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What NFPA standard covers the Standard for Automotive Fire Apparatus
NFPA 1901 Pumper Min. Capacity
750 GPM and increments of 250 thereafter
Fire Pumper includes (Basic)
- Fire pump
- Fire hose for Intake, Supply, Attack
Min tank capacity of Water Tender
Water Tender Single Axle
limit to 1500 gallons
Two methods of Water Tender use
- 1. Nurse Tender
- 2. Water Shuttle
Tender with a pump is called
Tactical Tender or Attack Tender
Pump and Roll
- PTO powers the pump
- Do not ride outside the vehicle while moving
Quints and min pump capacity
- Apparatus with Aerial, Ladders, Pump, Tank and fire hose.
- Aerial Min pump 250 GPM
- True Quint 750 GPM
Steering While Play
10 degrees from normal max
NFPA 1901 brake test
stop from 20 mph within 35 ft
Parking Brake Grade must hold
Air Brake pressure build time
from 5mph in 20 feet: for both brakes and air brake switch
Percent of FF injury caused by collision-responding or returning.
20-25% (up to 25 deaths per year)
Most frequent area of vehicle collision
Conditions under which most accidents occur
Daylight, dry roads
Exemptions for FD vehicles driving code
- Direction of travel and turns
No FD vehicle exemption for:
School buses with flashing lights
Charges possible for negligent FD driver
- Civil and Criminal
- Both driver and department
- If long periods required, use high idle
Hot engine shutdown
Allow to cool 3-5 minutes
First Element of safe driving
A safety conscious attitude
NFPA 1500 (Safety) seat belt requirements
All people seated and belted before moving.
Seat Belt expectations per NFPA
- 1. Patient Care
- 2. Loading Hose (5mph max)
- 3. Driver training for tiller ops
Backing the vehicle
- Use one or preferably two spotters.
- Do not back if you can't see spotters.
Intersections and red light/stop signs
- Stop if necessary (obstruction)
- Stop and proceed if red.
Taking oncoming traffic
Avoid if they can't see you
3-15x more distance
Siren and Horn use
Quick burst on horn and constant siren
Speed to outrun the siren
Above 50 MPH
Headlights and emergency response
- Headlights on while responding
- Off when they may blind oncoming
Multiple Unit response travel distance
300-500 feet apart
Attack pumper positioning
- If narrow, drop your own supply
- If rescue, ladders accessible
- On pavement
- Out of collapse zone (1.5x)
- On corner of building
- Away from power lines
- Out of growth area
- Below three stories can be on inside of ladder.
Positioning for Drafting
- On hard surface
- Attach hard suction just before draft placement
- Attach rope to control strainer
- Move into drafting place
Positioning for hydrants
- Offset (short or long of hydrant)
- At 45degree to prevent kinks
- Intake to Intake using one hydrant.
- Residual water will be used by second pumper.
- Short Relay (Discharge to Intake)
- Second engine increases pressure of hydrant (high rise or long lays)
- Up to 300 ft apart
- As in "Pump the supply"
- Level I (small response, one block out)
- Level II (IC calls for staging, 1st arriving officer at staging area is manager) Units must be within 3 min out
- Don't use sirens except to move people
- Use lights while responding then minimal
- Use advance waring (cones and flares)
- Protect the scene and pump panel
- Second unit 150-200ft
- Don't go direct to scene
- ID the material first
- Don't stop over manholes
Characteristics of water:
- 1. Weight: 62.5/lb per cubic foot or 8.33lb/gallon
- 2. Freeze at 32, boil at 212
- 3. Not compressible
The amount of heat required to raise 1 lb of water 1 degree F. (starting at 60 degrees)
Specific Heat-heat absorbing capacity
Ratio of heat it takes to raise the temp of identical quantities of water and another substance. Water=1.
Latent Heat of Vaporization
Quantity of heat absorbed by a substance when it changes from liquid to vapor.
The temp this starts is the Boiling Point (212 for water)
972 Btu required to convert each lb of water to steam (starting at 212)
Btu absorption from 1 gallon water converting to steam
972*8.33 for conversion, plus amount to raise to 212. Starting at 60 degrees=9346 total
Surface area and heat absorption
More surface area exposure=faster absorption
Expansion of Water
at 212 degrees water expands 1700 times its volume
Observable results of water application
- Fire extinguished or reduced
- Temperature decresed
- Visibility changed
- Density of liquid as compared to water
- <1 floats on water (most flam liquids)
- >1 sinks on water
Danger of floating flam liquids is they may float away on the runoff.
Force per unit of area.
The same weight (or force) may exert a different pressure depending on the area over which it is applied.
Pressure of 1 square inch of water 1 foot high
- 62.5 lbs/cubic foot
Height in feet that exerts 1 psi
2.304 feet (1/.434)
Speed at which a fluid travels
Atmospheric pressure at sea level
Gauge and Absolute pressure
- Gauge pressure measures pressure above normal (atmospheric)
- Absolute would include atmospheric as if in a absolute vacuum
- A pressure less than 0 gauge is a vacuum.
Any pressure less than atmospheric pressure
The height of water above the discharge orifice
The height above discharge x .434 or /2.304
therefore about .5 x the height
- Stored potential energy without any flow
- the pressure in a water system before water flows.
Normal operating pressure
Pressure with flow (static pressure reduced by friction from flow)
Left over pressure in the system not being used for flow.
Flow Pressure (Velocity Pressure)
- The forward velocity pressure at a discharge opening while water is flowing.
- Measured with pitot tube and gauge to measure the pressure.
- Used together with the size of opening to calc qty in GPM.
Pressure loss or gain do to elevation of nozzle above or below the pump.
Altitude effects on pressure
.5 psi per 1000 ft above sea level
The total pressure lost due to forcing water through pipes, fittings, hoses, etc.
4 Principles of friction loss
- 1. Varies directly with length
- 2. Varies with the square of velocity-GPM (x2)
- 3. Varies inversely with diameter to 1/x54. Pressure does not increase FL for a given flow velocity (GPM)
Summary: Less water less FL. Bigger hose much less FL. Pressure doesn't change FL. Double the length, double the FL
The GPM flowing in a hose, beyond which FL makes it impossible to increase flow by increasing pressure.
Water system delivery pipes
- 1. Primary Feeders (mains 6" or 8")
- 2. Secondary feeders (loops)
- 3. Distributers (serves hydrants and consumers)
Control Valves for water systems
- Indicating or Non
- Gate or Butterfly
- A partially opened valve causes FL that may not be noticed until Fire Flow is needed.
- Water or foam as is leaves the nozzle and reaches a desired point
- Influenced by velocity, gravity, wind, friction with air.
Three type of fire streams (and nozzles for each)
Solid vrs Straight Stream
- Solid stream requires solid bore nozzle
- Straight is best can be delivered from fog nozzle.
Solid bore nozzle description and nozzle pressures
- Tapered and then cylindrical to create the solid chunk of water.
- Length of bore=1-1.5 times the diameter
- Pump at 50 for handlines and 80 master streams.
GPM for solid bore
- D=diameter in inches of the opening
- NP=Nozzle pressure in psi (50=7, 80=9)
Constant Flow Nozzle
- Designed to flow same amount of water at specified nozzle pressure regardless of pattern.
- NP usually = 100psi (LP may be 50 or 75)
Manually adjustable nozzles
Can adjust the GPM as well as pattern.
- Adjust for changing volumes and maintain nozzle pressure and pattern regardless of actual flow.
- *Driver make sure to pump enough water to put out the fire.
- Within limits the nozzle maintains 100 psi at tip (like a pressure regulator)
Handline nozzle max GPM
Master Stream (def)
- Nozzle with too great a flow to be controlled without mechanical aid. (Above 350 GPM)
- Has a fixed placement, but movement is allowed through one or more sharp bends (in line or in piping)
- Most often used in defensive attacks.
Four basic Master Stream Types
- Monitor (able to changed direction and angle)
- Turret (supplied by permanent piping, not portable)
- Deluge (large nozzle, can't be moved)
- Elevated aka ladder pipe (on the end of an aerial)
Other nozzle types
- Water curtain
Max workable Velocity and PSI for handline NR
60-120 ft/sec or 25-100 PSI
Solid Stream NR formula
Can also be NR=GMP/3
Fog Stream NR formula
or GPM times 10 divied by 20
or 1/2 GPM
Friction Loss Equations
- L=Feetofhose/100 (per 100)
- 1 3/4 =15.5
- 2 1/2= 2
- 3 =.8
- 4 = .2
- 5 = .08
- Call it 0 below 350 GPM
- Appliance in a hose assembly 10 psi FL
- Master Stream appliance 25 psi regardless of flow.
Elevation Pressure (EP)
.5H or 5 psi per story (minus 1)
(1ft of water makes .434 psi pressure)
Total Pressure Loss (TPL) def
FL + EP = TPL
PDP (pump discharge pressure)
Nozzle Pressure plus Total Pressure Loss
Net Pump Pressure
PDP minus Hydrant Pressure (intake reading)
NFPA 1901 and flowmeters
- Allowed on 1 1/2 to 3 inch discharges
- Must also have pressure gauge if over 3"
+/- 3% (3 gallons/100)
Water flow problem diagnosis
- Kinked hose: hose hard no flow at nozzle or meter
- Burst Section: hose soft no/diminished flow to nozzle, flowmeter doesn't reduce
Relay Pumping with a flowmeter
Increase discharge to attack pumper until flowmeter stops increasing. This is their NFF.
- Field hydraulics formula
- 5"=/15 (20 in Kent)
Single Action Piston Pump
- First half stroke is intake
- Second half is discharge
Dual Action piston pump
Allows flow on both strokes
- Not a positive displacement pump
- Imparts velocity to the water and converts it to pressure.
Centrifugal Pump Key Parts
- Impeller- spins and imparts velocity to outward flowing water.
- Casing- collects and confines water creating pressure and directs it out outlet.
- Volute the area of increasing volume in which the water moves toward the outlet
Two Stage Pump ops
In volume for max water (over 1000 GPM) but creates more work for the pump. When in doubt run in volume.
In pressure for long high pressure lays with low volume or for short low volume fires, like small car fire nearby. Requires less engine RPM.
- Transfer valve used
- Changing from Volume to Pressure doubles the discharge pressure
- Gen rule: max of 50 psi net before changeover
- If in doubt run in volume mode (parallel)
PTO pumps and pump and roll ops
- PTO spins in proportion to engine speed.
- When pump and roll ops drive in the lowest gear at the (safest) speed that develops the proper pressure for the handline to operate.
- A pressure gauge is visible on the dash.
- Most common
- Power provided through split shaft (drive shaft "split" to allow insertion of pump transfer case between transmission and rear axle)
Pump Discharges (min) NFPA 1901
- Enough 2.5 and larger discharges to flow rated capacity of pump.
- Pumps over 750 GPM must have at lease two 2.5.
- Larger can not be on pump panel
- Smaller must still have 2" piping
Discharge rates by outlet size
- 2.5=250 GPM
- 3.5=500 GPM
- 5= 1000 GPM
Min tank fill line size
1" for tanks less than 1000 Gal
Two stage pump and "tank fill" cooling
Fill line can cause second stage impeller heating because it comes off the first stage to reduce pressure to tank. Use cooler instead.
- Ball- most common, full flow, min loss. T handle or quarter turn to operate.
- Gate- on large diameter, operate with handwheel
- Butterfly- Quarter turn handle
- 3" or more requires slow acting valve control
Pressure Control Devices standard
NFPA 1901 requires them to operate within 3-10 seconds after pressure rises and not allow more than 30 psi above level set.
Pressure sensor governor
A small line sends pressure reading and the controller reduces engine RPM (throttle)
Hydrant Color Codes (high to low)
- Light Blue 1500 or greater
- Green 1000-1499
- Orange 500-999
- Red <500
Dry Barrel Hydrant
- Frost Proof
- Must be opened all the way to close drain valve, then back 1/4 turn.
- Use Gate for second supply
- 2 1/2 port should be no longer than 300 ft lay
- Supplement Hydrant pressure
- Drafting ops
- 10 % drop = 3x current amount (3 more like lines)
- 15 % = 2 more
- 25 % = 1 more
- > 25% less than one more
Max Vacuum for most pumps
- 22 inches of mercury
- If increase throttle does not increase pressure you are near cavitation.
Master and Compound Gauges
Read from 0-600 psi for both and compound has 0-30 inches of Mercury
Drafting Strainer clearance
2 feet above and 2 feet around
Two Stage Pump position in a draft
In Volume, possible air entrapment otherwise
Drafting and lift
- tested at 10 ft with 20ft hard suction
- 14.7 ft should be min
- 25 ft max
- 15 ft at 70% capacity
- 20 ft at 60% capacity
- Set intake relief 10 psi tolerance above static pressure or incoming relay pressure
- Attack set intake to 50-75 PSI to keep shutdown of attack lines from building excess pressure.
- As long as between 10-100 psi don't adjust pressures.
- Shut down attack engine first
Max Distance Relay
- 4" at 1000 GPM is 825' at 185 psi
- 5" at 1250 GPM is 1320' at 185
Formula: Distance/max distance for line +1 and round up!
Constant Pressure Relay
- Attack pumper at fire finds NFF
- Largest capacity pumper at water source
- Lay supply for NFF
- Open a discharge for air to escape
- Pump at 175
NFPA Tender Requirements
- Tank to pump must supply 500 GPM
- Tank capacity must be at least 1000 Gallons
- Tank fill at least 2" capable of 1000 GPM fill
- Tank Dischare of at least 1000 GPM
Class A proportioning
Class B proportioning
- 1-3% for hyrdrocarbon
- 3-6% for polar solvents (most modern gasoline)
Yearly Pump Test
- 5 and 20 min at 150 PSI (in Volume)
- 10 min at 200 PSI
- 10 min at 250 PSI (in Series)
- 22 inches mercury
- can not drop more than 10 inches in 5 min
Flowmeters and gauges
Not off by more than 10% or 10 PSI
Post Manufacture Road Test
- Accelerate to 35 MPH in 25 seconds
- Top speed of 50 MPH
- Full stop from 20 MPH in 35 feet
Hydrostatically tested at 250 PSI for 3 min