flowmeters, types and working

2. FlowFlow
metersmeters
Tuba TanveerTuba Tanveer
12ABELT046712ABELT0467

3. ““FLOW METERS”FLOW METERS”
• Measure the flow rate or quantityMeasure the flow rate or quantity
of a gas or liquid in a pipe.of a gas or liquid in a pipe.
•Flow rate:Flow rate: the amount of fluidthe amount of fluid
that flows in a given time.that flows in a given time.

4. ““TYPES OF FLOWTYPES OF FLOW
METERS”METERS”
• Differential Pressure Flowmeters.Differential Pressure Flowmeters.
• Velocity Flowmeters.Velocity Flowmeters.
• Positive Displacement Flowmeters.Positive Displacement Flowmeters.
• Mass Flowmeters.Mass Flowmeters.
• Open Channel Flowmeters.Open Channel Flowmeters.
• Inferential Type Flowmeters.Inferential Type Flowmeters.
• Variable Area Flowmeters.Variable Area Flowmeters.

5. DIFFERENTIALDIFFERENTIAL
PRESSURE FLOWPRESSURE FLOW
METERSMETERS
• The most common units in use today.The most common units in use today.
• Estimates are that over 50 percent of allEstimates are that over 50 percent of all
liquid flow measurement applications useliquid flow measurement applications use
this type of unit.this type of unit.
• The pressure drop across the meter isThe pressure drop across the meter is
proportional to theproportional to the square of the flowsquare of the flow
raterate..

6. ““TYPES OFTYPES OF
DIFFERENTIAL TYPEDIFFERENTIAL TYPE
FLOW METERS”FLOW METERS”
• Orifice type.Orifice type.
• Venturi type.Venturi type.
• Nozzle type.Nozzle type.
• Pitot type.Pitot type.

7. ““CONSTRUCTION”CONSTRUCTION”
• They have a primary and secondaryThey have a primary and secondary
element.element.
• The primary element causes a change inThe primary element causes a change in
kinetic energy, which creates thekinetic energy, which creates the
differential pressure in the pipe.differential pressure in the pipe.
• The secondary element measures theThe secondary element measures the
differential pressure and provides thedifferential pressure and provides the
signal or read-out that is converted to thesignal or read-out that is converted to the
actual flow value.actual flow value.

8. ““TYPES OFTYPES OF
DIFFERENTIALDIFFERENTIAL
PRESSUREPRESSURE
FLOWMETERS”FLOWMETERS”• Orifice type.Orifice type.
• Venture type.Venture type.
• Nozzle type.Nozzle type.
• Pitot type.Pitot type.

9. VENTURI TUBESVENTURI TUBES
• Venturi tubes have theVenturi tubes have the
advantage of being ableadvantage of being able
to handle large flowto handle large flow
volumes at low pressurevolumes at low pressure
drops.drops.
• It is actually a section ofIt is actually a section of
pipe with a taperedpipe with a tapered
entrance and a straightentrance and a straight
throat.throat.
• Fluid passing through theFluid passing through the
throat causes a pressurethroat causes a pressure
difference between inletdifference between inlet
and outlet regions.and outlet regions.

10. ““APPLICATIONS OFAPPLICATIONS OF
VENTURI TUBES”VENTURI TUBES”
• They can be installed in large diameter
pipes using flanged, welded and threaded-
end fittings.
• Four or more pressure taps are usually
installed with the unit to average the
measured pressure.

11. ““ADVANTAGES OFADVANTAGES OF
VENTURI TUBES”VENTURI TUBES”
•They have the advantage of being able to
handle large flow volumes at low pressure
drops.
•Venturi tubes can be used with most
liquids, including those having a high solids
content.

12. ““POSITION DISPLACEMENTPOSITION DISPLACEMENT
TYPE FLOW METERS”TYPE FLOW METERS”
• They are volumetric flow meteringThey are volumetric flow metering
instruments.instruments.
• They measure flow by passing discreteThey measure flow by passing discrete
parcels of fluid in precisely known volumes.parcels of fluid in precisely known volumes.
• Position displacement meters are precisionPosition displacement meters are precision
instruments.instruments.
• Measures very low flows of both liquids andMeasures very low flows of both liquids and
gases.gases.

13. ““TYPES OF POSITIONTYPES OF POSITION
DISPLACEMENT TYPEDISPLACEMENT TYPE
FLOW METERS”FLOW METERS”
• Rotary piston type.Rotary piston type.
• Vane type.Vane type.
• Lobe type or meshing rotor.Lobe type or meshing rotor.
• Reciprocating piston typeReciprocating piston type
• Fluted spiral gear.Fluted spiral gear.

14. ““MESHING ROTORMESHING ROTOR
TYPE”TYPE”
• The meshing rotor type consists of twoThe meshing rotor type consists of two
rotors with lobes.rotors with lobes.
• The lobes are mechanically in contact withThe lobes are mechanically in contact with
one another.one another.

15. “WORKING OFWORKING OF
MESHING ROTOR”MESHING ROTOR”
• Incoming liquid exerts aIncoming liquid exerts a
pressure difference against thepressure difference against the
lower face of oval gear A,lower face of oval gear A,
causing the two interlockedcausing the two interlocked
oval gears to rotate to positionoval gears to rotate to position
2.2.
• In this position 2, the flowingIn this position 2, the flowing
liquid enters the cavityliquid enters the cavity
between oval gear B and thebetween oval gear B and the
flow meter body wall.flow meter body wall.
• The upstream pressureThe upstream pressure
continues to force the two ovalcontinues to force the two oval
gears to rotate to position 3gears to rotate to position 3

16. ““CONSTRUCTION &CONSTRUCTION &
WORKING”WORKING”
• At this position, a predetermined quantity ofAt this position, a predetermined quantity of
liquid has again filled the cavity between ovalliquid has again filled the cavity between oval
gear B and the flow meter body.gear B and the flow meter body.
• This pattern is continuously repeated movingThis pattern is continuously repeated moving
four times the liquid capacity of each cavityfour times the liquid capacity of each cavity
with each revolution of the rotating gears.with each revolution of the rotating gears.
• the flow rate is proportional to the rotationalthe flow rate is proportional to the rotational
speed of the gears.speed of the gears.

17. ““APPLICATIONS”APPLICATIONS”
• PaintsPaints
• CoatingsCoatings
• Lubricating OilLubricating Oil
• GreasesGreases
• High Viscosity FluidsHigh Viscosity Fluids
• Printing InksPrinting Inks
• EpoxiesEpoxies
• PolyurethanesPolyurethanes
• FuelsFuels
• AdditivesAdditives
• SolventsSolvents
• ChemicalsChemicals

18. VARIABLE-AREA FLOWVARIABLE-AREA FLOW
METERSMETERS
• Often calledOften called “rotameters”.“rotameters”.
• They are classified as differential pressureThey are classified as differential pressure
units.units.
• They are constant differential pressureThey are constant differential pressure
devices.devices.

19. ““TYPES OF VARIABLETYPES OF VARIABLE
AREA TYPE FLOWAREA TYPE FLOW
METERSMETERS””
• Flow type.Flow type.
• Tapered plug type.Tapered plug type.

20. ““FLOW TYPE FLOWFLOW TYPE FLOW
METERS”METERS”
• They consist essentially of a tapered tubeThey consist essentially of a tapered tube
and a float.and a float.
• Tapered tubes are variable area tubes.Tapered tubes are variable area tubes.
• The float is inside a tapered tube.The float is inside a tapered tube.

21. ““BASIC PRINCIPLE”BASIC PRINCIPLE”

22. ““CONSTRUCTION ANDCONSTRUCTION AND
WORKING”WORKING”
• When there is no liquidWhen there is no liquid
flow, the float rests freelyflow, the float rests freely
at the bottom of the tube.at the bottom of the tube.
• As liquid enters theAs liquid enters the
bottom of the tube, thebottom of the tube, the
float begins to rise.float begins to rise.
• Density of float is higherDensity of float is higher
than that of the fluid.than that of the fluid.
• The position of the floatThe position of the float
varies directly with thevaries directly with the
flow rate.flow rate.

23. ““CONSTRUCTION ANDCONSTRUCTION AND
WORKING”WORKING”
• When the pressure between the upperWhen the pressure between the upper
and lower surfaces balance the weight ofand lower surfaces balance the weight of
the float, the exact position of float can bethe float, the exact position of float can be
measured.measured.
• The flow rate can be read directly on aThe flow rate can be read directly on a
scale mounted next to the tube.scale mounted next to the tube.

24. ““COMPENSATION INCOMPENSATION IN
FLOW TYPE FLOWFLOW TYPE FLOW
METERS”METERS”
• Used for liquids causing cracks to glassUsed for liquids causing cracks to glass
walls.walls.
• They have non magnetic metallic body.They have non magnetic metallic body.
• Float contains a magnet with a followerFloat contains a magnet with a follower
and pointer on the outside.and pointer on the outside.
• The position of the float may be measuredThe position of the float may be measured
electrically using a position transducer.electrically using a position transducer.

25. ““INFERENTIAL TYPEINFERENTIAL TYPE
FLOW METERS”FLOW METERS”
• The flow of the fluid is inferred from someThe flow of the fluid is inferred from some
effect produced by the flow.effect produced by the flow.
• Usually it consists of a rotor which is madeUsually it consists of a rotor which is made
to spin and the speed of the rotor isto spin and the speed of the rotor is
sensed mechanically or electronically.sensed mechanically or electronically.

26. ““TYPES OFTYPES OF
INFERENTIAL TYPEINFERENTIAL TYPE
FLOW METERS”FLOW METERS”
• Turbine rotor types.Turbine rotor types.
• Rotor shunt types.Rotor shunt types.
• Rotating vane types.Rotating vane types.
• Helical turbine types.Helical turbine types.

27. ““TURBINE TYPE”TURBINE TYPE”
• It translates the mechanicalIt translates the mechanical
action of the turbine rotating inaction of the turbine rotating in
the liquid flow around an axisthe liquid flow around an axis
into a user-readable rate ofinto a user-readable rate of
flow.flow.
• It has an axial rotor which isIt has an axial rotor which is
made to spin by the fluid andmade to spin by the fluid and
the speed represents the flowthe speed represents the flow
rate.rate.
• Often this consists of aOften this consists of a
magnetic slug on the rotormagnetic slug on the rotor
which generates a pulse ofwhich generates a pulse of
electricity each time it passeselectricity each time it passes
the sensor.the sensor.

28. ““FEATURES OFFEATURES OF
TURBINE TYPE FLOWTURBINE TYPE FLOW
METERS”METERS”
• Used for the measurement of natural gasUsed for the measurement of natural gas
and liquid flow.and liquid flow.
• They are less accurate than displacementThey are less accurate than displacement
and jet meters at low flow rates.and jet meters at low flow rates.
• They have higher flow rates and lessThey have higher flow rates and less
pressure loss than displacement-typepressure loss than displacement-type
meters.meters.

29. ““CONSTRUCTION &CONSTRUCTION &
WORKING OF TURBINEWORKING OF TURBINE
TYPE FLOWMETERS”TYPE FLOWMETERS”
• They have an axial rotor which is made toThey have an axial rotor which is made to
spin by the fluid.spin by the fluid.
• The speed represents the flow rate.The speed represents the flow rate.