Po Review1 Flashcards
Smooth bore tip sizes
1"-210 gpm 1 1/8-264 gpm 1 1/4-325 gpm 7/8-150 gpm At 50 psi at the tip
Master stream tip sizes
1 3/8-500 gpm
1 1/2-600 gpm
1 3/4-800 gpm
2” -1,000 gpm
At 80 psi at the tip for masterstreams
1 1/2 line per 100’ friction loss
60 gpm -9psi per 100’
95 gpm -22psi per 100’
125 gpm -36psi per 100’
2 1/2 line friction loss per 100’
Drop the last digit from the gpm and subtract 10
Less the 350 gpm
250= 15 per 100’
For flows over 350 gpm drop the last digit OLNY!!!
450=35 per 100’
5”” friction loss
Fl=CQ2
1,000gpm
1,000 divided by 100 =10
10x10=100
.08x100=8psi friction loss per 100’
Gpm less then 1,000 use half Q
Gpm greater the 1,000 use Q
Friction loss coefficients
1 1/2”=24
2 1/2”=2
5”=.08
FL=CQ2
Nozzle pressures
Combination=100psi Smoothbore =50psi MasterStream=80psi Low pressure=75psi Foam pro=100psi Sprinkler nozzle= Piercing nozzle=100psi
Friction loss
Friction loss is
CQ2xL
Coefficient x Q squared x length
Coefficient Q= gpm divided by 100
24-1 1/2”. X 100’ ft sections
2-2 1/2”
.08-5”
Stand pipes
Starting pressure 150psi
*imperial 100psi
Add 25psi for stand pipe piping
Relay pumping
Start sending water at 60 psi
Keep 20psi residual pressure at all times unless notify the ic
Operations must be shut down from the fire to the hydrant.
Pressure to volume
Pressure =series
Green lightVolume= parallel yellow light
Pressure- 1/2 pump capacity 750gpm or high pressure above 200 psi(top floors of a high raise)
Volume-above 1/2 pump capacity 750+ gpm or low psi below 750 gpm (relay or BIG WATER)
Engine speed must be at idle or below 50 psi
Tank to pump piping size?
3”
Tank to fill piping size?
1”
Pump ratings for testing?
1,500 gpm at 100% 150 psi
1,050 gpm at 70% 200 psi
750 gpm at 50% 250 psi
Drafting
Atmospheric pressure is 14.7 psi 1 psi will lift water 2.31 ft The more vacuum the more lift 4.7psi will lift water 10' 10' is max lift
Pump priming
500-1,250 gpm pumps less the 30 seconds
1,250 to 2,500 gpm pumps take 45 seconds
Add up to 15 seconds for front or rear hook ups
Make sure atmospheric cap and antisyphon hole is free from debris. .04 cm use a paper clip
Impeller speed is —– faster then drive shaft speed?
2x faster
Per NFPA 1901
Relief valve
When pump is at capacity and all lines are shut off the internal relief valve or pressure governor should not increase more then ——psi and must happen which in — to — seconds
30 psi per NFPA 1901
3 th 10 seconds
How does the internal relief valve work?
Recirculates pump gallons inside the pump to maintain the set pump pressure
Pressure govener works by?
Regulating the RPMs to main rain the set pump pressure
The RPMS must be over 200 above idle
Pressure relief valves must be —- psi above intake pressure in order to work
50 psi above intake pressure
External relief valve works by——-
Releases excess pressure to the ground or else it will increase discharge pressure.
Set at 125 psi
Or should be 10 psi higher then the highest hydrant pressure in the city
Why is a BTU
British thermal unit
Amount of heat it takes to raise 1 lb of water 1 degree Fahrenheit
Friction loss
Doubling the flow of water will increase friction loss—– times
4 times
100 gpm= 4 lbs fl
200 gpm= 16 lbs fl
ICS method for fire flow is——
Length x with divided by 3
Then times by the number of floors involved
Variable flow nozzles mean—–
Change in gpm when stream pattern changes (straight to fog stream)