ASME MFC-18M pdf free download

ASME MFC-18M pdf free download MEASUREMENT OF FLUID FLOW USING VARIABLE AREA METERS
1 sCOPE
This Standard describes the common variable areaflowmeter.This Standard does not attempt to standardizedimensions because the commercial products differ toowidely.
The variable area meter is manufactured in a varietyof designs.This Standard addresses only those metersbased on a vertical tapered tube of round or a modifiedround cross section. Specifically not addressed are thevarious vane type meters，meters with horizontal flow,or meters which use a spring deflection to oppose flowforces.
2REFERENCES AND RELATED DOcUMENTSASME MFC-1M Glossary of Terms Used in the Mea-surement of Fluid Flow in Pipes
ASME MFC-2M Measurement Uncertainty for FluidFlow in Closed Conduits
ASME Fluid Meters，6t Ed
Publisher: The American Society of Mechanical Engi-neers (ASME)，Three Park Avenue，New York,NY10016; Order Department: 22 Law Drive, Box 2300,Fairfield,NJ07007-2300
3 SYMBOLS AND DEFINITIONS
For symbols and their definitions,see Table 1.
4 FLOW RATE EQUATIONS
The variable area flowmeter is composed of a bodycontaining the fluid and a“float,”which is free tomove in the body to a position related to the flowrate. The balance of forces positions the float. Gravitypulls the float downward. The buoyancy of the floatplus the velocity related dynamic fluid forces lift thefloat.The float rises to increase the flow area until thefluid forces lifting the float match the downward force.The meter must be oriented with flow vertically upfor the analysis to be correct. Orientation substantially
1 sCOPE
This Standard describes the common variable areaflowmeter.This Standard does not attempt to standardizedimensions because the commercial products differ toowidely.
The variable area meter is manufactured in a varietyof designs.This Standard addresses only those metersbased on a vertical tapered tube of round or a modifiedround cross section. Specifically not addressed are thevarious vane type meters，meters with horizontal flow,or meters which use a spring deflection to oppose flowforces.
2REFERENCES AND RELATED DOcUMENTSASME MFC-1M Glossary of Terms Used in the Mea-surement of Fluid Flow in Pipes
ASME MFC-2M Measurement Uncertainty for FluidFlow in Closed Conduits
ASME Fluid Meters，6t Ed
Publisher: The American Society of Mechanical Engi-neers (ASME)，Three Park Avenue，New York,NY10016; Order Department: 22 Law Drive, Box 2300,Fairfield,NJ07007-2300
3 SYMBOLS AND DEFINITIONS
For symbols and their definitions,see Table 1.
4 FLOW RATE EQUATIONS
The variable area flowmeter is composed of a bodycontaining the fluid and a“float,”which is free tomove in the body to a position related to the flowrate. The balance of forces positions the float. Gravitypulls the float downward. The buoyancy of the floatplus the velocity related dynamic fluid forces lift thefloat.The float rises to increase the flow area until thefluid forces lifting the float match the downward force.The meter must be oriented with flow vertically upfor the analysis to be correct. Orientation substantially