Your Logo Here FLOW INSTRUMENTATION 101 Dave Schmitt

Your Logo Here FLOW INSTRUMENTATION 101 Dave Schmitt Escondido / Irvine “Serving the Southwest’s Instrumentation Needs Since 1987”

Overview – n Rep S. C. CONTROLS, INC. / Distributor / Integrator n Escondido / Irvine offices n Founded in 1987 n Specializing in FLOW, LEVEL, TEMPERATURE, DENSITY MEASUREMENTS n Degreed Engineers n Offering solutions not just sales

Overview n Briefly describe theory of flow measurements n Outline different types of flow meters. n Discuss advantages/ disadvantages in applications. n Present examples of instruments for measurement solutions n Questions / Answers

Flow Measurement Theory n WHAT IS FLOW ? ? – Measure of the velocity of a fluid per unit area in a closed conduit; ie: pipe or duct – FLOW = VELOCITY (fluid) X Area of Pipe or Duct or Stack – FLOW = FPM X FT 2 or IN 2 – Q = AV (Area X velocity) – Q = ρ AV (density x area x vel) • Mass flow

FLOW - In our everyday lives n Water flow meter at our home or apartment – used for billing purposes – Mechanical flow meter with local rate and total – Relative accuracy

FLOW - In our everyday lives Gas Flow Meter - natural gas measurement of gas used for cooking and heating – Mechanical Meter - turbine type n Liquid flow meter - Gasoline - at the local gas station where we pumped gas this morning – Positive displacement type with output signal to electronic counter for billing n We use flow meters every day to measure fluids we use.

Why meter? • Business Need Mitigate rising energy costs • Manage energy consumption efficiently • Apportion energy costs by usage and not square footage, creating behavior change • You cannot control what you do not measure. 7

Basic Flow Theory n n n 8 Volumetric Flow Mass Flow Density - Liquid Density - Steam Actual vs. Standard Flow - Gas Energy Flow - Water Flow Profiles & Reynolds Number Viscosity Accuracy Repeatability Straight Run Requirements Meter Installation

Volumetric Flow (all fluids) Q = A* V = ft ² * ft sec = ft ³ sec where: Q = volumetric flow ft ³ sec A = cross sectional area ( ft ² ) V = average fluid velocity ( ft sec 9 )

Mass Flow = Q = A V m * * * = ft ² * ft sec * lbs ft ³ = lbs sec where: m = mass flow ( lbs sec ) = density ( lbs ft ³ ) Q = average fluid velocity ( ft sec ) A = cross sectional area ( ft ² ) V = average fluid velocity ( ft sec ) 10

Density - Liquids The density of a liquid is inversely proportional to temperature: WATER 1 T 11 Temperature °F Weight Density Lbs/gal 32 8. 3436 40 8. 3451 50 8. 343 60 8. 3378 70 8. 329 80 8. 3176 90 8. 3037 100 8. 2877

Density - Gases The density of a gas varies proportionally with pressure and inversely with temperature: = a 1 T Density of Gas: = 2. 7 a SG Ta where: = Density ( lbs ft 3 ) a = absolute pressure (psia) = 14. 7 + Pgage SG =Specific Gravity Ta = absolute temperature = F° + 460 = ° Rankin 12

Density - Steam Saturated steam: Superheated steam: Saturated Steam Table 13 Superheated Steam Table Pressure psia Temperature °F Density lbs/ft³ 89. 6 320 0. 203 20 320 0. 044 152. 92 360 0. 338 20 360 0. 041 247. 10 400 0. 536 20 400 0. 039 381. 20 440 . 820 20 440 0. 038 680. 00 500 1. 480 20 500 0. 035 811. 40 520 1. 780 80 320 0. 181 361. 50 540 2. 150 80 360 0. 170 1131. 80 560 2. 580 80 400 0. 161 1324. 30 580 3. 100 80 440 0. 153 1541. 00 600 3. 740 80 500 0. 143

Actual vs. Standard Flow - Gas Actual Volume Flow: Q = V * A (actual ft³ sec, ft³ min, etc) (actual m³ sec, hr, m³ sec, etc) Standard Volume Flow: Gas flow in standard units relates the volume flow of gas to the same amount of mass flow of gas at standard conditions: Qstandard = Q actual operating standard conditions where: Qstandard = standard ft³ unit time or standard m³ unit time Qactual = actual volumetric flow (ACFM, ACFH, etc…) SG = specific gravity ( gas air , at standard conditions ) operating standard 14 = density of gas at operating pressure and temperature = density of gas at standard conditions (at 14. 7 psia, 60°F)

Energy Flow E = m (hs – hr ) E = A V (hs - hr ) lbs Btu ft E = ft² sec ft³ lbs Btu E= sec where: 15 Chilled/hot water energy (Btu) calculations require (1) flow and (2) temperature inputs. Btu is defined as the amount of energy required to raise the temperature of 1 lb water at 39°F by 1°F. E = energy flow (Btu = mass flow m ) sec (lbs sec ) A = cross sectional area (ft²) V = average fluid velocity ( ft sec ) = density ( lbs ft³ ) ( Btu lbs) = Btu’s (heat content) of water at return temperature ( Btu lbs) hs = Btu’s (heat content) of water at supply temperature hr

Flow Profiles & Reynolds Number 16 Re = inertial forces frictional forces Re = density velocity diameter viscosity Re = V D µ

Viscosity Dynamic viscosity c. P (centipoise) Kinematic Viscosity cst (centistoke) A measure of how freely a fluid flows: Vc. P = Vcst *SG where: Vcst = kinematic viscosity V c. P = dynamic viscosity SG = specific gravity 17

Viscosity can be highly temperature dependent in liquids. Steam/gas – 0. 01 c. P Water – 1. 0 c. P Honey – 300 c. P 18

Accuracy % of Rate or Reading Error = % of rate measurement % of Full Scale Error = % of full scale flow ACCURACY +/-1% % of Rate Max flow 1, 000 lb/h = 1, 010 to 990 lb/h Min flow 100 lb/h = 101 to 99 lb/h % Full scale (FS) Max flow 1, 000 lb/h = 1, 010 to 990 lb/h Min flow 100 lb/h = 110 (100 + 10) lb/h to 90 (100 - 10) lb/h i. e. +/- 10% error at minimum flow 19

Repeatability Accurate & Repeatable Repeatability: Differs from Accuracy Not accurate, or repeatable Measures the same all the time Not accurate, but repeatable 20

Installation – Straight Run 21 Straight run requirements ¨ Minimum 10 pipe diameters upstream and 5 pipe diameters downstream required to get proper flow profile ¨ Less straight run affects meter accuracy

Installation – Meter Location Install before valve to avoid air Vertical orientation– insure full pipe Liquid horizontal orientation– insure full pipe Gas & steam horizontal orientation – insure no condensate 22 Top View

Orifice Plate Flowmeter The orifice plate is a differential pressure flow meter (Primary element). Based on the work of Daniel Bernoulli the relationship between the velocity of fluid passing through the orifice is proportional to the square root of the pressure loss across it. To measure the differential pressure when the fluid is flowing, connections are made from the upstream and downstream pressure tappings to a secondary device known as a DP (Differential Pressure) cell. 23 Fig. 4. 3. 1 Orifice plate

Orifice Plate Flowmeter 24

Orifice Plates Advantages: l Low cost, especially on large sizes Complete Customer Data Sheet: Customer details Fluid l No need for recalibration Operating pressure l Widely accepted Operating temperature Estimate flow rate Disadvantages: l Poor turndown (4: 1 typical) l Long installations (20 D to 30 D) l 25 Accuracy dependant on geometry. Line size, Pipe Schedule, Material Flange Specification Required package option

Variable orifice flow meter n n n 26 Line sizes 2 -8” Temp up to 842°F (450°C) Accuracy ± 1. 0% of rate Gas and Steam applications Compact installation 6 up and 3 down Up to 100: 1 turndown

Digital variable orifice flow meter n n n n 27 Line sizes 2 -4” Saturated Steam ONLY 347°F (175°C) Accuracy ± 2. 0% of flow Internal RTD for Integrated mass flow measurement Compact installation 6 up and 3 down Up to 50: 1 turndown

Vortex Flowmeter n n n n n 28 Liquid, Gas, and Steam 1 -12” (25 to 300 mm) Temperature up to 750°F(400°C) EZ-Logic menu-driven user interface In-process removable sensor (below 750 psig) Fully welded design with no leak path Optional remote mount electronic Accuracy ¨ Liquid ± 0. 7% of rate ¨ Gas and Steam ± 1. 0% of rate Turndown up to 20: 1 Vortex

Insertion Vortex Meter n n n n n 29 Liquid, Gas, and Steam Model 60/60 S Hot Tap, retractable Model 700 Insertion low temp, low pressure Model 910/960 Hot tap, retractable ¨ 960 -high temp up to 500°F (260°C), high pressure Optional Temperature and/or Pressure Transmitter Line sizes 3 -80” (76 to 2032 mm) No moving parts EZ-Logic menu driven user interface Accuracy ¨ Liquid ± 1. 0% of rate ¨ Gas and Steam ± 1. 5% of flow rate test conditions Turndown up to 20: 1 VBar

Turbo-Bar Insertion Turbine Flow Meter n n n n n 30 Liquid, Gas, and Steam Liquid flow velocity down to 1 ft/sec Model 60/60 S Hot Tap, retractable Model 700 Insertion low temp, low pressure Model 910/960 Hot tap, retractable ¨ 960 -high temp up to 750°F (400°C), high pressure Optional Pressure and/or Temperature Transmitter Line sizes 3 -80” (76 to 2032 mm) EZ-Logic menu driven user interface Nominal Accuracy ¨ Liquids ± 1. 0% of rate ¨ Gas and Steam ± 1. 5% of rate Turndown up to 25: 1 TMP

Low-cost Water Vortex Meter n n n 31 No Moving Parts Flow Range 1 to 15 ft/s (0. 3 to 4. 5 m/sec) Accuracy ± 1. 0% of Full Scale 1/2 to 20” Line Size Microprocessor-based electronics with optional local display Maximum Fluid temperature 160°F (70°C) Model 2300 for acids, solvents, Deionized, and ultra pure water (1/2 to 8”) Model 2200 Fixed Insertion for (2 to 20”) Model 1200 for water, water/glycol (1 -3”) Model 3100 retractable insertion (3 -20”) Models 1200 and 2200 have Aluminum Enclosure option for wet environments or heavy industrial installations 2200 2300 1200 3100

Transit Time Ultrasonic Flowmeter n n n n n Liquid applications-Clean 2 -100” (50 to 2540 mm) Accuracy typically ± 2. 0% of rate Non-Intrusive No wetted parts Multiple outputs available EZ-Logic menu driven user interface Bi-Directional Transducer cable length up to 300’ Sono-Trak 32

Electromagnetic Flowmeter § § § 33 Field Serviceable Design § Field replaceable sensors and coils No Liner Required § No liner failure Solid State Sensor Design § Encapsulated coil and electrode assembly insensitive to shock and Vibration Plurality of Sensors § Uniquely powerful magnetic field Non-standard Flow Tube Lengths § Easy replacement of existing meters Measures Low Conductivity Media § Conductivity down to 0. 8 µS/cm

Other technologies q. Positive displacement q. Gear q. Oval gear q. Piston q. Helix

Other technologies q. Coriolis Mass Flow

Other technologies q. Open Channel Flow

Thermal Mass Flow Meters for Measuring Gas Flows

WHAT IS A THERMAL MASS FLOW METER? n 38 It is a Meter that directly measures the Gas Mass Flow based on the principle of conductive and convective heat transfer –

MEASURE MASS FLOW RATE OR TOTALIZE COMMON GASES n Air (Compressed Air, Blower Air, Blast Furnace Air, Combustion Air, Plant Air, Make-Up Air) n Natural Gas Industrial (Plant Usage, Sub-Metering, Boiler Efficiency, Combustion Control) n Natural Gas Commercial & Governmental (Building Automation–Reduce Energy Costs, LEED Credits) n Digester Gas, Bio Gas, Landfill Gas (EPA regulations and Carbon Credits) 39 n Flare Gas (Vent Gas and Upset – Dual Range) n Other: Propane, Nitrogen, Argon, CO 2

Immersion type inferential mass flowmeters utilizing constant temperature thermal dispersion sensor technology. Rate of heat absorbed from the sensor by the flowing gas molecules contacting the sensor is proportional to the gas mass velocity. Mass flow rate is mass velocity passing through a fixed area. mass velocity x area = mass flow. Sensor construction - two ratiometrically-matched, reference-grade platinum Resistance Temperature Detectors (RTDs) sheathed in 316 stainless steel thermo wells. Wetted sensors are 316 SS (or optional Hastelloy C 276).

• One of the RTDs is self-heated by the circuitry and serves as the Flow Sensor • Second RTD acts as a Reference Sensor. Used for Temperature Compensation

continued Transitions in pipe sizes, old pipes…. .

Inline style connections For line sizes 0. 250" to 2. 50“ • Pipe thread (MNPT) ends For 3" lines and greater • 150# class ANSI flanged ends (optional 300# or 600# class flanges) Specialty fittings are available. . • VCRs • Tri-Clamps • Electro-polished tube flow sections for high-purity applications

Insertion style (> line sizes 2. 00" ) mounting connections • Pipe nipples • Compression fittings • Flanges • Ball valve retractor assemblies • The flowmeter can be inserted into vertical or horizontal pipes, and at any location around the pipe diameter. • Probes are positioned so the RTDs are located at the Point-of-Average-Flow or 0. 243 r from the inside insertion wall. (Actual probe length may be shorter than half the pipe diameter. )

Inputs • 24 VDC Power (draws less than 100 ma) • 115 VAC/ 230 VAC • 12 VDC Optional Outputs • 4 – 20 ma of Flow Rate • 12 VDC Pulses of Totalized Flow (Solid State, sourcing, transistor drive – 500 ms Pulse) • Modbus® compliant RS 485 Communications

THERMAL MFM ADVANTAGES (OVER OTHER TYPES OF TECHNOLOGIES) n n n 50 Direct Mass Flow – No need for separate temperature or pressure transmitters High Accuracy and Repeatability Turndown of 100 to 1 and resolution as much as 1000 to 1 Low-End Sensitivity – Detects leaks, and measures as low as 5 SFPM! Very high gas flow velocities

Compressed Dry Air (CDA) is one of the primary components of overall energy use. Benefits : v Monitor general usage for energy and plant cost conservation v Track peak usage to correctly determine optimum compressor capacity

Applications -Compressed Air Facilities Monitoring n Sub-metering/Billing n Leak Detection n Energy Conservation n Compressor Optimization n Performance Testing n 52

Accurately tracking the natural gas usage within a facility, whether used for seasonal heating or for critical production processes. . . Benefits • Information needed to adjust for peak usage • Correctly assign costs to general operating expenses

For new facilities or for improvements to existing facilities • Eliminate the undesirable system pressure drops and high maintenance costs associated with the older technology of differential flow meters and rotary load meters. • Example Compressed Air is needed to promote optimal bacteria growth in aeration basins. Closely controlling the aeration process can reduce energy usage by as much as 25%.

Improving efficiency…. . v Basic fuel costs — by monitoring the fuel-to-air ratio, the most cost-effective mixture for efficient combustion is better controlled; v Reduced emissions — efficient combustion helps to avoid fines associated with excess environmental pollution; v Lower plant maintenance costs — efficient combustion reduces the amount of routine maintenance associated with this volatile process; v Extended equipment life — by keeping the combustion process within its optimum design specifications, the overall system's operating life is extended.

TECHNOLOGY SUMMARY

Technologies Technology 58 Operating Principle Advantages Disadvantages Fluids Measured DP (Differential Pressure) Orifice plate Pitot tube Variable area Venturi V-Cone Accelabar An obstruction in the flow, measure pressure differential before and after the obstruction Low initial cost No moving parts Handle dirty media Easy to use Well understood technology Supported by AGA and API Not highly accurate, particularly in gas flow Orifice plate and pitot tube can become clogged High maintenance to maintain accuracy Typically low turndown Pressure drop Liquids Gases Steam Vortex Inline Insertion Bluff body creates alternating vortices, vortex shedding frequency equal to fluid velocity High accuracy No moving parts No maintenance Measures dirty fluids Can be affected by pipe vibration Cannot measure low flows Liquids Gases Steam Turbine Inline Insertion Dual turbine Turbine rotates as fluid passes by, fluid velocity equal to blade rotational frequency High accuracy Low flow rates Good for steam Wide turndown Moving parts require higher maintenance Clean fluids only Liquids Gases Steam Magnetic Mag Electromagnetic Measures voltage generated by electrically conductive liquid as it moves through a magnetic field, induced voltage is equal to fluid velocity High Accuracy Wide turndown Bi-directional No moving parts No pressure loss to system Conductive fluids only Expensive to use on large pipes Conductive liquids (condensate)

Technologies Cont’d Technology Operating Principle Advantages Transit-time Ultrasonic Fluid velocity measured by time arrival difference of sound waves from upstream and downstream transducers Low cost clamp-on installation Non-intrusive No maintenance Bi-directional Best for larger pipes Doppler Ultrasonic Fluid velocity measured by sensing signals from reflective materials within the liquid and measuring the frequency shift due to the motion of these reflective Low-cost, clamp-on installation Non-intrusive Measures liquids containing Disadvantages Fluids Measured Typically not used on pipes < 2” Less accurate than inline or insertion meters Used primarily for liquids Susceptible to changes in fluid sonic properties Most liquids (condensate) Gas (when spoolpiece) Can’t be used in clean liquids Less accurate than in-line or Most liquids containing reflective materials transit-time ultrasonic particulates or bubbles Low maintenance Best for larger pipes materials Thermal Mass 59 Measure heat loss of heated wire thermistor in fluid flow Measure flow at low pressure Relative low cost Measure fluids not dense enough for mechanical technologies Easier to maintain than DP meter Susceptible to sensor wear and failure Not very accurate Limited to fluids with known heat capacities Gases

? ? ? ? ? ? n. QUESTION S AND ANSWERS

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