Building Services Engineering Processes

Transcription

1 CORK INSTITUTE OF TECHNOLOGY INSTITIÚID TEICNEOLAÍOCHTA CHORCAÍ Autumn Examinations 2008 Module Title: Building Services Engineering Processes Module Code: MECH 6002 School: School of Mechanical & Process Engineering Programme Title: Bachelor of Engineering in Building Services Engineering Stage 1 Programme Code: EBSEN_7_Y1 External Examiner(s): Internal Examiner(s): Mr. Declan Leonard and Dr. Mervyn Smyth Mr. Fergus Delaney Instructions: Attempt one question from Section A, one question from Section B, one question from Section C and one other question from any section. Use separate answer books for each section. Duration: 2 Hours Sitting: Autumn 2008 Note to Candidates: Please check the Programme Title and the Module Title to ensure that you have received the correct examination paper. If in doubt please contact an Invigilator.

2 QA1 Section A Attempt the following 20 multiple choice questions. Fill in your answers on the attached sheet, put your name on it and return it with your answer book for Section A. 1 mark for each multiple choice question. i) Low NOx burners produce small amounts of a) Nitrogen Oxide and Nitrogen Dioxide b) Nitrogen Dioxide and Carbon Dioxide c) Carbon Monoxide and Carbon Dioxide ii) In critical pumping applications pumps should be installed in the following configuration a) duty standby b) Reverse return c) Opposed flow iii) Motor connections to pumps can be a) Close coupled, direct coupled or parallel coupled b) Close coupled, direct coupled or belt & pulley c) None of the above iv) The acronym VSD stands for a) Vertical speed drive b) Variable speed drive c) Variable speed dynomometer v) The function of a pressurisation unit is to a) maintain minimum pressure in the piping system to ensure the water does not boil b) pressurise the pump c) none of the above vi) The flow temperature and pressure for a LPHW system is a) 100 o C, 0.5 bar b) 100 o C, 1.0 bar c) 82 o C, 1.0 bar vii) Isolating valves can be used for a) On/off applications only b) Flow regulation c) None of the above viii) Commissioning valves can be used for a) On/off applications only b) Flow regulation c) To ensure flow in one direction only

3 ix) The specification for medium weight black mild steel pipe is a) ISO EN (BS 1387) b) ISO EN 666 ( BS 1387) c) None of the above x) With respect to flanges what does the PN rating refer to a) Maximum operating pressure b) Maximum flow rate c) Minimum flow rate xi) State two functions of Aluclad xii) State 2 space requirements that affect plantroom design xiii) State 2 economic factors that affect plantroom design xiv) A primary circuit is a) The largest heating circuit in the building. b) The main heat generating circuit in the boiler plantroom. c) The return piping on a heating circuit. xv) A secondary circuit is a) A heating circuit of the header serving heat emitters. b) The second largest heating circuit in the building c) None of the above xvi) Which of the following statements describes a BEMS a) A computerised supervisory control system for all mechanical and electrical building services systems. b) A software programme to calculate energy usage. c) A control valve to limit energy usage. xvii) Which of the following statements describes a motor control panel a) A device to allow variable speed control of motors. b) A computerised supervisory control system for all mechanical and electrical building services systems. c) A panel consisting of relays and contactors to bring power on to motors with visual indication of motor status (run, standby, tripped) xviii) A compensated heating circuit is typically used on a) Hot water calorifiers. b) AHU circuits c) Radiator circuits

4 xix) A header is a a) A piping manifold to allow the distribution of water to different heating circuits. b) The highest point on a heating system. c) A piping manifold to allow the distribution of water to different boilers. xx) The flow temperature and pressure for an MPHW system is a) 110 o C, 0.5 bar b) 110 o C, 4.0 bar c) 82 o C, 4.0 bar QA2 a) State the function of each of the following valves and draw the symbol commonly used to depict these valves on schematics: Isolating valve Non return valve Pressure relief valve Fixed orifice double regulating valve (4 marks) b) Mark up the attached schematic with all valves necessary for the isolation, commissioning and safe operation of the system/plant. Return the schematic in your answer book for section A (16 marks) QB1 Section B (a) (b) (c) In relation to Tungsten Arc Gas Shielded welding state the purpose of a high frequency unit and state one advantage of using such a device. (4 marks) Due to the thermal expansion/contraction exceeding the yield strength of the parent metal distortion occurs in a welded joint. Sketch two types of distortion and discuss the factors that effect distortion on a butt joint. (10 marks) State two advantages and two limitations of using the Magnetic Particle Inspection (MPI) method on long fillet welds when compared to dye penetrant testing. (6 marks)

5 QB2 (a) State 2 items of safety clothing that are essential during MMA (2 marks) (b) Give 1 advantages and 1 limitation of any three of the following types of welding plant: AC Transformer DC Rectifier DC Generator Inverter (6 marks) (c) Explain the following methods of non-destructive testing: X-Ray testing (6 marks) Magnetic particle inspection (6 marks) QC1 Section C (a) List the tools and equipment required to make straight connection joint between a 15mm mild-steel pipe and a 15mm copper pipe. (5 marks) (b) Describe how the pipe ends are prepared and how the joint is made leak- proof. (15 marks) QC2 (a) Describe the plastic pipe jointing processes termed as follows: 1. Plastic pipe fusion welding (5 marks) 2. Plastic pipe solvent welding. (5 marks) (b) List the tools and equipment required to make these joints. (5 marks) (c) Suggest a suitable workshop method which may be used to pressure test a pipe section with completed joints. (5 marks)

6

7

8