10 Operating Fire Punps Flashcards
Typically the least desirable hydrants are those located on
Dead end mains
The most direct method of supplementing hydrant pressure or performing drafting operations is what type of lay
Reversed lay
What is important in order to determine how many extra lines you can flow
Static pump pressure with no water flowing intake connected
0 to 10% drop indicates how much more water is available
Three times amount of water being delivered
11 to 15% drop indicates how much water additionally is available
Two times amount being delivered
16 to 25% pressure drop indicates how much additional water is available
Same amount as being available
25% or more pressure decrease indicates how much additional water is available
More might be available but not as much as being delivered
Increasing the height of the drafting lift will decrease what
The total pump capacity
A condition that occurs when water is being discharged faster than it is coming into the pump. Creating air cavities or bubbles inside the pump and the shock that occurs as water fills these cavities
Cavitation
The surest indication of cavitation may be a lack of what on the pressure gauge to increases in the throttle
Response or reaction
Although cavitation can occur when operating from a hydrant system, it often occurs during what water supply operations
Drafting
Most important factor in choosing a draft site is
Amount of water available
In order for a pumper to approach it’s rated capacity using a traditional strainer there must be at least how many inches of water over the strainer
At least 24 inches
Because a floating strainer takes in water only from one side, the pumper may not
May not achieve its rated discharge capacity
When drafting from a portable tank or swimming pool what type of strainer is the appliance of choice
Low level or low profile
Bumpers are required to have a lift capacity for drafting at a minimum of how many feet of lift
10 feet of lift
To create an effective fire stream a lift from draft of no greater than how many feet is recommended
No more than 20 feet
When lifting water from draft 20 feet the pump operates at what percent of its rated capacity
About 60% of rated capacity
True false older butterfly type intake valves are normally removed before drafting because they reduce capacity
True
Most common cause of an air leak in a drafting operation
And open drain or valve
After obtaining a draft what should the pressure of the pump be increased to before opening discharges
50-100 psi
If while opening a discharge while drafting, the pump drops below 50 psi what do you do
wait a moment for the pressure to stabilize. If continues to drop, primer
Without water moving through the pump during drafting what can happen to the draft
An air leak can develop losing the draft
The most common source of problems while operating at draft is
Air leak on the intake side
If a whirlpool develops above the strainer what could happen during drafting
Strainer could suck in air
If the pump is operating draft, a gradual increase in vacuum is noted with no change in flowrate it is an indication of what
The blockage is developing
Appliance friction loss in a standpipe system
25 psi
Many manual standpipe systems are designed to be pumped at a pressure of what
150 psi
Hydrants served by a large means that are interconnected and grid pattern receive water from several directions and usually have a lesser amounts of
Sedimentation and deterioration
