4.1 FIGURE 4.1 below is a drawing of a device used in cold-water systems - NSC Civil Technology Civil Services - Question 4 - 2021 - Paper 1
Question 4
4.1 FIGURE 4.1 below is a drawing of a device used in cold-water systems. Study FIGURE 4.1 and answer the questions that follow.
4.1.1 Name the device in FIGURE 4.1... show full transcript
Worked Solution & Example Answer:4.1 FIGURE 4.1 below is a drawing of a device used in cold-water systems - NSC Civil Technology Civil Services - Question 4 - 2021 - Paper 1
Step 1
4.1.1 Name the device in FIGURE 4.1.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The device in FIGURE 4.1 is a full-way valve.
Step 2
4.1.2 Identify parts A, B and C.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Part A is the hand wheel, part B is the valve head, and part C is the valve body.
Step 3
4.1.3 Explain the function of D if part D is turned anti-clockwise.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
When part D is turned anti-clockwise, it will move upwards, opening the tapered gate. This action allows for the flow of water through the valve.
Step 4
4.2 Differentiate between a pillar tap and a bibcock by referring to the way in which it is installed to/on a sanitary fitment.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
A pillar tap is installed directly onto a sanitary fitment in a vertical position with a long leg, while a bibcock is fixed into the pipework, allowing for an attachment to the wall.
Step 5
4.3 Choose a description from COLUMN B that matches an item in COLUMN A.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
4.3.1 F, 4.3.2 G, 4.3.3 E, 4.3.4 J, 4.3.5 B, 4.3.6 C, 4.3.7 H, 4.3.8 A.
Step 6
4.4.1 Identifying the tool to determine differences between levels and vertical heights.
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The tool to be used is a dumpy level.
Step 7
4.4.2 Identifying the tool for moving sludge or liquid containing suspended matter.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
A centrifugal pump should be used.
Step 8
4.4.3 Identifying the tool for ensuring a proper free-flowing sewer operation.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
A drain cleaning machine (jetting machine) is suitable for this task.
Step 9
4.5 Explain ONE method to limit water usage in a water closet.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
One method to limit water usage in a water closet is to place a brick or solid object inside the cistern to reduce the volume of water used for each flush.
Step 10
4.6 Name the device that protects the water supply inside a cistern.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The device that protects the water supply inside a cistern is a ball valve or float valve.
Step 11
4.7.1 Explain the function of A.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Part A functions as a vacuum breaker, allowing air to enter the pipe when necessary to prevent siphoning.
Step 12
4.7.2 Name the device omitted at B.
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The device omitted at B is a pressure control valve.
Step 13
4.7.3 Identify C.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Part C is identified as a stopcock or full-way valve.
Step 14
4.7.4 Is the water in pipe D HOT or COLD? Motivate your answer.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The water in pipe D is cold. Cold water enters at the bottom of the geyser, while hot water exits at the top.
Step 15
4.7.5 Identify E.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
Part E is a drip tray.
Step 16
4.8 Draw SANS approved symbols for hot-water systems.
98%
120 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
4.8.1 Symbol for balancing device: [B symbol], 4.8.2 Symbol for pressure-control valve: [J symbol], 4.8.3 Symbol for pressure switch: [PS symbol].
Step 17
4.9.1 Predict the cause for water spluttering through taps.
97%
117 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The cause of water spluttering through taps could be a trapped airlock in the pipes.
Step 18
4.9.2 Explain how this fault can be prevented.
97%
121 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
This fault can be prevented by ensuring that pipes shorter than 1 meter are installed horizontally with an upward slope, and using vent valves if the pipes are longer.
Step 19
4.10 State TWO precautionary methods to avoid an electrolytic reaction.
96%
114 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
To avoid an electrolytic reaction in a water system, use materials of the same type for fittings and pipes, and avoid joining materials of different types without proper insulation.
Step 20
4.11.1 Name ONE type of acid for cleaning galvanised sheeting.
99%
104 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
One type of acid that can be used is hydrochloric acid.
Step 21
4.11.2 Give the scientific name of the white rust/corrosion.
96%
101 rated
Only available for registered users.
Sign up now to view full answer, or log in if you already have an account!
Answer
The scientific name for the white rust or corrosion that occurs is zinc oxide.
