Chapter 10 - Operating Fire Pumps Flashcards
Three sources of water to supply pumping operation
onboard water tank, pressurized water source, static water source
The two basic pressurized water supply sources that a driver/operator will encounter are a ?
fire hydrant or supply hose from another pumper p 339
Pumping at a low residual pressure (below _____ psi) while being supplied by other apparatus is dangerous. This may cause the supply hose to __________, interrupting the supply of water. It may also lead to cavitation of the pump.
20 psi / collapse p 339
Driver/Operators should maintain a residual pressure of at least ______ psi on their master intake gauge at all times during pumping operations.
20 psi p 340
The initial water source is often the apparatus ________ _______.
water tank p 337
Typically the least desirable hydrants are those located on “________ ______ ________” that are served by smaller mains from only one direction.
“dead end mains” p 340
- Water main that is not looped and in which water can flow in only one direction.
Dead End Mains p 340
One of the most common ways for a pumper to be supplied with water from a hydrant is by making a ?
forward hose lay p 341
- Method of laying hose from the water supply to the fire scene.
Forward Lay p 341
- Method of laying hose from the fire scene to the water supply.
Reverse Lay p 344
Load hose with a _________ coupling to come out of the bed first when using hose with threaded couplings for a reverse lay.
male p 344
Use double _________ adapters at the hydrant and double ________ adapters at the pump panel to execute a reverse lay using hose with threaded couplings if the hose bed has been set up for a forward lay.
female / male p 344
Executing a reverse lay is a common method for setting up a water supply operation or relay pumping using __________ diameter hose as a supply line.
medium p 344
With medium diameter hose, it is necessary to position a pumper at the ___________ to supplement the pressure to the supply hose.
hydrant p 344
The reverse lay is the most direct method of supplementing _____________ ____________ or performing ____________ _____________.
hydrant pressure or performing drafting operations p 344
- 2 1/2 or 3 inch hose used for both fire fighting attack and relay supply purposes.
Medium Diameter Hose (MDH) p 344
- (1) Pumper that is positioned at the fire scene and is directly supplying attack lines. (2) Light truck equipped with a small pump and water tank. Also know as Midi-pumper or Mini-pumper.
Attack Pumper p 344
- Pumper that takes water from a source and sends it to attack pumpers operating at the fire scene.
Water Supply Pumper p 344
If water is allowed to enter the tank _________ _____________, the venting may not be adequate to allow the pressure to dissipate, resulting in damage to the tank.
under pressure p 345
Regardless of whether a particular apparatus is equipped with a check valve in the tank to pump line or a shutoff valve on the intake, the driver/operator should close the tank to pump valve after transitioning to an ?
external water supply p 345
When the pump is full of water and the pressure in the system has stabilized with no water flowing, a reading of the pressure on the master intake gauge indicates the ___________ _____________ in the water supply system. The reading is important for estimating the remaining _________ of the hydrant as the water begins to move.
static pressure / capacity p 346
Pumps supplying a relay operation or master stream are usually used to supply large amounts of water, requiring the use of a ____________ (___________) setting of the transfer valve.
parallel (volume) p 346
Open all valves slowly, especially when using ________ ____________ hose. The hose must be __________ before pressure can be established.
large diameter / filled p 346
While observing the master intake and discharge gauges, the D/O should increase the engine ______. If the master intake gauge drops below _____ psi, the throttle must not be ____________ any further because the pump may begin to cavitate.
rpm / 20 psi / increased p 346
Several methods for preventing overheating are as follows: * Establish a continuous minimum _______ during intermittent use of water in fireground operations to keep the pump from overheating. * Pull a length of ___________ line or other _________ ___________ line off the reel and fasten it to a sturdy object. * Open the valve that supplies the booster reel and ___________ __________ in a direction that will not interfere with the operation or damage to other property. The booster line may also be directed back into the ________ to circulate water continuously.m
* flow * booster / small diameter * discharge water / tank p 347
During prolonged pumping operations, a bypass circulator may not provide sufficient cooling under some conditions and additional measures will be required to avoid overheating. * Open a ____________ _________ valve. * Partially open the ______-______ valve or ______-___-_______ line. Even if the water tank becomes full and _____________ through the tank vent, this result is preferable to the pump overheating.
* discharge drain * tank-fill / tank-to-pump / overflows p 347
When a pumper is connected to a hydrant and is not discharging water, the pressure shown on the intake gauge is __________ pressure. When the pumper is discharging water, the intake gauge displays the ___________ pressure. The difference between the two pressures is used to determine how much more water the ___________ can supply.
static / residual / hydrant p 347
Available Water from Hydrant Percent Method: Percent Drop = ( _________ - ___________ )(100) / ___________
Percent Drop = (Static - Residual)(100) / Static p 348
Available Water from Hydrant Percent Method: If the percent is ____ or less, three additional lines with the same flow as the line being supplied may be added. For ____-____ percent, two lines may be added, and for ____-_____ percent one line. When the result is over _____ percent, more water may be available, but not as much as is flowing through the first line.
10 / 11-15 / 16-25 / 25 p 348
All fire department pumpers should be capable of pumping water from a _________ _________ supply source. In most cases, this source is located some distance below the level of the ?
static water / fire pump p 352
It is not possible to ______ water into the pump. However, it is possible to evacuate some of the air inside the pump creating a ____________ ___________ (__________ __________), which allows atmospheric pressure acting on the surface of the water to force the water into the fire pump.
pull / pressure differential ( partial vacuum) p 352
- Effect of altering the atmospheric pressure within a confined space by mechanical means. When air is exhausted from within the space, a low pressure environment is created and replacement air will be drawn in; when air is blown into the space, a high-pressure environment is created and air within will to the outside.
Pressure Differential p 352
In order to create a pressure differential ( partial vacuum ), an airtight, ______________ waterway ( _______ __________ hose ) must be used between the fire pump and the static water source.
noncollapsible / hard intake p 352
Drafting Operations A hose with smaller diameter and greater length has __________ friction loss, which allows ________ water at the pump.
higher / less p 352
Most pumps are able to develop a vacuum capacity of approximately _____ inches of mercury.
22 inches p 354
In theory, cavitation can be described as water being ?
discharged faster than it is coming into the pump. p 354
Cavitation occurs when _____ _________ are created in the pump or __________ pass through the pump.
air cavities / bubbles p 354
The first consideration in establishing a drafting operation is _________ _______________.
site selection p 354
The most important factor in choosing the draft site is the ?
amount of water available p 355
In order for a pumper to approach it’s rated capacity using a traditional strainer, there must be at least _____ inches of water over the strainer.
24 inches p 355
When using a portable tank or swimming pool for drafting operations a _____-_______ strainer is the appliance of choice.
low-level strainer p 356
What type of strainers are designed to sit directly on the bottom of a tank or pool and allow water to be effectively drafted down to a depth of approximately 2 inches?
low-level strainers p 356
Water temperature will also affect drafting operations. Water below ____F or above ____F may adversely impact the ability of the pump to reach capacity.
35*F / 90*F p 356
- Water that has not been examined, properly treated, and not approved by appropriate authorities as being safe for consumption.
Nonpotable Water p 356
All fire pumps meeting NFPA and Underwriters Laboratories Inc. requirements are rated to pump their capacity at _____ feet of lift. If the lift is less, the capacity of the pump is ________; if the lift is greater the capacity _________.
10 feet / higher / decreases p 357
A pumper in good working order can lift water a maximum of _____ feet. However all available atmospheric pressure is required to overcome this lift. As a result, the remaining capacity of the pump is of little value for ?
25 feet / fire suppression p 357
To create an effective fire stream, a lift of no greater than _____ feet is recommended. Working with this lift, the pump operates at about ____ percent of its rated capacity.
20 feet / 60 percent p 357
When selecting a site for drafting, the lift must be kept as ? It is more desirable to lay out an extra 100 feet of ________ _____ to set up at a draft location where the lift will be lower and more water supplied.
low as possible / supply line p 357
