Water Utilities (ch.5)

Question 1

The pressure of water to elevation;
____ psi per foot of elevation

Answer 1

.433psi

Question 2

The city of LA uses a combination system to supply an average of ______gallons of water per day to ___
million people

Answer 2

600 million gal.
4 million people

Question 3

Tr u n k l i n e s c a r r y w a t e r f r o m a p r i m a r y s o u r c e ( r e s e r v o i r s , p u m p s , e t c . ) t o m a i n s w i t h i n a
distribution system. Trunk lines can vary from ___ inches to ____feet in size, and are
constructed from iron or concrete

Answer 3

36”to 10’

Question 4

MAINS
Mains normally run beneath a street and parallel to a curb, can vary from ___to ___inches
in size, and are constructed from iron pipe.

Answer 4

2 to 72in

Question 5

Service lines run between____
Customer lines run between ____

Answer 5

Service line = between main and water meter
Customer line = between water meter and structure

Question 6

Building owners are normally responsible for maintenance and repair of: x2

Answer 6

1. Plumbing from shut off valve
2. All plumbing inside of structure

Question 7

The centerpiece or lid normally identifies the type of utility with the word(s) “WATER,” “DWP,” “L.A. Water,” “LA DWP WATER,” or “CITY WATER METER,” and are often marked with _____paint.

Answer 7

Blue

Question 8

Indicating Type Valve These valves indicate an open or closed position and are characterized by ______ and ______

Answer 8

outside stem and yoke (OS&Y) valves and post indicator valves (PIV).

Question 9

Water Meter is used to calculate water usage for a domestic water service. Water
meters are normally directly adjacent to shut-off valves and vary in size from____to _____
inches (inlet-outlet size).

Answer 9

1/2 to 10 in

Question 10

Used to calculate water usage for domestic water services that can use low and high water flows

Answer 10

Compound meter

Question 11

Compound meters are ____ inches or larger

Answer 11

4inches

Question 12

Pressure reducing valves

Dwellings commonly use ___ to ___ psi

Answer 12

40 to 80

Question 13

SFD
Domestic water services consists of a ___ to __ in single water meter

Apt.’s
Domestic water service consists of _ to _ inch customer line’s

Hotels= ___ to ___ inch water meter

High rise
___ to ___ water meter

*if a structure has dorthy may what size vault?

Answer 13

1/2 to 2 in
1 to 3in
4 to 6inch
4 to 10
*dorthy Mae sprinklers have a separate 2inch fire service vault

Question 14

Types of sprinkler systems; x 4

Answer 14

Automatic wet pipe system-pipes filled with water,
Automatic dry pipe system-pipes filled w/ air
Non automatic system-dry pipes/fdc required
Deluge system- can be open or closed

Question 15

Standpipe systems; x2

Answer 15

Dry standpipe -Siamese connection, 2 1/2 in outlets each floor
Wet standpipe- 100’ of 1 1/2” unlined single jacket hose with a 1/2”straight tip with no shut off

Question 16

When closing a ball, cone, or gate valves that are _____inches or larger, it may be necessary to exercise a valve to completely eliminate the flow of water as valves can become encrusted with rust and scale. When a stubborn cone valve is encountered, slightly loosen the nut on the bottom of the valve (if accessible) and strike the threaded shaft with a hammer. This will drive the shaft into the valve and free the valve. The valve may now be shut off

Answer 16

3inches

Question 17

Ball valves do not or do have nut on the bottom valve

Answer 17

Do not

Question 18

What size service line should dip be requested to handle shut off

Answer 18

4” or larger

Question 19

Depending upon the buildings system a partial system shut down or full system shut down will control the water. Use Sectional shut off or ___ valves

Answer 19

Zone valves

Question 20

The fire hydrant gate valve is normally found in direct line with the fire hydrant and perpendicular to the curb. A _____ inch diameter cap (usually painted _____) covers access to the gate valve. Some gate valve locations are indicated by arrows etched on the adjacent curb.

Answer 20

6 in

Question 21

Fire hydrant gate valves may require ___ to ___ full turns

Approximately ___% of all fire hydrant gate valves close in a clockwise direction

Answer 21

18 to 26 turns

98 percent clockwise

Question 22

When notifying OCDS of a sheared off fire hydrant, include the following:
X3

Answer 22

Hydrant location
If shut off
Number of valves operated

*ocd will notify dwp operating trouble board

Question 23

Service lines = ____ to ____”

Answer 23

1/2” to 12”