Chp 10 Operating Fire Pumps Flashcards
Sources of water
Tank
Pressurized source
Non pressurized (drafting)
Skill engage pump
1-Stop, set brake, set chocks
2-Put in neutral or drive, depending on mfg
3-Hit PTO (lever, switch, push pull)
4-Put into recommended gear (most neutral), check light
5-Release brake if pump and roll
Skill disengage pump
1-Idle engine
2-Set brake
3-Put in recommended gear
4-Unhit PTO, check light is off
5-Normal operations
Skill engage midship pump
1-Stop
2-Shift to neutral
3-Set brake
4-Hit pump shift control
5-Shift to appropriate gear, check light
Skill pump from tank
1-Position, set brake and chocks
2-Throw lever
3-Open tank to pump
4-If multi stage select series or pressure
5-Throttle up
6-Watch gauge, prime if needed (if it was empty may need to open discharge valve to bleed off air) or may not be in gear
7-Circulate water if not flowing through attack line
8-Charge hose line
9-Set relief valve
10-Circulate to prevent overheating
11-Monitor tank level
Skill hydrant transition
1-Position, set brake, chock wheels
2-Engage pump
3-Open tank to pump
4-Set transfer valve to series if applicable
5-Open discharge and throttle up, prime if needed
6-Set relief valve
7-Open intake valve while throttling down, close tank to pump
8-Open tank fill
Skill pump from hydrant
1-Position, set brake, chock wheels
2-Connect to hydrant, bleed air
3-Note static pressure
4-Set transfer valve to series if applicable
5-Throttle up
6-Watch pressure if not advancing with throttle prime or open discharge to bleed air
7-If no attack lines, circulate water
8-Charge hose lines
9-Set pressure regulator
10-Monitor pump temp and take action if overheating
Skill drafting
1-Select site
2-Ensure apparatus will operate
3-Position to allow draft hose to reach
4-Assemble hose and strainers
5-Connect sections of intake hose (use mallet if needed)
6-Connect strainer
7-Tie guide rope to strainer
8-Connect to apparatus
9-Place hose into water slowly
10-Put pump in gear, prime
11-Pump
Skill supply standpipe
1-Position close to water supply, establish water supply
2-Attach water supply to FDC: remove cap, spin swivels, check FDC for gaskets obstructions and flappers, attach the right size hose
3-Note static pressure
4-Charge lines (100 psi for 1.5” FDC or 150 psi for 2.5”
5-Pump to correct pressure
6-Trouble shoot, check all outlets closed if low pressure, pump to 1st floor outlet if FDC is unusable
If hoselines aren’t flowing
Circulate water via tank fill or recirc line to manage overheating
Residual pressure
Maintain 20 psi residual always to avoid:
Cavitation
Contamination of sources outside the main
Knocking loose sediment
Hydrant selection
Closest may not be best
Must supply adequate volume
Not too close to fire
Forward lay
Hydrant to fire scene
If a long lay, may need to place pumper by the hydrant
Some use 4 way valve to allow charging by hydrant pressure then pumper connects without interruption to boost pressure using a second intake connection on the valve
4 Way hydrant valve
pg 343
Reverse lay
Fire to water
For drafting or when pressure boost at hydrant needed
Use double female at hydrant and double make at pump panel
Remember to drop tools at fire scene
Medium diameter hose
2.5” or 3” hose used for fire attack and relay supply
Requires reverse lay to bump hydrant pressure
From hydrant close tank to pump
New models have check valve to stop pressurized water from entering the tank but not old ones
Two stage pump settings
Series (pressure): high pressure, elevation, supplying high rise
Parallel (volume): relay, master stream or large volume needs
Overheating
For long operations bypass circulator may not be enough
Also if relay pumping far from fire, may not know if water is flowing
Open booster line tied off or discharge drain valve or tank fill
Make sure you still supply adequate flow
Like volumes
Percentage: (static-residual)x100/Static
First digit: of static, if <= multiplied number
Square the lines: Residual pressure - # of lines squared x diff of static and residual
Pressure differential
Artificially created partial vacuum
Drafting friction loss
Hose or appliance loss (proportionally to flow)
Inertial of water through the pump
Intake hose friction loss, strainer
Max pump vacuum reading
Around 22” mercury
Not exact measure so if you are getting close, you are maxing out
Cavitation
Pressure drops below atmospheric and boils
Bubbles move from highest vacuum to pressurized section and collapse violently
Can happen from out pumping pipes from on board tank, or drafting
Signs of cavitation
Pressure gauge fluctuates
Hose streams pulsate with popping or sputtering sound
Sound of gravel going through the pump (extreme case)
Best is lack or reaction to gauge when throttling up
Selecting drafting site
If fire attack, may have no choice
If shuttle select on: amount of water, type or quality of water, accessibility of water
Drafting amount of water available
Pool has 12,000 gallons can’t support master stream
Small stream may be ok if flowing quickly (create a dam or dig out the bottom)
Need 24” of water over the strainer (also good to have 24” in all directions)
Whirlpool may introduce air into the pump
Floating strainer takes in water from holes on the bottom
For tanks and pools use low level strainer (sit on the bottom, drain to 2”, low Q)
Below 35* or above 90* affects pump
Drafting type and quality of water
Nonpotable may hurt pumpn (must flush with fresh water)
Salty or mining operations may corrode
Sand is abrasive, causing slippage from dishcarge
Dirty water causes packing, make seal impossible
Drafting accessibility
NFPA and UL rate pump at 10’ lift
Pump can lift 25’ but no pressure to fight fire
20’ gives an effective stream (60% of pump rated capacity)
Better to extend horizontally to save on lift
Also ground stability, convenience of connecting hose lines, safety of engineer
Priming the pump
Two stage must be put in parallel (volume)
If positive displacement transfer case set rpm to mfg (1,000-1,200)
If Electric rpm doesn’t matter
If vacuum type primer keep rpm as low as possible
Intake gauge s/b 1’Hg per ft of lift (from surface of water to eye of impeller)
Don’t stop till all air is out and steady flow of water on the ground 10-15 seconds (30 for 20’ lift)
If not, check for air leaks (open discharge valves), gaskets, couplings
Or not enough fluid in reservoir, rpm to loo, lift too high, high point in hose
Throttle up to 50-100 psi before opening discharge
Running a booster helps keep prime if attack line is shut off
Pumping from draft
May get air leak on intake side (most common)
Whirlpool lets air into the pump
Air leak due to defective pump packaging (maybe bad seal on tank to pump valve)
Water in a steady stream indicates ineffective packaging (can’t be fixed)
Increasing vacuum with no change in flow is a blockage (reduce rpm to avoid cavitation and clear block-back flush)
Cavitation plus high vacuum reading is pump to high
Shutting down drafting
Disconnect, allow to drain then run primer till oil comes out
Flush with clean water
Supporting sprinklers
Most systems designed to only support a portion of sprinklers in the system
If no info avail, pump at 150 psi
Open closed control valves
Check fire pump is working
Supporting standpipes
Connections may be 2.5” or 1.5”
Don’t use installed hose, use yours
Can be wet or dry
Supplied by water, fire pump, or us
FL is usually low unless very high volume of water
If pressure reducing valves, use total height of standpipe for elevation
Can be done with aerial or hoisting hose up, securing 2-3 floors, or up stairs (last resort)
Troubleshooting
Notify command
trace problem back to its source, then troubleshoot
Pump overheating
Bypass valve good choice
Tank fill, but if you open all the way may cause cavitation; open a thumbs width
Or booster line into the tank
