9. Fire pump theory Flashcards Preview

*IFSTA Pumping > 9. Fire pump theory > Flashcards

Flashcards in 9. Fire pump theory Deck (16)
Loading flashcards...
1

__ pumps are self priming, deliver a definite volume of water or air, and exhaust air from the pump and deliver water.

Positive displacement pump

Constant flow machines

2

$$$

___ pumps operate using a piston they moved back and forth in a cylinder.

Piston

3

This pump is classified as a non-positive displacement pump as it does not pump a definite amount of water with each at Revolution.

Centrifugal pump

4

$$$

The off center mounting of the impeller within the casing create a water passage of gradually increasing size as it nears the discharge outlet at the pump. This section of the__

Volute

5

$$$

Three main factors influence a centrifugal fire pumps discharge pressure:

Amount of water being discharge

speed at which the impeller is turning

pressure of water when it enters the pump from a pressurize source

6

Two basic types of centrifugal pumps are used by the fire service

Single stage and multi stage

7

In the parallel mode, the pump will be capable of supplying ___% of its rated capacity at ___ psi at 10 feet of left with 20 feet of suction hose while drafting.

100%
150psi

8

__ valve are essential to the operation of a multistage pump that permits the flow of water in one direction only

Clapper or check valve

9

Heat developed by friction where the packing rings come into contact with the shaft. In order to overcome this a spacer known as a __ is supplied with the packing to provide cooling.

Lantern or slinger ring

10

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

11

$$$

As a minimum, all fire apparatus with a rated pump capacity of 750 GPM’s or greater must be equipped with at least two __ inch discharges.

2 1/2 inch

12

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

3 inches

3 seconds

13

Pressure control device must operate within __ seconds after the discharge pressure rises and restrict the pressure from exceeding __ psi above the set level.

3-10 sec

30 psi

14

$$$

It is generally recommended that the intake relief valve be set to open when the intake pressure rises more than __ psi above the necessary operating pressure.

10 psi

15

The electronic governor also features cavitation protection by returning the engine to idle when intake pressure drops below __ psi

30 psi

16

A throttle is used to increase or decrease the speed of the engine that powers the fire pump. There are several types of the throttles available, including a __, That can be turned clockwise or counterclockwise to achieve the required pressure.

throttle knob also called a vernier