84 terms

# Engineer Study 1

Hydraulics Pump Theory

#### Terms in this set (...)

How many square inches in a square foot
144 sq inches
How many cubic inches in a cubic foot
1728 cu inches
How many cubic inches in a gallon
231 cu inches
12 cubic inches of fresh water weigh
.434 pounds
27.7 cubic inches of fresh water will weigh
1 pound
One gallon of fresh water weighs___ pounds
8.35
One cubic foot of fresh water weighs __ pounds
62.5
How many gallons in one cubic foot
7.481
How many gallons of fresh water in one ton
239.5 (240)
Barometric pressure at sea level is ___ inches
29.92
Atmospheric pressure at sea level is
14.7 psi
Theoretical maximum height of draft is
33.9 feet
volume of a circular tank
v=.7854 x D2x H or 3.14 x r² x D x 7.5 D= avg. dept in feet, 7.5=# of gallons per cubic foot
volume of square/rectangular pools
v= L x W x D x 7.5
Discharge from a nozzle
dis= 30 xD² x square root of the pressure (field) dis= 29.7 x D² x square root of the pressure
Nozzle reaction
Tip 1.5 x D² x NP Fog .0505 x Q x square root of pressure
Discharge from an open butt
29.7 x D² x square root of pressure
to determine pressure when head is known
multiply the head by .434 psi
to determine head when pressure is known
multiply the pressure in psi by 2.304 feet
a column of water 2.304 feet high and 1" square will exert a pressure of
1 pound at the base (1 / .434)
a depth of one foot of water will create a pressure of
.434 psi at the base
FL principle - diameter
FL varies inversely to the 5th power of diameter of hose
FL principle- Length
FL varies directly with the length of lay
FL principle - GPM flow
FL varies appromately with square of increase in gpm (velocity flow)
FL principle - pressure
FL does not vary with pressure
1 cubic inch of mercury (Hg)
.49 psi
Pressure change due to elevation
minus .5 psi per 1000 feet of rise
1 inch of mercury (Hg) creates
1.13 feet of lift
Max. theoretical lift
33.9 ft (14.7x 2.304)(29.9x 1.13)
Max. practical lift
22.6 ft at sea level
2.304 of water column creates
1 psi
1 foot column of water creates
.434 psi at the base
1500 pumper capacity at 150 psi
100% 1500 gpm
1500 pumper capacity at 200 psi
70% 1050 gpm
1500 pumper capacity at 250 psi
50% 750 gpm
Drafting pressure correction
feet of lift + hose FL / divided by 2.304
E5 unit#
6236
E5 make
KME
E5 year
1999
E5 engine type
Catapillar 3406 E
E5 engine horsepower
435 horsepower at 2,100 RPM
E5 fuel tank size
65 gallons
E5 Transmission
Allison HD 4060 PR
E5 2nd brake
Trans Retarder
E5 pump type
Hale Qmax 1500
E5 water tank size
500 gallons
E5 foam tank size
both A Foam at 25 gallons each
E5 foam system
Hale Foam Pro
E5 pressure control device
Hale Relief valve
What is a Relief Valve?
Automatic pressure control device that protects firefighters and equipment by relieveing excess pressure to the intake side of the pump
How does a relief valve operate?
Water pressure vs. spring tension. Spring tension created in the pilot valve holds a needle valve shut. When water pressure over comes spring tension, water is allowed to flow through the needle valve and to the relief piston. The water pressure forces the relief piston down and allows water to flow from the discharge side of the pump to the intake side.
What is the operating range of the relief valve?
75-300 psi
What in (NPP) Net Pump Pressure
When taking water from a hydrant, it is the difference between the intake pressure and the discharge pressure. When drafting, it is the sum of the intake pressure and the discharge pressure. Intake pressures accounts for Lift and Intake hose FL.
Determine flow from smooth bore tips
GPM = 29.7 x d² x √NP
Definition of a Compound Gauge
The intake pressure on a fire pump. Capable of measuring positive or negative pressures.
feet above/below x .434 or for every 1 foot .434 psi is gain or loss.
What is the Indirect Cooler used for?
to control the temperature of the coolant in the apparatus engine during pumping operations
How does the Indirect Cooler work?
water being supplied fire pump passes through a coil mounted inside the cooler/heat exchanger so that it's immersed in the coolant. As cooler water passes through coil, some of the heat is absorbed and dissipated in the pump water and back to tank.
What is a definition of a Centrifugal Pump
Pump with impellar that utilizes centrifugal force to move water
How does the Centrifugal Pump work
imparts velocity to the water and converts it to pressure withing pump itself.
Explain how Theoretical Lift is determined
Although not possible, with a total vacuum at sea level a pump could theorectically lift water 33.9 feet.
Explain Practical Lift
maximum height to which any amount of water may be raised through a hard intake hose to the pump. It varies depending on the atmospheric pressure and the condition of the fire pump and primer.
What is the definition of Nozzle Reaction
it's the counterforce directed against the firefighter on the nozzle by the velocity of water being discharged
How to calculate Nozzle Reaction for a Fog nozzle
.0505 x Q x √NP Q= GPM Flow or 1/2 GPM @100psi
How to calculate Nozzle Reaction for a Smooth Bore nozzle
1.57 x d² x NP
What is the definition of Residual Pressure
means a remainder or what is left. It is a part of the total available pressure not used to flow lines and associated FL
What is the definition of Static Pressure
means at rest or without motion. The pressure in a water system before water flows from a hydrant.
definition of a Triple Combination Pumper
a pumper that carries a fire pump, hose, and water tank
What is a Positive Displacement Pump used for on our engines
it is used as a priming pump to get the water into the centrifugal pump during drafting operations
How many feet does 1 psi raise water in 1"x1' column of water
2.304 ft (2 ft field)
Name 5 things that effect drafting operations
1. Elevation 2. Temperature of water 3. Excessive Feet of lift 4. suction hose too small 5. clogged strainer 6. condition of the pump 7. ground instability
How do you keep hard suction hose from resting on bottom of drafting location
fasten a rope to strainer and tie it off keeping 2 ft off bottom
What is a Tachometer?
dashboard and pump panel guage that measures the engine speed in revolutions per minute (rpm)
What is the Angle of Departure?
angle formed by level ground and a line from the point where the rear tires of vehicle touch the ground to the lowest projection at the rear of the apparatus
At what speed will an emergency vehicle outrun the effective range of it's siren
speeds above 50mph
Traveling distance behind emergency vehicle Code 3
more than one emergency vehicle 300-500 ft.
Name 5 factors that determine placement of Attack Pumper
1. Method of attack 2. Rescue situations 3. Water Supply 4. Exposures 5. Terrain 6. Wind
What is Water Hammer?
Force created by the rapid deceleration of water
What type of Positive Displacement pump does CFD have on their Engines?
Rotary Vane, oil-less except for Br3 has oil
What are the 3 Tips we flow at 50psi (handlines)
1", 1 1/8", and 1 1/4"
What are the GPM's of the 3 handline tips
200, 250, 325
What are te 4 Tips we flow on our Master Stream (Deck Gun)?
1 3/8", 1 1/2", 1 3/4", 2"
What are the GPM's of the master stream tips
500, 600, 800, 1000
Fill in Blank... For every action there is_____
an equal and opposite reaction