Plant Maintenance And Work Services 11 2004 question paper
INSTRUCTIONS TO CANDIDATES:
You should have the following for this examination:
Answer any FIVE of the following EIGHT questions.
All questions carry equal marks
Maximum marks for each part of a question are as shown.
1.(a) (i) Briefly explain the procedure of clearing the interior parts of a water tube boiler.
(ii) List down any SIX maintenance checks that may be carried out on fire tube boilers.
(iii) State any FOUR causes of boiler explosions.(8marks)
(b) (i) Using a sketch, show a steam main drainage system.
(ii) State any THREE causes and their remedies for each of the following problems of steam traps:-
(I) trap does not discharge
(II) trap blows steam
(i) With the aid of a sketch,describe the construction and operation of an open top bucket steam trap.(12marks)
2.(a) State in each case any THREE problems that result in a hydraulic system when the fluid viscosity is:-
(i) too low
(ii) too high(3marks)
(b) List any THREE maintenance checks for following valves used in hydraulic systems:-
(i) Spoon directional control
(ii) Direct acting relief(3marks)
(c) State any THREE causes and their remedies for each of the following problems of a hydraulic oil:-
(d) (i) With the aid of a diagram,describe the spigot and socket method of joining cast iron pipes in water distribution systems.
(ii) With the aid of a diagram,explain the method of water filtration using a slow sand filter.(8marks)
3.(a) (i) Explain any FOUR causes of fabric failure in air pollution control filters.
(ii) List any SIX maintenance checks of venture scrubbers used in pollution control.(7marks)
(b) (i) State any THREE causes and their remedies for each of the following problems in a centrifugal pump:-
(I) overheating of bearings
(II_Loss of prime after starting.
(ii)State any EIGHT annual maintenance checks of a centrifugal pump.(10marks)
(c) List any SIX necessary checks before starting up a water-cooling tower for the first time or after a long shut down.(3marks)
4.(a) (i) State any TWO causes and their remedies for each of the following problems in an air cooled compressor:-
(II) Delivery pressure too low
(ii) Briefly explain the installation requirements of a rotary helical-screw air compressor with respect to:-
(III) Inlet Lines
(IV) Oil reservoir drains(9marks)
(b) (i) Explain the cause of crankcase explosion in a reciprocating internal combustion engine.
(ii) State any TWO causes and their remedies for each of the following problems of a diesel engine:-
(I) hard starting
(II) high fuel consumption(8marks)
(c)Explain any THREE causes of bearing failures in internal combustion engines.(3marks)
5.(a) (i) State the maintenance checks carried out on the following air conditioning equipment:-
(I) heat pumps
(iii) State any TWO causes and their remedies for each of the following fan problems:-
(I) Capacity below rating
(II) Excessive vibration and noice(10marks)
(b) (i) State any TWO causes and their remedies for each of the following problems of a vapor compression domestic refrigerator:-
(I) freezer and refrigerator sections too warm.
(II) unit runs throughout
(ii) Explain the procedure to be followed when fitting a valve adapter on a refrigerator system.
(iv) Briefly explain the procedure to be followed when testing for leaks on the high side of a vapor compression refrigeration system using both pressure gauges and soap solution methods.(10marks)
6.(a) (i) State any TWO causes and their remedies for each of the following problems of direct current motors for:-
(I) general overheating of housing and field coils
(II) abnormal speed
(ii) With the aid of sketches,explain the method of testing the capacitor of a capacitor-start motor for:-
(I) shorting using a test lamp
(II) loss of capacity
(iii) State any FIVE maintenance checks for brush assembly of electrical motors.(12marks)
(b) (i) State any FOUR causes of failures in couplings used in power transmission systems.
(ii) State any FOUR factors to be considered when selecting the couplings in b(i),
(iii) Outline any FOUR maintenance requirements of V-belt drives.(8marks)
7.(a) (i) List any THREE primary and any THREE secondary functions of a maintenance department in an organization.
(ii) Explain any THREE basic concepts of a well organized maintenance department.
(iii) List any THREE advantages of each of the following maintenance organizations:-
(b) (i) Define the term maintenance work authorization and control and state its objective.
(ii) Explain any FOUR advantages of computerized preventive maintenance
(iii) Explain any FIVE benefits of planned maintenance for an organization.(11marks)
8.(a) (i) State any FIVE factors considered when selecting hoists.
(ii) State any SIX specifications required when ordering spare parts for an overhead traveling crane.
(iii) List the “yearly checks” carried out on an overhead traveling crane.(10 1/2marks)
(b) With the aid of sketch,describe the construction and operation of:-
(i) a screw conveyer
(ii)vertical belt and elevator.(9 1/2marks)