AOTM Flashcards
atmospheric pressure
14.7 psi at sea level
What is the three phase maintenance program consist of
- Preventive maintenance
- Periodic maintenance
- Inspection tests
Preventive maintenance includes
- keeping equipment clean
- tightening leaky joints
- replacing hose gaskets as necessary
- Listening for unusual noises and watching for anything unusual in pump operation
- Performing the steps listed after pumping
When using the pump in cold weather, run it at least __ minutes to warm up gear case and drive out moisture that can damage internal parts
20 minutes
Double jacket hose allows higher working pressure
Cords running around the hose are called
woof
Cords of hose running lengthwise are called
warp
what material used for woof cords
dacron
What material used for warp cords
cotton
old lafd identification hose strip
2 black, 4 white, 2 red, 4 white and 2 black
hose working test pressure
600 psi
hose burst test pressure
900 psi
hose beds should be reloaded at least once each __ days to change the folds and prevent kinks which may damage the linear of the hose
30
dirty hose washed w/
cold, clear water only
no other agent used except with permission of the storeroom
damp hose shall not remain on apparatus longer than
24 hours
purpose of 4 way valve
change from direct hydrant pressure to pump pressure w/o shutting off the flow of water
static pressure
water w/o motion or standing still
what makes a good fire stream
reaches seat and pass 9/10 of its volume of water inside a 15” circle and
3/4 of it inside a 10” circle
fire stream greatest horizontal range when angle is
30 degree
Greatest vertical range when angle is
75 degree
momentary nozzle reaction when the nozzle is first opened is __ % greater than the reaction after the water is flowing
20%
when flow of water in a hose line suddenly stops
water hammer
When a pump is connected to a hydrant, it is desirable to maintain at least __ to __ pounds pressure on the intake (compound) gage
5 to 10 psi
what does a soft and flabby suction indicate
maximum flow for the hydrant has been reached
pump is beginning to run away from the water
what is the condition where vapor cavities are formed in the pump and can cause serious damage
cavitation
operation runs pump faster than suction hose can deliver water to pump when drafting results in
cavitation
Pump operator supplying a ladder pipe should pump __ to __ psi above the required operating pressure after filling the lines laid to the base of the ladder
25-40 psi
*insures against an excessive pressure drop when ladder pipe nozzle is first opened
what is the difference in elevation between the water level and the center of the pump when a pumper is drafting water
Lift
At sea level the atmospheric pressure is 14.7 psi. This pressure is capable of sustaining a column of water 33.9 feet in height. This is arrived by multiplying 14.7 pounds by 2.304, the height of water which will exert 1 pound pressure. If a pump could produce perfect vacuum, the max height it could lift water at sea level is __ ft
33.9 feet
Taking into consideration the inability to create a perfect vacuum, the effect of minute air leakage and the frictional resistance through the suction hose, the common practice is to use two-thirds of the theoretical distance, or 22-2/3 feet at sea level for the practical limit of draft
reference
Atmospheric pressure is reduced ___ pound for each 1000 feet of elevation above sea level.
one-half
When drafting suction strainer will be submerged at least __ feet below the sea level of the water
2’
When drafting water should be at least __ feet deep where the strainer is located to provide clearance below and sufficient depth above it
4’
Pumps are rated at cap acting using a __ inch suction and a lift of 10 feet
6”
rotary gear and rotary vane pumps are vacuum producing units. They are positive displacements pumps capable of displacing __ and __ at the same time
air and water
Centrifugal pumps are not capable of creating a vacuum due to the fact that __ can leak through the pump
air
*in order for centrifugal pumps to be used at draft, priming pumps must be utilized
During temporary shutdown of draft maintain __ psi discharge pressure to avoid losing prime
35 psi
considerations when setting up for a relay
- Topography
- Time necessary to set up
- Total amount (gpm) of water estimated to be necessary at the point of ultimate consumption
- Size and length of hose necessary to carry the amount of water needed
- Apparatus available to do the pumping
relay operation:
necessary to keep individual pumps in a line to a __ pound maximum
200
Priming vacuum max should be at least __ inches of mercury
20
Drafting; do not attempt lifts exceeding __ feet except at low altitudes and with equipment in new condition
22
water over what temp is too hot for drafting
over 85F
downtown area curbs are approx. ___ feet from the building line
11 feet
where spotting made next to curb operating aerial between 5th and 8th floors maintain a climbing angle of
70-80 degrees
When spotting is made outside line of cars, any operation below the 7th floor will conduct at a climbing angle less than __ degrees
70 degrees
if uphill throw aerial
stop short of intended spot and raise aerial
*more stable ladder and rung tilt reduced
if headed downhill throw aerial
spot past where the intended throw
best to have aerial hoisted at least __ degrees before operating other controls
45
extreme caution when operating aerial in winds as fast as
35 mph and over
safe driving is made up of
20% safe vehicle
20% good physical condition of driver
60% good attitude
perception and reaction time
3/4 second each
smith system:
get big picture ___ mile ahead when on rural roads
1/2 mile
air brake equipment
perception/reaction distance + brake lag + effective breaking distance= total stopping distance
descending grade with constant brake application of approx __ psi
10
brake lag distance
.4 (four tenths of a second)
do not idle diesel engine in excess of __ minutes
30 minutes
