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Flashcards in Pump Manual Deck (97)
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1

Atmospheric Pressure

Pressure exerted by the atmosphere at the surface of the earth due to the weight of air. At sea level it is 14.7 psi.

2

BTU

British Thermal Unit: a unit of energy needed to cool or heat one pound of water by one degree Fahrenheit.

3

Freeman's Formula

Determines flow from solid bore nozzles and solid stream orifices such as a hydrant port.

4

Equation for determining GPM from a solid bore

GPM = 29.7 x D squared x Square Root of NP (80 or 50)

5

Eductor Rate

Class B: 3% for hydrocarbons, 6% for polar solvents. Class A: 0.1%-1.0% based on situational need

6

Flow Pressure

aka Velocity Pressure. Pressure created by the rate of flow or velocity of water coming from a discharge. Measured using a pitot gauge.

7

Head Pressure

Pressure generated by the weight of a column of water above the pump. For every 1-foot increase in elevation, .434 psi is gained.

8

Master Stream

A large caliber hose stream capable of flowing 350 GPM or more.

9

Maximum Lift

The height a pumper in good condition can be expected to lift water at draft. Generally considered 2/3 of theoretical lift, or between 22 and 25 feet.

10

Maximum Dependable Flow

75% of the total capacity of an engine. This is the maximum flow for an engine during a relay operation (NFPA standard).

11

NFF

Needed Fire Flow. The amount of water needed to control the fire within 1 minute.

12

Net PDP

Net Pump Discharge Pressure. The actual amount of pressure being produced by the pump. Net PDP = discharge pressure - incoming supply pressure.

13

Reasonable Efficiency

Term to describe the percentage of water that is actually converted to steam when applied to a fire. The accepted amount is 80% of water will be converted to steam and 20% will be wasted.

14

Residual Pressure

Pressure at the test hydrant while water is flowing. Represents the pressure remaining in the water system while the test water is flowing and is that part of the total pressure that is not used to overcome friction or gravity while forcing water through the hose, etc.

15

Static Pressure

The stored potential energy available to force water through pipes, fittings, fire hose, and adaptors while water is at rest.

16

Theoretical Lift

Theoretical, scientific height that a column of water may be lifted by atmospheric pressure in a true vacuum; at sea level it is considered 33.9 feet.

17

Type 1 or Class A pumper

A centrifugal pump that delivers 100% of its capacity at 150 psi, 70% at 200 psi, and 50% at 250 psi as measured from draft lifting water higher than 10 feet.

18

1 gallon contains how many cubic inches?

231

19

1 cubic foot of water weighs how much?

62.5 lbs

20

1 cubic foot contains how many gallons?

7.48 gallons

21

1 gallon of water weighs how much?

8.34 lbs

22

A column 1 foot high exerts how much pressure at the base?

.434 psi

23

1 psi will raise a column of water how high?

2.304 feet

24

Doubling the velocity of water through hose will have what effect?

Quadruple the friction loss

25

A perfect vacuum is what?

About 30" Hg

26

A perfect vacuum will raise water how high?

33.9 feet

27

One gallon of water will absorb how many BTU's?

9343 BTU

28

1 BTU means what?

The heat required to raise 1 lb of water 1 degree F

29

1 cubic foot of water expands how much at 212 degrees F?

1700 cubic feet of steam

30

Iowa formula for estimating GPM needed to control a fire.

GPM = Cubic feet involved / 100 (Used with legacy fuels)