement of Fluid Flows in Pipes
Publisher: The American Society of Mechanical Engineers (ASMEL Three Park Avenue. New York, NY 10016-5990; Order Department: 22 Law Drive, P.O. Box 2300, Fairfield, NJ 07007-2300
ISO Guide to the expression of uncertainty in measurement
Publisher: International Organ iza t ion for Standardization (ISO), 1 ch. de Ia Voie-Creuse, Case postale 56, CH-l211, Genève 20, Switzerland/Suisse
NIST Technical Note 1297 (TN 1297), Guidelines for Evaluating and Expressing the Uncertainty of NIST Measurement Results
Meter factors are determined by proving the meter under conditions of flow rate, viscosit temperature, dertsit and pressure similar to that of actual operating conditions. The meter performance curve can be developed from a set of proving results.
7.2 Causes in Variations in Meter Factor
7.2.1 Many factors can change the performance of a turbine meter. Some factors, such as the entrance of foreign matter into the meter, can be remedied only by eliminating the cause. Other factors, such as the buildup of deposits in the meter, depend on the characteristics of the liquid being measured; these factors must be overcome by properly designing and operating the meter system.
7.2.2 The variables that have the greatest effect on the meter factor are flow rate, viscosity, temperature, deposits, or foreign matter. If a meter is proved and operated on liquids with inherently identical properties, and operating conditions such as flow rate remain similar, the highest level or accuracy can be anticipated. If there an changes in one or more of the liquid properties or in the operating conditions between the proving and the operating cycles, a change in meter factor may result and a new meter factor must be determined.
7.3 VariatIons in Flow Rate
At the low end of the range of flow rates, the meter factor curve may become less linear than it is at the medium and higher rates (see Fig. 1, Applications A and B). If a plot of meter factor versus flow rate has been developed for a particular liquid and other variables are constant, a meter factor may be selected from the plot for flow rates within the meter’s working range; however, for greatest accuracy, the meter should be reproved at the new operating flow rate.
If the metering installation is monitored and flow rate is computed by an electronic flow computer, a multipoint meter performance curve as a function of the rotational speed of the rotor can be developed and used to determine the flow rate. A multipoint meter calibration curve can improve the measurement accuracy relative to using a mean or fixed K-factor value for the meter (Fig. 1). Many commercially available flow computers for turbine meters offcr optional capability of the flow computer to update the meter performance curve with the latest data when the meter is calibrated. Using fitted curve and/or updating meter performance curve with most recent data can noticeably improve the measurement of accuracy and linearity of the meter.