Proportioning Systems. 69 Proportioning Systems Now you know the benefits and uses of water...

Proportioning SystemsProportioning Systems

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Proportioning SystemsProportioning Systems

• Now 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

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A bigger sweet spot

Why Clubs And Racquets With Why Clubs And Racquets With Larger Heads?Larger Heads?

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The Proportioning Sweet SpotThe Proportioning Sweet Spot

• The range in which the proportioner can deliver acceptable performance– Flow range– Pressure range– Proportioning rates– Foam viscosity– Desired accuracy

• Every proportioner has a sweet spot– Size varies by type of system

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NFPA Accuracy RequirementsNFPA Accuracy Requirements

6%

30%30% 20%20% 10%10% 10%10% 20%20% 30%30%

3%

1%

- +40%40%

Lean Rich

RatioRatio Allowable RangeAllowable Range

6%6% 6.0 - 7.0%6.0 - 7.0%

3%3% 3.0 - 3.9%3.0 - 3.9%

1%1% 1.0 - 1.3%1.0 - 1.3%

0.5% 0.5 - 0.7%0.5% 0.5 - 0.7%

0.2% 0.2 - 0.28%0.2% 0.2 - 0.28%

• For proportioning rates equal or greater than 1%:– - 0% to + 30% or 1 percentage point, whichever is less

• For proportioning rates less than 1%:– - 0% to + 40%

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• Manual systems

• Automatic systems

Foam Proportioner DesignFoam Proportioner Design

Manual Foam ProportionersManual Foam Proportioners

• Eductors• Around the pump systems• Self-educting nozzles

Eductor SystemsEductor Systems

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In-Line EductorsIn-Line Eductors

Check Valve

Metering Valve

WaterPump Foam

Concentrate

Eductor200 psiInlet

130 psiOutlet

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By-Pass EductorBy-Pass Eductor

Shut-Off Closed

WaterPump

200 psi 130 psi

FoamConcentrate

Check valve

Metering valve

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EductorsEductors

• Capabilities:– Operate over narrow range of flows and pressures

• Limitations:– 35% pressure loss– Sensitive to pressure changes downstream– Must match flow and nozzle– Nozzle height limited to ten feet – Narrow sweet spot (single flow and pressure point)

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125 gpm Eductor Cutaway125 gpm Eductor Cutaway

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125 gpm eductor

125 gpm nozzle

Must Match Flow, Eductor & NozzleMust Match Flow, Eductor & Nozzle

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200 psi Inlet130 psi Outlet

20" of Vacuum

Performance reduction of 35% creates required vacuum

Eductor - Correct Pressure & FlowEductor - Correct Pressure & Flow

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Longer hose lay, increased elevation or nozzle restriction reduces vacuum

Eductor - Incorrect Pressure & FlowEductor - Incorrect Pressure & Flow12" of Vacuum

140 psi Outlet 200 psi Inlet

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Increasing restriction even more on outlet side can eliminate vacuum

Eductor - Incorrect Pressure & FlowEductor - Incorrect Pressure & Flow

150 psi Outlet 200 psi Inlet

No Vacuum

Around The Pump SystemsAround The Pump Systems

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Eductor

Check Valve Metering Valve

FoamConcentrate

Shut off Valve

Shut off Valve

Max. 10 psi.Incoming Pressure

WaterPump

Foam solution from all discharges

Around The Pump ProportionerAround The Pump Proportioner

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• Capabilities:– Foam solution available to all discharges

• Limitations:– Maximum incoming pump pressure of 5 to 15 psi– Average operating foam proportioning error of 1 to

1-1/2 percentage points– Pump solely dedicated to foam operation– Narrow sweet spot

Around The Pump ProportionerAround The Pump Proportioner

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Around The Pump EductorAround The Pump Eductor

Eductor

To pump suction

From pump discharge

Foam concentrate

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Around The Pump Around The Pump

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Around The PumpAround The Pump

Class A foam control Class B foam control

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Around The PumpAround The Pump

“Incoming pressure less than 12 psi”

“When flow stops, immediately turn

metering valve off”

Self-Educting NozzlesSelf-Educting Nozzles

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Metering Valve

Monitor

WaterPump

Control ValveFoamTank


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• Capabilities:– Large flows at 1%, 3% or 6%– Lower pressure drop than regular eductors, 10% or

less– Increased stream reach– Flexibility in use, not a fixed system

• Limitations:– Narrow sweet spot

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Self-Educting NozzleSelf-Educting Nozzle

Foam percentage selection

Automatic Foam ProportionersAutomatic Foam Proportioners

• Balanced pressure bladder systems• Balanced pressure pump systems• Electronic direct injection systems

Balanced Pressure Bladder SystemsBalanced Pressure Bladder Systems

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Modified Venturi/Pressure Differential Valve

CheckValve

FoamConcentrate

Pressure Tankwith Bladder

MeteringValve

Concentrate Fill Line

Water DumpLine

WaterPump

Three-way Valve


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• Capabilities:– Requires water flow to operate proportioner

• Limitations:– Operator does not know how much foam is in bladder– Must shut down to refill – Water flow up to 350 gpm and discharge pressure

restrictions– Medium Sweet Spot


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5 Gallon Portable5 Gallon Portable

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Differential ValveDifferential Valve

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Panel MountPanel Mount

Balanced Pressure Pump SystemsBalanced Pressure Pump Systems

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CheckValve

FoamTank

ConcentratePump

Metering Valve

Check Valve

Modified Venturi or Ratio Controller(one per discharge)

WaterPump

Pilot-OperatedBalance Valve

oorr

Balanced Pressure Pump ProportionersBalanced Pressure Pump Proportioners

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• Capabilities:– Foam concentrate flow to over 300 GPM– Plumbed discharges capable of foam or water– Ability to vary foam concentrate % rates by discharge

• Limitations:– Water flow limits– Discharge pressure restriction– Low flow and low percentage operation– Medium sweet spot


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Metering ValveMetering Valve

ADJUSTINGKNOB

POINTERPLUG

STEM

CONCENTRATEFLOW

TODISCHARGE

PROPORTIONER

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Balanced Pressure Pump SystemBalanced Pressure Pump SystemMetering/Shut-Off ValveMetering/Shut-Off Valve

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LOW PRESSURE AREA

SOLUTIONRECOVERY AREA

CONCENTRATE INLET

FLOW

BLENDING AREA

WATER FLOW

Ratio ControllerRatio Controller

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2” Modified Venturi Cut-Away2” Modified Venturi Cut-Away

Foam capabilities of 60 to 200 GPM

Water flow and pressure restrictions

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Balanced Pressure Pump SystemBalanced Pressure Pump SystemParts Cut-AwayParts Cut-Away

Ratio Controller (venturi) creates a pressure drop allowing the foam concentrate to be pumped into the water way

Metering/Shut-off valve sets amount of foam concentrate entering the system by percentage selected

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Duplex Pressure Gauge

Balanced Pressure Pump SystemBalanced Pressure Pump SystemPanel ControlsPanel Controls

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Balanced Pressure Pump SystemBalanced Pressure Pump SystemPlumbingPlumbing

Modified venturi or ratio flow controller (one required per

discharge)

Crowded pump compartment

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Balanced Pressure Accuracy TestBalanced Pressure Accuracy Test

Balanced Pressure Accuracy Test125 gpm @ 125 psi

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2

4

6

8

10

12

14

16

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1% 2% 3%

Proportioning Rate - %

Concentrate Flow - GPM

NFPA Upper Limit

Desired Injection Rate

Actual Injection Rate

Recalibrated

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FOAM SYSTEM OPERATING PARAMETERS

FOAM CONCENTRATE TYPES(S): CLASS A OR CLASS BSYSTEM OPERATING PRESSURE RANGE: 75-200 PSI

DO NOT EXCEED 200 PSI OPERATING PRESSURESYSTEM PROPORTIONING AND FLOW RATES:

SOLUTION FLOW RATE (GPM)NOMINAL RATEPROPORTIONERSIZE

0.3 - 1% 3% 6%

2 60-200 60-200 60-200

2.5 80-320 80-320 80-250

4 300-1250

3 150-625 150-500

Balanced Pressure Pump System Balanced Pressure Pump System CapabilitiesCapabilities

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GPM Friction loss 0 0 psi 50 10 psi 75 12 psi 100 15 psi 125 20 psi 150 25 psi 175 35 psi 200 40 psi 225 55 psi 250 70 psi

Pressure drop through venturi

Electronic Direct InjectionElectronic Direct Injection

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WaterTank

WaterPump

MultipleDischarges

Line Strainer

FoamTank

Check Valves

FlowMeter

FoamPro Single Point DirectFoamPro Single Point DirectInjection ProportionerInjection Proportioner

Digital Display Control

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Multi-Point, Electronic DirectMulti-Point, Electronic DirectInjection ProportionerInjection Proportioner

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Electronic Direct InjectionElectronic Direct Injection

• Capabilities– Extremely accurate– No flow or pressure restriction– Indifferent to changes in flows and pressures– Easy to operate– Re-supply foam without interruption– Dual foam capability with automatic presets– Commences operation immediately– Ideal CAFS interface– Broad sweet spot

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• Commences operation with

the push of the RED button…

• Or throw of a switch

OperationOperation

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How Accurate?How Accurate?

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PipeSize Bal. Press.

(Max Acc) (Max Rng)

2" 60 - 200 15 - 520 5 - 625

2-1/2" 80 - 320 20 - 750 8 - 900

3" 150 - 625 30 - 1,150 12 - 1,380

4" 300 - 1,250 55 - 1,980 20 - 2,380

Flow RangeElectronic Direct Injection

No restriction permits maximum flow

Flow ComparisonFlow ComparisonBalance Pressure & Electronic Direct InjectionBalance Pressure & Electronic Direct Injection

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What To Consider-ProportionersWhat To Consider-Proportioners

• Required range of flows and pressures• Proportioning percentage rates• Foam capable discharges• Foam viscosity• Allowable pressure drop• Operating conditions

– Hose length, elevations, etc.

• Accuracy requirements

Proportioning Systems. 69 Proportioning Systems Now you know the benefits and uses of water...

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