Flashcards in Pump Manual Deck (97)
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.
British Thermal Unit: a unit of energy needed to cool or heat one pound of water by one degree Fahrenheit.
Determines flow from solid bore nozzles and solid stream orifices such as a hydrant port.
Equation for determining GPM from a solid bore
GPM = 29.7 x D squared x Square Root of NP (80 or 50)
Class B: 3% for hydrocarbons, 6% for polar solvents. Class A: 0.1%-1.0% based on situational need
aka Velocity Pressure. Pressure created by the rate of flow or velocity of water coming from a discharge. Measured using a pitot gauge.
Pressure generated by the weight of a column of water above the pump. For every 1-foot increase in elevation, .434 psi is gained.
A large caliber hose stream capable of flowing 350 GPM or more.
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.
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).
Needed Fire Flow. The amount of water needed to control the fire within 1 minute.
Net Pump Discharge Pressure. The actual amount of pressure being produced by the pump. Net PDP = discharge pressure - incoming supply pressure.
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.
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.
The stored potential energy available to force water through pipes, fittings, fire hose, and adaptors while water is at rest.
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.
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.
1 gallon contains how many cubic inches?
1 cubic foot of water weighs how much?
1 cubic foot contains how many gallons?
1 gallon of water weighs how much?
A column 1 foot high exerts how much pressure at the base?
1 psi will raise a column of water how high?
Doubling the velocity of water through hose will have what effect?
Quadruple the friction loss
A perfect vacuum is what?
About 30" Hg
A perfect vacuum will raise water how high?
One gallon of water will absorb how many BTU's?
1 BTU means what?
The heat required to raise 1 lb of water 1 degree F
1 cubic foot of water expands how much at 212 degrees F?
1700 cubic feet of steam