CH.10 Operating Fire Pumps Flashcards
(41 cards)
when is cavitation created?
when air cavities are created in the pump or bubbles pass through the pump
what is the benefit of a fout-way hydrant valve
a second pumper can connect and boost pressure and not interrupt the flow of water
what is static pressure
pressure on the master intake gauge when connected to a water source but not flowing water
what is the general discharge psi for a standpipe (SBC number also)
150psi
what is the max lift an engine can do when in good working order?
25’
what is the benefit of the reverse lay?
it is the most direct method of supplementing hydrant pressure or doing drafting operations
what can happen to the pump if discharge pressure increases too much and the supply can’t keep up
cavitation could occur to the pump and or the supply system
what is medium diameter hose?
2.5-3” hose
what can occur if dirt or sand is taken into the pump?
it can act as an abrasive and can get into the pump packing and reduce its ability to seal
what is the distance the pump should be rated to lift when operating at its capacity
10’
what is cavitation?
in theory, water being discharged faster than it is coming into the pump
which type of hydrant is the “worst” option to be aware of?
A dead end main hydrant
what is the unit of measure for each foot of lift when drafting?
should be 1” mercury for each 1’ of lift
what is the best hose lay for a drafting operation?
a reverse lay
what is the unit of measurement on the intake gauge when drafting?
inches of mercury (since changes in pressure are so minute)
what should be done after nonpotable water is pumped through the apparatus?
the tank should be flushed
how much FL is found per floor on a multistory building?
5psi
what should be done when attempting to flow from a drafted source?
as the throttle is increased, open the discharge valve slowly (to maintain a prime) until the discharge pressure is achieved.
what are 3 ways to reduce pump from overheating when assisting in a relay operation or having to support a long lay
- establish a continuous minimum flow
- pull the booster line a distance and flow
- partially open tank-fill or tank-to-pump valve
in a severe case, what noise may be heard in the pump?
sound of gravel passing through the pump
what is an easy way to establish prime if the pump primer fails?
open the tank to pump to fill the tank and intake hose (assuming tank to pump valve is able to close)
what prevents water from backing from a standpipe at the FDC
clapper valves
how is a static water pressure reading obtained when connected to an external water source
when the tank is full and there isn’t any flowing water - read the master intake guage
why are dead end main hydrants the “worst” option to be aware of?
there is higher amounts of sediment & deterioration and are served by smaller mains from only one direction