Flashcards in Chapter # 11 Operating Fire Pumps Deck (79):
On some newer apparatus the pump will not throttle up if what is not set?
The parking brake.
Test have indicated that a apparatus may override the parking brake system at engine speeds as low as what?
1300 rpms. This is why the wheels should be chocked.
Some newer apparatus do not provide a speedometer check to ensure the pump is engaged, why?
Because the speed reading is taken from the rear of the transfer case.
What should be done in a pumping operation after the wheels are chocked?
Pull the tank to pump valve.
A pump should be set in volume (parallel) if it appears that what percent of the pumps capacity will be needed?
50% (some manufacturers recommend 70%)
When an external water supply becomes available, open the intake valve while closing what?
The tank to pump valve.
These do not have sufficient flow to prevent encrustation and sedimentation from decreasing the flow capacity.
Single mains that supply small amounts of water.
Subjecting dead ends mains to high flow requirements may make what happen.
Sediment to flow into the fire pump intake screen, reducing water flow.
Recommended Practice for Fire Flow Testing and Marking Hydrants.
Class AA / light blue
1500 gpm or greater
Class A / Green
1,000 - 1,499 gpm.
Class B / Orange
Class C / Red
Less then 500 gpm.
Many departments that prefer a forward lay also carry what to aid in the process?
A four way hydrant valve.
What is another name for a dry barrel hydrant?
Frost Proof Hydrant
What is the max recommended length of hose when using 2 /12" or 3" hose to connect a hydrant to a pumper?
What is the most direct way to supplement hydrant pressure and perform drafting operations?
A reverse lay.
This method is used in cases when a size up must be made before laying a supply line.
A reverse lay.
When reverse laying a supply hose, it is not necessary to use what?
A four way hydrant
After a hydrant connection is made the tank-to-pump valve must be closed if the intake is not equipped with what?
A shutoff valve.
A dry barrel hydrant should;d be opened fully, but it is also recommended that after fully opening the hydrant that it be closed how much, to relive the strain on the valve stem and internal components.
One quarter turn.
Name four methods for preventing pump overheating while hoselines are not flowing.
Pull booster line. Open a discharge drain valve. Partially open the tank fill or pump tank line. Use a bypass or circulator valve.
T or F When a pumper is connected to a hydrant and is not discharging water, the pressure shown on the intake gauge is the STATIC PRESSURE. When the pumper is discharging water, the intake gauge reading is the RESIDUAL PRESSURE. The difference between the two is used to determine how much more water the hydrant can supply.
Name the three methods for determining additional water available from a hydrant.
Percentage Method. First- Digit Method. Squaring the lines method.
What is the percentage method equation?
Percent drop = ( Static - Residual )(100) / Static
Percentage method table.
0-10 % = 3 times the amount of water being delivered.
11-15% = 2 times the amount of water being delivered.
16-25% = Same amount as being available.
25% + = more water might be available, but not as much as is being delivered.
Faster and easier method then the percentage method, but can not be used when using metrics.
Find the difference in psi between the static and residual. Multiply the first digit in the static by either 1, 2, or 3. Determine which of these number the first digit must be mutiplyed by to become equal to or less then the first digit in the static pressure. Then that tells you if you can add 3,2,or 1 additional line with equal flow.
The additional amount of water can be determined by squaring the number of lines currently flowing and multiplying this by the original pressure drop.
Squaring the lines method
When using the squaring the lines method the pressure drop is quadrupled each time the flow is what?
Should a pressure control device be shut off when shutting down the pump?
All fire department pumpers should be capable of pumping water from what?
A static water source.
When drafting it is possible to increase the capacity of a certain sized pump if what?
The size of the intake hose is increased.
What is atmospheric pressure at sea level?
Atmospheric pressure decrease 0.5 psi for every ..........of elevation gain.
Increasing the height of lift during drafting will decrease what?
The total pump capacity.
What is the max amount of vacuum that most pumps develop for primer.
About 22 inches of mercury.
Sometimes refereed to as "the pump running away from the water".
What are three things that effect the point of cavitation when drafting?
Temp of water. Height of lift. Amount of water being discharged.
Name signs of cavitation.
Hose streams pulsate. Gauges fluctuate. pooping or sputtering sound. Gravel like sound also. The best indicator is the lack of reaction on the pressure gauge in throttle settings.
T or F Cavitation often results when a pump has been equipped with inadequate piping from the water tank.
Cavitation can occur while operating from a poor hydrant system, but it most often occurs during what?
1 foot of lift is equal to how many inches of mercury?
0.885 inches of mercury.
What is the max theoretical lift?
The first consideration in establishing a drafting operation is what?
The drafting site.
What three factors should be considered when determining a drafting site?
Amount of water. Type of Water. Accessibility of water.
What may be placed above the strainer to prevent a whirlpool effect?
Wooden board, capped plastic bottle, or a beach ball.
A disadvantage of a floating strainer is what?
It only take water in from one side. This may limit the pump from reaching it rated discharge capacity.
Designed to draft water down to a depth of 2 inches. Sit on the bottom of a tank or pool.
Low level strainer.
Water that is below ........F, or above .......F may adversely impact the pumps ability to reach capacity,
35 F, 90 F
What is the most common source of water contamination and possibly the most damaging?
Dirty or sandy water.
list the three things that happen when the amount of lift increases.
Elevation pressure increases. Less FL can be overcome. Pump capacity decreases.
All fire pumps meeting NFPA and underwriter lab requirements are designed to pump their capacity at how much lift?
What is the most reasonable lift possible for most fire pumps? and what is the percent of pump capacity at that height?
20' of max lift. 60% of rated pump capacity.
When performing a drafting operation should engaging the pump be delayed until all connections are made and ready for operation?
What is the key to ensuring tight connections to hard intake hose?
Get each section of hose in line with each other before making the connection.
Hard intake hose connections should be made where?
In the air. Not on the ground.
It is usually easier to place the hose and strainer in the water then make what connection?
The connection to the pumper.
What position should a two stage pump be in when drafting?
The master intake gauge registers a reading of 1" of mercury for how many feet of lift?
The entire priming process typically take how long? What is the max amount of time it should be attempted?
15-20 second. 30 seconds.
Should the circulator valve be closed when attempting to draft or prime?
What should be done after gaining a prime but before opening a discharge valve.
Throttle up to 50 -100 psi.
T or F Do not try to set the discharge pressure to the desired value until water is flowing and the gauge has stabilized.
Should a constant flow of water be established when drafting so that prime is not lost?
Name the three problems that can occur when operating from a draft.
Air leak on the intake side of the pump.(most common) Whirlpool allowing air into the pump. Air leak due to defective packing in the pump.
What is a indication that a blockage is developing?
A gradual increase in the vacuum reading with no change in flow rate.
When shutting down a drafting operation, after the pump has been drained. What should be done?
Operate the primer for a few seconds until primer oil or fluid come out the discharge from the priming pump. This lubricates the parts in the primer.
T or F Fixed fire protection systems are a buildings first line of fire defense.
A 1,000 gpm rated pumper should supply how many flowing sprinkler heads?
If interior crews are operating off a combination standpipe / sprinkler FDC, what should pressures be set for.
For the safe operation of the hand lines.
What stage should muti stage pumps be in when supplying a FDC?
The general rule of thumb for what pressure to pump a FDC at?
PDP in excess of ......psi are not encourage unless the standpipe system has been designed to withstand high pressures.
What changes in pressure elevation should be made if a standpipe has pressure reducing valves.
Calculate for the total height of the stand pipe. The pressure reducing valves are designed to reduce the flow to the proper amount.
Why may there be a delay when operating from a dry stand pipe system?
Because the air has to exit first before the water can reach the hoselines.
What can be used if a FDC on the outside is found to be inoperable.
Connect to the first floor hose connection.
When it is required that hose must be ran up the side of a building, how should it be accomplished?
Roll a hose roll down from inside every 2-3 floors.