1305/314
PLUMBING CRAFT THEORY
June/July 2017
Time: 3 hours
THE KENYA NATIONAL EXAMINATIONS COUNCIL
CRAFT CERTIFICATE IN PLUMBING
PLUMBING CRAFf THEORY
3 hours
INSTRUCTIONS TO CANDIDATES
You should have the following for this examination:
Answer booklet;
Drawing instruments;
Mathematical tables/calculator.
The paper consists of EIGHT questions.
Answer FWE questions.
ALL questions carry equal marks.
Maximum marks for each part of the question are indicated.
Candidates should answer the questions in English.
This paper consists of 4 printed pages.
Candidates should check the question paper to ascertain that
all the pages are printed as indicated and that no questions are missing.
© 2017 The Kenya National Examinations Council Thmover
(a) Outline how safety is observed in each of the following:
(i) clothing;
(ii) behaviour;
(iii) self care;
(iv) storage of tools.
(6 marks)
(b) Sketch and label the following plumbing hand tools.
t.-\- (i) hacksaw;
(ii) pipe reamer.
(8 marks)
(c) Differentiate between ferrous and non-ferrous metals, stating two examples in each
case. (4 marks)
(d) State:
(i) the chemical name of water
(ii) the chemical symbol of water
(2 marks)
2. (a) Name three major sources of water. (3 marks)
.
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(b) Sketch and label a flange joint for a mild steel pipe water main. (5 marks)
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(c) A 14 storey building is to be supplied with water from the main. If the pressure on the
main is 300 Kpa, show the pipe arrangements for supplying the building with water, if
the local water authority allows a direct pumping from the mains. (12 marks)
(a) O~tline four design principles of direct system of hot water supply. (6 marks)
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~(b) ;~Differentiate between a tap and a valve in plumbing ins~allat' .ns_<'-' (3 marks)
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i~C)~:Sketchandlabelpipeconnectiontoawatertank. c~.,~~ '!!'~_:. ~~ ~tI' (4 marks)
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~ 0- List four Kenya building code requirements for sanitary appliances.
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(2 marks)
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_ Q (e) l~ § (i) Define the term alloy. _,,"
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1 a, (1 mark)
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e ~. (ii) Describe the following alloys:
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s, :;~ (I) brass; -:>- c.~?\,e< z ,,(
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1~1 (II) bronze. - <J>V
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June/July 2017
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4. (a) Explain the following water treatment processes:
(i) screemng;
(ii) sedimentation;
(iii) chlorination.
(6 marks)
(b) With the aid of a labelled sketch, explain the operation of a double trap siphonic water
closet. (8 marks)
(c) Sketch and label a single stack drainage system. (6 marks)
5. (a) Name three types of gas welding flames. 1>"-~:eN! (3 marks)
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(b) (i) With the aid of labelled sketches, differentiate between rightward and leftward
gas welding techniques. ~ (8 marks)
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(ii) Name four gas welding defects. (2 marks)
(c) Calculate the power output of a centrifugal pump which can lift 200 litres of water from
a shallow well 6 m deep in 10 seconds. 'O?~~l'" (7 marks) N
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(a) Name two physical and chemical properties of water. (4 marks)
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(b) List two examples of the following: ""II' ,.1 o'Co
(i) soil appliances;
(ii) waste appliances.
(4 marks)
(c) Sketch and label an indirect hot water supply system for a domestic house. (8 marks)
(d) Sketch and label a running joint on mild steel pipe. (4 marks)
7. (a) Outline four reasons for arc welding electrode coating. (6 marks)
(b) Sketch and label an alternating current arc welding set.
~markS)
1305/314 Turn over
June/July 2017
(c) Estimate the cost of installing sanitary appliances using the information shown
in table 1.
Table 1
SINo. Description Quantity Unit Unit cost
1 Water closet suite 2 No 3,750.00
2 Bath tub 1 No 7,850.00
3 Wash hand basin 2 No 1,900.00
Assume any other relevant information
Labour @ 10% cost of appliance
Overheads @ 5% cost of appliance
Profit @ 8% cost of appliance
(7 marks)
8. (a) Describe the procedure of tinning a soldering bit. (4 marks)
(b) State four positions where manholes are used in drainage systems. (4 marks)
(c) List two reducing agents used in water treatment. (2 marks)
(d) (i) Outline the four properties of a coagulant. (4 marks)
(ii) Outline four characteristics of below ground drainage system. (6 marks)
TIDS IS THE LAST PRINTED PAGE.
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June/July 2017
