September 2003 Slide 5-5-1

Driver/Operator 1B

Principles of Relay Pump Principles of Relay Pump OperationsOperations

September 2003 Slide 5-5-2

Driver/Operator 1B

Relay Pumping PrinciplesRelay Pumping Principles

RelayRelay2+ pumpers move water from distances 2+ pumpers move water from distances that would require excessive pressures that would require excessive pressures if only one pumper is employedif only one pumper is employed

Relay operationRelay operation2+ pumpers move water over a long 2+ pumpers move water over a long distance by operating them in seriesdistance by operating them in series

September 2003 Slide 5-5-3

Driver/Operator 1B

Relay Pumping PrinciplesRelay Pumping Principles

Water discharged from one pumper Water discharged from one pumper flows through hoses to the inlet of flows through hoses to the inlet of the next pumper, and so onthe next pumper, and so onPurposePurpose

To boost inadequate water pressure To boost inadequate water pressure over an extensive distance from source over an extensive distance from source to incidentto incident

September 2003 Slide 5-5-4

Driver/Operator 1B

Apparatus Relay PrinciplesApparatus Relay Principles

Source pumperSource pumperApparatus connected to the actual water Apparatus connected to the actual water sourcesource

Relay pumper (inRelay pumper (in--line pumper)line pumper)Pumper(s) connected within a relayPumper(s) connected within a relayReceives water from the source pumperReceives water from the source pumperBoosts the water pressure and supplies Boosts the water pressure and supplies water to the next inwater to the next in--line pumper or line pumper or attack pumperattack pumper

September 2003 Slide 5-5-5

Driver/Operator 1B

Apparatus Relay PrinciplesApparatus Relay Principles

Attack pumperAttack pumperPumper located at the incident scenePumper located at the incident sceneReceives water from the inReceives water from the in--line pumpersline pumpersSupplies water to the appliances Supplies water to the appliances necessary for suppressionnecessary for suppression

Determining maximum relay capacity Determining maximum relay capacity Limited to the capacity of the smallest Limited to the capacity of the smallest pumppumpLimited to smallest hoseline used within Limited to smallest hoseline used within the relaythe relay

September 2003 Slide 5-5-6

Driver/Operator 1B

Relay Pumping OperationsRelay Pumping Operations

Maximum distance relayMaximum distance relayInvolves flowing predetermined volume of Involves flowing predetermined volume of water for the maximum distancewater for the maximum distance

September 2003 Slide 5-5-7

Driver/Operator 1B

ChartChart

Used to determine maximum pumping Used to determine maximum pumping distance through a particular hose lay distance through a particular hose lay Based upon Based upon

20 psi residual pressure available at next, 20 psi residual pressure available at next, inin--line pumperline pumperDischarge pressure of 200 psi for 2Discharge pressure of 200 psi for 2½½" and " and 3" hose3" hoseDischarge pressure of 185 psi for 4" and Discharge pressure of 185 psi for 4" and 5" hose5" hose

September 2003 Slide 5-5-8

Driver/Operator 1B

Relay Pumping OperationsRelay Pumping Operations

Minimum pump capacities based on Minimum pump capacities based on maximum distance relay charting maximum distance relay charting Flows needed: Pump capacity Flows needed: Pump capacity requiredrequired

250/500 gpm flows:250/500 gpm flows: 750 gpm rated750 gpm rated750 gpm flow:750 gpm flow: 1,250 gpm rated1,250 gpm rated1,000 gpm flow:1,000 gpm flow: 1,500 gpm rated1,500 gpm rated1,250 gpm flow:1,250 gpm flow: 1,750 gpm rated1,750 gpm rated

September 2003 Slide 5-5-9

Driver/Operator 1B

Equation UEquation U

Relay distanceRelay distance + 1 = Total pumpers+ 1 = Total pumpersMDRMDR

ExampleExample2,0002,0001,600=1.25+1=2.25 or 3 pumpers1,600=1.25+1=2.25 or 3 pumpersRound up to nearest whole numberRound up to nearest whole number

September 2003 Slide 5-5-10

Driver/Operator 1B

Constant Pressure RelayConstant Pressure Relay

Establishes maximum flow Establishes maximum flow available from a particular relay available from a particular relay setupsetup

By using a constant pressure in the By using a constant pressure in the systemsystem

September 2003 Slide 5-5-11

Driver/Operator 1B

Constant Pressure RelayConstant Pressure Relay

AdvantagesAdvantagesSpeeds relay activationSpeeds relay activationRequires no complicated calculationsRequires no complicated calculationsReduces radio trafficReduces radio trafficCan govern hoselines with greater easeCan govern hoselines with greater easeCan guide and adjust pressure to one Can guide and adjust pressure to one constant figureconstant figure

September 2003 Slide 5-5-12

Driver/Operator 1B

Constant Pressure Relay Constant Pressure Relay FormationFormation

Attack pumper at the fireAttack pumper at the fireLargest capacity pumper at the Largest capacity pumper at the sourcesourcePump 175 psi from the water Pump 175 psi from the water sourcesource

September 2003 Slide 5-5-13

Driver/Operator 1B

Constant Pressure Relay Constant Pressure Relay FormationFormation

Relay pumper pumps 175 psi to Relay pumper pumps 175 psi to next pumper in linenext pumper in lineEach successive driver/operator Each successive driver/operator follows the same procedurefollows the same procedureAttack pumper driver/operator Attack pumper driver/operator adjusts the discharge pressure(s) adjusts the discharge pressure(s) to supply the attack line(s)to supply the attack line(s)

September 2003 Slide 5-5-14

Driver/Operator 1B

Constant Pressure Relay Constant Pressure Relay FormationFormation

Maintain the flow from the attack Maintain the flow from the attack pumper during temporary pumper during temporary shutdownsshutdownsFor a ruptured hoseline, open a For a ruptured hoseline, open a discharge gate on the relay pumper discharge gate on the relay pumper before the rupture to dump water before the rupture to dump water until line is replaceduntil line is replaced

September 2003 Slide 5-5-15

Driver/Operator 1B

Constant Pressure Relay Constant Pressure Relay FormationFormation

PDP at 175 psi untilPDP at 175 psi untilIntake pressure drops below 20 psiIntake pressure drops below 20 psi

Constant pressure of 175 psi may Constant pressure of 175 psi may be modifiedbe modified

Increase for greater spacingIncrease for greater spacingDecrease for lesser spacingDecrease for lesser spacingSevere elevation differencesSevere elevation differencesIncrease fire flow Increase fire flow Large diameter hoseLarge diameter hose

September 2003 Slide 5-5-16

Driver/Operator 1B

Relay Pressure AdjustmentRelay Pressure Adjustment

Increase Increase Adjust source pumper until desired Adjust source pumper until desired pressure is reachedpressure is reachedAdjust successive pumper similarlyAdjust successive pumper similarly

Decrease relay pressureDecrease relay pressureAttack pumper throttles downAttack pumper throttles downOpen dump lineOpen dump lineRelay pumpers toward the water source, Relay pumpers toward the water source, in decreasing succession in decreasing succession

September 2003 Slide 5-5-17

Driver/Operator 1B

Operational ConsiderationsOperational Considerations

Basis for relay operationBasis for relay operationAmount of water required at sceneAmount of water required at sceneDistance from scene to water sourceDistance from scene to water source

Methods to increase flowMethods to increase flowSize of hoselinesSize of hoselinesNumber of hoselinesNumber of hoselinesPDP of the pumpersPDP of the pumpersNumber of pumpersNumber of pumpers

September 2003 Slide 5-5-18

Driver/Operator 1B

General RulesGeneral Rules

Operation always begins with the Operation always begins with the source pumpersource pumperLargest diameter hose should be Largest diameter hose should be used at the beginning of the relayused at the beginning of the relay

September 2003 Slide 5-5-19

Driver/Operator 1B

General RulesGeneral Rules

Once water has been established, Once water has been established, source pumper opens uncapped source pumper opens uncapped discharge or allows water to waste discharge or allows water to waste through dump line until first relay through dump line until first relay pumper is ready for waterpumper is ready for waterRelay pressure not to exceed maximum Relay pressure not to exceed maximum operating pressure rating for the hoseoperating pressure rating for the hoseElevation pressuresElevation pressures

September 2003 Slide 5-5-20

Driver/Operator 1B

Placing a Relay Into Placing a Relay Into OperationOperation

Largest capacity pumper at the sourceLargest capacity pumper at the sourceSource and relay pumper ready for Source and relay pumper ready for waterwaterDischarge supply hoseline on source Discharge supply hoseline on source pumper is openedpumper is opened

Valve on dump line is closed in conjunctionValve on dump line is closed in conjunction

Maintain intake pressure of 20 psiMaintain intake pressure of 20 psi

September 2003 Slide 5-5-21

Driver/Operator 1B

Placing a Relay Into Placing a Relay Into OperationOperation

Receiving water at the attack Receiving water at the attack pumperpumper

Bleed out air from the supply lineBleed out air from the supply lineOpen bleed valve on intake being usedOpen bleed valve on intake being usedOpen dischargeOpen dischargeClose dump lineClose dump line

Once water is flowingOnce water is flowingSet automatic pressure controlSet automatic pressure control

September 2003 Slide 5-5-22

Driver/Operator 1B

Placing a Relay Into Placing a Relay Into OperationOperation

Relay operation shutdownRelay operation shutdownShutdown from the fire scene firstShutdown from the fire scene firstDriver/operators should shut down in Driver/operators should shut down in successionsuccessionSlowly decrease the throttleSlowly decrease the throttleOpen the dump lineOpen the dump lineTake pump out of gearTake pump out of gear