Flashcards in Chapter 9 Fireground Hydraulic Calculations Deck (31):
water flow in gpm (L/min).
Flowmeters are particularly advantageous in:
supplying hoselines or master stream devices equipped with automatic nozzles.
Flowmeters are allowed to be used instead of pressure gauges on all discharges:
1½ to 3 inches (38 mm to 77 mm) in diameter.
What size discharges may be equipped with a flowmeter but must also have a pressure gauge?
3½ inches or larger
Flowmeters must provide a readout in increments no larger than:
10 gpm (38 L/min).
Which of the following are basic types of flowmeters?
Paddlewheel and spring probe
Which of the following statements about spring probe flowmeters is TRUE?
A. It is located at the top of the pipe so that sediment does not deposit on it.
B. Its placement reduces the problems of impeded flow and damage by debris.
C. It is relatively maintenance free because its spring probe has only one moving part.*
D. It may be used instead of pressure gauges on all discharges regardless of diameter.
How accurate should flowmeters be when properly calibrated and in good working condition?
+/- 3 percent
Flowmeters have a discharge readout display mounted within ___ of the valve control for each discharge equipped.
6 inches (150 mm)
A central flowmeter device provides the driver/operator with all of the following EXCEPT:
A. the amount of foam being flowed.
B. the required pump discharge pressure needed.*
C. the flow through any particular discharge at that time.
D. the total amount of water being flowed through the pump at that time.
Which of the following is NOT a flowmeter application?
A. Relay pumping
B. Standpipe operations
C. Pump discharge pressures*
D. Diagnosing waterflow problems
If water volume at the nozzle suddenly diminishes, but there is no reduction in the flowmeter reading, what is the most likely assumption?
The hose has burst.
Use of a flowmeter during relay pumping makes it possible to feed a supply line without having to know the:
number of gallons flowing from the pumper receiving the water.
When using a flowmeter for relay pumping, as the engine speed increases:
the discharge and gpm (L/min) reading increase.
When using a flowmeter for relay pumping, do not allow the incoming pressure to drop too much below:
20 psi (140 kPa).
Manual or mechanical hydraulic calculators operate by moving a slide or dial in which the ___ are indicated.
A. Water flow
B. Size of hose
C. Length of the hose lay
D. All of the above*
Electronic hydraulic calculators allow the driver/operator to input all of the following EXCEPT:
A. water flow.
B. size of hose.
C. length of hose lay.
D. pump discharge pressure.*
Which of the following statements about hydraulic calculators is TRUE?
A. They are particularly advantageous when supplying hoselines or master stream devices equipped with automatic nozzles.
B. They make it possible for driver/operators to pump the correct volume of water to nozzles without having to know the length of hoseline.
C. They make it possible to feed a supply line without having to know the number of gallons (liters) flowing from the pumper receiving the water.
D. They enable the driver/operator to determine the pump discharge pressure required to supply a hose layout without having to perform tedious mental hydraulic calculations.*
Which of the following is NOT a column on a pump chart?
A. NP column
B. FL column*
C. Nozzle column
D. GPM (L/min) column
What is the first step in developing a pump chart?
Identifying all nozzles, devices, and hose layouts used by the department
When calculating the required pump discharge pressures for each of the listed layouts, be certain to include friction loss in master stream appliances flowing in excess of:
350 gpm (1 400 L/min).
When calculating the required pump discharge pressures for each of the listed layouts, round pump discharge pressure to the nearest:
5 psi (35 kPa).
What is the hand method used to estimate?
To what size hoselines may the hand method be applied?
1¾- and 2½-inch
The hand method starts with:
the thumb of the left hand.
When applied to 2½-inch hose, each finger is numbered at the base in terms of:
hundreds of gallons per minute.
In order for the hand method to be applied to 1¾-inch hose, calculate the friction loss in 100 feet of 1¾-inch hose by going to the finger that corresponds to the flow you are using and multiplying the number at the tip of the finger by:
the number at the base of the same finger
What is the GPM flowing method used to estimate?
What does the driver/operator need to know in order to use the GPM flowing method?
Water flow in gpm
When using the GPM flowing method for 2½-inch hose, subtract ___ from the first two numbers of the gpm flow.