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Proportioning Systems

Proportioning SystemsNow you know the benefits and uses of water additives, especially Class A foam. So how do we get the concentrate into the water?

The following reviews various proportioning technologies along with capabilities and limitations of each

Why Clubs And Racquets With Larger Heads?A bigger sweet spot

The Proportioning Sweet SpotThe range in which the proportioner can deliver acceptable performanceFlow rangePressure rangeProportioning ratesFoam viscosityDesired accuracyEvery proportioner has a sweet spotSize varies by type of system

NFPA Accuracy RequirementsRatio Allowable Range

6%6.0 - 7.0%

3%3.0 - 3.9%

1%1.0 - 1.3%

0.5% 0.5 - 0.7%

0.2% 0.2 - 0.28%For proportioning rates equal or greater than 1%:- 0% to + 30% or 1 percentage point, whichever is lessFor proportioning rates less than 1%:- 0% to + 40%

Manual systems

Automatic systems

Foam Proportioner Design

Manual Foam Proportioners Eductors Around the pump systems Self-educting nozzles

Eductor Systems

In-Line Eductors

By-Pass Eductor

EductorsCapabilities:Operate over narrow range of flows and pressuresLimitations:35% pressure lossSensitive to pressure changes downstreamMust match flow and nozzleNozzle height limited to ten feet Narrow sweet spot (single flow and pressure point)

125 gpm Eductor Cutaway

Must Match Flow, Eductor & Nozzle125 gpm eductor125 gpm nozzle

Eductor - Correct Pressure & Flow200 psi Inlet130 psi Outlet20" of VacuumPerformance reduction of 35% creates required vacuum

Eductor - Incorrect Pressure & FlowLonger hose lay, increased elevation or nozzle restriction reduces vacuum12" of Vacuum140 psi Outlet200 psi Inlet

Eductor - Incorrect Pressure & FlowIncreasing restriction even more on outlet side can eliminate vacuum 150 psi Outlet200 psi InletNo Vacuum

Around The Pump Systems

Around The Pump Proportioner

Around The Pump ProportionerCapabilities:Foam solution available to all dischargesLimitations:Maximum incoming pump pressure of 5 to 15 psiAverage operating foam proportioning error of 1 to 1-1/2 percentage pointsPump solely dedicated to foam operationNarrow sweet spot

Around The Pump EductorEductorTo pump suctionFrom pump dischargeFoam concentrate

Around The Pump

Around The PumpClass A foam controlClass B foam control

Around The PumpIncoming pressure less than 12 psiWhen flow stops, immediately turn metering valve off

Self-Educting Nozzles

Self-Educting NozzlesCapabilities:Large flows at 1%, 3% or 6%Lower pressure drop than regular eductors, 10% or lessIncreased stream reachFlexibility in use, not a fixed systemLimitations:Narrow sweet spot

Self-Educting Nozzle

Automatic Foam Proportioners Balanced pressure bladder systems Balanced pressure pump systems Electronic direct injection systems

Balanced Pressure Bladder Systems

Balanced Pressure Bladder SystemsModified Venturi/Pressure Differential ValveCheckValveFoamConcentratePressure Tankwith BladderMeteringValveConcentrate Fill LineWater DumpLineWaterPumpThree-way Valve

Balanced Pressure Bladder SystemsCapabilities:Requires water flow to operate proportioner Limitations:Operator does not know how much foam is in bladderMust shut down to refill Water flow up to 350 gpm and discharge pressure restrictionsMedium Sweet Spot

5 Gallon Portable

Differential Valve

Panel Mount

Balanced Pressure Pump Systems

Balanced Pressure Pump ProportionersCheckValve

Balanced Pressure Pump ProportionersCapabilities:Foam concentrate flow to over 300 GPMPlumbed discharges capable of foam or waterAbility to vary foam concentrate % rates by dischargeLimitations:Water flow limitsDischarge pressure restrictionLow flow and low percentage operationMedium sweet spot

Metering ValveADJUSTING KNOBPOINTERPLUGSTEMCONCENTRATE FLOWTO DISCHARGE PROPORTIONER

Balanced Pressure Pump SystemMetering/Shut-Off Valve

Ratio ControllerLOW PRESSURE AREACONCENTRATE INLETBLENDING AREA

2 Modified Venturi Cut-AwayFoam capabilities of 60 to 200 GPMWater flow and pressure restrictions

Balanced Pressure Pump SystemParts Cut-AwayRatio Controller (venturi) creates a pressure drop allowing the foam concentrate to be pumped into the water wayMetering/Shut-off valve sets amount of foam concentrate entering the system by percentage selected

Duplex Pressure GaugeBalanced Pressure Pump SystemPanel Controls

Balanced Pressure Pump SystemPlumbingModified venturi or ratio flow controller (one required per discharge)Crowded pump compartment

Balanced Pressure Accuracy Test

Chart3

1.255.91.6250.5

2.57.83.252.5

3.7516.94.87512

NFPA Upper Limit

Desired Injection Rate

Actual Injection Rate

Recalibrated



NFPA Maximum

Recalibrated

Proportioning Rate - %

Concentrate Flow - GPM

Balanced Pressure Accuracy Test125 gpm @ 125 psi

Sheet1

Proportioning RateDesired Injection RateActual Injection RateRecalibratedNFPA MaximumNFPAAllowable RangeFlow (GPM)

1%1.255.90.520.30%1.30%125

2%2.57.82.530.60%2.60%

3%3.7516.91250.90%3.90%

Proportioning RateDesired Foam Flow RateActual Foam Flow RateNFPA Maximum

0.55.05.16.0

1.010.010.213.0

2.020.020.326.0

3.030.030.239.0

4.040.040.250.0

5.050.050.060.0

6.060.060.070.0

Sheet2

Sheet3

Balanced Pressure Pump System Capabilities

Balanced Pressure Pump ProportionersGPM Friction loss 0 0 psi 5010 psi 7512 psi 10015 psi 12520 psi 15025 psi 17535 psi 20040 psi 22555 psi 25070 psiPressure drop through venturi

Electronic Direct Injection

FoamPro Single Point DirectInjection ProportionerWaterTankWaterPumpMultipleDischargesDigital Display Control

Multi-Point, Electronic DirectInjection Proportioner

Electronic Direct InjectionCapabilitiesExtremely accurateNo flow or pressure restrictionIndifferent to changes in flows and pressuresEasy to operateRe-supply foam without interruptionDual foam capability with automatic presetsCommences operation immediatelyIdeal CAFS interfaceBroad sweet spot

OperationCommences operation with the push of the RED button

Or throw of a switch

How Accurate?

Chart3

55.16

1010.213

2020.326

3030.239

4040.250

505060

606070

NFPA Upper Limit



Desired Foam Flow Rate

Actual Foam Flow Rate

NFPA Maximum



FoamPro Model 3060 Accuracy1000 gpm @ 200 psi

Sheet1

Proportioning RateDesired Foam Flow RateActual Foam Flow RateNFPA Maximum

0.55.05.16.0

1.010.010.213.0

2.020.020.326.0

3.030.030.239.0

4.040.040.250.0

5.050.050.060.0

6.060.060.070.0

Sheet1

000

000

000

000

000

000

000

NFPA Upper Limit



Desired Foam Flow Rate

Actual Foam Flow Rate

NFPA Maximum



FoamPro Model 3060 Accuracy1000 gpm @ 200 psi

Sheet2

Sheet3

Flow ComparisonBalance Pressure & Electronic Direct InjectionNo restriction permits maximum flow

Sheet1

3x620

3x325

1x330

Hydrocarbon

3x660

3x375

1x330

Polar Solvent

3x6120

3x375

1x390

0.50.6250.754.38

11.251.6254.95

1.51.8752.4386.008

22.53.257.065

2.53.1254.0638.123

33.754.8759.18

0.511.522.53

0.6251.251.8752.53.1253.75

0.751.6252.4383.254.0634.875

4.384.956.0087.0658.1239.18

Flowmeter

Sheet1

0

0

0

3x6%

1x3%

3x3%

Cost Per Gallon

Sheet2

0

0

0

3x6%

3x3%

1x3%

Cost Per 100 Gallons Of Foam Solution - Hydrocarbon

Sheet3

0

0

0

3x3%

3x6%

1x3%

Cost Per 100 Gallons Of Foam Solution - Polar Solvents

PipeFlow Range

SizeBal. Press.Electronic Direct Injection

(Max Acc)(Max Rng)

2"60 - 20015 - 5205 - 625

2-1/2"80 - 32020 - 7508 - 900

3"150 - 62530 - 1,15012 - 1,380

4"300 - 1,25055 - 1,98020 - 2,380

3x6%

1

2

3

3

9

6

Proportioning Rate (%)

Gallons Per Minute

Balanced Pressure Accuracy125 gpm @ 125 psi

0

0

0

1

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

What To Consider-ProportionersRequired range of flows and pressuresProportioning percentage ratesFoam capable dischargesFoam viscosityAllowable pressure dropOperating conditionsHose length, elevations, etc.Accuracy requirements

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