Pump Ops Chpt 7 Flashcards Preview

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Flashcards in Pump Ops Chpt 7 Deck (26)
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Friction loss and elevation pressure loss are combined with the loss associated with appliances added to the layout to create ______.

Total pressure loss TPL


May be determined using calculations or for more precise information, by performing tests using the actual equipment and conditions likely to be encountered in the field.

Friction loss


The only truly accurate method for determining _______ in a particular hose lay involves pressure at both ends of the hose line and subtracting the difference.

Pressure loss


Friction loss formula


FL friction loss

C friction loss coefficient

Q flow rate in hundreds of gallons per minute

L hose length in hundreds of feet


Generally, a loss of ____ or greater is assumed when flowing the rated capacity. For this text, it is assumed that there is a _____ loss for flows less than 350 gpm and a ____ loss for each appliance in a hose assembly when flowing 350 gpm or greater. For this manual, a friction loss of ______ for all master streams appliances, regardless of flow, will be used.

25 psi

0 psi

10 psi

25 psi


Elevation Pressure loss

EP= 0.5H

EP elevation pressure in pounds per square inch

0.5 a constant

H height in feet


Pump discharge pressure


PDP pump discharge pressure in pounds per square inch

NP nozzle pressure in pounds per square inch

TPL total pressure loss


Solid steam nozzle handline

50 psi


Solid stream nozzle (master stream)

80 psi


Fog nozzle

100 psi


Low pressure fog nozzle

50 or 75 psi


When required to discharge a specified pressure, fire apparatus pumps take advantage of the water pressure coming into the pump water supply and add the required pressure to achieve________.

Net pump discharge pressure NPDP


NDNP = PDP - intake reading

NDNP net pump discharge pressure from a positive source

PDP pump discharge pressure


____ operate using a ____ that moves back and forth in a cylinder.

Piston pumps



As a minimum, all fire apparatus with a rated pump capacity of 750 gpm of greater must be equipped with at least ____ 2 1/2 inch discharges. Pumps rated less than 750 rpm are required to have only ____ 2 1/2 inch discharge.




A friction loss of ___ for all master stream appliances, regardless of flow, will be used

25 psi


Involves friction loss, loss to gain due to elevation, as well as appliance friction loss when flows exceed 350 gpm

Total pressure loss


The _______ whether used as a supply or attack line, presents the simplest friction loss calculation

Single hose lay


When using more than one hoseline of equal length and equal diameter, friction loss calculations need only be made for

One line


When two hoselines of equal length are Siamesed to supply a fire stream, friction loss is approximately _______ less than that of a single hoseline at the same nozzle pressure

25 percent less


In order to determine the required pressure for a standpipe system, the _____ must be calculated

Total pressure loss


Occasionally, and incident may require the use of multiple hoselines of the same or different diameter that are of unequal length. When presented with this scenario, the driver must calculate the friction loss for each hoseline supplied by separate discharges to individual nozzle. The hose with the highest friction loss represents the __

Total pressure loss at the pump, assuming that there is minimal change in elevation

Multiple hoseline unequal length


When hoselines are unequal in and or diameter is different, the total pressure loss is based on the

Highest pressure loss in any of the lines


When calculating pressure loss with a master stream device, the driver operator must add _____ to the pressure loss calculation

25 psi


When considering pressure loss in an elevated waterway, assume a loss of _____ for the waterway and master steam device

25 psi


When supplying multiple hoselines, the driver operator will need to compensate for the specific pressure requirements of individual lines. Calculate and set the pump discharge pressure based on the hoseline with the

Greatest pressure requirement