Simplified Hydraulics

Question 1

How many cubic inches of water are in a gallon?

Answer 1

231 cubic inches

Question 2

How much does a gallon of water weigh?

Answer 2

8.33 pounds

Question 3

How much does a cubic foot of fresh water weigh?

Answer 3

62.5 pounds

Question 4

How many cubic inches are in a foot?

Answer 4

1728

Question 5

How many gallons are in a cubic foot of water?

Answer 5

7.5

Question 6

A 1 square inch and 1 foot high column of water will create a downward pressure of___psi.

Answer 6

.434

Question 7

1 square inch of water ____ high will exert 1psi.

Answer 7

2.304

Question 8

Pressure gain or loss from elevation is equal to .5 psi per foot or ___ per 10 feet.

Answer 8

5psi

Question 9

Atmospheric pressure decreases approximately ___ psi per 1000 feet

Answer 9

.5psi

Question 10

1 foot of lift is equal to ___ inches of Mercury

Answer 10

.885

Question 11

What is the maximum theoretical lift?

Answer 11

33.9 feet

Question 12

What is the required vacuum for priming?

Answer 12

22” of Mercury

Question 13

The largest tip size used on a fire stream should not exceed ___ the diameter of the hose

Answer 13

1/2

Question 14

100 feet of 1 3/4” hose will contain ___ gallons of water and weigh ____ pounds

Answer 14

12. 25 gallons

102. 29 pounds

Question 15

100 feet of 2 1/2” hose will contain ___ gallons of water and weigh ____ pounds

Answer 15

25 gallons

208.75 pounds

Question 16

100 feet of 5” hose will contain ___ gallons of water and weigh ____ pounds

Answer 16

100 gallons

835 pounds

Question 17

Water converted to steam expands approx ____ times it’s size when converted to a gas

Answer 17

1700

Question 18

What is atmospheric pressure at sea level?

Answer 18

14.7 psi

Question 19

What is the engine pressure formula?

Answer 19

NP+FL+-HP+AL

Question 20

What is a Class A pumper?

Answer 20

Capable of delivering 100% it’s rated capacity at 100psi, 70% at 150psi, and 50% at 200 psi.

Question 21

What NFPA is the “Standard for Automotive Fire Apparatus”?

Answer 21

NFPA 1901

Question 22

What is the max recommended tip size for aerial ladders because of possible unsafe engine pressures?

Answer 22

1 3/4

Question 23

What is the maximum pressure pumped to a double jacket lined hose?

Answer 23

250psi

Question 24

What is the maximum pressure pumped to a double jacked unlined hose?

Answer 24

150psi

Question 25

What is the maximum pressure pumped to a polymer jacked locking hose?

Answer 25

180psi

Question 26

What is the NR formula for smooth bore nozzles?

Answer 26

1.5xD²xNP

Question 27

What is the NR formula for fog nozzles?

Answer 27

.05xGPMx√NP

Question 28

What is the GPM formula?

Answer 28

29.7xD²x√NP

Question 29

What is the friction loss formula for over or equal to 100GPM?

Answer 29

2Q²+Q

Question 30

What is the friction loss formula for under 100GPM?

Answer 30

2Q²+1/2Q

Question 31

What is the hydrant GPM formula?

Answer 31

29.7xD²x√NPx.9

Question 32

What is the square root of 50?

Answer 32

7.07

Question 33

What is the square root of 80?

Answer 33

8.94

Question 34

What are the 3 functions of a nozzle?

Answer 34

Control flow
Provide reach
Create stream shape

Question 35

What GPM is considered a master stream?

Answer 35

350GPM or greater

Question 36

A good fire stream…

Answer 36

90% in 15” circle

75% in 10” circle

Question 37

What are 4 factors that affect fire stream?

Answer 37

Air resistance
Gravity
Wind
Condition of the nozzle

Question 38

What is the formula for finding the horizontal reach of a fire stream?

Answer 38

1/2NP+26

Question 39

What is the percentage formula for calculating remaining hydrant water?

Answer 39

(Static-Flow)x100
          Over
Static
0-10 3 times
11-15 2 times
16-25 1 time
over 25 less than 1 times