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Flashcards in 8 Water Supply Distribution Systems Deck (66):
1

Two basic types of water supply systems

Public,
private

2

For components of an effective public water supply distribution system

Water supply source.
Processing or treatment facility.
Means of moving water.
Distribution system, including storage.

3

Primary source of water in North America

Groundwater

4

Layers of porous rock the capture groundwater and retain it

Aquifer

5

Three methods for moving water through the system

Gravity. Direct pumping. Combination

6

Water pressure caused by the source being at elevation

Elevation head pressure

7

Interlocking network of water mains the compose a water distribution system

Grid, or grid iron

8

Arterial Water mains beginning at 16 inches and exceeding 72 inches

Primary feeders

9

Intermediate water pipes that interconnect with the primary felines to create a grid 12 to 14 inches in size

Secondary feeder

10

Small water mains, 6-8 inches in diameter, that serve individual fire hydrants and commercial/residential customers. May form intermediate grid or dead ends

Distributors

11

Minimum size pipe often used

8 inches, although 6 inches is used in some subdivisions

12

Gravity tanks are used for

Maintaining and ensuring constant water pressure

13

Device used to control or interrupt the flow of water to individual hydrants or properties

Control valve

14

How often should control valves be exercised

Once a year

15

Maximum spacing for water control valves and high-value districts

500 feet

16

Maximum control valve spacing in other areas that arent considered high value

800 feet

17

Control valve for water distribution systems are probably divided into

Indicating, nonindicating

18

Two common indicator type valves

Post-indicator valve PIV
Outside stem and yoke valve OS&Y

19

A partially closed valve would not be noticed during normal water usage however during fire suppression operations it would be noticed because

High friction loss would reduce quality of water available

20

A valve that prohibits water that may be contaminated, from flowing back into public water system

Backflow preventer

21

Advantage of a wet barrel system

All working parts located above grade for easier maintenance and use

22

Disadvantage of wet barrel hydrant

Cannot be using claimant susceptible to freezing

23

Size of the large outlet on a hydrant often referred to as the pumper outlet nozzle or steamer connection

4, 4 1/2 inches

24

Hydrant discharge outlets are considered standard if they contain the following two components

4-4 1/2 inch main outlet, two 2.5 inch couplings

25

Hydrant specifications require what size valve opening for standard three-way hydrants

5 inches

26

Hydrant specifications require what size connection to the Watermain

6 inches

27

How often should hydrant inspections occur

Twice a year

28

Generally the barrel of the fire hydrant is painted chrome yellow for municipal hydrants and what color for private hydrants

Red

29

The use of violet to designate hydrants is done in the case when

Non-potable water supply has been established

30

Light blue indicates what class and fire flow of hydrant

AA CLASS
1500 gpm or more

31

What class and fire flow is a green hydrant indicate

Class A
1000-1499 gpm

32

What class and gallons per minute flow does a orange hydrant indicate

Class B. 500-999 GPM

33

What classification and fire flow is a red-indicate

Class C 500 GPM

34

Private water supply distribution systems are most commonly found on

Large commercial industrial or institutional properties

35

In general private water supply distribution systems exist for one of the three following purposes

Fire protection purposes.
Sanitary and fire purposes.
Manufacturing and fire purposes

36

Private water supply distribution systems commonly receive their water from

Municipal supply

37

Almost all private water supply distribution systems maintain what for private fire protection and domestic or industrial services

Separate piping for each

38

Many significant fire losses can be traced to

Failure of private water supply systems being used for firefighting

39

Mand open lake or pond or enclosed truck are similar to a tank used as a water source

Reservoir

40

Tanks located at ground level and provide a water supply source for pressure increasing fire pumps. Capacities typically from 100,000-300,000 gallons

Suction tanks

41

Pressure tanks usually range in size from

3000-9000 gallons

42

Gravity tanks are used to

Stabilize or balance water pressure at times of peak demand

43

Gravity tanks that are 100 feet high generate a pressure of only

43 PSI

44

Gravity tank capacity ranges from

5000-500,000 gallons

45

Small structures that contain standpipe connections and a large hoseline pre-connected to the discharge outlet

Hose houses

46

Pressure remaining at any given point in the water supply system while water is flowing

Residual pressure

47

Fire flow test of water supply systems include what pressures

Static and residual pressure

48

When should flow test be done of a water main systems and hydrants

After extensive improvements.
Construction of water line extensions.
Every five years

49

Although fire hydrants on private water supply systems are the responsibility of the property owner, inspector should still

Witness the hydrant test

50

Materials needed to complete inspection of fire hydrant

gauge for checking discharge outlet threads (female coupling)
Lubrication
Gate valve key
Pressure gauge in hydrant cap
Pitot gauge
12 quart Pail
Stream diffuser

51

The clearance between the bottom of the butt (discharge) of the hydrant and the great should be at least

15 inches

52

A pitot gauge should be held in the center of the screen with a small opening or point centered and approximately how far from the opening

One half the diameter of the opening.
That's 1.25" for a 2.5 " discharge

53

Generally 2.5 inch outlets should be used to conduct hydrant flow test because streams of the larger outlet are

Contain voids in the stream

54

20 PSI residual pressure can be defined as enough pressure to overcome friction inside anyone of the following

Short 6 inch branch pipe.
Hydrant.
Apparatus intake hose

55

20 PSI minimum residual pressure is often required by the EPA for health reasons because

It prevents contaminants from external sources from being drawn into the system

56

Hydrant from where A pitot or cap gauge is used to find static and residual

Test hydrant

57

Hydrant from which water is discharged in a fire flow test is done

Flow hydrant

58

Flow hydrant should be located how in reference to the test hydrant

Downstream

59

A strong probable flow may require several hydrants be open to ensure accurate results. And of hydrants should be open to drop the static pressure by at least

10%. And a 25% should more accurate results be required

60

Growth crust or lump corrosion on the inside walls of water mains can reduce the diameter of the pipe and lower capacity

Encrustations

61

Encrustation is caused by

Chemicals
Organism or bio growth
Degradation of pipe materials
Rust deposits
Salt accumulated
Bioreactor a from organisms in water

62

Sedimentation deposits are

Mud Clay or leaves
Foreign matter like rocks tools woods or lead

63

Two ways to compute fire flow test results

Graphical analysis, mathematical computation

64

Size of primary feeders

16-72"

65

Size of distributors

6-8"

66

Size of secondary feeders

12-14"