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1304/314, , PLUMBING CRAFT THEORY, June/July 2012, , Time: 3 hours, , THE KENYA NATIONAL EXAMINATIONS COUNCIL, PLUMBING CRAFT CERTIFICATE, PLUMBING CRAFT THEORY, , 3 hours, , INSTRUCTIONS TO CANDIDATES, , You should have the following for this examination:, Answer booklet, Drawing instruments, Mathematical tables/Calculator, , Answer any FIVE of the following EIGHT questions., , All questions carry equal marks., Maximum marks for each part of a question are as shown., , This paper consists of 6 printed pages., , Candidates should check the question paper to ascertain that all the, pages are printed as indicated and that no questions are missing., , ©2012 The Kenya National Examinations Councit, , easytvet.com, , Turn over
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(b), , {c), , 1305/314, , easytvet.com, , Explain four classifications of fire stating a suitable extinguishing agent for each., (6 marks), , Fig. | shows details of a steel pipe fixed along a return angle masonry wall. Another, steel pipe, 35 mm in diameter, is to be bent and jointed to the existing pipe using a, union connection such that the distance from end of the pipe in union to the centre line, after bending is 700 mm., , Outline the procedure of making the 90° bend on the pipe using a hydraulic pipe bender., (8 marks), , , , Fixed point-where the pipe will, Screw up into the union, , , , , , , Existing steel, Pipe 35mm @, , , , , Union connection, , Masonry wal!, , FIG1, , (i) Explain furring in hot water systems and state three of its effects., , (ii) Sketch and label a typical water meter connection to a domestic water supply., (6 marks)
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—, , , , 2. fa), (b), {c), 3. (a), {b), (c), 4. {a), {b), 1305/314, , (i), (ai), , easytvet.com, state six safety precautions taken when using hacksaws., , Sketch and label an adjustable frame hacksaw. (6 marks), , Assess the quality of water obtained from the following sources for drinking purposes., , @, Gi), , Gii), , Rain water, Rivers and lakes, Wells and boreholes. (6 marks), , Milustrate with labelled sketches, details of the following fixtures:, , ®), (ii), , pillar tap, gate valve. (8 marks), , Classify the following into ferrous or non ferrous metals:, , - Copper - Zine, - Pig iron - Staintess steel, - Lead - Tin, - Aluminium - mild steel, - Cast iron - carbon steel, (5S marks), With the aid of a sketch, describe a wash down w.c. plan. (7 marks), , With the aid of a sketch, explain the operation of a solar water heating system., , @, (ii), , (i), , (ii), , (8 marks), Define the term “alloy”., Describe the following alloys stating the metal composition of each:, - Brass, - Bronze, (4+ marks), , Write down Thomas Box formula for sizing pipes for hot, and cold water installations and define all the terms., , Calculate the diameter of a pipe to discharge 1.45 litres per second when, the head is 5 m and the effective length is 36 metres. (6+ marks)
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easytvet.com, , (c) Sketch the Isyout plan for a separate system of drainage for the house and garage, , , , , , , , , , shown in fig. 2. (5 marks), AWP IO], GARAGE, rwe[O}, , rwp|O}, PONTE QGSUWAC Se Dall Ganon 9 Oe ee ee, Sayed Lala eo basa. oP i pe Re ie Tt EO ae, , FiG2, , (d) State four properties considered when selecting insulating materials for hot water, systems. (4 marks), , 5. @ @ Distinguish between gas welding and welding:, (ii) Explain the following types of braze welding, , I Bronze brazing;, , Tl Silver brazing. (6 marks), (b) Describe the following weld defects in are welding and state two causes of each, (i) Under-cut, (ii) Spatter, (iii) Porosity (6 marks), (c) Sketch and label the main features of a single stack system. (8 marks) |, , 6. (fa) 8) List four materials used for making rain water gutters,, , (ii) State three problems that can prevent rain water gutters from functioning, properly, (3+ marks), , 1305/314 4
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(b), , (©), , (d), , * (a), , (b), , (c), , (b), , 1305/314, , easytvet.com, , (i) Write down the specific heat capacity equation and define all the terms,, (ii) Caleulate the amount of heat required to raise the temperature of 250 litres, , of water from 20° C to 100 °C., , Take specific heat capacity of water = 4.18 Kj, (4 marks), Sketch and label the following types of joints:, (i) Manipulative joint in copper pipes., (i) Flexible *O" ring joint in clay pipes, (iii) Saddle connection to sewers. (8+ marks), With the aid of a sketch, explain the operation of 2 ball float steam trap. (4 marks), Explain the following in cold water supply:, (i) Water - hammer, (ii) Back - siphonage, (iii) Hydro - preumatic accumulator. (4> marks), (i) State six factors considered when designing rain water goods., (ii) A300 mm diameter UPVC sewer running at half bore at a velocity of, , 1.526 m/s is to be installed, Using the Chezy formula, calculate the minimum, , gradient for the sewer., , Take Chezy constant = 55 é, , (67 marks), , @ With the aid of a sketch, describe the working principle of a fusible soldered, strut head type of a sprinkler system., , (ii) With the aid of a sketch, describe the wet pipe sprinkler installations system,, (9 marks), , (i) State six factors observed when installing gas pipe work., , (ii) With the aid of a sketch, outline the procedure for soundness test in newly, , installed gas pipe work. (8 marks), Outline five design requirements for above ground drainage in multi-storey, buildings. (5 marks), 5s Turn over
