Definition of Terms Flashcards
generic term applied to any nozzle, wye, siamese, deluge monitor, or any other piece of hardware used in conjunction with fire hose for the purpose of delivering water.
Appliance
any pumping apparatus that is supplying water directly to attack lines.
Attack pumper
pumps used on all modern fire apparatus. This type of pump takes advantage of incoming pressure. Water enters the eye of the pump then travels through one or more impellers.
Centrifugal pumps
the quantity of water issuing from an opening expressed in gpm.
Discharge
actual velocity pressure of the water (measured in psi) for an individual hose line.
Discharge pressure
the rate at which water travels from an orifice and can be measured using a pitot gauge.
Discharge velocity
gain or loss of pressure in a hose line or system due to a change in elevation.
Elevation pressure
pressure created by the velocity of water coming from a discharge opening.
Flow pressure
the loss of pressure created by the turbulence of water moving against the interior walls, couplings, and connections of the hose or pipe
Friction loss
line run directly from a hydrant to an attack pumper.
Gutter line
water pressure due to elevation. For each foot of elevation above the pump the pressure increases by 0.434 psi.
Head pressure
master stream nozzle mounted to the fly of an aerial ladder.
Ladder pipe
any variety of heavy caliber water streams delivering 350 gallons or more.
Master stream
the pressure found in a water distribution system during normal consumption demands, at any moment in time.
Normal operating pressure
the velocity pressure at which water is discharged from the nozzle.
Nozzle pressure
counterforce directed against a person or a device holding a nozzle by the velocity of water being discharged.
Nozzle reaction
small positive displacement pump used to evacuate air from a centrifugal pump housing allowing the pump to receive water.
Primer pumps-
actual velocity pressure of the water (measured in psi) as it leaves the pump.
Pumper discharge pressure
a pumper that is between the source pumper and attack pumper. This pumper receives water from the direction of the source pumper and boosts pressure towards the attack pumper.
Relay pumper
pressure remaining in a water system when water is flowing.
Residual pressure
an appliance that combines two or more hose lines into one.
Siamese
the pressure exerted by water at rest in a confined vessel available to force the water through pipe, fittings, fire hose, and adapters.
Static pressure
the pumper connected to the water supply at the beginning of a relay operation.
Supply pumper or source pumper
the total amount of pressure loss in a hose assembly due to friction loss in the hose and appliances, elevations pressure, or any other factors.
Total pressure loss
the speed at which water passes a given point.
Velocity
the force created by the rapid deceleration of water. Generally occurs from opening or closing a valve too quickly. Damage to pumps, plumbing, and hose lines may occur.
Water hammer
an appliance that breaks one hose line into two or more hose lines with one female and two or more male outlets, usually gated.
Wye
