IFSTA Chapter 10 Operating Fire Pumps

Question 1

When operating at the pump panel, drivers must wear

Answer 1

full PPE

Question 2

What does the placement of chocks provide

Answer 2

an extra measure of safety should the apparatus jump into road gear or override the parking brake system

Question 3

When operating the pump when should you reach the appropriate pressure

Answer 3

When water is flowing

Question 4

When using the tank fill valve to cool the pump what must be concidered

Answer 4

Tank Fill Line may be piped large enough to cause the pump to cavitate when using the onboard tank

Question 5

When discharge pressure increases, intake pressure from the source will drop due to friction loss,

what happens when intake pressure drops too low

Why must you not pump below a residual pressure of 20 psi

Answer 5

Allowing the discharge pressure to decrease the intake from the source can cause damage to the pump

pumping at a residual pressure below 20 psi while being supplied by other apparatus may cause the supply line to collapse or lead to cavitation

Question 6

Why should supply systems maintain a residual pressure of 20 psi also

Answer 6

Contamination from sources outside the main may occur and overtaxing the water system may cause sediment or debris that has formed to become lose and damage the pump

Question 7

what are dead end hydrants and why are they least desirable source

Answer 7

Hydrants served by smaller mains from only one direction and generally have higher amounts of sediment and deterioration

Question 8

In Prolonged pumping operations a bypass circulator may not provide enought cooling, what other methods can be used to keep the pump from overheating

Answer 8

Open Discharge Drain Valve: Some need opened before valve is under pressure

Partially open tank-fill valve or tank to pump

Question 9

Exact explanation of Like Volumes

Answer 9

10% of less = 3 lines of the same flow can be added

11 - 15% = 2 lines of the same flow can be added

16 - 25% = 1 lineof the same flow can be added

more than 25%= more water may be available but not as much as is flowing through first line

Question 10

A_______ _____ is created when air inside the pump is evacuated

Answer 10

Pressure Differential

allows atmospheric pressure acting on the surface of the water to force water into the fire pump

Question 11

With an atmospheric pressure at sea level of 14.7 psi what is a partial vacuum of -2 psi measured as

Answer 11

4” of mercury which causes water to rise 4.6ft

The Weight of water combined with reduced air pressure creates a balance

Question 12

When drafting other than bends in plumbing, hose or appliance what else created friction loss

Answer 12

The Inertia of water

Question 13

To what level of mercury are pumps able to develop a vacuum approximately

Answer 13

22” of mercury but

Compound gauges not providing accurate readings on the vacuum side it must be acknowledged that at this reading the pump is nearing the limits of its ability to supply water.

Question 14

Describe cavitation

Answer 14

Water being discharged faster than it is coming into the pump

Question 15

What causes cavitation

Answer 15

Air cavities are created in the pump as they move from highest vacuum into the presurized section where they collapse (fill with water)

High velocity of these cavities filling causes severe shock to pump

Question 16

What occurs to the state of water during cavitation

Answer 16

Pressure drops below atmospheric and the boiling point of water drops to the point that water changes to a vapor creating voids of steam

Question 17

Indicators of a pump cavitating

Answer 17

Pressure gauge on the pump will fluctuate and hose streams may pulsate (popping, sputtering sound)

The pump makes noises compared to gravel passing through the pump

The surest indicator will be a lack of reaction of the pressure gauge when increasing the throttle

Question 18

In order for a pumper to reach its rated capacity during draft using a traditional strainer, how much water (in inches) must be above it

Answer 18

24 inches

It is also helpful to have that much clearance around the strainer to avoid drawing foreign objects

Question 19

What may cause a whirlpool resulting in air entering the intake hose during draft

Answer 19

Rapid Intake of water may cause the pump to lose its prime

whirlpool can be fixed by placing a floating object above the strainer

Question 20

What steps can be taken to use a shallow source of water

Answer 20

A dam can be built or the bottom be dug out

Ideally a floating strainer will be used

Question 21

Negative of using a floating strainer

Answer 21

Since it only uses one side to allow water in, the pump may not be used at its highest capacity due to receiving lower water amount

Question 22

Low-Level strainers can be used in water as low as _______ but will not allow the pump to

Answer 22

2 inches approx and will not allow the pump to operate at rated capacity due to drafting lower quantities

Question 23

What sources can expose the pump to (when drafting) to corrosion from salt contents, or caustic chemicals that may be present in the water

Answer 23

Using non-potable (untreated) water sources such as that from a salt water source or ground water in the vicinity of mining operations

Question 24

When debris passes through the pump what does the abrasive effect damage?

Answer 24

As water passes through the eye of the impeller, the area between the clearance rings and the hub of the impeller. It creates spacing that causes slippage from discharge back into intake ultimately reducing the capacity of the pump

Question 25

All Fire Pumps meeting NFPA and UL requirements are rated to pump their capacity at?

Answer 25

10ft of lift.

a pumper in good condition can lift water a maximum of 25ft

Question 26

To create an effective fire stream a lift no greater than this height is recommended

Answer 26

20ft

Question 27

at 20 feet lift at what capacity is the pump able to work at (percent)

Answer 27

60% of its rated capacity

Question 28

Prelem actions to connecting to the pump during draft

Answer 28

Engage the pump once all connections have been made and its ready to be put into operation

Park vehicle short of final drafting spot if area is limited and drive closer once all connections are made

Inspect gaskets, then connect strainer

If needed use a rubber mallet to make connections tighter

avoid placing intake hose on the ground (debris)

Fasten a rope to the end of strainer for handling

Question 29

When priming a pump for draft what should the intake master gauge read

Answer 29

1” of Hg for 1 Foot of lift required

Vacuum is measured from the surface of the water to the eye of the pump

Question 30

When lift is not able to be achieved during priming what is the most common reason

Answer 30

Air Leaks around the pump possibly from an open drain or valve

Intake relief valves may also prevent lift

Question 31

Other than loose gaskets, opened valves what else can create issues when drafting

Answer 31

Insufficient fluid in the priming reservoir

Engine Speed (rpm) too low

Lift is Too High

High point in the intake hose creating an air pocket

Question 32

Increasing the throttle setting is required to raise the pressure to between

Answer 32

50 and 100 psi

if pressure drops below 50 psi while slowly opening a discharge, pause for a brief time to allow stabilization to prevent air entering the pump

Question 33

When should you set desired discharge pressures while drafting

Answer 33

Wait until water is flowing and the discharge gauge has stabilized

Question 34

Types of problems found during drafting operations

Answer 34

Discharge pressure gauge begins to fluctuate with loss of vacuum on the intake gauge indicates air is coming into the pump

If there isn’t enough water above the strainer and whirlpool can be formed allowing air into the pump

an empty onboard water tank may cause the tank-to-pump line be a source of pressure/water leaks.

Question 35

What indicates a gradual increase in vacuum with no change to flow rate

Answer 35

A blockage is developing

usually caused after a pump has been operating at a high rate of discharge increasing the max velocity of water entering the strainer

Question 36

Common place for blockages during draft

Answer 36

in the strainer

if reached easily leaves or other debris may be removed by hand or using a booster line

Pump may have to be backflushed.

Question 37

Shutting down a drafting operation

Answer 37

Deacrease engine speed to idle

take pump out of gear

allow the pump to drain

remove all connections and operate the primer pump and operate for a few seconds until primer oil or fluid comes out

Pump should be thoroughly flushed with a supply of fresh water

Question 38

During stand pipe operations encountering a Pressure reducing valve what leads to inadequate pressure for hose lines

Answer 38

The pressure set for standpipe must match the total height where the hose is being connected to. The pressure must match that to which the valve was set to.

Question 39

Standpipe frozen connection fix

Answer 39

double male to a double female adapter can be added to provide movement