Sample Questions 356 Flashcards
Name four maintenance activities. ( 4 Marks)
Answer:
Maintenance activities: carrying out routine servicing schedules or planned preventative maintenance, repair and replacement following breakdowns, monitoring and performance testing
Describe three benefits of carrying out maintenance. (6 marks)
Answer: Suitable description of any three of the following
benefits: upholding or improving safety standards, maintaining production output at the required levels and quality, maximising the useful working life of engineering assets, increasing production efficiency
Describe one documentary and one physical method of ensuring safe working before commencing maintenance. (5 marks)
Answer: Suitable description of one of each of the following.
Physical: isolating power or pressure sources, barriers etc.
Document: Permit to work / authorisation.
List five different resources required to carry out maintenance activities. (5 marks)
Answer: Any five of the following:
Time, people (suitably trained, other trades etc.), tools, materials, equipment, spares, space, support, facilities etc.
State two factors to consider when selecting a suitable site before installing any new equipment and machinery. (2 marks)
Any two: Factors to consider: site conditions and locations, storage of parts and materials, tools and equipment, provision of services – electricity, compressed air, water and drainage, minimising disruption to adjacent work areas.
Describe how one of the factors in part a) would affect the length of time needed to install new plant and equipment. (2 marks)
Adequate description covering, e.g. for provision of services there would need to be resource (time, people, e.g. sub-contractors etc.) factored in for the extension of supply
cables/pipelines etc. For minimising disruption there may be access arrangements to consider or protect others from the effects of the installation activities.
Any sensible answer that links the factor to consider and the implications of them.
Describe two activities that should be carried out before the installation of a fixed air compressor. (4 marks)
Suitable descriptions covering two of the following:
Evaluation of site conditions, provision of services for the prime mover, storage of parts, tools and equipment or other suitable answer
Describe fully one piece of information which may be found in a maintenance report. (3 marks)
Adequate description of one of the following.
Work undertaken, location(s), dates/times (commencement, completion and handover), parts and consumables used, test data, work outstanding defects rectified, any certification referencing.
Describe two symptoms that would suggest a fault has occurred or is developing. (4 marks)
Two appropriate descriptions given, for example:
Symptoms from overheating, excessive vibration, noise, obvious damage or deterioration, smell (e.g. burning or leaking gases etc.) or any sensible answer.
Causes Physical damage from external sources, lack of maintenance or other valid reason linked to maintenance, poor alignment of components, poor protection from conditions/elements, personnel training issues, quality issues with components, wrong components, any other sensible cause.
Name a suitable instrument used to measure rotational speed.
Tachometer/ stroboscope
Name a suitable instrument used to measure temperatures above 400°C.
Pyrometer / electrical resistance device.
Name a suitable instrument used to measure Pressure.
Bourdon gauge or manometer.
Give one application where each of the instruments named in part a) would be used. (3 marks)
Any sensible application, for example:
i) To measure engine speed/timing.
ii) To measure exhaust temperatures.
iii) To measure compressed air, steam pressure etc. or to measure pressure difference.
Explain the purpose of calibration. (3 marks)
To determine the accuracy of the unit under test compared to that of one of known magnitude or correctness and inform the user of the results (or similar answer)
Give three reasons why it is important to use calibrated instruments. (3 marks)
In order to determine accurate measurement, quality assurance of measurement, confidence for the user of the equipment (any other sensible answers).
Describe two applications where a Dial Test Indicator (DTI) would be used. (4 marks)
Answer: Two descriptions of the instrument’s application, for example set up and use in a suitable situation such as trueing of components held in a four jaw chuck or to align coupling flanges or other suitable descriptions.
List four checks that should be carried out when re-commissioning an air compressor after maintenance. (4 marks)
Answer: Any four:
Freedom of movement, check security of mountings or components, reconnect electrical supply, reestablish compressed air distribution system, work area cleared of all tools, materials and equipment, cancellation of work permit, system running check, any other sensible answer.
Explain, with the aid of a sketch, how friction is caused between two surfaces in contact. (3 marks)
Answer: Explanation similar to the following.
The contact surface area of the peaks causes the initial friction. Then the breaking or merging of peaks would require a force that would generate additional heat.
Sketch should show peaks on both surfaces.
State one reason for lubrication. (1 mark)
Answer: Any one:
To separate component parts, to remove/reduce heat, prevent ingress of dirt, prevent corrosion.
Explain briefly Splash lubrication.
Internal combustion engine or gearbox to cater for high speeds and temperatures etc. (any other sensible answer).
Explain briefly Mist lubrication
Used in compressed air systems, most effective method for lubricating air tools (any other sensible answer).
Explain briefly grease
Exposed shaft bearings such as in conveyers or ventilating systems – high speed motion without need for oil/sealed/prevents ingress of dirt etc. (any other sensible answer).
With reference to lubricants. State the nomenclature terms for the following. Resistance to flow.
Viscosity.
With reference to lubricants. State the nomenclature terms for the following. Temperature reached where lubricant will ignite if in contact with a flame.
Flash point
Explain briefly the meaning of ‘pour point
Temperature reached where lubricant begins/ceases to flow.
Explain what is meant by a synthetic lubricant. (3 marks)
Synthetic lubricants are manufactured using chemically modified petroleum components rather than whole crude oil, and can also be synthesized from other raw materials.
Give three advantages of using synthetic lubricants instead of mineral lubricants. (3 marks)
Any three advantages:
improved viscosity, more environmentally friendly, decreased evaporative losses, better lubrication in extreme hot/cold environments (any other sensible answer).
Explain the principle of operation of a simple cathodic protection system. (3 marks)
The basic principles are when two dissimilar metals come in contact with each other, a current will flow between the two and one of the metals will be sacrificed due to this flow process.
Describe fully one method of cathodic protection. (3 marks)
Any one from
Attach sacrificial anodes to a structure, such as a ship’s hull (Galvanic method), which will corrode instead of the hull and can be replaced.
Or description of Impressed Current Cathodic Protection (ICCP) where dc current is used. Or any other acceptable answer.
Give one reason why each of the following bearing types would be selected.
i) Sealed roller.
ii) Needle roller.
iii) Angular contact. (3 marks)
i) Use in dirty conditions etc. where the bearing could be contaminated.
ii) Where there is limited space.
iii) Where dealing with axial loads, low to medium speeds
State two benefits of using each of the following bearing types. i) Plain.
ii) Roller. (4 marks)
i) Can take high loads and high speeds (or any other acceptable answer).
ii) Can take high loads and lower friction (or any other acceptable answer).
Name one method of fitting a bearing with an interference fit on to a shaft without the use of force. (1 mark)
Heating/ oil bath method (accept contraction method).
List two pieces of equipment that should be used to fit a bearing with an interference fit into a housing. (2 marks)
Arbor press (accept vice or fabricated set up if adequate description is used) and hydraulic press or any other sensible answer
With reference to screw threads, state what is meant by each of the following terms.
i) Truncation.
ii) Lead.
iii) Pitch. (3 marks)
i) Where the crest of the thread is cut short (or similar answer).
ii) The distance along the screw’s axis that is covered by one complete rotation of the screw.
iii) The distance between the crest of one thread (or trough) to the next.
Explain briefly two methods of removing sheared or broken studs. (4 marks)
Drilling & re-tapping (with explanation of process). Stud extraction tools (with explanation of use). Accept any other known method with explanation, e.g. heating etc.
