________ 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.
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.
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
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.
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.
The maximum capacity of a front mounted pump depends on the limitations of the engine driving it, typically up to _____ 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
The piping system and the fire pump itself must be capable of withstanding a hydrostatic test of ____ psi before being placed into service.
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.
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.
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.
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
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
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.
The two basic types of intake pressure relieve valves include:
> One that is supplied by the pump manufacturer and an integral part of the pump intake manifold
The second type is an add-on device that is screwed onto the pimp intake connection.
The ___________ is designed to regulate the engine speed to match the pump discharge requirements.
The electronic governor also features ________ protection by returning the engine to idle when intake pressure drops below ___ psi.
A ____________ is needed to create a vacuum that makes drafting posssible.
Primers fall into several categories including _________, _____, ______, and ________.
NFPA 1901 requires that all controls and instrucments necessary to operatet the pump are located on the pump operator’s panel. These include:
> Master pump intake pressure indicating gauge
Master pump discharge indicating gauge
Pump engine tachometer
Pumping engine coolant temperature indicator
Pimp pressure controls (discharge valves)
Pumping engine throttle
Water tank to pump valve
Water tank level indicator
The master intake gauge is usually calibrated from __ to ____ psi of positive pressure and from __ to ___ inches of mercury on the negative side.
0 to 600 psi
0 to 30 in Hg
When the vacuum reading approaches ___ psi, the pump is nearing its capacity and is not able to supply additional lines.
There are severl types of throttles available, inclduing a throttle knob (also called a _______), that can be turned clockwise or wounterclockwaide to achieve the required pressure. Automatic throttle controls operated by a ________ or ________ are commonly found on newer apparatus.
Throttle switch or Push Button
The primary function of an _________________ is to control the temperature of coolant in the apparatus engine during pumping operations. Older apparatus usually contain one of two ___________: either the _______ or ________ type
Auxiliary cooling system
Marine or Immersion