Pump Manual - Properties of Water

Question 1

Cubic inches in 1 gal

Answer 1

231

Question 2

cubic inches in a cubic ft

Answer 2

1,728

Question 3

Weight of 1 cubic foot of water

Answer 3

62.4 lbs

Question 4

Gallons in 1 cubic foot

Answer 4

7.48

Question 5

Weight of 1 gal

Answer 5

8.34 lbs

Question 6

PSI in 1 ft column of water

Answer 6

0.434 PSI at base

Question 7

1 PSI will raise a column of water how high?

Answer 7

2.304 ft ( = 1 / 0.434 )

Question 8

Parallel hose lines reduce friction loss by what %?

Answer 8

75%

Question 9

One gal water absorbs how many BTUs?

Answer 9

9,343

Question 10

Heat need to raise 1 lb of water 1 degree F?

Answer 10

1 BTU

Question 11

Heat to vaporize 1lb of water at 212 degrees

Answer 11

971 BTU

Question 12

Heat to vaporize 1 gal of water at 212 F?

Answer 12

8,080 BTU

Question 13

1 cubic foot of water expands to how many of steam at 212 degrees?

Answer 13

1700 cubic feet

Question 14

1 gal water expands to how many cubic feet of steam at 212?

Answer 14

227

Question 15

1 gal will absorb all of the heat that can be produced with available oxygen in how many cubic ft of air?

Answer 15

200

Question 16

“Reasonable Efficiency” (80%) - how many BTUs are absorbed per gal of water with this assumption?

Answer 16

7,474 BTUs

Question 17

Iowa Formula - what is it?

Answer 17

Estimates GPM needed to control a fire in a specific area

GPM = cubic feet involved / 100

Question 18

Two formulas needed when estimating water for fire attack

Answer 18

Needed fire flow (NFF)

Total water needed for extinguishment

Question 19

Needed Fire Flow (NFF)

Answer 19

NFF = [ (length x width) / 3 ] x % involvement

Question 20

Total Water Needed for extinguishment (formula)

Answer 20

Total Water Needed = (Area x FLD x BTU) / 9,343

FLD = 4.3 lbs/ft (constant)

BTU/pound = 16,000 (constant)

So…

Total Water Needed = (Area x 4.3 x 16,000) / 9,343

Question 21

Principles of Water Pressure #1

Answer 21

Fluid pressure is perpendicular to any surface on which it acts

Question 22

Principles of water pressure #2

Answer 22

When a fluid is at rest, fluid pressure is the same in all directions

pg 10

Question 23

Principles of Water Pressure #3

Answer 23

When there is an increase in pressure at any point in a confined fluid, there is equal increase at every other point in the container (Pascal’s law)

pg 10

Question 24

Principles of water pressure #4

Answer 24

The downward pressure of a liquid in an open vessel is proportional to its depth

pg 10

Question 25

Principles of water pressure #5

Answer 25

The downward pressure of a liquid in an open vessel is proportional to the liquid density (e.g. mercury is 13.55 times as heavy as water and exerts more downward pressure) pg 11

Question 26

Principles of Water Pressure #6

Answer 26

The downward pressure of a liquid in an open vessel is not affected by the shape of the container pg 11

Question 27

7 types of pressure: Atmospheric

Answer 27

Pressure exerted on surface of earth by weight of air - 14.7 PSI at sea level (decreases w/ increase in elevation; 1 PSI of atmosphere will raise a column of water 2.31 ft) - Feet of water 33.9ft theoretical lift (14.7 psi x 2.31ft = 33.9) - good pumper max lift = 22-25ft - dependable lift = 14.7ft - Hg = 30 inches (inches of mg in vacuum gauges) -- pumpers in good condition can create vacuum of 22" mg - 1" mg on the pump vacuum gauge = 1.13 ft column of water can be lifted (1.13 x 22 = 25ft max lift) pg 12

Question 28

7 types of pressure: Elevation Pressure

Answer 28

0.434 psi / ft or 5 psi / floor pg 12

Question 29

7 types of pressure: flow pressure

Answer 29

measurement of water coming from a discharge opening (reading on pressure gauge) pg 12

Question 30

7 types of pressure: head pressure

Answer 30

refers to the height of a water supply above the discharge Convert feet to head by dividing feet by 2.304 1 / 0.434 = 2.304 pg 12

Question 31

7 types of pressure: normal operating pressure

Answer 31

Pressure in a water system during normal consumption demands; once water starts flowing we no longer have static pressure. Difference between static pressure and NOP is friction loss pg 12

Question 32

7 types of pressure: Residual pressure

Answer 32

Pressure remaining in the system after water is flowing (used to estimate additional flow capacity) pg 12

Question 33

7 types of pressure: static pressure

Answer 33

pressure when water is not flowing; this is the pressure you read on the fire pump when no discharges are open pg 12.

Question 34

10/15/25 rule

Answer 34

10% drop from initial residual compound reading = additional 3x the current GPM flow 15% drop = additional 2x the current GPM flow 25% drop = additional 1x the current GPM flow pg 13