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easytvet.com, , }, , 1305/314, PLUMBING CRAFT THEORY, , June/July 2018, ‘Time: 3 hours, , THE KENYA NATIONAL EXAMINATIONS COUNCIL, , CRAFT CERTIFICATE IN PLUMBING, , PLUMBING CRAFT THEORY, , 3 hours, , INSTRUCTIONS TO CANDIDATES, , You should have the following jor this examination:, Answer booklet;, Drawing instruments,, Mathematical tables/calculator., Answer any FIVE of the following EIGHT questians,, All questions carry equal marks., Maximum marks for each part of a question are as 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., , © 2018 The Kenya National Examinations Council Turn over

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easytvet.com, , , , 1, (a) Explain the principle of the fire triangle and state how it may be used in fire fighting., , (5 marks), (b) Sketch and label cach of the following tools used in plumbing:, (i) chain pipe wrench;, (i) wheel cutter,, (6 marks), (c) With the aid of a labelled sketch, explain the operation of an equilibrium bail valve., (9 marks), 2, (a) Explain cach of the following water treatment processes:, (i) coagulation;, (ii) disinfection,, (5 marks), , (b) With the aid ofa labelled sketch explain the operation of a pressure water filter., (8 marks), , (c) State four safety precautions observed when using oxy-acetylene gas welding, equipment, (4 marks), , ({d) __IMlustrate each of the following defects in gas welding:, , (i) undercut;, (ii) poor penetration., (3 marks), 3 (a) Sketch and label a fully vented one-pipe system to a two storey building serving three, appliances on cach floor. (9 marks), (b) Outline four causes of loss of seal water in a trap. (6. marks), (c) Explain two below ground drainage tests. (5 marks), , 4. (a) With the aid of a labelled sketch explain the operation ofa hydraulic ram. (12 marks), (b) Sketch and label a bimetal flame-failure device and describe how it works. (8 marks), , 1305/314 2, Sunes July 2018

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5, {a), {b), (c), , (b), , (c), , T {a), (b), , fe), , (b), (c), , 1305/314, June/huly 2018, , easytvet.com, , List six points in a drainage system where a manhole must be provided. (3 marks), Sketch and label a septic tank and explain how it operates. (11 marks), Sketch the symbols used for the following appliances:, , (i) water closet;, , (ii) wash hand basin;, , (iii) kitchen sink, (6 marks), , (i) Sketch and label as direct domestic hot water system., (ii) Outline the situation that would necessitate the use of an indirect hot water, , system. (10 marks), , With the aid of a labelled sketch explain how a delay action ball valve operates,, (6 marks), State four factors that influence the selection of a pump. {4 marks), State four sources of heat of boilers. a (2 marks), , With the aid of a labelled sketch, explain the operation of a gas storage water heater., (8 marks), , Sketch and label a cold water storage cistern and explain three specifications for pipe, connections, (10 marks), , Sketch each of the following arc welding joints:, , (i) but joint;, (ii) fillet, (4 marks), Sketch and label a grease trap and outline its operation. (5 marks), Tilustrate each of the following pipe joints:, (i) cast iron joint;, (ii) serewed joint;, (iii) PVC cement weld joint;, (iv) copper silver soldered joint., (6 marks), 3 ‘Turn over, , thi

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easytvet.com, , (d) A32 mm diameter black mild steel pipe is to be heat bent to the shape shown in, figure 1., , Calculate the total length of the pipe required. (5 marks), , , , , , , , Fig. 1, , NB all dimensions in mm., , THIS IS THE LAST PRINTED PAGE.