Module 2 Sanitation Systems Above Ground Drainage

Question 1

What is the purpose of above ground waste?

Answer 1

1) permit the speedy removal of soil/waste to the underground drainage system without leakage 2) prevent the ingress of foul air and gasses into the building by efficient trapping 3) have adequate access for inspection/cleaning

Question 2

What is the term stack related to?

Answer 2

The vertical pipe

Question 3

What is the portion of pipe that carries the waste know as??

Answer 3

The discharge stack

Question 4

What is the portion of pipe that does not carry waste water??

Answer 4

Ventilation stack

Question 5

What is the branch discharge pipe??

Answer 5

It’s the pipe that carries waste water from a fitting to the main discharge pipe

Question 6

What are the different types of systems??

Answer 6

The single stack 2) the 1 pipe system 3) the 2 pipe system

Question 7

What is the single stack system??

Answer 7

It consists of only 1 main stack and has a set of rules to function

Question 8

What is the 1 pipe system?

Answer 8

It uses 2 stacks 1 for soil and 1 for waste discharge band 1 vent for each

Question 9

What is the 2 pipe system??

Answer 9

It uses 4 stacks 1 for soil discharge 1 for soil ventilation 1 for waste discharge and 1for waste ventilation

Question 10

Explain the 2 pipe system?

Answer 10

It was the first system of sanitation used and it consists of 4 pipes or stacks, the waste from the wc was discharged separately from the basin/bath water and each of these stacks ran separately to the drain, also each stack had its own vent pipes

Question 11

What is the one pipe system?

Answer 11

This system was first used in the USA it has been used extensively upon till recently

Question 12

What is trap ventilating pipes?

Answer 12

Every trap in the system must be ventilated with a pipe not less than 32mm (1 1/4”) this ensures a good circulation of air in the system preventing siphonage and compression

Question 13

What is the single stack system?

Answer 13

Initially it was limited to building of 5 stories high , after some years modifications were proposed which enabled buildings of up to 10 stories to be served recently instillation sip to 20 stories high using 6”(150mm) stacks have been installed

Question 14

Where is single stack system best used??

Answer 14

Apartment blocks hotels etc where sanitary fittings are grouped above each other on successive floors

Question 15

What are the rules of the single stack system??

Answer 15

1) connect each appliance separately to the stack. 2) limit the flows in the stack so plugs won’t form 3) maintaining a straight stack. 4) use correct pipe size 5) do not exceed specified lengths 6) correct fall on the pipes 7) lowest connection to the stack is a min of 450mm above invert drain 8) all fittings must be grouped closely to the main stack 9) traps of less than 50mm internal bore should have a seal no less than 75mm deep 10) waste connection shouldn’t be made within 200mm across/below from a ex branch 11) adequate access points should be fitted 12) the bend at the base of the discharge stack should be a long radius to prevent air compression

Question 16

What are the terms SOIL PIPE and WASTE PIPE?

Answer 16

The are both derived from the original two pipe system of sanitation where a soil pipe was connected to a wc and a waste pipe to an ablutionary fitting

Question 17

Name 3 types of soil fitting?

Answer 17

Rubber ring , solvent welded, electrofusion

Question 18

Where would you use a shallow sink trap??

Answer 18

Where a gully is been used

Question 19

What is a hopper head?

Answer 19

Is recommended for all first floor appliances to prevent flooding of septic system also allows the use of shallow traps on all systems when discharge is to a gully

Question 20

What are waste pipe connections?

Answer 20

For general purpose all water discharged from a waste or soil appliance is deemed to contaminated and must be disposed of in a safe efficient manner for this reason all sanitary fixtures must be connected to a waste pipe

Question 21

What is a trap???

Answer 21

It’s a fitting or part of an.appliance designed to retain an amount of water which then prevents the passage of foul air and dangerous gasses from the drain entering the building

Question 22

Where should traps be fitted??

Answer 22

Close to the waste or soil appliance unless it has an integral trap (a toilet)

Question 23

What are the different types of traps??

Answer 23

S traps , p traps, bottle , running, anti siphon

Question 24

What are two types of bottle trap?

Answer 24

Dip tube and dip partition

Question 25

What are the 7 most likely way to loss a trap seal ??

Answer 25

1) leakage 2) self siphonage 3) induced siphonage 4) evaporation 5) capillary attraction 6) compression 7) wavering out 8) momentum

Question 26

What is the waterless trap??

Answer 26

No water is used so no problem of siphonage or evaporation compression etc

Question 27

Talk about the waterless trap?

Answer 27

The valve can open when necessary to allow air into the system to neutralise any negative pressure, for this reason the rule of the single stack may be relaxed in the future where these valves are used