4.1 Identify the water-heating system above - NSC Civil Technology Civil Services - Question 4 - 2019 - Paper 1
Question 4
4.1 Identify the water-heating system above.
4.1.2 What will be the result of continuous use of hot water from this system?
4.1.3 Why must the glass panel of this ... show full transcript
Worked Solution & Example Answer:4.1 Identify the water-heating system above - NSC Civil Technology Civil Services - Question 4 - 2019 - Paper 1
Step 1
Identify the water-heating system above.
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Answer
The system depicted in Figure 4.1 is a solar water heating system, commonly referred to as a solar geyser or solar panel with a geyser.
Step 2
What will be the result of continuous use of hot water from this system?
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Answer
Continuous use of hot water from this system without replenishing can lead to water getting cold, as the system requires sunlight to heat water effectively.
Step 3
Why must the glass panel of this system be cleaned regularly?
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The glass panel must be cleaned regularly to ensure maximum operating efficiency and to prevent dirt accumulation that can obstruct sunlight absorption.
Step 4
Briefly explain an airlock in a hot-water system.
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An airlock is a pocket of trapped air within a pipe that prevents the flow of water, disrupting the hot-water supply in the system.
Step 5
State TWO causes of water hammer.
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Sudden drops in secondary supply pipes.
Pipes in walls are not properly secured.
Step 6
Draw the following symbols:
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Answer
4.5.1: (single manual control, single lever)
4.5.2: (combined with an air release valve).
Step 7
Identify the type of water trap.
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Answer
The type of water trap shown in Figure 4.6 is an S-Trap.
Step 8
Name the minimum diameter of the waste pipe that connects to the water trap.
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The minimum diameter of the waste pipe that connects to the water trap is 40/50 mm.
Step 9
Identify the pipe fittings in A and B above.
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A: T Junction (Plain).
B: 90° bend with inspection eye.
Step 10
State where you would install EACH of the pipe fittings in A and B.
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A: Where the soil pipes with the same diameter meets.
B: Above ground where soil pipes have to change direction at a 90° angle.
Step 11
Recommend ONE tool that can be used: To thread and cut pipes.
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A pipe-thread cutting machine is recommended for threading and cutting pipes.
Step 12
Recommend ONE tool that can be used: For pressure testing of water systems.
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A water pressure testing pump can be used for pressure testing of water systems.
Step 13
Recommend ONE tool that can be used: To clean and unblock drains using high water pressure.
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A drain-cleaning machine or jetting machine can be utilized to clean and unblock drains using high water pressure.
Step 14
Identify the tap in FIGURE 4.11 above.
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The tap shown in Figure 4.11 is a pillar tap.
Step 15
Recommend TWO places where you could use this tap.
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Sinks/Kitchen.
Baths/Bathroom/En-suite.
Step 16
Local authorities use A to determine the water usage of a household. What is this fitting called?
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This fitting is called a water meter.
Step 17
Identify B and explain what the function of this fitting is.
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B is a full way valve/stop cock, which functions to shut off the water supply.
Step 18
Name the type of tap that is used at C.
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The type of tap used at C is a bibcock or bib tap.
Step 19
Predict if a chemical reaction will take place if a high-density polyethylene pipe is connected to A.
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No reaction will take place between the polyethylene pipe and the water meter.
Step 20
What is the electrochemical reaction called when zinc is selectively leached from copper pipe?
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The electrochemical reaction is referred to as dezincification.
Step 21
Name TWO water-saving devices that can reduce water waste due to taps that are left open when water supply is shut down and restored later.
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Sensor taps.
Demand pillar taps.
Step 22
Differentiate between a pressure-control valve and temperature and pressure safety valve in terms of its use.
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Answer
A pressure-control valve regulates and controls the incoming water pressure to a building, while a temperature and pressure safety valve reduces/releases pressure within a water system to prevent excessive pressure buildup.
