Driver/Operator 1BSeptember 2003 Slide 2-1-1

Types of Fire Pumps Types of Fire Pumps

Driver/Operator 1BSeptember 2003 Slide 2-1-2

Types of Fire PumpsTypes of Fire Pumps

Positive displacement Positive displacement Centrifugal Centrifugal

Driver/Operator 1BSeptember 2003 Slide 2-1-3

Positive Displacement Positive Displacement PumpPump

Driver/Operator 1BSeptember 2003 Slide 2-1-4

Centrifugal PumpsCentrifugal Pumps

Driver/Operator 1BSeptember 2003 Slide 2-1-5

Positive Displacement Positive Displacement Pumps Pumps

Can pump air Can pump air Has a small amount of slippageHas a small amount of slippage

Ability of water to pass through the inner Ability of water to pass through the inner workings of the pump, not allowing workings of the pump, not allowing 100% discharge 100% discharge

Has a fixed displacement of water Has a fixed displacement of water

Driver/Operator 1BSeptember 2003 Slide 2-1-6

Piston Pump

Rotary Gear

Rotary Vane

Driver/Operator 1BSeptember 2003 Slide 2-1-7

Types of Piston Pumps Types of Piston Pumps

Single action Single action Pumps in a forward stroke onlyPumps in a forward stroke only

Double action Double action Pumps in both forward and reverse strokes Pumps in both forward and reverse strokes

Examples Examples Backpack pump Backpack pump Foam injection pump Foam injection pump Wells Wells Bicycle pump Bicycle pump

Piston PumpsPiston Pumps

Discharge

Intake

Floating Valves

Piston

Cylinder

Driver/Operator 1BSeptember 2003 Slide 2-1-9

Types of Rotary PumpsTypes of Rotary Pumps

Commonly used in the fire service Commonly used in the fire service as a primer pump as a primer pump Rotary gear Rotary gear

Two gears that rotate in a tightly Two gears that rotate in a tightly meshed pattern forming pockets meshed pattern forming pockets As each gear tooth reaches the As each gear tooth reaches the discharge chamber, the air or water discharge chamber, the air or water contained in that pocket is forced out of contained in that pocket is forced out of the pump the pump

Intake

Discharge

Driver/Operator 1BSeptember 2003 Slide 2-1-11

Types of Rotary PumpsTypes of Rotary Pumps

Rotary vane Rotary vane Movable vanes that automatically Movable vanes that automatically compensate for wear and maintain a compensate for wear and maintain a tighter fit tighter fit Vanes are forced against the outer Vanes are forced against the outer housing by centrifugal force housing by centrifugal force

Vanes

Discharge

Rotor

Driveshaft

Intake

Driver/Operator 1BSeptember 2003 Slide 2-1-13

Centrifugal Pumps Centrifugal Pumps Can not pump air Can not pump air Capable of 100% slippage Capable of 100% slippage The main fire pump used on modern fire The main fire pump used on modern fire apparatus apparatus Classified as a nonpositive Classified as a nonpositive displacement pump displacement pump Imparts velocity on water and converts it Imparts velocity on water and converts it to pressureto pressureSingle or multiple stage Single or multiple stage

Driver/Operator 1BSeptember 2003 Slide 2-1-14

Casing

Intake

Impeller

Volute CavityEye

Discharge Hub

Shroud

Vanes

Shaft

Impeller

Hub

Vanes

Shroud

Centrifugal PumpsCentrifugal Pumps

Driver/Operator 1BSeptember 2003 Slide 2-1-17

Pump Wear Rings Pump Wear Rings Between the pump Between the pump casing and the hub casing and the hub Seal is between the Seal is between the lower pressure of lower pressure of the intake side and the intake side and the higher pressure the higher pressure in the volute in the volute Dirt/sediment can Dirt/sediment can damage ring damage ring resulting in resulting in decreased pump decreased pump effectivenesseffectiveness

Driver/Operator 1BSeptember 2003 Slide 2-1-18

Pump Packing Pump Packing

Located around the pump shaft, Located around the pump shaft, within the stuffing box within the stuffing box Lubricates and seals pump shaft Lubricates and seals pump shaft Too loose Too loose

Can result in drafting difficulties and Can result in drafting difficulties and pump efficiency pump efficiency

Too tight Too tight Can result in damaging the pump shaft Can result in damaging the pump shaft due to overheating due to overheating

Driver/Operator 1BSeptember 2003 Slide 2-1-19

Principles Of Operation Principles Of Operation

Centrifugal force Centrifugal force Based on the principle that a Based on the principle that a rapidly revolving impeller hurls the rapidly revolving impeller hurls the water from the impeller eye water from the impeller eye outward outward The faster the impeller is turned, The faster the impeller is turned, the farther the water is thrownthe farther the water is thrown

Increasing the velocity Increasing the velocity

Driver/Operator 1BSeptember 2003 Slide 2-1-20

Principles Of OperationPrinciples Of Operation

Driver/Operator 1BSeptember 2003 Slide 2-1-21

Influencing FactorsInfluencing Factors

Amount of water being discharged Amount of water being discharged Speed at which the impeller is Speed at which the impeller is turning turning

Doubling the speed results in four times Doubling the speed results in four times the pressure the pressure

Pressure of water when it enters Pressure of water when it enters the pump from a pressurized the pump from a pressurized source source

Pressure (Series) SettingPressure (Series) Setting

Driver/Operator 1BSeptember 2003 Slide 2-1-23

Intake

Clapper Valve

Transfer Valve2nd Stage1st Stage

500 GPM @150psi + 150psi

500 GPM @ 300 psi

Pressure (Series) SettingPressure (Series) Setting

Parallel (Volume) SettingParallel (Volume) Setting

Driver/Operator 1BSeptember 2003 Slide 2-1-25

Intake

Transfer Valve

Clapper Valve

1st Stage 2nd Stage

500 GPM @150psi 500 GPM @150psi

1000 GPM @ 150 psi

Volume (Parallel) SettingVolume (Parallel) Setting