Chapter 9 - Fire Pump Theory Flashcards Preview

IFSTA Pumping and Aerial Apparatus Driver/Operator Handbook - 3rd Edition > Chapter 9 - Fire Pump Theory > Flashcards

Flashcards in Chapter 9 - Fire Pump Theory Deck (40)
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________ operate using a piston that moves back and forth in a cylinder. These multicylinder, PTO-driven pumps can provide pressures up to _____ psi for high-pressure fog lines, or to inject foam concentrate into a water line or manifold at a higher pressure than the water pump is creating.

Piston Pumps
1,000 psi


The total amount of water than can be pumped by a rotary gear pump depends on the ______________ and _________.

Size of the pockets in the gears and the speed of rotation.


Three main factors influence a centrifugal fire pump's discharge pressure:

> Amount of water being discharged
> Speed at which the impeller is turning
> Pressure of water when it enters the pump from a pressurized source.


The increase is ______ is roughly equal to the square of the change in impeller ____. For all other factors remaining constant, doubling the ______ of the impeller will result in four times as much _______.


2x speed = 4x pressure


In parallel mode, the pump will be capable of supplying 100% of its rated capacity at ____ psi at ___ feet of lift with ___ feet of suction hose while drafting.

150 psi
10 ft
20 ft


A very close tolerance must be maintained between the pump casing and the hub of the impeller. This opening is usually limited to ____ inch or less

0.01 inch


The most common type of seal packing material is composed of ____________________________.

Rope fibers impregnated with graphite or lead.


The most common applications for auxiliary engine driven pumps are:

> Airport rescue fire fighting (ARFF) vehicles
> Wildland fire apparatus
> Mobile water supply apparatus
> Trailer mounted fire pumps
> Portable fire pumps


In some cases, Auxiliary Engine Driven Pumps may be part of a skid-mounted assembly that includes small water tank, booster reel, and small diameter attack lines. With a pumping capacity of generally ____ gpm or less.

500 gpm


In the past, conventional PTO units were limited to powering pumps up to approximately ____ gpm. However, some manufacturers now provide full torque power take-offs that allow for the installation of pumps as large as _____ gpm.

500 gpm
1,250 gpm


The maximum capacity of a front mounted pump depends on the limitations of the engine driving it, typically up to _____ gpm.

1,250 gpm


On mid-ship mounted pumps the gear ratio is arranged so that the impeller turns faster than the engine, usually ____ to ____ times as fast

1-1/2 to 2-1/2 times


Some mid-ship mounted pumps can be rated anywhere from ____ to _____ gpm with no major changes to the pump itself.

500 to 2,250 gpm


With the engine idling and the pump engaged, most speedometers will indicate between ___ to ___ mph.

10 to 15 mph


The rear-mount design offers a number of advantages, including _________ and ____________.

More even weight distribution on the chassis and more usable compartment space.


The primary parts of the piping system are ______ and _________ piping as well as _________ and ______.

Intake and discharge piping
pump drains and valves


Most pipes are constructed of __________, _______, ________, or ____________ and may include __________ in certain applicaitons

Cast Iron, Brass, Stainless Steel, or Galvanized Steel
Rubber Hoses


The piping system and the fire pump itself must be capable of withstanding a hydrostatic test of ____ psi before being placed into service.

500 psi


According to NFPA 1901, pumpers with a capacity of _____ gpm or less should have the piping capable of flowing ____ gpm. Pumpers with a capacity greater than ____ gpm should be able to flow at least ____ gpm.

<= to 500 gpm - 250 gpm
> than 500 gpm - 500 gpm


Many pumpers are equipped with tank-to-pump piping as large as __-inch in diameter



Pumps rated greater than _____ gpm capacity may require more than one large intake connection at each location.

1,500 gpm


Based on NFPA 1901, a sufficient number of 2-1/2-inch discharge openings must be provided to flow the rated capacity of the pump. As a minimum, all fire apparatus with a rated pump capacity of ____ gpm or greater must be equipped with at least ___ 2-1/2-inch discharges. Pumps rated less than ____ gpm are required to have only ___ 2-1/2-inch discharge. Discharges greater than 2-1/2-inches in diameter may not be located on the pump operator's panel.

>=750 gpm - 2 x 2-1/2 inch discharges
< 750 gpm - 1 x 2-1/2 inch discharge


A minimum of _____-inch pimping, valves, and elbows must be used to supply discharges where 1-1/2, 1-3/4, or 2-inch handlines are attached.



All valves should be designed and maintained so that they are easily operable at pressures of up to ____ psi.

250 psi


According to NFPA 1901, apparatus equipped with tanks of less than _____ gallons must have a tank fill line of at least __-inch in diameter. Tanks greater than _____ gallons must be provided with at least a __-inch tank fill line.

< 1000 gallons - 1-inch tank fill line
> 1000 gallons - 2-inch tank fill line


The most common type of valve is the ____-____ valve that permits the full flow of water through a line with the minimum friction loss. The most common actuators for ____-____ valves are either ____-____ handles (T-handles) or _______-____ handles. The ____-____ valve handles on some pumpers use a sliding gear tooth rack that engages a sector gear connected to the valve stem.

push-pull handles (T-handles) or quarter-turn handles


____ valves are most commonly operated by a _________. _________ valves are most commonly operated by _______-____ handles.

Gate valves
Butterfly valves
quarter-turn handles


NFPA 1901 requires that all intake or discharges that are __ inches or greater be equipped with slow acting valve controls. This feature prevents the valve movement from open to close (or vice versa) in less than __ seconds

3 seconds


NFPA 1901 requires some type of pressure control device to be part of any fire apparatus pumping system. This device must operate within ___ to ____ seconds after the discharge pressure rises and restricts the pressure from exceeding ___ psi about the set level.

3 to 10 seconds
30 psi


There are two basic concepts for pressure relief valves:

> Those that relieve excess pressure on the "discharge side" of the pump.
> Those that relieve the excess pressure on the "intake side" of the pump.