types of fire pumps - la county firefighters pumps.pdf · types of fire pumps positive displacement...
Post on 15-Sep-2019
23 Views
Preview:
TRANSCRIPT
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
top related