Chapter 11 Operating Fire Pumps Flashcards
When does IFSTA recommend wheel chocks to be used?
Every time the apparatus is stopped with the engine running and the driver/ operator exits the cab.
Tests have indicated that the apparatus may override the parking brake system at engine speeds as low as what?
1300 RPMs
If the engine is running and the pump is turning, what must be open so that the pump will not run dry?
Intake valve
In a multi-stage pump, in most cases, the pump should remain in ______ position
series (pressure)
If a multi-stage pump is required to furnish more than ____ percent of its rated capacity, it should be set to the PARALLEL (VOLUME) position from the start
50%
If using 2 ½” or 3” hose to supply the pumper directly off hydrant pressure, it is recommended that the lines be no longer than how long?
300 ft.
What type of lay is the most direct way to supplement hydrant pressure and perform drafting operations?
Reverse Lay
When switching to an external water supply, what valve must the driver/ operator ensure is closed?
Tank-to-Pump
If the master intake gauge drops below ____ psi, do not increase the throttle further because the pump is in danger of cavitation.
20 psi
When a pumper is connected to a hydrant and is not discharging water, the pressure shown on the intake gauge is what?
static pressure
When the pumper is connected to a hydrant and IS discharging water, the pressure shown on the intake gauge is what?
residual pressure
What are the 3 methods used for determining how much more water the hydrant can supply?
- Percentage method
- First digit method
- squaring the lines method
What is the equation for using the PERCENTAGE METHOD in determining how much more water a hydrant can flow?
Percentage drop = (static-residual)(100) / static
When using the PERCENTAGE METHOD, how much additional water is available from the hydrant when the percent decrease of pumper intake pressure is:
a. 0-10
b. 11-15
c. 16-25
d. 25+
Additional water available is:
a. 3 times amount being used
b. 2 times amount being used
c. same amount being used
d. more water might be available, but not as much as is being delivered
Describe the FIRST DIGIT METHOD.
Difference in psi between static and residual = x
Multiply the first digit of the static pressure by 1,2, or 3
If the psi drop (x) ≤ first digit of static pressure multiplied by:
1–then 3 additional lines can be added
2–then 2 additional lines can be added
3–then 1 additional line can be added
When can the FIRST DIGIT METHOD NOT be used?
When using metric measurements