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  • COMMONLY USED FLOW DEVICES

    Differential Pressure (Head) Type

    Orifice Plate - Concentric, Eccentric, Segmental, Quadrant Edge, Integral, ConditioningVenturi TubeFlow NozzlesElbowPitot Tube, Averaging Pitot Tube (Annubar)Variable Area (Rotameter)Wedge MeterV-Cone

    Mass Type measures the mass flow rate directly.

    CoriolisThermal

    Velocity Type

    MagneticUltrasonic - Transit Time, DopplerTurbineVortex

    Open Channel Type

    WeirParshall Flume

    Other Types

    Positive DisplacementTarget

    The following is a list of commonly used flow devices in the Oil & Gas Industry. A corporate standard in many cases provides guidance on the evaluation criteria for flowmeter selection. There are many types of flowmeters available and each has its own application and advantages & limitations, but should always follow project specifications first and be aware that information can vary for the same type of flowmeter between different manufacturers.

    There the Differential Pressure (Head) Type, which is the most common flow measuring system, where flow is inferred from the differential pressure caused by the flow. This type of flow meter is based on Bernoullis Equation. Differential Pressure (Head) Type flowmeters include the following:

    Orifice Plate - Concentric, Eccentric, Segmental, Quadrant Edge, Integral, Conditioning

    Venturi Tube

    Flow Nozzles

    Elbow

    Pitot Tube, Averaging Pitot Tube (Annubar)

    Variable Area (Rotameter)

    Wedge Meter

    V-Cone

    Another type of flowmeter is the Mass Type, which measures the mass flow rate directly. Mass Type flowmeters include the following:

    Coriolis

    Thermal

    Another type of flowmeter is the Velocity Type, where flow is calculated by measuring the speed in one or more points in the flow and integrating the flow speed over the flow area. Velocity Type flowmeters include the following:

    Magnetic

    Ultrasonic - Transit Time, Doppler

    Turbine

    Vortex

    Other Types of flowmeters commonly used in the oil and gas industry include:

    Positive Displacement

    Target

    Another type of flowmeter is the Open Channel Type, where the common method of measuring flow through an open channel is to measure the height of the liquid as it passes over an obstruction (flume or weir) in the channel. Open Channel Type flowmeters include the following:

    Weir

    Parshall Flume

  • FLOW MEASUREMENT - TERMS

    DENSITY (r) A Measure Of Mass Per Unit Of Volume (lb/ft3 or kg/M3).SPECIFIC GRAVITY The Ratio Of The Density Of A Material To The Density Of Water Or Air Depending On Whether It Is A Liquid Or A Gas. COMPRESSIBLE FLUID Fluids (Such As Gasses) Where The Volume Changes With Respect To Changes In The Pressure. These Fluids Experience Large Changes In Density Due To Changes In Pressure.NON-COMPRESSIBLE FLUID Fluids (Generally Liquids) Which Resist Changes In Volume As The Pressure Changes. These Fluids Experience Little Change In Density Due To Pressure Changes.

  • FLOW MEASUREMENT - TERMS

    LinearTransmitter output is directly proportional to the flow input.Square RootFlow is proportional to the square root of the measured value.Beta Ratio (d/D)Ratio of a differential pressure flow device bore (d) divided by internal diameter of pipe (D).A higher Beta ratio means a larger orifice size. A larger orifice plate bore size means greater flow capacity and a lower permanent pressure loss.Pressure HeadThe Pressure At A Given Point In A Liquid Measured In Terms Of The Vertical Height Of A Column Of The Liquid Needed To Produce The Same Pressure.

    The following terminology is normally used in flow measurement, including:

    Rangeability (Turndown), the ratio of maximum flow to minimum flow, but not zero flow.

    Repeatability, the ability of a flow meter to indicate the same readings each time the same flow conditions exist. These readings may or may not be accurate, but will repeat. This capability is important when a flow meter is used for flow control.

    Linear, where the transmitter output is directly proportional to the flow input.

    Square Root, where flow is proportional to the square root of the sensed differential pressure (head).

    Beta Ratio (d/D), which is the ratio of orifice plate or other differential pressure flow device bore (d) divided by internal diameter of pipe (D). A higher Beta ratio means a larger orifice plate bore size. A larger orifice plate bore size means greater flow capacity and a lower permanent pressure loss.

  • FLOW MEASUREMENT - UNITS

    Flow is measured as a quantity (either volume or mass) per unit timeVolumetric units Liquidgpm, bbl/day, m3/hr, liters/min, etc. Gas or Vaporft3/hr, m3/hr, etc.Mass units (either liquid, gas or vapor) lb/hr, kg/hr, etc.Flow can be measured in accumulated (totalized) total amounts for a time period gallons, liters, meters passed in a day, etc.

    Flow can be measured as a rate per unit time.

    For Liquids, the common units used are: gpm, m3/hr, liters/min, etc.

    For Gas, the common units used are: ft3/hr, etc.

    Flow can be measured as a mass per unit time.

    Common units used are: lb/hr, kg/hr, etc.

    Flow can be measured in accumulated (totalized) total amounts for a time period.

    Common units used are: gallons, liters, meters passed in a day, etc.

  • LAMINAR FLOW

    Laminar Flow - Is Characterized By Concentric Layers Of Fluid Moving In Parallel Down The Length Of A Pipe. The Highest Velocity (Vmax) Is Found In The Center Of The Pipe. The Lowest Velocity (V=0) Is Found Along The Pipe Wall.

    Laminar Flow - Is Characterized By Concentric Layers Of Fluid Moving In Parallel Down The Length Of A Pipe. The Highest Velocity (Vmax) Is Found In The Center Of The Pipe. The Lowest Velocity (V=0) Is Found Along The Pipe Wall.

  • TURBULENT FLOW

    Turbulent Flow - Is Characterized By A Fluid Motion That Has Local Velocities And Pressures That Fluctuate Randomly. This Causes The Velocity Of The Fluid In The Pipe To Be More Uniform Across A Cross Section.

    Turbulent Flow - Is Characterized By A Fluid Motion That Has Local Velocities And Pressures That Fluctuate Randomly. This Causes The Velocity Of The Fluid In The Pipe To Be More Uniform Across A Cross Section.

  • REYNOLDS NUMBER

    The Reynolds number is the ratio of inertial forces (velocity and density that keep the fluid in motion) to viscous forces (frictional forces that slow the fluid down) and is used for determining the dynamic properties of the fluid to allow an equal comparison between different fluids and flows.Laminar Flow occurs at low Reynolds numbers, where viscous forces are dominant, and is characterized by smooth, constant fluid motionTurbulent Flow occurs at high Reynolds numbers and is dominated by inertial forces, producing random eddies, vortices and other flow fluctuations. The Reynolds number is the most important value used in fluid dymanics as it provides a criterion for determining similarity between different fluids, flowrates and piping configurations.

    The Reynolds number is the ratio of inertial forces (velocity and density that keep the fluid in motion) to viscous forces (frictional forces that slow the fluid down) and is used for determining the dynamic properties of the fluid to allow an equal comparison between different fluids and flows.

    Laminar Flow occurs at low Reynolds numbers, where viscous forces are dominant, and is characterized by smooth, constant fluid motion

    Turbulent flow occurs at high Reynolds numbers and is dominated by inertial forces, producing random eddies, vortices and other flow fluctuations.

    The Reynolds number is the most important dimensionless number in fluid dynamics and provides a criterion for determining similarity between different fluids, flowrates and piping configurations.

  • REYNOLDS NUMBER

    This is the equation for determining the Reynolds number. You can get the required values from process.

  • IDEAL GAS LAW

    An Ideal Gas or perfect gas is a hypothetical gas consisting of identical particles with no intermolecular forces. Additionally, the constituent atoms or molecules undergo perfectly elastic collisions with the walls of the container. Real gases act like ideal gases at low pressures and high temperatures.

    Real Gases do not exhibit these exact properties, although the approximation is often good enough to describe real gases. The properties of real gases are influenced by compressibility and other thermodynamic effects.

    An ideal gas or perfect gas is a hypothetical gas consisting of identical particles with no intermolecular forces. Additionally, the constituent atoms or molecules undergo perfectly elastic collisions with the walls of the container. Real gases act like ideal gases at low pressures and high temperatures.

    Real gases do not exhibit these exact properties, although the approximation is often good enough to describe real gases. The properties of real gases are influenced by compressibility and other thermodynamic effects.

  • IDEAL GAS LAW

    PV = nRT

    Where:P = Pressure (psia)

    V = Volume (FT3)

    n = Number of Moles of Gas

    (1 mole = 6.02 x 1023 molecules)

    R = Gas Constant (10.73 FT3 PSIA / lb-mole oR)

    T = Temperature (oR)

    This is the equation for an Ideal Gas

  • REAL GASES

    Compressibility Factor (Z) - The term "compressibility" is used to describe the deviance in the thermodynamic properties of a real gas from those expected from an ideal gas.

    Real Gas Behavior can be calculated as:

    PV = nZRT

    Compressibility Factor (Z) - The term "compressibility" is used to describe the deviance in the thermodynamic properties of a real gas from those expected from an ideal gas.

    This is the equation for an Ideal Gas

  • STANDARD CONDITIONS

    P = 14.7 PSIAT = 520 deg R (60 deg F)Behavior of gases in a process can be equally compared by using standard conditions This is due to the nature of gases.

    Standard conditions allow gases and vapors of different compositions to be compared equally.

  • ACTUAL CONDITIONS

    Standard conditions can be converted to Actual Conditions using the Ideal Gas Law.

    This is the method to convert from standard conditions to actual conditions

  • BERNOULLIS LAW

    Bernoulli's Law Describes The Behavior Of An Ideal Fluid Under Varying Conditions In A Closed System. It States That The Overall Energy Of The Fluid As It Enters The System Is Equal To The Overall Energy As It Leaves.

    PE1 + KE1 = PE2 + KE2

    PE = Potential Energy

    KE = Kinetic Energy

    Bernoulli's Law Describes The Behavior Of An Ideal Fluid Under Varying Conditions In A Closed System. It States That The Overall Energy Of The Fluid As It Enters The System Is Equal To The Overall Energy As It Leaves.

  • BERNOULLIS EQUATION

    Bernoullis Law Is Described By The Following Equation For An Ideal Fluid.

    V2 > V1

    P2 < P1

    Increased Fluid Speed Decrease Fluid Pressure

    V1, P1

    V2, P2

    P1 +

    2

    rV12 +

    1

    Pressure Energy

    rgh1

    = P2 +

    rgh2

    rV22 +

    2

    1

    Kinetic Energy Per Unit Volume

    Potential Energy Per unit Volume

    Energy Per Unit Volume Before = Energy Per Unit Volume After

    Bernoullis law explains the movement of fluid through an orifice or nozzle. It shows that the total energy upstream of the nozzle is equal to the energy at the nozzle throat. It explains how the potential energy is converted to kinetic energy as the fluid speeds up and the pressure drops at the nozzle throat.

  • HEAD METER THEORY OF OPERATION

    Beta Ratio b = d/D Should Be 0.3 0.75

    Meter Run Dependent On Piping

    Normally 20 Diameters Upstream & 5 Diameters Downstream

    This diagram shows how fluids flow through an orifice. The Beta ratio is the ratio of the orifice size to the inside diameter of the pipe. These type of meters require a straight section of pipe both upstream and downstream. This is called the meter run. The length of this is dependent on the piping layout. For most piping systems it is 20 pipe diameters upstream and 5 downstream for an orifice plate. This must be checked for every meter against the P, I, P standard.

    Note that increasing the beta ratio provides increased accuracy, but also requires increased straight run.

  • dP METER FLOW PRINCIPLES

    Flow is measured by creating a pressure drop and applying the flow equation below.

    Basic Flow Equation for single phase compressible and non-compressible fluids:

    qm = Flow

    C = Constant

    e = Expansion Factor

    a = Orifice Area

    Dp = P1 - P2

    r1 = Density

    b = d / D

    d = Diameter of Orifice

    D = Diameter of Pipe

    Orifice Plate Flow Principles. The most often used flow sensor is the orifice plate shown to the right. Flow is measured by creating a pressure drop and applying the flow equation below. The basic flow equation for single phase compressible and non-compressible fluids is shown below.

  • METER RANGEABILITY

    METER RANGEABILITY

    NORMAL RANGE

    % MAXIMUM FLOW RATE

    % MAXIMUM METER HEAD

    The square root functions impact on a differential pressure device limits the measurement turndown (rangeability) to between 4:1 and 6:1.

    Chart2

    0

    0.25

    1

    2.25

    4

    6.25

    9

    12.25

    16

    20.25

    25

    30.25

    36

    42.25

    49

    56.25

    64

    72.25

    81

    90.25

    100

    % FLOW

    Sheet1

    % HEAD% FLOW

    00

    0.255

    110

    2.2515

    420

    6.2525

    930

    12.2535

    1640

    20.2545

    2550

    30.2555

    3660

    42.2565

    4970

    56.2575

    6480

    72.2585

    8190

    90.2595

    100100

    Sheet1

    % FLOW

    Sheet2

    Sheet3

    The square root functions impact on a differential pressure device limits the measurement turndown (rangeability).

  • ORIFICE PLATE

    A simple device, considered a precision instrument. It is simply a piece of flat metal with a flow-restricting bore that is inserted into the pipe between flanges. The orifice meter is well understood, rugged and inexpensive. Its accuracy under ideal conditions is in the range of 0.75-1.5%. It can be sensitive to a variety of error-inducing conditions, such as if the plate is eroded or damaged.

    Orifice Plate

    Orifice Flanges

    The Orifice Plate is a simple device, considered to be a precision instrument. It is simply a piece of flat metal with a flow-restricting bore that is inserted into the pipe between flanges. The orifice meter is well understood, rugged and inexpensive. Its accuracy under ideal conditions is in the range of 0.75 to 1.5 percent. It can be sensitive to a variety of error-inducing conditions, such as if the plate is eroded or damaged.

  • CONCENTRIC ORIFICE PLATE

    The most common orifice plate is the square-edged concentric bored orifice plate. The concentric bored orifice plate is the dominant design because of its proven reliability in a variety of applications and the extensive amount of research conducted on this design. It is easily reproduced at a relatively low cost. It is used to measure a wide variety of single phase, liquid and gas products, typically in conjunction with flange taps.

    The most common orifice plate is the square-edged concentric bored orifice plate. The concentric bored orifice plate is the dominant design because of its proven reliability in a variety of applications and the extensive amount of research conducted on this design. It is easily reproduced at a relatively low cost. It is used to measure a wide variety of single phase, liquid and gas products, typically in conjunction with flange taps.

  • ECCENTRIC ORIFICE PLATE

    Eccentrically bored plates are plates with the orifice off center, or eccentric, as opposed to concentric. This type of plate is most commonly used to measure fluids which carry a small amount of non-abrasive solids, or gases with small amounts of liquid, since with the opening at the bottom of the pipe, the solids and liquids will carry through, rather than collect at the orifice plate. A higher degree of uncertainty as compared to the concentric orifice. Eccentric orifice plates are used in many industries including heavy and light chemicals and petrochemicals.

    Eccentrically bored plates are plates with the orifice off center, or eccentric, as opposed to concentric. This type of plate is most commonly used to measure fluids which carry a small amount of non-abrasive solids, or gases with small amounts of liquid, since with the opening at the bottom of the pipe, the solids and liquids will carry through, rather than collect at the orifice plate. A higher degree of uncertainty as compared to the concentric orifice. Eccentric orifice plates are used in many industries including heavy and light chemicals and petrochemicals.

  • QUADRANT EDGE ORIFICE PLATE

    The quadrant, quadrant edge or quarter-circle orifice is recommended for measurement of fluids with high viscosity which have pipe Reynolds Numbers below 10,000. The orifice incorporates a rounded edge of definite radius which is a particular function of the orifice diameter.

    Quadrant in U.S.

    Conical in Europe

    The quadrant, quadrant edge or quarter-circle orifice is recommended for measurement of fluids with high viscosity which have pipe Reynolds Numbers below 10,000. The orifice incorporates a rounded edge of definite radius which is a particular function of the orifice diameter.

    Quadrant in U.S.

    Conical in Europe

  • INTEGRAL ORIFICE PLATE

    Integral Orifice Plate

    identical to a square-edged orifice plate installation except that the plate, flanges and DP transmitter are supplied as one unit.used for small lines (typically under 2) and is relatively inexpensive to install since it is part of the transmitter

    Integral Orifice Plate is identical to a square-edged orifice plate installation except that the plate, flanges and DP transmitter are supplied as one unit. They are used for small lines (typically under 2 or 50mm) and is relatively inexpensive to install since it is part of the transmitter.

  • CONDITIONING ORIFICE PLATE

    The Conditioning Orifice Plate is designed to be installed downstream of a variety of disturbances with minimal straight pipe run, providing superior performance.Requires only two diameters of straight pipe run after an upstream flow disturbanceReduced installation costsEasy to use, prove, and troubleshootGood for most gas, liquid, and steam as well as high temperature and high pressure applications

    Most conditioning orifice plates have the following characteristics:

    Recommended Service: Liquids, Gases & Steam

    Rangeability: 4 to 1

    Pressure Loss: Medium

    Accuracy: 0.5%

    Straight Run Required: 2D Upstream, 2D Downstream

    Viscosity Effect: High

    Relative Cost: Low

    Size: 2 to 24

    Connection: Between Flanges

    Type of Output: Square Root

  • VENT AND WEEP HOLES

    There are times when a gas may be have a small amount of liquid or a liquid may have a small amount of gas but not enough in either case to warrant the use of an eccentric orifice. In these cases it is best to simply add a small hole near the edge of the plate, flush with the inside diameter of the pipe, allowing undesired substances to pass through the plate rather than collect on the upstream side. If such a hole is oriented upward to pass vapor bubbles, it is called a vent hole. If the hole is oriented downward to pass liquid droplets, it is called a drain hole.

    VENT

    DRAIN

    There are times when a gas may be have a small amount of liquid or a liquid may have a small amount of gas but not enough in either case to warrant the use of an eccentric orifice. In these cases it is best to simply add a small hole near the edge of the plate, flush with the inside diameter of the pipe, allowing undesired substances to pass through the plate rather than collect on the upstream side. If such a hole is oriented upward to pass vapor bubbles, it is called a vent hole. If the hole is oriented downward to pass liquid droplets, it is called a drain hole.

  • ORIFICE PLATE SELECTION CONSIDERATIONS

    Quadrant Edge Orifice Plate can be considered if Reynolds number is too low.Orifice plate must be specified with proper flange rating to account for proper bolt circle.Typical acceptable beta ratio is .25 to .7 for non commerce meter, .3 to .6 for accounting meter but also check specifications.Assure that calculation accounts for vent or drain hole, if required.For dual transmitter installation on a common set of orifice flanges, custom tap locations must be specified.

    Quadrant Edge Orifice Plate can be considered if Reynolds number is too low.

    Orifice plate must be specified with proper flange rating to account for proper bolt circle.

    Typical acceptable beta ratio is .25 to .7 for non commerce meter, .3 to .6 for accounting meter but also check specifications.

    Assure that calculation accounts for vent or drain hole, if required.

    For dual transmitter installation on a common set of orifice flanges, custom tap locations must be specified.

  • Gas

    Differential pressure is measured through pressure taps located on each side of the orifice plate. Pressure taps can be positioned at a variety of different locations.Flange TapsCorner TapsRadius TapsVena-Contracta TapsPipe Taps

    ORIFICE PLATE TAP LOCATIONS

    Liquid or Steam

    Orifice taps in horizontal lines should be as follows:

    Differential pressure is measured through pressure taps located on each side of the orifice plate. Pressure taps can be positioned at a variety of different locations. The most common are flange taps. They are located 1 inch from the upstream face of orifice plate and 1 inch from downstream face. They are used for all standard orifice onfigurations.

    Corner Taps are used for honed meter runs like an integral orifice. They are located immediately adjacent to plate faces both upstream and downstream.

    Radius Taps are located 1 pipe diameter upstream of orifice plate and one half pipe diameter downstream of orifice plate. They are not commonly used.

    Vena-Contracta Taps are located 1 pipe diameter upstream of orifice plate and at the point of minimum pressure downstream, this point is called the vena-contracta. This point varies with Beta ratio and are seldom used other than for plant measurement where the flows are relatively constant and plates are not changed. Exact dimensions for the downstream tap are given in appropriate tables.

    Pipe Taps are located two and one half pipe diameters upstream of orifice plate and eight pipe diameters downstream of orifice plate this puts the downstream tap at the point of maximum pressure recovery.

    Orifice taps in horizontal lines for gas service should be from the top of the pipe or no more than 45 degrees from vertical as shown.

    Orifice taps in horizontal lines for liquid or steam should be at horizontal or 45 degrees down from horizontal as shown. For pipe racks, it is recommended that horizontal taps not be used in order to maximize pipe rack space.

  • In a Venturi tube, the fluid is accelerated through a converging cone, inducing a local pressure drop. An expanding section of the meter then returns the flow to near its original pressure. These instruments are often selected where it is important not to create a significant pressure drop and where good accuracy is required.

    Used when higher velocity and pressure recovery is required.May be used when a small, constant percentage of solids is present.

    VENTURI TUBE

    In a Venturi tube, the fluid is accelerated through a converging cone, inducing a local pressure drop. An expanding section of the meter then returns the flow to near its original pressure. These instruments are often selected where it is important not to create a significant pressure drop and where good accuracy is required.

    Used when higher velocity and pressure recovery is required.

    May be used when a small, constant percentage of solids is present.

  • FLOW NOZZLE

    DP Type FlowmeterUsed when higher velocity & pressure recovery are requiredBetter suited for gas service than for liquid

    Another DP Type Flowmeter is the Flow Nozzle. It is used when higher velocity & pressure recovery are required and are better suited for gas service than for liquid.

  • Wedge flow meters can be used on just about any liquid or gas, just like orifice plates. However they are generally chosen for dirty service applications, or high viscosity applications such as slurry or heavy oil, or where solids are present. For regular service applications consider other types of meters first unless wedge meters are specified by customer as preferred.

    Since they are a differential pressure device their sizing calculation is similar to that of other dP flowmeters.

    WEDGE METER

    Wedge flow meters can be used on just about any liquid or gas, just like orifice plates. However they are generally chosen for dirty service, or high viscosity applications such as slurry or heavy oil, or where solids are present. For regular service applications consider other types of meters first unless wedge meters are specified by customer as preferred.

    Since they are a differential pressure device their sizing calculation is similar to that of other d, P flowmeters.

  • V-CONE

    The V-Cone is similar to other differential pressure (Dp) meters in the equations of flow that it uses. V-Cone geometry, however, is quite different from traditional Dp meters. The V-Cone constricts the flow by positioning a cone in the center of the pipe. This forces the flow in the center of the pipe to flow around the cone. V-cones can be used with viscous fluids and require little straight run.

    V-Cone is another differential pressure type flowmeter.

    The V-Cone is similar to other differential pressure (Dp) meters in the equations of flow that it uses. V-Cone geometry, however, is quite different from traditional Dp meters. The V-Cone constricts the flow by positioning a cone in the center of the pipe. This forces the flow in the center of the pipe to flow around the cone.

  • Multivariable Pressure Transmitter

    A Multivariable pressure transmitter provides gauge pressure, differential pressure, and temperature measurement in a single instrument. Uses Smart digital HART communications for multiple measurements. Minimizes the number of transmitters and process connections

    Basic information of a multivariable transmitter.

  • In a pitot tube (insertion DP meter), a probe consisting of two parts senses two pressures: impact (dynamic) and static. The impact pressure is sensed by one impact tube bent toward the flow (dynamic head). The averaging-type pitot tube has four or more pressure taps located at mathematically defined locations, averaging the velocity profile across the pipe or flow area, to measure the dynamic pressure. The static pressure is sensed through a small hole on the side (static head). They develop low differential pressure and like all head meters they use a differential pressure transmitter to convert the flow to an electrical transmission signal.

    PITOT TUBE

    In a pitot tube (insertion DP meter), a probe consisting of two parts senses two pressures: impact (dynamic) and static. The impact pressure is sensed by one impact tube bent toward the flow (dynamic head). The averaging-type pitot tube has four or more pressure taps located at mathematically defined locations, averaging the velocity profile across the pipe or flow area, to measure the dynamic pressure. The static pressure is sensed through a small hole on the side (static head). They develop low differential pressure and like all head meters they use a differential pressure transmitter to convert the flow to an electrical transmission signal.

  • PITOT TUBE FLOW PRINCIPLES

    Pitot tubes make use of dynamic pressure difference. Orifices in the leading face register total head pressure, dynamic + static, while the hole in the trailing face only conveys static pressure. Pressure difference between the two gives dynamic pressure in pipe, from which flow can be calculated.

    Basic Mass rate of flow equation for single phase compressible and non-compressible fluids:

    Pitot tubes make use of dynamic pressure difference. Orifices in the leading face register total head pressure, dynamic + static, while the hole in the trailing face only conveys static pressure. Pressure difference between the two gives dynamic pressure in pipe, from which flow can be calculated.

    Basic Mass rate of flow equation for single phase compressible and non-compressible fluids is shown below.

  • PIP PCCFL001STRAIGHT RUN REQUIREMENTS

    PIP PCCFL001 includes tables for minimum straight run lengths with various upstream disturbances, providing upstream requirements for different beta ratios and downstream requirements per beta ratios regardless of upstream disturbance type.

    28.pdf

    COMPLETE REVISION PIP PCCFL001 August 2006 Flow Measurement Design Criteria

    Table 1 Minimum Straight Run Lengths for Orifice Runs and Other Flow Elements

    in Accordance with ISO 5167-2 Column B Beta Ratio Upstream disturbance Dimension 0.2 0.4 0.5 0.6 0.67 0.75

    A

    3 3 9 13 20 20 Single elbow

    S

    A

    Note 4 Note 4 10 18 18 18 Two elbows in same plane 30D>S>10D

    S

    A

    Note 4 Note 4 10 18 20 22 Two elbows in same plane 10D>S

    A

    18 18 18 18 20 20 Two elbows in different planes 30D>S>5D

    A

    Note 4 Note 4 5 5 6 8 Reducer

    A

    Note 4 8 9 11 14 18 Expander

    A

    6 6 6 7 9 12 Full Bore Ball or Gate valve, fully open

    Downstream Length for all pictured disturbances

    B 2 3 3 3.5 3.5 4

    Process Industry Practices Page 11 of 15

    COMPLETE REVISION PIP PCCFL001 August 2006 Flow Measurement Design Criteria

    Table 2 Minimum Straight Run Lengths for Orifice Runs in Accordance with

    ANSI/API (ISO 5167-2, Column A) Beta Ratio Upstream disturbance Dimension 0.2 0.4 0.5 0.6 0.67 0.75

    A

    6 16 22 42 44 44 Single elbow

    S

    A

    10 10 18 30 44 44

    Two elbows in same plane 30D>S>10D

    S

    A

    10 10 22 42 44 44

    Two elbows in same plane 10D>S

    A

    19 44 44 44 44 44 Two elbows in different planes 30D>S>5D

    A

    5 5 8 9 12 13.5 Reducer

    A

    6 12 20 26 28 36.5 Expander

    A

    12 12 12 14 18 24 Full bore Ball or Gate Valve Fully Open Downstream Length for all pictured disturbances B 4 6 6 7 7 8

    Process Industry Practices Page 13 of 15

    COMPLETE REVISION PIP PCCFL001 August 2006 Flow Measurement Design Criteria

    Table 3 Minimum Straight Run Lengths for Venturi Tubes and Flow Nozzles in

    Accordance with ANSI/API (ISO 5167-3)

    Upstream Straight Run Required Beta Ratio Piping Configuration Additional

    Uncertainty 0.2 0.4 0.5 0.6 0.7

    0.5% 6 7 7 9 14 Single 900 bend upstream

    0% 10 14 14 18 28

    0.5% 7 9 10 13 18 Two 900 Bends in the Same Plane

    0% 14 18 20 26 36

    0.5% 17 18 20 24 31 Two 900 Bends in Different Planes

    0% 34 36 40 48 62

    0.5% Note 1 Note 1 5 5 7 Reducer 2D to D over a Length of 1.5D to 3D

    0% 5 5 6 9 14

    0.5% 8 8 9 11 15 Expander 0.5D to D over a Length of 1.5D to 3D

    0% 16 16 18 22 30

    0.5% 9 10 11 13 16 Globe Valve Fully Open

    0% 18 20 22 26 32

    0.5% 6 6 6 7 10 Full Bore Ball or Gate Valve Fully Open

    0% 12 12 12 14 20

    0.5% 2 3 3 3.5 3.5 Downstream Run Required

    0% 4 6 6 7 7

    NOTES for Table 3 - PCCFL001: (1) For additional information on Orifice Plates refer to ISO-5167-2.

    Process Industry Practices Page 15 of 15

    PIP PCCFL001 includes tables for minimum straight run lengths with various upstream disturbances, providing upstream requirements for different beta ratios and downstream requirements per beta ratios regardless of upstream disturbance type.

  • DP METER CHARACTERISTICS

    Recommended Service: Clean & Dirty Liquids, Gases, Some SlurriesRangeability: 3:1 to 6:1Maximum Flow: 95% of RangePressure Loss: 20 to 60% of Measured HeadAccuracy: 0.5 to 4%Straight Run Reqd: 5 - 40D Upstream, 2-5D DownstreamViscosity Effect: HighSize: 2 to 24Connection: Dependent on meter typeType of Output: Square Root

    Here are some characteristics of the concentric orifice plate. The unrecovered pressure lost across an orifice plate sized for 100 inches of water is usually in the range of 40 to 60 inches. The amount of upstream straight run required will depend on the piping configuration. The accuracy of an orifice plate depends on a number of factors including piping system design and installation.

  • VARIABLE AREA FLOWMETER (ROTAMETER)

    FLOW PRINCIPLES

    Rotameters are a variable area device. The float moves up and down in proportion to the fluid flow rate and the annular area between the float and the tube wall. As the float rises, the size of the annular opening increases. As this area increases, the differential pressure across the float decreases. The float reaches a stable position when the upward force exerted by the flowing fluid equals the weight of the float. Every float position corresponds to a particular flow rate for a particular fluid's density and viscosity. For this reason, it is necessary to size the rotameter for each application. When sized correctly, the flow rate can be determined by matching the float position to a calibrated scale on the outside of the rotameter. Many rotameters come with a built-in valve for adjusting flow manually.

    Rotameters are a variable area flow device. The float moves up and down in proportion to the fluid flow rate and the annular area between the float and the tube wall. As the float rises, the size of the annular opening increases. As this area increases, the differential pressure across the float decreases. The float reaches a stable position when the upward force exerted by the flowing fluid equals the weight of the float. Every float position corresponds to a particular flow rate for a particular fluid's density and viscosity. For this reason, it is necessary to size the rotameter for each application. When sized correctly, the flow rate can be determined by matching the float position to a calibrated scale on the outside of the rotameter. Many rotameters come with a built-in valve for adjusting flow manually.

  • VARIABLE AREA (ROTAMETER)

    CHARACTERISTICS

    Recommended Service: Clean, Dirty & Viscous LiquidsRangeability: 10 to 1Pressure Loss: MediumAccuracy: 1 to 10%Straight Run Required: NoneViscosity Effect: MediumRelative Cost: LowSizes:
  • Direct mass flow measurement is generally chosen for more critical control applications such as the blending of feedstocks or the custody transfer of valuable fluids. Generally chosen for high rangeability and mass flow applications, Coriolis technology is unaffected by changes in temperature, density, viscosity and conductivity. In most flow meters changes in these conditions require monitoring and correction.

    CORIOLIS

    Direct mass flow measurement is generally chosen for more critical control applications such as the blending of feedstocks or the custody transfer of valuable fluids. Generally chosen for high rangeability and mass flow applications, Coriolis technology is unaffected by changes in temperature, density, viscosity and conductivity. In most flow meters changes in these conditions require monitoring and correction.

  • CORIOLIS

    FLOW PRINCIPLES

    Flow is measured by using velocity sensors to detect the twist in the tube and transmit electrical signals having a relative phase shift that is proportional to mass flow.

    Coriolis meters also measure density, whereby the resonant frequency of the forced rotation is a function of fluid density.

    When the fluid is flowing, it is led through two parallel tubes. An actuator (not shown) induces a vibration of the tubes. The two parallel tubes are counter-vibrating, to make the measuring device less sensitive to outside vibrations. The actual frequency of the vibration depends on the size of the mass flow meter, and ranges from 80 to 1000 vibrations per second.

    When no fluid is flowing, the vibration of the two tubes is symmetrical.

    Flow is measured by using velocity sensors to detect the twist in the tube and transmit electrical signals having a relative phase shift that is proportional to mass flow.

    Coriolis meters also measure density, whereby the resonant frequency of the forced rotation is a function of fluid density.

    Fluid is flowing in a tube as shown at a velocity V.

    The tube is forced to rotate about axis x with angular velocity w.

    Due to the rotation of the tube and forward movement of the fluid, forces are created as shown. A Coriolis force (Fcor) is created in opposition to the rotating force F shown.

    As a result the tube will twist.

  • CORIOLIS CHARACTERISTICS

    Recommended Service: Clean, Dirty & Viscous Liquids, Gases, Some Slurries Rangeability: 10 to 1 Pressure Loss: Medium to High Accuracy: to 0.1% in liquids & to 0.35% in gas Straight Run Required: None Viscosity Effect: None Relative Cost: High Sizes: > Connections: Flanged & Clamp-on Design Type of Output: Linear

    Most coriolis flowmeters have the following characteristics:

    Recommended Service: Clean, Dirty & Viscous Liquids, Gases, Some Slurries

    Rangeability: 10 to 1

    Pressure Loss: Medium to High

    Accuracy: to 0.1% in liquids & to 0.35% in gas

    Straight Run Required: None

    Viscosity Effect: None

    Relative Cost: High

    Sizes: >

    Connections: Flanged & Clamp-on Design

    Type of Output: Linear

  • THERMAL MASS FLOWMETER

    FLOW PRINCIPLES

    Thermal mass flow meters introduce heat into the flow stream and measure how much heat dissipates using one or more temperature sensors. This method works best with gas mass flow measurement.The constant temperature differential method have a heated sensor and another sensor that measures the temperature of the gas. Mass flow rate is computed based on the amount of electrical power required to maintain a constant difference in temperature between the two temperature sensors.In the constant current method the power to the heated sensor is kept constant. Mass flow is measured as a function of the difference between the temperature of the heated sensor and the temperature of the flow stream.

    Both methods are based on the principle that higher velocity flows result in a greater cooling effect. Both measure mass flow based on the measured effects of cooling in the flow stream.

    Thermal mass flow meters introduce heat into the flow stream and measure how much heat dissipates using one or more temperature sensors. This method works best with gas mass flow measurement.

    The constant temperature differential method have a heated sensor and another sensor that measures the temperature of the gas. Mass flow rate is computed based on the amount of electrical power required to maintain a constant difference in temperature between the two temperature sensors.

    In the constant current method the power to the heated sensor is kept constant. Mass flow is measured as a function of the difference between the temperature of the heated sensor and the temperature of the flow stream.

    Both methods are based on the principle that higher velocity flows result in a greater cooling effect. Both measure mass flow based on the measured effects of cooling in the flow stream.

  • THERMAL MASS FLOWMETER

    CHARACTERISTICS

    Recommended Service: Clean, Dirty & Viscous Liquids, Some Slurries, Gases Rangeability: 10 to 1 Pressure Loss: Low Accuracy: 1% Straight Run Required: None Viscosity Effect: None Relative Cost: High Sizes: 2 to 24 Connections: Threaded, Flanged Type of Output: Exponential

    Most thermal mass flowmeters have the following characteristics:

    Recommended Service: Clean, Dirty & Viscous Liquids, Some Slurries, Gases

    Rangeability: 10 to 1

    Pressure Loss: Low

    Accuracy: 1%

    Straight Run Required: None

    Viscosity Effect: None

    Relative Cost: High

    Sizes: 2 to 24

    Connections: Threaded, Flanged

    Type of Output: Exponential

  • MAGNETIC FLOWMETER

    FLOW PRINCIPLES

    A magnetic flow meter (mag flowmeter) is a volumetric flow meter which does not have any moving parts and is ideal for wastewater applications or any dirty liquid which is conductive or water based. Magnetic flowmeters will generally not work with hydrocarbons, distilled water and many non-aqueous solutions). Magnetic flowmeters are also ideal for applications where low pressure drop and low maintenance are required.

    The operation of a magnetic flowmeter or mag meter is based upon Faraday's Law, which states that the voltage induced across any conductor as it moves at right angles through a magnetic field is proportional to the velocity of that conductor.

    A magnetic flow meter or mag meter is a volumetric flow meter which does not have any moving parts and is ideal for any conductive fluid. Typical applications include wastewater, slurries or any dirty liquid which is conductive or water based. Magnetic flowmeters will generally not work with hydrocarbons, distilled water and many non-aqueous solutions. Magnetic flowmeters are also ideal for applications where low pressure drop and low maintenance are required.

    The operation of a mag meter is based upon Faraday's Law, which states that the voltage induced across any conductor as it moves at right angles through a magnetic field is proportional to the velocity of that conductor. When the fluid moves faster, more voltage is generated. Faradays Law states that the voltage generated is proportional to the movement of the flowing liquid. The electronic transmitter processes the voltage signal to determine liquid flow.

    In contrast with many other flowmeter technologies, magnetic flowmeter technology produces signals that are linear with flow. As such, the turndown associated with magnetic flowmeters can approach 40 to 1 without sacrificing accuracy.

  • MAGNETIC FLOWMETER

    CHARACTERISTICS

    Recommended Service: Clean, Dirty & Viscous Conductive Liquids & SlurriesRangeability: 40 to 1Pressure Loss: NoneAccuracy: 0.5%Straight Run Required: 5D Upstream, 2D DownstreamViscosity Effect: NoneRelative Cost: HighSizes: 1 to 120Connections: FlangedType of Output: Linear

    Most magnetic flowmeters have the following characteristics:

    Recommended Service: Clean, Dirty & Viscous Conductive Liquids & Slurries

    Rangeability: 40 to 1

    Pressure Loss: None

    Accuracy: 0.5%

    Straight Run Required: 5D Upstream, 2D Downstream

    Viscosity Effect: None

    Relative Cost: High

    Sizes: 1 to 120

    Connections: Flanged

    Type of Output: Linear

  • Transit time ultrasonic meters employ two transducers located upstream and downstream of each other. Each transmits a sound wave to the other, and the time difference between the receipt of the two signals indicates the fluid velocity. Transit time meters usually require clean fluids and are used where high rangeability is required. Accuracy is within 1% for ideal applications.

    ULTRASONIC METER

    Transit time ultrasonic meters employ two transducers located upstream and downstream of each other. Each transmits a sound wave to the other, and the time difference between the receipt of the two signals indicates the fluid velocity. Transit time meters usually require clean fluids and are used where high rangeability is required. Accuracy is within 1% for ideal applications.

  • ULTRASONIC METER FLOW PRINCIPLES

    FLOW

    Flow is measured by measuring the difference in transit time for two ultrasonic beams transmitted in a fluid both upstream and downstream.

    Ultrasonic Meters are mainly used on large size lines where high rangeability is required.

    t up

    Transmitter/

    Receiver (T/R)

    t dn

    Frequency pulse

    Vm = (L / 2 * cos ) * [(TAB TBA) / (TAB . TBA)]

    Basic Flow Equation: Q = A * V

    Transit time difference is proportional to mean velocity Vm, therefore Vm can be calculated as follows:

    A

    B

    Transit length L

    Flow is measured by measuring the difference in transit time for two ultrasonic beams transmitted in a fluid both upstream and downstream.

    Ultrasonic Meters are mainly used on large size lines where high rangeability is required.

    Transit time difference is proportional to mean velocity Vm. Therefore Vm can be calculated as follows:

    The Basic Flow Equation is shown below.

  • ULTRASONIC (DOPPLER)

    FLOW PRINCIPLES

    Ultrasonic flowmeters are ideal for wastewater applications or any dirty liquid which is conductive or water based. The basic principle of operation employs the frequency shift (Doppler Effect) of an ultrasonic signal when it is reflected by suspended particles or gas bubbles (discontinuities) in motion. Current technology requires that the liquid contain at least 100 parts per million (PPM) of 100 micron or larger suspended particles or bubbles.

    The basic principle of operation employs the frequency shift (Doppler Effect) of an ultrasonic signal when it is reflected by suspended particles or gas bubbles (discontinuities) in motion. This metering technique utilizes the physical phenomenon of a sound wave that changes frequency when it is reflected by moving discontinuities in a flowing liquid. Ultrasonic sound is transmitted into a pipe with flowing liquids, and the discontinuities reflect the ultrasonic wave with a slightly different frequency that is directly proportional to the rate of flow of the liquid (Figure 1). Current technology requires that the liquid contain at least 100 parts per million (PPM) of 100 micron or larger suspended particles or bubbles.

  • ULTRASONIC CHARACTERISTICS

    Recommended Service: Clean & Viscous Liquids, Natural/Flare Gas Rangeability: 20 to 1 Pressure Loss: None Accuracy: 0.25% to 5% Straight Run Required: 5 to 30D Upstream Viscosity Effect: None Relative Cost: High Sizes: > Connections: Flanged & Clamp-on Design Type of Output: Linear

    Most ultrasonic (Transit Time) flowmeters have the following characteristics:

    Recommended Service: Clean & Viscous Liquids, Natural/Flare Gas

    Rangeability: 20 to 1

    Pressure Loss: None

    Accuracy: 1 to 5%

    Straight Run Required: 5 to 30D Upstream

    Viscosity Effect: None

    Relative Cost: High

    Sizes: >

    Connections: Flanged & Clamp-on Design

    Type of Output: Linear

  • TURBINE METER

    Turbine meter is kept in rotation by the linear velocity of the stream in which it is immersed. The number of revolutions the device makes is proportional to the rate of flow.

    Turbine meter is kept in rotation by the linear velocity of the stream in which it is immersed. The number of revolutions the device makes is proportional to the rate of flow.

  • TURBINE METER

    CHARACTERISTICS

    Recommended Service: Clean & Viscous Liquids, Clean Gases Rangeability: 20 to 1 Pressure Loss: High Accuracy: 0.25% Straight Run Required: 5 to 10D Upstream Viscosity Effect: High Relative Cost: High Sizes: > Connections: Flanged Type of Output: Linear

    Most turbine meters have the following characteristics:

    Recommended Service: Clean & Viscous Liquids, Clean Gases

    Rangeability: 20 to 1

    Pressure Loss: High

    Accuracy: 0.25%

    Straight Run Required: 5 to 10D Upstream

    Viscosity Effect: High

    Relative Cost: High

    Sizes: >

    Connections: Flanged

    Type of Output: Linear

  • Vortex meters can be used on most clean liquid, vapor or gas. However, they are generally chosen for applications where high flow rangeability is required. Due to break down of vortices at low flow rates, vortex meters will cut off at a low flow limit. Reverse flow measurement is not an option. For regular service applications this meter is the meter of choice by many end users.

    VORTEX METER

    Vortex meters can be used on most clean liquid, vapor or gas. However, they are generally chosen for applications where high flow rangeability is required. Due to break down of vortices at low flow rates, vortex meters will cut off at a low flow limit. Reverse flow measurement is not an option. For regular service applications this meter is the meter of choice by many end users.

  • VORTEX METER

    FLOW PRINCIPLES

    Recovery

    Recovery

    Basic Flow Equation: Q = A * V

    Flowing Velocity of Fluid: V = (f * d) / St

    f = Shedding Frequency

    d = Diameter of Bluff Body

    St = Stouhal Number (Ratio between Bluff Body Diameter and Vortex Interval)

    A = Area of Pipe

    The Basic Flow Equation for a Vortex Meter is shown below.

  • VORTEX CHARACTERISTICS

    Recommended Service: Clean & Dirty Liquids, Gases Rangeability: 10 to 1 Pressure Loss: Medium Accuracy: 1% Straight Run Required: 10 to 20D Upstream, 5D Downstream Viscosity Effect: Medium Relative Cost: Medium Size: to 12 Connection: Flanged Type of Output: Linear

    Most vortex flowmeters have the following characteristics:

    Recommended Service: Clean & Dirty Liquids, Gases

    Rangeability: 10 to 1

    Pressure Loss: Medium

    Accuracy: 1%

    Straight Run Required: 10 to 20D Upstream, 5D Downstream

    Viscosity Effect: Medium

    Relative Cost: Medium

    Size: to 12

    Connection: Flanged

    Type of Output: Linear

  • PD meters measure flow rate directly by dividing a stream into distinct segments of known volume, counting segments, and multiplying by the volume of each segment. Measured over a specific period, the result is a value expressed in units of volume per unit of time. PD meters frequently report total flow directly on a counter, but they can also generate output pulses with each pulse representing a discrete volume of fluid.

    POSITIVE DISPLACEMENT (PD) FLOWMETER

    PD meters measure flow rate directly by dividing a stream into distinct segments of known volume, counting segments, and multiplying by the volume of each segment. Measured over a specific period, the result is a value expressed in units of volume per unit of time. PD meters frequently report total flow directly on a counter, but they can also generate output pulses with each pulse representing a discrete volume of fluid.

  • POSITIVE DISPLACEMENT (PD) FLOWMETER

    FLOW PRINCIPLES

    PD meters have 3 parts:

    Body Measuring Unit Counter Drive Train

    Liquids inlet pressure exerts a pressure differential against the lower face of oval gear A, causing the two interlocked oval gears to rotate to position 2.

    Liquid enters the cavity between oval gear B and meter body wall, while an equal volume of liquid passes out of the cavity between oval gear A and meter body wall. Meanwhile, inlet pressure continues to force the two oval gears to rotate to position 3

    Quantity of liquid has again filled the cavity between oval gear B and meter body. This pattern is repeated moving four times the liquid capacity of each cavity with each revolution of the rotating gears. Therefore, the flow rate is proportional to the rotational speed of the gears.

    Positive Displacement Flowmeters have 3 parts: Body, Measuring Unit and Counter Drive Train.

    Position 1: Liquids inlet pressure exerts a pressure differential against the lower face of oval gear A, causing the two interlocked oval gears to rotate to position 2.

    Position 2: Liquid enters the cavity between oval gear B and meter body wall, while an equal volume of liquid passes out of the cavity between oval gear A and meter body wall. Meanwhile, inlet pressure continues to force the two oval gears to rotate to position 3

    Position 3: Quantity of liquid has again filled the cavity between oval gear B and meter body. This pattern is repeated moving four times the liquid capacity of each cavity with each revolution of the rotating gears. Therefore, the flow rate is proportional to the rotational speed of the gears.

  • POSITIVE DISPLACEMENT (PD)

    CHARACTERISTICS

    Recommended Service: Clean & Viscous Liquids, Clean Gases Rangeability: 10 to 1 Pressure Loss: High Accuracy: 0.5% Straight Run Required: None Viscosity Effect: High Relative Cost: Medium Sizes: >12 Connections: Flanged Type of Output: Linear

    Most positive displacement (PD) flowmeters have the following characteristics:

    Recommended Service: Clean & Viscous Liquids, Clean Gases

    Rangeability: 10 to 1

    Pressure Loss: High

    Accuracy: 0.5%

    Straight Run Required: None

    Viscosity Effect: High

    Relative Cost: Medium

    Sizes: >12

    Connections: Flanged

    Type of Output: Linear

  • PRACTICES, INDUSTRY STANDARDS & OTHER REFERENCES

    Process Industry Practices (PIP)

    PIP PCCGN002 General Instrument Installation CriteriaPIP PCEFL001 Flow Measurement Guidelines

    Industry Codes and Standards

    American Gas Association (AGA)AGA 9 Measurement of Gas by Multipath Ultrasonic MetersAmerican National Standards Institute (ANSI)ANSI-2530/API-14.3/AGA-3/GPA-8185 Natural Gas Fluids Measurement Concentric, Square-Edged Orifice MetersPart 1 General Equations and Uncertainty GuidelinesPart 2 Specification and Installation RequirementsPart 3 Natural Gas ApplicationsPart 4 Background, Development, Implementation Procedures and Subroutine DocumentationAmerican Petroleum Institute (API)API RP 551 Process Measurement InstrumentationAPI RP 554 Process Instrument and ControlAPI Manual of Petroleum Measurement Standards (MPMS):Chapter 4 Proving SystemsChapter 5 MeteringChapter 14 Natural Gas Fluids Measurement

    The following is a list of the Practices, Industry Standards and other references that are commonly used in the oil and gas industry when selecting and specifying flow instruments. References include:

    Process Industry Practices (PIP)

    PIP PCCGN002 General Instrument Installation Criteria

    Industry Codes and Standards

    American Gas Association (AGA)

    AGA 9 Measurement of Gas by Multipath Ultrasonic Meters

    American National Standards Institute (ANSI)

    ANSI-2530/API-14.3/AGA-3/GPA-8185 Natural Gas Fluids Measurement Concentric, Square-Edged Orifice Meters

    Part 1 General Equations and Uncertainty Guidelines

    Part 2 Specification and Installation Requirements

    Part 3 Natural Gas Applications

    Part 4 Background, Development, Implementation Procedures and Subroutine Documentation

    American Petroleum Institute (API)

    API RP 551 Process Measurement Instrumentation

    API RP 554 Process Instrument and Control

    API Manual of Petroleum Measurement Standards (MPMS):

    Chapter 4 Proving Systems

    Chapter 5 Metering

    Chapter 14 Natural Gas Fluids Measurement

    American Society of Mechanical Engineers (ASME)

    ASME B16.36 Orifice Flanges

    ASME MFC-1M Glossary of Terms Used in the Measurement of Fluid Flow in Pipes

    ASME MFC-2M Measurement Uncertainty for Fluid Flow in the Closed Conduits

    ASME MFC-3M Measurement of Fluid Flow in Pipes Using Orifice, Nozzle and Venturi

    ASME MFC-5M Measurement of Liquid Flow in Closed Conduits Using Transit-Time Ultrasonic Flowmeters

    ASME MFC-6M Measurement of Fluid Flow in Pipes Using Vortex Flow Meters

    ASME MFC-7M Measurement of Gas Flow by Means of Critical Flow Venturi Nozzles

    ASME MFC-11M Measurement of Fluid Flow by Means of Coriolis Mass Flowmeters

    ASME MFC-14M Measurement of Fluid Flows Using Small Bore Precision Orifice Meters

    ASME MFC-16M Measurement of Fluid Flow in Closed Conduit by Means of Electromagnetic Flowmeter

    The International Society for Measurement and Control (ISA)

    ISA S20 Specification Forms for Process Measurement and Control Instruments, Primary Elements and Control Valves

    International Organization for Standardization (ISO)

    ISO 5167 - Measurement of Fluid Flow by Means of Pressure Differential Devices Inserted in Circular Cross-Section Conduits Running Full

    Part 1: General principles and requirement

    Part 2: Orifice Plates

    Part 3: Nozzle and Venturi Tubes

    Part 4: Venturi Tubes

    Other References

    Miller, R.W., Flow Measurement Engineering Handbook

    ISA Flow Measurement Practical Guides for Measurement and Control, Spitzer, D.W., Editor

    ASME Fluid Meters, Their Theory and Application

  • PRACTICES, INDUSTRY STANDARDS & OTHER REFERENCES

    American Society of Mechanical Engineers (ASME)ASME B16.36 Orifice FlangesASME MFC-1M Glossary of Terms Used in the Measurement of Fluid Flow in PipesASME MFC-2M Measurement Uncertainty for Fluid Flow in the Closed ConduitsASME MFC-3M Measurement of Fluid Flow in Pipes Using Orifice, Nozzle and VenturiASME MFC-5M Measurement of Liquid Flow in Closed Conduits Using Transit-Time Ultrasonic FlowmetersASME MFC-6M Measurement of Fluid Flow in Pipes Using Vortex Flow MetersASME MFC-7M Measurement of Gas Flow by Means of Critical Flow Venturi NozzlesASME MFC-11M Measurement of Fluid Flow by Means of Coriolis Mass FlowmetersASME MFC-14M Measurement of Fluid Flows Using Small Bore Precision Orifice MetersASME MFC-16M Measurement of Fluid Flow in Closed Conduit by Means of Electromagnetic Flowmeter

  • PRACTICES, INDUSTRY STANDARDS & OTHER REFERENCES

    The International Society for Measurement and Control (ISA)ISA S20 Specification Forms for Process Measurement and Control Instruments, Primary Elements and Control ValvesInternational Organization for Standardization (ISO)ISO 5167 - Measurement of Fluid Flow by Means of Pressure Differential Devices Inserted in Circular Cross-Section Conduits Running FullPart 1: General principles and requirementPart 2: Orifice PlatesPart 3: Nozzle and Venturi TubesPart 4: Venturi Tubes

    Other References

    Miller, R.W., Flow Measurement Engineering HandbookISA Flow Measurement Practical Guides for Measurement and Control, Spitzer, D.W., EditorASME Fluid Meters, Their Theory and Application

  • QUESTIONS

    Any Questions???

    This completes the Control Systems Training Module 000.270.CSE156.1 Flow Instruments. Are there any questions?

    ISA = International Society of Automation

    The following is a list of commonly used flow devices in the Oil & Gas Industry. A corporate standard in many cases provides guidance on the evaluation criteria for flowmeter selection. There are many types of flowmeters available and each has its own application and advantages & limitations, but should always follow project specifications first and be aware that information can vary for the same type of flowmeter between different manufacturers.

    There the Differential Pressure (Head) Type, which is the most common flow measuring system, where flow is inferred from the differential pressure caused by the flow. This type of flow meter is based on Bernoullis Equation. Differential Pressure (Head) Type flowmeters include the following:

    Orifice Plate - Concentric, Eccentric, Segmental, Quadrant Edge, Integral, Conditioning

    Venturi Tube

    Flow Nozzles

    Elbow

    Pitot Tube, Averaging Pitot Tube (Annubar)

    Variable Area (Rotameter)

    Wedge Meter

    V-Cone

    Another type of flowmeter is the Mass Type, which measures the mass flow rate directly. Mass Type flowmeters include the following:

    Coriolis

    Thermal

    Another type of flowmeter is the Velocity Type, where flow is calculated by measuring the speed in one or more points in the flow and integrating the flow speed over the flow area. Velocity Type flowmeters include the following:

    Magnetic

    Ultrasonic - Transit Time, Doppler

    Turbine

    Vortex

    Other Types of flowmeters commonly used in the oil and gas industry include:

    Positive Displacement

    Target

    Another type of flowmeter is the Open Channel Type, where the common method of measuring flow through an open channel is to measure the height of the liquid as it passes over an obstruction (flume or weir) in the channel. Open Channel Type flowmeters include the following:

    Weir

    Parshall Flume

    The following terminology is normally used in flow measurement, including:

    Rangeability (Turndown), the ratio of maximum flow to minimum flow, but not zero flow.

    Repeatability, the ability of a flow meter to indicate the same readings each time the same flow conditions exist. These readings may or may not be accurate, but will repeat. This capability is important when a flow meter is used for flow control.

    Linear, where the transmitter output is directly proportional to the flow input.

    Square Root, where flow is proportional to the square root of the sensed differential pressure (head).

    Beta Ratio (d/D), which is the ratio of orifice plate or other differential pressure flow device bore (d) divided by internal diameter of pipe (D). A higher Beta ratio means a larger orifice plate bore size. A larger orifice plate bore size means greater flow capacity and a lower permanent pressure loss.

    Flow can be measured as a rate per unit time.

    For Liquids, the common units used are: gpm, m3/hr, liters/min, etc.

    For Gas, the common units used are: ft3/hr, etc.

    Flow can be measured as a mass per unit time.

    Common units used are: lb/hr, kg/hr, etc.

    Flow can be measured in accumulated (totalized) total amounts for a time period.

    Common units used are: gallons, liters, meters passed in a day, etc.

    Laminar Flow - Is Characterized By Concentric Layers Of Fluid Moving In Parallel Down The Length Of A Pipe. The Highest Velocity (Vmax) Is Found In The Center Of The Pipe. The Lowest Velocity (V=0) Is Found Along The Pipe Wall.

    Turbulent Flow - Is Characterized By A Fluid Motion That Has Local Velocities And Pressures That Fluctuate Randomly. This Causes The Velocity Of The Fluid In The Pipe To Be More Uniform Across A Cross Section.

    The Reynolds number is the ratio of inertial forces (velocity and density that keep the fluid in motion) to viscous forces (frictional forces that slow the fluid down) and is used for determining the dynamic properties of the fluid to allow an equal comparison between different fluids and flows.

    Laminar Flow occurs at low Reynolds numbers, where viscous forces are dominant, and is characterized by smooth, constant fluid motion

    Turbulent flow occurs at high Reynolds numbers and is dominated by inertial forces, producing random eddies, vortices and other flow fluctuations.

    The Reynolds number is the most important dimensionless number in fluid dynamics and provides a criterion for determining similarity between different fluids, flowrates and piping configurations.

    This is the equation for determining the Reynolds number. You can get the required values from process.

    An ideal gas or perfect gas is a hypothetical gas consisting of identical particles with no intermolecular forces. Additionally, the constituent atoms or molecules undergo perfectly elastic collisions with the walls of the container. Real gases act like ideal gases at low pressures and high temperatures.

    Real gases do not exhibit these exact properties, although the approximation is often good enough to describe real gases. The properties of real gases are influenced by compressibility and other thermodynamic effects.

    This is the equation for an Ideal Gas

    Compressibility Factor (Z) - The term "compressibility" is used to describe the deviance in the thermodynamic properties of a real gas from those expected from an ideal gas.

    This is the equation for an Ideal Gas

    Standard conditions allow gases and vapors of different compositions to be compared equally.

    This is the method to convert from standard conditions to actual conditions

    Bernoulli's Law Describes The Behavior Of An Ideal Fluid Under Varying Conditions In A Closed System. It States That The Overall Energy Of The Fluid As It Enters The System Is Equal To The Overall Energy As It Leaves.

    Bernoullis law explains the movement of fluid through an orifice or nozzle. It shows that the total energy upstream of the nozzle is equal to the energy at the nozzle throat. It explains how the potential energy is converted to kinetic energy as the fluid speeds up and the pressure drops at the nozzle throat.

    This diagram shows how fluids flow through an orifice. The Beta ratio is the ratio of the orifice size to the inside diameter of the pipe. These type of meters require a straight section of pipe both upstream and downstream. This is called the meter run. The length of this is dependent on the piping layout. For most piping systems it is 20 pipe diameters upstream and 5 downstream for an orifice plate. This must be checked for every meter against the P, I, P standard.

    Note that increasing the beta ratio provides increased accuracy, but also requires increased straight run.

    Orifice Plate Flow Principles. The most often used flow sensor is the orifice plate shown to the right. Flow is measured by creating a pressure drop and applying the flow equation below. The basic flow equation for single phase compressible and non-compressible fluids is shown below.

    The square root functions impact on a differential pressure device limits the measurement turndown (rangeability).

    The Orifice Plate is a simple device, considered to be a precision instrument. It is simply a piece of flat metal with a flow-restricting bore that is inserted into the pipe between flanges. The orifice meter is well understood, rugged and inexpensive. Its accuracy under ideal conditions is in the range of 0.75 to 1.5 percent. It can be sensitive to a variety of error-inducing conditions, such as if the plate is eroded or damaged.

    The most common orifice plate is the square-edged concentric bored orifice plate. The concentric bored orifice plate is the dominant design because of its proven reliability in a variety of applications and the extensive amount of research conducted on this design. It is easily reproduced at a relatively low cost. It is used to measure a wide variety of single phase, liquid and gas products, typically in conjunction with flange taps.

    Eccentrically bored plates are plates with the orifice off center, or eccentric, as opposed to concentric. This type of plate is most commonly used to measure fluids which carry a small amount of non-abrasive solids, or gases with small amounts of liquid, since with the opening at the bottom of the pipe, the solids and liquids will carry through, rather than collect at the orifice plate. A higher degree of uncertainty as compared to the concentric orifice. Eccentric orifice plates are used in many industries including heavy and light chemicals and petrochemicals.

    The quadrant, quadrant edge or quarter-circle orifice is recommended for measurement of fluids with high viscosity which have pipe Reynolds Numbers below 10,000. The orifice incorporates a rounded edge of definite radius which is a particular function of the orifice diameter.

    Quadrant in U.S.

    Conical in Europe

    Integral Orifice Plate is identical to a square-edged orifice plate installation except that the plate, flanges and DP transmitter are supplied as one unit. They are used for small lines (typically under 2 or 50mm) and is relatively inexpensive to install since it is part of the transmitter.

    Most conditioning orifice plates have the following characteristics:

    Recommended Service: Liquids, Gases & Steam

    Rangeability: 4 to 1

    Pressure Loss: Medium

    Accuracy: 0.5%

    Straight Run Required: 2D Upstream, 2D Downstream

    Viscosity Effect: High

    Relative Cost: Low

    Size: 2 to 24

    Connection: Between Flanges

    Type of Output: Square Root

    There are times when a gas may be have a small amount of liquid or a liquid may have a small amount of gas but not enough in either case to warrant the use of an eccentric orifice. In these cases it is best to simply add a small hole near the edge of the plate, flush with the inside diameter of the pipe, allowing undesired substances to pass through the plate rather than collect on the upstream side. If such a hole is oriented upward to pass vapor bubbles, it is called a vent hole. If the hole is oriented downward to pass liquid droplets, it is called a drain hole.

    Quadrant Edge Orifice Plate can be considered if Reynolds number is too low.

    Orifice plate must be specified with proper flange rating to account for proper bolt circle.

    Typical acceptable beta ratio is .25 to .7 for non commerce meter, .3 to .6 for accounting meter but also check specifications.

    Assure that calculation accounts for vent or drain hole, if required.

    For dual transmitter installation on a common set of orifice flanges, custom tap locations must be specified.

    Differential pressure is measured through pressure taps located on each side of the orifice plate. Pressure taps can be positioned at a variety of different locations. The most common are flange taps. They are located 1 inch from the upstream face of orifice plate and 1 inch from downstream face. They are used for all standard orifice onfigurations.

    Corner Taps are used for honed meter runs like an integral orifice. They are located immediately adjacent to plate faces both upstream and downstream.

    Radius Taps are located 1 pipe diameter upstream of orifice plate and one half pipe diameter downstream of orifice plate. They are not commonly used.

    Vena-Contracta Taps are located 1 pipe diameter upstream of orifice plate and at the point of minimum pressure downstream, this point is called the vena-contracta. This point varies with Beta ratio and are seldom used other than for plant measurement where the flows are relatively constant and plates are not changed. Exact dimensions for the downstream tap are given in appropriate tables.

    Pipe Taps are located two and one half pipe diameters upstream of orifice plate and eight pipe diameters downstream of orifice plate this puts the downstream tap at the point of maximum pressure recovery.

    Orifice taps in horizontal lines for gas service should be from the top of the pipe or no more than 45 degrees from vertical as shown.

    Orifice taps in horizontal lines for liquid or steam should be at horizontal or 45 degrees down from horizontal as shown. For pipe racks, it is recommended that horizontal taps not be used in order to maximize pipe rack space.

    In a Venturi tube, the fluid is accelerated through a converging cone, inducing a local pressure drop. An expanding section of the meter then returns the flow to near its original pressure. These instruments are often selected where it is important not to create a significant pressure drop and where good accuracy is required.

    Used when higher velocity and pressure recovery is required.

    May be used when a small, constant percentage of solids is present.

    Another DP Type Flowmeter is the Flow Nozzle. It is used when higher velocity & pressure recovery are required and are better suited for gas service than for liquid.

    Wedge flow meters can be used on just about any liquid or gas, just like orifice plates. However they are generally chosen for dirty service, or high viscosity applications such as slurry or heavy oil, or where solids are present. For regular service applications consider other types of meters first unless wedge meters are specified by customer as preferred.

    Since they are a differential pressure device their sizing calculation is similar to that of other d, P flowmeters.

    V-Cone is another differential pressure type flowmeter.

    The V-Cone is similar to other differential pressure (Dp) meters in the equations of flow that it uses. V-Cone geometry, however, is quite different from traditional Dp meters. The V-Cone constricts the flow by positioning a cone in the center of the pipe. This forces the flow in the center of the pipe to flow around the cone.

    Basic information of a multivariable transmitter.

    In a pitot tube (insertion DP meter), a probe consisting of two parts senses two pressures: impact (dynamic) and static. The impact pressure is sensed by one impact tube bent toward the flow (dynamic head). The averaging-type pitot tube has four or more pressure taps located at mathematically defined locations, averaging the velocity profile across the pipe or flow area, to measure the dynamic pressure. The static pressure is sensed through a small hole on the side (static head). They develop low differential pressure and like all head meters they use a differential pressure transmitter to convert the flow to an electrical transmission signal.

    Pitot tubes make use of dynamic pressure difference. Orifices in the leading face register total head pressure, dynamic + static, while the hole in the trailing face only conveys static pressure. Pressure difference between the two gives dynamic pressure in pipe, from which flow can be calculated.

    Basic Mass rate of flow equation for single phase compressible and non-compressible fluids is shown below.

    PIP PCCFL001 includes tables for minimum straight run lengths with various upstream disturbances, providing upstream requirements for different beta ratios and downstream requirements per beta ratios regardless of upstream disturbance type.

    Here are some characteristics of the concentric orifice plate. The unrecovered pressure lost across an orifice plate sized for 100 inches of water is usually in the range of 40 to 60 inches. The amount of upstream straight run required will depend on the piping configuration. The accuracy of an orifice plate depends on a number of factors including piping system design and installation.

    Rotameters are a variable area flow device. The float moves up and down in proportion to the fluid flow rate and the annular area between the float and the tube wall. As the float rises, the size of the annular opening increases. As this area increases, the differential pressure across the float decreases. The float reaches a stable position when the upward force exerted by the flowing fluid equals the weight of the float. Every float position corresponds to a particular flow rate for a particular fluid's density and viscosity. For this reason, it is necessary to size the rotameter for each application. When sized correctly, the flow rate can be determined by matching the float position to a calibrated scale on the outside of the rotameter. Many rotameters come with a built-in valve for adjusting flow manually.

    Most variable area flowmeters (rotameters) have the following characteristics:

    Recommended Service: Clean, Dirty & Viscous Liquids

    Rangeability: 10 to 1

    Pressure Loss: Medium

    Accuracy: 1 to 10%

    Straight Run Required: None

    Viscosity Effect: Medium

    Relative Cost: Low

    Sizes:

    Connections: Flanged & Clamp-on Design

    Type of Output: Linear

    Thermal mass flow meters introduce heat into the flow stream and measure how much heat dissipates using one or more temperature sensors. This method works best with gas mass flow measurement.

    The constant temperature differential method have a heated sensor and another sensor that measures the temperature of the gas. Mass flow rate is computed based on the amount of electrical power required to maintain a constant difference in temperature between the two temperature sensors.

    In the constant current method the power to the heated sensor is kept constant. Mass flow is measured as a function of the difference between the temperature of the heated sensor and the temperature of the flow stream.

    Both methods are based on the principle that higher velocity flows result in a greater cooling effect. Both measure mass flow based on the measured effects of cooling in the flow stream.

    Most thermal mass flowmeters have the following characteristics:

    Recommended Service: Clean, Dirty & Viscous Liquids, Some Slurries, Gases

    Rangeability: 10 to 1

    Pressure Loss: Low

    Accuracy: 1%

    Straight Run Required: None

    Viscosity Effect: None

    Relative Cost: High

    Sizes: 2 to 24

    Connections: Threaded, Flanged

    Type of Output: Exponential

    A magnetic flow meter or mag meter is a volumetric flow meter which does not have any moving parts and is ideal for any conductive fluid. Typical applications include wastewater, slurries or any dirty liquid which is conductive or water based. Magnetic flowmeters will generally not work with hydrocarbons, distilled water and many non-aqueous solutions. Magnetic flowmeters are also ideal for applications where low pressure drop and low maintenance are required.

    The operation of a mag meter is based upon Faraday's Law, which states that the voltage induced across any conductor as it moves at right angles through a magnetic field is proportional to the velocity of that conductor. When the fluid moves faster, more voltage is generated. Faradays Law states that the voltage generated is proportional to the movement of the flowing liquid. The electronic transmitter processes the voltage signal to determine liquid flow.

    In contrast with many other flowmeter technologies, magnetic flowmeter technology produces signals that are linear with flow. As such, the turndown associated with magnetic flowmeters can approach 40 to 1 without sacrificing accuracy.

    Most magnetic flowmeters have the following characteristics:

    Recommended Service: Clean, Dirty & Viscous Conductive Liquids & Slurries

    Rangeability: 40 to 1

    Pressure Loss: None

    Accuracy: 0.5%

    Straight Run Required: 5D Upstream, 2D Downstream

    Viscosity Effect: None

    Relative Cost: High

    Sizes: 1 to 120

    Connections: Flanged

    Type of Output: Linear

    Transit time ultrasonic meters employ two transducers located upstream and downstream of each other. Each transmits a sound wave to the other, and the time difference between the receipt of the two signals indicates the fluid velocity. Transit time meters usually require clean fluids and are used where high rangeability is required. Accuracy is within 1% for ideal applications.

    Flow is measured by measuring the difference in transit time for two ultrasonic beams transmitted in a fluid both upstream and downstream.

    Ultrasonic Meters are mainly used on large size lines where high rangeability is required.

    Transit time difference is proportional to mean velocity Vm. Therefore Vm can be calculated as follows:

    The Basic Flow Equation is shown below.

    The basic principle of operation employs the frequency shift (Doppler Effect) of an ultrasonic signal when it is reflected by suspended particles or gas bubbles (discontinuities) in motion. This metering technique utilizes the physical phenomenon of a sound wave that changes frequency when it is reflected by moving discontinuities in a flowing liquid. Ultrasonic sound is transmitted into a pipe with flowing liquids, and the discontinuities reflect the ultrasonic wave with a slightly different frequency that is directly proportional to the rate of flow of the liquid (Figure 1). Current technology requires that the liquid contain at least 100 parts per million (PPM) of 100 micron or larger suspended particles or bubbles.

    Most ultrasonic (Transit Time) flowmeters have the following characteristics:

    Recommended Service: Clean & Viscous Liquids, Natural/Flare Gas

    Rangeability: 20 to 1

    Pressure Loss: None

    Accuracy: 1 to 5%

    Straight Run Required: 5 to 30D Upstream

    Viscosity Effect: None

    Relative Cost: High

    Sizes: >

    Connections: Flanged & Clamp-on Design

    Type of Output: Linear

    Turbine meter is kept in rotation by the linear velocity of the stream in which it is immersed. The number of revolutions the device makes is proportional to the rate of flow.

    Most turbine meters have the following characteristics:

    Recommended Service: Clean & Viscous Liquids, Clean Gases

    Rangeability: 20 to 1

    Pressure Loss: High

    Accuracy: 0.25%

    Straight Run Required: 5 to 10D Upstream

    Viscosity Effect: High

    Relative Cost: High

    Sizes: >

    Connections: Flanged

    Type of Output: Linear

    Vortex meters can be used on most clean liquid, vapor or gas. However, they are generally chosen for applications where high flow rangeability is required. Due to break down of vortices at low flow rates, vortex meters will cut off at a low flow limit. Reverse flow measurement is not an option. For regular service applications this meter is the meter of choice by many end users.

    The Basic Flow Equation for a Vortex Meter is shown below.

    Most vortex flowmeters have the following characteristics:

    Recommended Service: Clean & Dirty Liquids, Gases

    Rangeability: 10 to 1

    Pressure Loss: Medium

    Accuracy: 1%

    Straight Run Required: 10 to 20D Upstream, 5D Downstream

    Viscosity Effect: Medium

    Relative Cost: Medium

    Size: to 12

    Connection: Flanged

    Type of Output: Linear

    PD meters measure flow rate directly by dividing a stream into distinct segments of known volume, counting segments, and multiplying by the volume of each segment. Measured over a specific period, the result is a value expressed in units of volume per unit of time. PD meters frequently report total flow directly on a counter, but they can also generate output pulses with each pulse representing a discrete volume of fluid.

    Positive Displacement Flowmeters have 3 parts: Body, Measuring Unit and Counter Drive Train.

    Position 1: Liquids inlet pressure exerts a pressure differential against the lower face of oval gear A, causing the two interlocked oval gears to rotate to position 2.

    Position 2: Liquid enters the cavity between oval gear B and meter body wall, while an equal volume of liquid passes out of the cavity between oval gear A and meter body wall. Meanwhile, inlet pressure continues to force the two oval gears to rotate to position 3

    Position 3: Quantity of liquid has again filled the cavity between oval gear B and meter body. This pattern is repeated moving four times the liquid capacity of each cavity with each revolution of the rotating gears. Therefore, the flow rate is proportional to the rotational speed of the gears.

    Most positive displacement (PD) flowmeters have the following characteristics:

    Recommended Service: Clean & Viscous Liquids, Clean Gases

    Rangeability: 10 to 1

    Pressure Loss: High

    Accuracy: 0.5%

    Straight Run Required: None

    Viscosity Effect: High

    Relative Cost: Medium

    Sizes: >12

    Connections: Flanged

    Type of Output: Linear

    The following is a list of the Practices, Industry Standards and other references that are commonly used in the oil and gas industry when selecting and specifying flow instruments. References include:

    Process Industry Practices (PIP)

    PIP PCCGN002 General Instrument Installation Criteria

    Industry Codes and Standards

    American Gas Association (AGA)

    AGA 9 Measurement of Gas by Multipath Ultrasonic Meters

    American National Standards Institute (ANSI)

    ANSI-2530/API-14.3/AGA-3/GPA-8185 Natural Gas Fluids Measurement Concentric, Square-Edged Orifice Meters

    Part 1 General Equations and Uncertainty Guidelines

    Part 2 Specification and Installation Requirements

    Part 3 Natural Gas Applications

    Part 4 Background, Development, Implementation Procedures and Subroutine Documentation

    American Petroleum Institute (API)

    API RP 551 Process Measurement Instrumentation

    API RP 554 Process Instrument and Control

    API Manual of Petroleum Measurement Standards (MPMS):

    Chapter 4 Proving Systems

    Chapter 5 Metering

    Chapter 14 Natural Gas Fluids Measurement

    American Society of Mechanical Engineers (ASME)

    ASME B16.36 Orifice Flanges

    ASME MFC-1M Glossary of Terms Used in the Measurement of Fluid Flow in Pipes

    ASME MFC-2M Measurement Uncertainty for Fluid Flow in the Closed Conduits

    ASME MFC-3M Measurement of Fluid Flow in Pipes Using Orifice, Nozzle and Venturi

    ASME MFC-5M Measurement of Liquid Flow in Closed Conduits Using Transit-Time Ultrasonic Flowmeters

    ASME MFC-6M Measurement of Fluid Flow in Pipes Using Vortex Flow Meters

    ASME MFC-7M Measurement of Gas Flow by Means of Critical Flow Venturi Nozzles

    ASME MFC-11M Measurement of Fluid Flow by Means of Coriolis Mass Flowmeters

    ASME MFC-14M Measurement of Fluid Flows Using Small Bore Precision Orifice Meters

    ASME MFC-16M Measurement of Fluid Flow in Closed Conduit by Means of Electromagnetic Flowmeter

    The International Society for Measurement and Control (ISA)

    ISA S20 Specification Forms for Process Measurement and Control Instruments, Primary Elements and Control Valves

    International Organization for Standardization (ISO)

    ISO 5167 - Measurement of Fluid Flow by Means of Pressure Differential Devices Inserted in Circular Cross-Section Conduits Running Full

    Part 1: General principles and requirement

    Part 2: Orifice Plates

    Part 3: Nozzle and Venturi Tubes

    Part 4: Venturi Tubes

    Other References

    Miller, R.W., Flow Measurement Engineering Handbook

    ISA Flow Measurement Practical Guides for Measurement and Control, Spitzer, D.W., Editor

    ASME Fluid Meters, Their Theory and Application

    This completes the Control Systems Training Module 000.270.CSE156.1 Flow Instruments. Are there any questions?

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