Chapter 7 - Theoretical Pressure Calculations Activities

Question 1

Which of the following would be the first step when determining friction loss in Siamesed hoselines?

Answer 1

Compute the total gallons per minute (L/min) flowing.

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Question 2

What two things are necessary to calculate pump discharge pressure?

Answer 2

Nozzle pressure
total pressure loss

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Question 3

The primary consideration for friction loss is the:

Answer 3

volume of water flowing per minute.

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Question 4

total pressure loss is made up of the __________, __________ , and __________

Answer 4

Friction loss, elevation loss, and appliance loss

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Question 5

friction loss for handline nozzles is generally ___________

Answer 5

insignificant

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Question 6

Which method of determining friction loss involves the use of in-line gauges to measure friction loss at various flows through specific hose layouts?

Answer 6

Performing tests

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Question 7

Which method of determining friction loss relies on the use of mathematical equations or field application methods?

Answer 7

Using calculations

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Question 8

The use of standard formulas and field applications for determining friction loss are generally relied upon for:

Answer 8

safe fireground operations.

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Question 9

customary formula to determine elevation pressure in a multistory building?

Answer 9

5 psi × (number of stories - 1)

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Question 10

For which nozzle type is a pressure of 100 psi (700 kPa) a safe and efficient nozzle pressure?

Answer 10

Fog nozzle

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Question 11

metric formula for elevation pressure loss on the fireground?

Answer 11

10 × Height in meters

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Question 12

When a pumper is being supplied by another pumper, net pump discharge pressure is the difference between pump discharge pressure and:

Answer 12

incoming pressure from supply source.

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Question 13

for which nozzle is a pressure of 50 psi (350 kPa) a safe and efficient nozzle pressure?

Answer 13

Solid stream nozzle (handline)

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Question 14

for which nozzle is a pressure of 50 or 75 psi (350 or 525 kPa) a safe and efficient nozzle pressure?

Answer 14

Low pressure fog nozzle

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Question 15

The current formula for friction loss accounts for the:

Answer 15

diameter of the hose, the volume of water flowing, and the length of the hose layout.

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Question 16

What is the formula for friction loss?

Answer 16

FL= C(Q^2)L

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Question 17

Which is the correct formula for Net Pump Discharge Pressure?

Answer 17

Pump Discharge Pressure - Intake Reading

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Question 18

customary formula for elevation pressure loss calculations on the fireground?

Answer 18

0.5 × Height in feet

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Question 19

When two hoselines of equal length are Siamesed to supply a fire stream, friction loss is approximately:

Answer 19

25 percent less than that of a single hoseline at the same nozzle pressure.

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Question 20

In the formula for friction loss, the “L” refers to:

Answer 20

hose length.

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Question 21

when flowing 350 gpm (1 400 L/min) or greater there is a loss of ________ for each appliance, other than master stream devices.

Answer 21

10 psi (70 kPa)

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Question 22

Pressures for standpipe operations for fire departments may be labeled on ________ of the fire department connection.

Answer 22

the faceplate

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Question 23

When determining pressure loss for elevated waterways, the elevation of the master stream:

Answer 23

must be considered as part of the total pressure loss.

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Question 24

friction loss for master stream appliances

Answer 24

25 psi (175 kPa) for all appliances

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Question 25

For which nozzle is a pressure of 80 psi (560 kPa) a safe and efficient nozzle pressure?

Answer 25

Solid stream nozzle (master stream)

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Question 26

Which is the correct customary formula for determining pump discharge pressure?

Answer 26

Nozzle pressure plus total pressure loss

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