Chapter 13 : Sanitary Drainage Systems

Question 1

1.	All horizontal piping should have an adequate slope and size to maintain a minimum flow velocity of \_\_\_\_\_ so that the solids are always kept in suspension, thereby preventing pipe blockage.
A.	m/s (0.3 ft/sec)
B.	0.6m/s (2 ft/sec)
C.	m/s (1 ft/sec)
D.	0.5 m/s (1.6 ft/sec)
E.	0.8 m/s (2.6 ft/sec

Answer 1

B. 0.6m/s (2 ft/sec)

Question 2

2.	Horizontal branch piping 76 mm (3 in) or less in diameter should have a minimum gradient of \_\_\_\_\_ toward the stack.
A.	5 cm/m (5/8 in/ft)
B.	1 cm/m (1/8 in/ft)
C.	2 cm/m (1/4 in/ft)
D.	4 cm/m (1/2 in/ft)
E.	3 cm/m (3/8 in/ft)

Answer 2

C. 2 cm/m (1/4 in/ft)

Question 3

3.	Horizontal branch piping larger than 76 mm (3 in) should be installed with a slope of not less than:
A.	cm/m (5/8 in/ft)
B.	4 cm/m (1/2 in/ft)
C.	2 cm/m (1/4 in/ft)
D.	1 cm/m (1/8 in/ft)
E.	3 cm/m (3/8 in/ft)

Answer 3

D. 1 cm/m (1/8 in/ft)

Question 4

4.	The standard or common trap has \_\_\_\_\_ of maintaining the seal.
A.	16 mm (5/8 in)
B.	10 cm (4 in)
C.	38 mm (1-1/2 in)
D.	cm (2 in)
E.	75 mm (2-15/16 in)

Answer 4

C. 38 mm (1-1/2 in)

Question 5

5.	Each horizontal branch connection to the discharge stack should have a long turn elbow that meets the vertical stack at an angle of:
A.	45°
B.	80°
C.	90°
D.	33°
E.	25°

Answer 5

A. 45°

Question 6

6.	The temperature relief valve on a hot water heater is designed to open and prevent the temperature of the water in the tank from exceeding:
A.	99°C (210°F)
B.	80°C (176°F)
C.	89°C (192°F)
D.	100°C (212°F)
E.	160°C (320°F)

Answer 6

A. 99°C (210°F)

Question 7

7.	Water hammer noise is a pounding or banging of pipes and shuddering of fixtures, caused by a shock wave that results when the water flow in a pipe is:
A.	Suddenly started
B.	Suddenly stopped
C.	Slowly stopped
D.	Slowly started
E.	Suddenly heated

Answer 7

B. Suddenly stopped

Question 8

8. Water may leak from the flush valve of a water closet flush tank for the following reasons except:
   A. The ball could be defective
   B. There might be dirt on the ball or the seat
   C. The flush ball might not be seating properly
   D. The lift chain could be properly adjusted
   E. The flush seat might be corroded or worn

Answer 8

D. The lift chain could be properly adjusted

Question 9

9.	A water closet flush tank operates by means of two valves, one is the float-controlled valve (ball cock or float valve) that:
A.	Opens to flush the bowl
B.	Closes to fill the bowl
C.	Opens to drain the tank
D.	Closes to drain the tank
E.	Opens to fill the tank

Answer 9

E. Opens to fill the tank

Question 10

10. The first step in the procedure for replacing a faucet bibb washer is:
    A. Turn on the water supply
    B. Remove the valve handle or wheel
    C. Unscrew the cartridge from the valve body
    D. Shut off the supply of water at the nearest isolation valve
    E. Turn the faucet handle to a closed position

Answer 10

D. Shut off the supply of water at the nearest isolation valve

Question 11

11. The purpose of a trap in a sanitary sewer piping system is to:
    A. Stop hair and other solids from entering the sewer
    B. Keep soap scum from getting into the septic system
    C. Allow condensate to escape while holding back steam
    D. Trap sewer in the system
    E. Stop sewer gases from escaping from the waste system through the fixture

Answer 11

E. Stop sewer gases from escaping from the waste system through the fixture

Question 12

12. The float-controlled valve in a water closet flush tank may persistently leak and maintain water level at the top of the overflow pipe or the ball cock may not close, or may leak, for all of the following reasons except:
    A. The float arm has become incorrectly bent so that the float rubs against the side of the tank
    B. The float is holding a steady level in the tank
    C. The float rod requires adjustment so that the valve will close when water is at the correct level
    D. The valve washer may require replacement or the valve seat may be so badly damaged that positive shut-off is impossible
    E. Sand, grit, or other foreign material may hold the valve open

Answer 12

B. The float is holding a steady level in the tank

Question 13

13.	If the faucet leaks around the stem/spindle when opened, new \_\_\_\_\_ material is needed around the stem/spindle.
A.	Seat
B.	Stem
C.	Packing
D.	Disc
E.	Spindle

Answer 13

C. Packing

Question 14

14.	When the lowest drain in a building (such as in a sub-basement), is below the level of the municipal sewer line, a sump must be provided to collect and \_\_\_\_\_ the liquid sewage into the sanitary building drain.
A.	Pump
B.	Elevate
C.	Raise
D.	Lift
E.	Float

Answer 14

D. Lift

Question 15

15.	Soil and waste material are moved through the drainage piping with the help of:
A.	Water
B.	Air
C.	Steam
D.	Oil
E.	Grease

Answer 15

A. Water

Question 16

16.	A term used to describe the type of material conveyed in a sewage pipe is:
A.	Water
B.	Soil
C.	Drainage
D.	Grease
E.	Urine

Answer 16

B. Soil

Question 17

17.	The pressure in a plumbing vent system is:
A.	Slightly above atmospheric
B.	Atmospheric
C.	Neutral
D.	Slight vacuum
E.	Vacuum

Answer 17

B. Atmospheric

Question 18

18.	The material used for indoor sanitary drainage piping in commercial buildings is:
A.	Galvanized steel
B.	Cast iron
C.	ABS plastic
D.	PVC plastic
E.	Copper

Answer 18

B. Cast iron

Question 19

19.	The storage section of the hot water heater should be flushed at least once a \_\_\_\_\_ to prevent sediment from building up in the bottom of the heater.
A.	Shift
B.	Day
C.	Week
D.	Month
E.	Year

Answer 19

D. Month