TOPIC 7: Sanitary Drainage Systems

Question 1

TRUE OR FALSE: General Rules in designing the Sanitary system; The pipes should take the longest possible route to the house sewer or the terminating point of the Sanitary system.

Answer 1

FALSE: The pipes should take the shortest possible route to
the house sewer or the terminating point of the Sanitary system

Question 2

TRUE OR FALSE: General Rules in designing the Sanitary system; Control components such as clean-outs, traps, and vents, should be located strategically so as to ensure efficient circulation

Answer 2

TRUE

Question 3

Subsystems of the
Sanitary System:

Answer 3

Waste Collection System
Ventilation System

Question 4

Essential Parts of the
Sanitary Drainage System

Answer 4

Waste Pipe
Vent Pipe
Trap
Stack
Branch
House/Building Drain
House/Building Sewer

Question 5

Conveys only wastewater or liquid waste free of fecal matter

Answer 5

Waste Pipe

Question 6

used for ensuring the circulation of air in a plumbing system and for relieving the negative pressure exerted on trap seals.

Answer 6

Vent Pipe

Question 7

a fitting or device designed and constructed to provide, when properly vented, a liquid seal which prevents the backflow of foul air or methane gas without materially affecting the flow of sewage or wastewater through it.

Answer 7

Trap

Question 8

the vertical main of a system of soil, waste or vent pipings extending through one or more stories and extended thru the roof.

Answer 8

Stack

Question 9

any part of the piping system other than a main, riser or stack.

Answer 9

Branch

Question 10

part of the lowest horizontal piping of a plumbing system which receives the
discharges from the soil, waste and other
drainage pipes inside of a building and conveys it to the house sewer outside of the building.

Answer 10

House/Building Drain

Question 11

extends from the house drain at a point 0.60 meters from the outside face of the foundation wall of a building to the junction with the street sewer or to any point of discharge, and conveying the drainage of one building site.

Answer 11

House/Building Sewer

Question 12

House/Building Sewer extends from the house drain at a point ______ from the outside face of the foundation wall of a building to the junction with the street sewer or to any point of discharge, and conveying the drainage of one building site.

Answer 12

0.60 meters

Question 13

CHANGES IN DIRECTION OF SANITARY
DRAINAGE LINES

Answer 13

• Horizontal to Horizontal change in direction
• Vertical to Horizontal change in direction
• Horizontal to vertical change in direction

Question 14

use 45° wye branches, combination wye – 1/8 bend branches, or other approved fittings of equivalent sweep

Answer 14

Horizontal to Horizontal change in direction

Question 15

45° wye branches or other approved fittings of equivalent
sweep

Answer 15

Vertical to Horizontal change in direction

Question 16

use 45° or 60° wye branches, combination wye -1/8 bend branches, sanitary tee or sanitary tapped tee branches, or other approved fittings of equivalent sweeps.

Answer 16

Horizontal to vertical change in direction

Question 17

TRUE OR FALSE: No fitting having more than one inlet at the same level
shall be used (i.e., sanitary cross)

Answer 17

TRUE

Question 18

TRUE OR FALSE: Double sanitary tees may be used when the barrel of the fitting is at least two pipe (3) sizes larger than the largest inlet, (pipe sizes recognized for this purpose are 51, 64, 76, 89, 102, 114, 127, & 152 mm dia.)

Answer 18

FALSE: Double sanitary tees may be used when the barrel of the fitting is at least two pipe (2) sizes larger than the largest inlet, (pipe sizes recognized for this purpose are 51, 64, 76, 89, 102, 114, 127, & 152 mm dia.)

Question 19

TRUE OR FALSE: The size of waste pipes or soil pipes depend on the amount of waste it carries.

Answer 19

TRUE

Question 20

A lavatory discharges _______ (7.5 gallons per min or 1 cu ft per min), which is equivalent to the Fixture Unit (F.U.)

Answer 20

0.47 liters/sec or 28.3 liters/min

Question 21

A lavatory discharges 0.47 liters/sec or 28.3 liters/min (______), which is equivalent to the Fixture Unit (F.U.)

Answer 21

7.5 gallons per min or 1 cu ft per min

Question 22

A lavatory discharges 0.47 liters/sec or 28.3 liters/min (7.5 gallons per min or 1 cu ft per min), which is equivalent to the ______

Answer 22

Fixture Unit (F.U.)

Question 23

TRUE OR FALSE: The F.U. rating of plumbing fixtures is based on the color of the required trap.

Answer 23

FALSE: The F.U. rating of plumbing fixtures is based on the size of required trap.

Question 24

Maximum Trap Loading: Pipe Size: F.U.
32 mm: 1

Answer 24

Item No.: 1

Question 25

Maximum Trap Loading: Pipe Size: F.U. 38 mm: 3

Answer 25

Item No.: 2

Question 26

Maximum Trap Loading: Pipe Size: F.U. 51 mm: 4

Answer 26

Item No.: 3

Question 27

Maximum Trap Loading: Pipe Size: F.U. 76 mm: 6

Answer 27

Item No.: 4

Question 28

Maximum Trap Loading: Pipe Size: F.U. 102 mm: 8

Answer 28

Item No.: 5

Question 29

Capacity over 3.15 L/s shall be determined by the Administrative Authority.

Question 30

For a continuous flow into a drainage system, such as from sump pump or ejector, air-conditioning equipment or similar devices, _____ fixture units shall be allowed for every ____ of flow.

Answer 30

two (2); 0.063 L/s

Question 31

1 gpm = ____ L/s

Answer 31

0.063

Question 32

Discharge Capacity: Liters/Sec (GPM): F.U. Up to 0.47 L/s (Up to 7.5 gpm) : 1

Answer 32

Item No.: 1

Question 33

Discharge Capacity: Liters/Sec (GPM): F.U. 0.50 to 0.95 (8 to 15 gpm) : 2

Answer 33

Item No.: 2

Question 34

Discharge Capacity: Liters/Sec (GPM): F.U. 1 to 1.89 (16 to 30 gpm) : 4

Answer 34

Item No.: 3

Question 35

Discharge Capacity: Liters/Sec (GPM): F.U. 1.95 to 3.15 (31 to 50 gpm) : 6

Answer 35

Item No.: 4

Question 36

Minimum slope or pitch of horizontal drainage pipe – ____.

Answer 36

2% or 20mm/m (¼” per foot)

Question 37

Where it is impracticable due to depth of street sewer, adverse structural features and irregular building plans, pipes _____ diameter or larger may have a slope of not less than _____ approved by the Administrative Authority

Answer 37

102 mm ; 1% or 10mm/m (1/8” per foot),

Question 38

Types of Permissible Traps:

Answer 38

Common P-Trap Deep Deal P-Trap Stand Trap Running Trap Drum Trap

Question 39

Used for lavatories, kitchen sinks, laundry tubs, & urinals

Answer 39

Common P-Trap

Question 40

Materials commonly used for the P-trap: nickel, chrome plated brass, Galvanized malleable copper, & PVC.

Answer 40

Common P-Trap

Question 41

Water seal is about twice the size of The common P-trap

Answer 41

Deep Deal P-Trap

Question 42

Used for fixtures such as slop sinks that are usually built low in the ground, leaving very little space for a foundation & a trap

Answer 42

Stand Trap

Question 43

Used for extreme conditions because resealing quality is greater

Answer 43

Deep Deal P-Trap

Question 44

Serves as a water seal & structural support for the fixture

Answer 44

Stand Trap

Question 45

Used within the line of the house drain

Answer 45

Running Trap

Question 46

Has a large diameter (around 0.16 m) Used for fixtures that discharge large amount of water (bathtubs, shower or floor drains)

Answer 46

Drum Trap

Question 47

Types of Prohibited Traps:

Answer 47

- Traps with movable parts or concealed interior partitions - No shall be double-trapped - The S-Trap

Question 48

The S-Trap

Answer 48

- Predecessor of P-traps - Used before traps had to connect to a ventilation line

Question 49

Traps REQUIREMENT: TRUE OR FALSE: Each plumbing fixture, except those with integral traps, shall be separately trapped with an approved-type waterseal trap.

Answer 49

TRUE

Question 50

Traps REQUIREMENT: TRUE OR FALSE: Multiple traps shall be permitted on a trap arm (portion of a fixture drain between a trap and the vent).

Answer 50

FALSE: Only one trap shall be permitted on a trap arm (portion of a fixture drain between a trap and the vent)

Question 51

Traps REQUIREMENT: One trap, centrally located, may serve ____ single compartment sinks or laundry tubs or lavatories, adjacent to each other and in the same room, where their waste outlets are not more than ____ apart.

Answer 51

three; 0.75 m

Question 52

SIZE OF TRAPS: The trap shall be a different size than the trap arm to which it is connected.

Answer 52

FALSE: The trap shall be the same size as the trap arm to which it is connected.

Question 53

Each fixture trap shall have a trap seal of water of not less than ____ and not more than ____ (except where a deeper seal is found necessary by the Administrative Authority for special conditions.

Answer 53

51 mm; 102 mm

Question 54

Minimum sizes of traps for common plumbing fixtures: Trap and Trap arm size: F.U. 38 mm : 2

Answer 54

1. Bathtubs 2. Bidets

Question 55

Minimum sizes of traps for common plumbing fixtures: Trap and Trap arm size: F.U. 51 mm : 2

Answer 55

3. Floor drains 4. Shower, single stall

Question 56

Minimum sizes of traps for common plumbing fixtures: Trap and Trap arm size: F.U. 38 mm : 2

Answer 56

5. Sink (residential)

Question 57

Minimum sizes of traps for common plumbing fixtures: Trap and Trap arm size: F.U. 51 mm : 3

Answer 57

6. Urinal, wall mounted, integral trap

Question 58

Minimum sizes of traps for common plumbing fixtures: Trap and Trap arm size: F.U. 32 mm : 1

Answer 58

7. Wash Basin (single)

Question 59

Minimum sizes of traps for common plumbing fixtures: Trap and Trap arm size: F.U. 76 mm : 4

Answer 59

8. Water Closet (private installation)

Question 60

Minimum sizes of traps for common plumbing fixtures: Trap and Trap arm size: F.U. 76 mm : 6

Answer 60

9. Water Closet (public installation)

Question 61

INSTALLATION OF TRAPS: The vertical distance between a fixture outlet tailpiece and the trap weir shall not exceed ____ in length.

Answer 61

0.60 m

Question 62

Horizontal Distance of Trap Arms: Distance to vent: 0.76

Answer 62

32 mm

Question 63

Horizontal Distance of Trap Arms: Distance to vent: 1.07

Answer 63

38 mm

Question 64

Horizontal Distance of Trap Arms: Distance to vent: 1.52

Answer 64

51 mm

Question 65

Horizontal Distance of Trap Arms: Distance to vent: 1.83

Answer 65

76 mm

Question 66

Horizontal Distance of Trap Arms: Distance to vent: 3.05 m

Answer 66

102 mm and larger

Question 67

The developed length of the trap arm (measured from the top of closet ring to inner edge of vent ) of a water closet or similar fixture shall not exceed ___.

Answer 67

1.8 m

Question 68

For trap arm ___ diameter or larger, a cleanout is required for a change of direction of greater than ___

Answer 68

76 mm; 22 ½ °

Question 69

a device designed and installed to separate and retain deleterious, hazardous or undesirable matters from normal wastes and permits normal sewage or liquid wastes to discharge into the disposal terminal by gravity

Answer 69

Interceptors

Question 70

Interceptors shall have a water seal of not less than ____ deep.

Answer 70

152 mm

Question 71

TRUE OR FALSE: Each interceptor shall be properly vented.

Answer 71

TRUE

Question 72

TRUE OR FALSE: Slaughterhouses, packing establishments, and any establishment which discharges wastewater with considerable amounts of grease, hairs, feathers, etc. shall drain directly into the sewer system without passing through a screening device or grease interceptor.

Answer 72

FALSE: Slaughterhouses, packing establishments, and any establishment which discharges wastewater with considerable amount of grease, hairs, feathers , etc. shall drain through a screening device and thence into a grease interceptor.

Question 73

TRUE OR FALSE: Auto wash racks and/or floor or slabs used for cleaning machinery or machine parts shall be adequately protected against storm or surface water and shall drain into an interceptor which will separate oil and grease before the effluent reaches the public stream.

Answer 73

TRUE

Question 74

Cleanout required: at the _____ of every horizontal sewer or waste line

Answer 74

upper terminal

Question 75

Cleanout required: at each run of piping more than _____ in total developed length

Answer 75

15 meters (50 feet)

Question 76

Cleanout required: at every 15 m (50 ft) of total ___ thereof

Answer 76

developed length or a fraction

Question 77

Cleanout required: additional clean-out shall be provided on a horizontal line with an aggregate offset angle exceeding ___

Answer 77

135°

Question 78

Cleanout required: inside the building near the connection between the building __and the___ or installed outside the building at the lower end of the building drain and extended to grade.

Answer 78

drain ; building sewer

Question 79

Cleanouts not required: on a horizontal drain _____ in length unless such line is serving sinks or urinals.

Answer 79

less than 1.5 m

Question 80

Cleanouts not required: on short horizontal drainage pipe installed at a slope of ____ or less from the vertical line (or at an angle of ___)

Answer 80

72 deg; 1/5 bend

Question 81

TRUE OR FALSE: The size of the clean-out shall have no relation to the size of the pipe served.

Answer 81

FALSE: Size of clean-out shall be in conformity with the size of pipe served

Question 82

Clean-Out Size: Size of pipe: Size of cleanout 38 mm : 38 mm

Answer 82

11-1/2 THREADS PER 25.4MM

Question 83

Clean-Out Size: Size of pipe: Size of cleanout 51 mm : 38 mm

Answer 83

11-1/2 THREADS PER 25.4MM

Question 84

Clean-Out Size: Size of pipe: Size of cleanout 64 mm : 64 mm

Answer 84

8 THREADS PER 25.4MM

Question 85

Clean-Out Size: Size of pipe: Size of cleanout 76 mm : 64 mm

Answer 85

8 THREADS PER 25.4MM

Question 86

Clean-Out Size: Size of pipe: Size of cleanout 102 mm and larger : 89 mm

Answer 86

8 THREADS PER 25.4MM

Question 87

INSTALLATION OF CLEAN-OUTS: Each clean-out shall be installed so it opens with the ___ or ___ to the direction of flow except in the case of a wye branch.

Answer 87

direction of flow or at right angles

Question 88

INSTALLATION OF CLEAN-OUTS: Each 90° clean-out extension shall be constructed from _____

Answer 88

a wye fitting or an approved fitting of equivalent sweep.

Question 89

INSTALLATION OF CLEAN-OUTS: Each clean-out 51 mm or less shall have a front clearance of not less than ___ ; those 51 mm or more shall have a front clearance of _____.

Answer 89

305 mm ; 450 mm

Question 90

INSTALLATION OF CLEAN-OUTS: Clean-outs in underfloor piping shall be extended to or above finish floor or shall be extended outside the building when there is less than ____ or _____ to the means of access.

Answer 90

450 mm vertical clearance or 750 horizontal clearance

Question 91

INSTALLATION OF CLEAN-OUTS: No underfloor clean-out for residential occupancies shall be located ______ an access door, trap door or crawl hole.

Answer 91

more than 6.1 m from

Question 92

GREASE TRAPS: For establishments like restaurants, cafes, lunch counters, cafeterias, bars and clubs, hotel, hospital, sanitarium, factory or school kitchens. A grease trap is not required for _____.

Answer 92

individual dwelling units

Question 93

GREASE TRAPS: No grease trap shall be installed for a facility that has an approved rate of flow of more than ____ nor less than ____.

Answer 93

3.4 liters per second (54.26 gpm) ; 1.3 L/s (20.74 gpm)

Question 94

GREASE TRAPS: Each grease trap shall have an approved water seal of not less than ____or the diameter of its outlet, whichever is greater.

Answer 94

51 mm in depth

Question 95

GREASE TRAPS: No food waste disposal unit shall discharge into a ___ or ___.

Answer 95

grease interceptor or grease trap

Question 96

Used for fixtures where grease may be introduced into the drainage or sewer system in quantities that can effect line stoppage or hinder sewage treatment or private sewage disposal.

Answer 96

GREASE TRAPS:

Question 97

2 Main types of Grease traps

Answer 97

- Earth Cooled Grease Trap - Mechanical Grease Trap

Question 98

Operating Principles (separation of grease from water): grease suspended in waste ______

Answer 98

floats to the surface

Question 99

Grease Trap Capacity: Required rate of flow: Grease Retention Capacity 76 L/ min. 18 Kg

Answer 99

Total # of fixtures connected: 1

Question 100

Grease Trap Capacity: Required rate of flow: Grease Retention Capacity 95 L/ min. 23 Kg

Answer 100

Total # of fixtures connected: 2

Question 101

Grease Trap Capacity: Required rate of flow: Grease Retention Capacity 132 L/ min. 32 Kg

Answer 101

Total # of fixtures connected: 3

Question 102

Grease Trap Capacity: Required rate of flow: Grease Retention Capacity 189 L/ min. 45 Kg

Answer 102

Total # of fixtures connected: 4

Question 103

Placed in the house drain immediately inside the foundation wall of the building

Answer 103

HOUSE TRAPS:

Question 104

Used to prevent groundwater from seeping through the basement walls & foundation Hollow tiles are placed around the perimeter of the foundation where water is collected; drain tiles are connected to the house drain or sump pit

Answer 104

DRAIN TILES:

Question 105

a.k.a. garage catch basin Operating Principles: trap is filled with water & located at the lowest point of the garage so it can collect all wastes.

Answer 105

Garage Traps:

Question 106

Used in house drain to prevent the unlikely occurrence of back flows Similar to check valves

Answer 106

Back Flow Valves:

Question 107

Pumps the wastes up form the sump pit to the sewers (which are usually higher than basement levels)

Answer 107

Sewage Ejectors: