Hydraulics manual for driver promotional test

what is a BTU and how is it calculated

British thermal unit (BTU)

1 BTU is the amount of heat needed to raise the temp of 1 pound of water 1 degree

what is the latent heat of vaporization

quantity of heat absorbed by a substance when it changes from a liquid to a vapor

when 1 lb of water is changed into a vapor at 212 degrees it will absorb 970 BTU

expansion of water when converted

when water is converted to steam at 212 degrees it will expand 1700 times its original volume

when water is converted at 500 degrees it will expand 2400 times its original volume

what type of pumps does the FD use

single stage centrifugal pumps

what turns at a very high speed but can be damaged by contaminated water or cavitation

impellers

are centrifugal pumps capable of pumping air

no and due to this they are not capable of priming themselves and will require an external priming device

are the centrifugal pumps capable of using positive pressure that is entering the pump

yes they can use any positive pressure entering the pump

the pump will simply add additional pressure to the pressure it is receiving from the hydrant

what PSI must be maintained to prevent cavitation

20 PSI

what is the working part of the pump that is made of 2 shrouds separated by curved vanes

impeller

what in the pump reduces the velocity of the water after passing through the impeller

the volute which gradually increases in size as it approaches the discharge

what is used to prime the main pump

rotary vane pump

what does priming do

removes air from the main pump and suction hose

can you prime the pump while the impellers are moving

yes

where is the priming valve located and what does it do

located in the priming line between the priming pump and the main pump and allows air to be removed from the main pump

what is not a reliable indicator of discharge pressure

the pump pressure gauge

what will give the most accurate pressure reading when pumping to various hose layouts

discharge pressure gauge

the pressure for each hose lay should be set according to what

the discharge gauge

what is the net pump discharge pressure

is the difference between the discharge pressure and residual intake pressure

what causes cavitation

when the pump is operated at excessive speeds or the intake is restricted causing the pressure on the liquid to fall below its vapor pressure

when cavitation occurs what happens inside the pump

liquid vapor is released in the low pressure regions of the pump forming bubbles which are then carried into the high pressure sections of the impellers where they collapse with considerable force

what does cavitation sound like

rattling resembling gravel going through the pump

how to fix cavitation

reduce speed of pump or improve intake conditions

what is the purpose of the pressure governors on the apparatus

regulates engine speed automatically to maintain the desired pump pressure

due to the apparatus not having separate relief valves what performs this function instead

the pressure governor

what mode do we pump in

pressure mode

what can happen if you pump in throttle mode

can cause too high of pressure and pressure spikes

does the PUC pump have the ability to operate if the hand throttle on the pump panel malfunctions

yes if it malfunction you can assign someone to use the foot throttle in the cab to continue pump ops

when this occurs the parking break must be released and the wheels must be chocked

where is the manual override for the PUC pump

in the lower right of the pump panel

when performing pump and roll ops with the PUC pump what gear must be selected and maintained

1st gear and if the the transmission shifts out of 1st gear the water pump will be disengaged

when doing pump and roll what does the foot throttle control

both the ground speed and pump pressure

what is normal operating pressure

pressure found in a water system before a hydrant is opened

what is residual pressure

amount of water that is not being used and can be used somewhere else

this is an indication of how much water is still available

what is the coefficient of the 1 inch hose

150

what is the coefficient of the 1 ¾ inch hose

15.5

what is the coefficient of the 2.5 inch hose

2

what is the coefficient of the 3 inch hose

.8

what is the coefficient of the 5 inch hose

.08

what is the 3 inch hose primarily used for

support fixed fire suppression systems and to extend attack lines

what is the 5 inch hose most often for

supply line

What is the friction loss in a 5 inch hose at 1000 gpm

5 psi per 100 feet

what is the operating nozzle pressure for the 1 ¾ fog nozzle

75 PSI

what nozzle is on all high rise packs

7/8 smoothbore

what is the nozzle pressure of the 7/8 smoothbore tip

nozzle pressure of 50 psi

what is the nozzle pressure for a 2.5 fog nozzle

100 PSI nozzle pressure

how many GPM do you get out of the 1 ¾ crosslay nozzle

70-200

how many GPM do you get out of the 7/8 smoothbore nozzle on the crosslay

144-176

how many gpm do you get out of the 2.5 fog nozzle

50-350

what does the high rise packs consist of

2 × 50 ft sections of orange true ID hose with 7/8 smoothbore tips

1 × 50 ft section of orange true ID hose with gated wye and 3 inch pigtail

1 × 50 section orange true ID attack hose with nothing attached

how should the high rise packs be loaded

male end first

what is the max operating pressure for the blitzfire

175 psi

what is the max flow rate for the blitzfire

500 gpm

what is the elevation angle for the blitzfire

10-50 degrees above horizontal

what is the horizontal angle for the blitzfire

20 degrees either side of center

the safety shutoff on the blitzfire is only sensitive to what kind of movement

sideways movements

what is the max nozzle pressure for the master stream smoothbore nozzle

80 psi

what is the highest risk of movement when anchoring the blitzfire

anchoring by weight

what is the lowest risk of movement when anchoring the blitzfire

using a tie off strap

what are the 4 ways to anchor a blitzfire

weight

leg spikes

hook legs on a vertical surface

tie off strap

when FFs are inside of a structure are master streams allowed to be used on that structure

no master streams are to be shut down when FFs are inside the structure or about to make entry into the structure

when is the max stability of the aerial achieved when using the nozzle

when the nozzle is operated within 45 degrees left/right if the center of the ladder

the 75ft aerial has a wind condition of what

35 mph

The 75 ft aerial has a tip load of what when it is a dry waterway

750 at the lowest angle and 1000 at the highest

When the 75 ft aerial has a charged waterway what is the tip load capacity

500 at the lowest angle and 750 at the highest

the 105 ft aerial has a wind condition of

50 mph

the 105 ft ladder has what tip load

500 lbs dry and wet

when dual pumping are both apparatus working together or independently of one another

when dual pumping each apparatus pump is working independently of one another

when should dual pumping be utilized

only as an emergency water supply method

when a engine is hooked up to a hydrant and pumping its max handlines what must the PSI be in order for the hydrant to supply a 2nd engine

at least 40 PSI

when dual pumping how are both engines hooked up to each other

intake to intake

when relay pumping how are the engines hooked up to each other

discharge to intake

when would relay pumping be needed

a hose lay of 1,000-1500 ft would be excessive and would require relay

what is the max operating pressure for the yellow 5 inch supply line

185 psi

when relay pumping what is the max pressure you are able to pump to the other engine

150 psi

class A foams are used for

ordinary combustibles

what are the 2 ways of delivering class A foam

batch mixing

injection

what proportion will batch mixing give you

.1-.3 percent

where must you use the injection method for foam use

on the discharge side of the pump

when do you use class B foams (FFF)

use on flammable and combustible liquids

It is also used to suppress vapors from igniting

what are the 2 basic types of flammable liquids

polar solvents

hydrocarbon fuels

what flammable liquid with readily mix with water

polar solvents (alcohol)

what flammable liquid does not mix with water but floats on top

hydrocarbons (floats on top)

what percentage of foam concentration do you need for hydrocarbons

3 percent

what percentage of foam concentration do you need for polar solvents

3 percent

what is the correct way to mix 3% foam concentration

3 gallons of foam with 97 gallons of water which produces 100 gallons of foam solution

the foam Eductor that we use has what flow rate

95 GPM

what is the PSI needed for the Eductor to work

200 PSI

when the backpressure on the eductor falls below what the eductor will stop working

130 PSI

what is the max hose lay limit on the discharge side if the Eductor

350 ft assuming there is no more than 10 ft of elevation loss

what is the max hose lay from the pump to the Eductor

can be as long as it needs to be as long as the inductor is getting 200 psi

What must the PDP be in order to effectively pump the in line educator

200 psi

when there is a working fire in a sprinkled building what is required of a apparatus

apparatus must hook up to the FDC and be prepared to supplement the sprinkler system

what buildings do not have fire pumps

most 1 floor commercial buildings

multi-rise under 4 floors

most small-medium warehouses

buildings that do not have fire pumps and require you to pump the fdc require what from the driver

2 × 3 inch lines or 1 × 5 inch line

remove all FDC caps prior to pressurizing system

throttle up to and maintain 175 PSI

where must the supply lines be hooked to the engine when pumping a FDC

must be hooked up to the opposite side of the pump panel

what is the max pressure of the orange/red 5 inch hose

275 PSI

buildings with fire pumps should initially have a PDP set at what

150 PSI to see if the fire pump is working or not

how do you know if the buildings fire pump is working or not

a pressure drop in the engines compound gauge or master pressure gauge

or gate down the discharge being used and if the pressure changes the fire pump has failed

what must the driver do when they have hooked up to the FDC

notify command

when there is no water flowing but the pumper is throttled up how do you keep it from over heating

open a unused discharge and its corresponding drain valve

what is the friction loss for 3 inch hose

20 psi per 100ft