Sample Questions – Third Class, Parts B1 & B2 (Old Version)

(NOTE: these questions are intended as representations of the style of questions that may appear on examinations, they are not intended as study material and, as such, may not be in line with any current examination syllabus)

1. Describe the procedure for “boiling out” a boiler. Identify the chemicals that are used.

2.
(a) Define four advantages and two disadvantages of mechanical draft compared to natural draft.

(b) List three factors which influence the power required to drive a fan.

(c) Explain why performance curves are required for fans.

(d) What four quantities are shown on a typical fan performance curve chart.

3.
(a) Describe the correct procedure for starting up a balanced draft, gas-fired water-tube boiler and put it on line with a battery of boilers already in service.

(b) Describe the correct procedure for taking this boiler out of service.

4. With respect to a high pressure reaction steam turbine;

(a) What is the purpose of having dummy pistons on the turbine rotor?

(b) Provide a single-line sketch of a dummy piston. Label the components and show the forces acting on the piston.

(c) Explain the principle of operation of a dummy piston.

5.
(a) The two types of sootblowers are stationary and retractable. Explain where each type is installed and explain why that type is selected.

(b) Explain four precautions to be taken to ensure maximum
sootblower and boiler tube life.

(c) Describe the procedure for manually soot blowing a high pressure (10000 kPa) water tube boiler burning pulverized coal. The boiler is fitted with a superheater, economizer and an air heater.

6. Sketch and describe a method of combustion control suitable for a high pressure water tube boiler.
The sequence of events must be clearly described.

7.
(a) Describe the principle of operation of two types of automatic air vents used on hot water heating systems.

(b) With the aid of a sketch, describe the operation of a diaphragm air vent.

8.
(a) Define the following water treatment terms:
turbidity, colloidal particles, deionization coagulation floc

(b) With the aid of a sketch, explain the operation of a coagulating water clarifier.

9.
(a) Describe the differences between the two types of mechanical seals.

(b) Define 4 advantages of mechanical seals.

(c) Sketch a mechanical seal and explain how it operates.

(d) List 4 causes of leaking in mechanical seals.

10. With respect to operation of heat recovery steam generators (HRSGs);

(a) Provide a diagram of an HRSG. Label the components.

(b) Describe the operation of the HRSG that you provided in (a).

11. During the start-up of some reaction steam turbines, the thrust block is pushed against a stop in the direction of the inlet for:

A. maximum axial seal clearance clearance

B. minimum axial seal clearance

C. maximum blade efficiency

D. maximum radial blade

E. minimum radial blade clearance

Answer: A

12. Air in a surface condenser:

1. increases the pressure steam

2. retards heat transfer

3. enters with the high pressure ejector

4. is cooled before being removed

A. 1, 2, 3

B. 2, 3, 4

C. 1, 3, 4

D. 1, 2, 4

E. 1, 2, 3, 4

Answer: D

13. The deaerator is usually operated to maintain constant:

A. pressure

B. temperature

C. level

D. flow rate

E. oxygen content

Answer: C

14. Barring or turning gears are used to:

1. start the rotation of the shaft to start the turbine

2. rotate the turbine shaft periodically to prevent it from sagging

3. rotate the shaft at slow speed when the turbine is not in service

4. lift the turbine shaft off the bearing surface to prevent damage during start-up

A. 3

B. 3, 4

C. 2, 3

D. 1, 4

E. 1, 3

Answer: C

15. If the speed of a turbine decreases due to additional generator loading, the correct sequence of events that occurs in the speed governor is as follows:

1. centrifugal force on governor decreases

2. governor linkage causes steam valve to open

3. RPM’s decrease

4. RPM’s increase

5. spring causes governor flyballs to move inward

6. more steam is admitted

A. 2, 4, 5, 6, 1, 3

B. 4, 1, 5, 6, 2, 3

C. 6, 4, 5, 2, 1, 3

D. 3, 1, 5, 2, 6, 4

E. 1, 5, 3, 2, 6, 4

Answer: D

16. The main purpose of a cooling tower is to:

A. add heat to condenser water.

B. remove heat from condenser water.

C. remove heat from the refrigerant.

D. add air to the cooling water.

E. add heat to the refrigerant.

Answer: B

17. Before starting a small non-condensing turbine which of the following procedures would be performed?

1. Turn the turbine shaft using a pipe wrench.

2. Drain the condensate from steam line and turbine casing.

3. Turn the oil cooler water supply on before starting turbine.

4. Check oil level in bearing sumps or reservoir.

A. 1 and 2

B. 1 and 3

C. 2 and 4

D. 3 and 4

E. 1 and 4

Answer: C

18. Steam turbine stationary nozzles serve to:

1. decrease steam pressure

2. increase steam enthalpy

3. decrease steam friction

4. increase steam

A. 1, 2, 3

B. 1, 3, 4

C. 1, 4

D. 2, 3

E. 2, 3, 4

Answer: C

19. The condenser extraction (condensate) pump normally supplies cooling water to the :

1. turbine casing drain coolers

2. air ejectors

3. gland steam condensers

4. main condenser

A. 1, 2, 3

B. 2, 3, 4

C. 1, 3, 4

D. 1, 2, 4

E. 1, 2, 3, 4

Answer: A

20. The jet condenser is so named because:

1. it uses steam jets to extract air from the condenser

2. it sprays jets of cooling water into the exhaust steam to condense it

3. it sprays jets of boiler feedwater into the exhaust steam to condense it

4. it passes the exhaust steam through jets to cause a pressure drop and condensation

A. 1, 2

B. 1, 3

C. 1, 4

D. 2

E. 2, 3, 4

Answer: D

21. A pressure drop created across the turbine blades by the expanding steam is the basic operating principle of the:

A. impulse turbine

B. reaction turbine

C. pressure compounded impulse turbine

D. temperature compounded impulse turbine

E. All the above

Answer: B

22. In order to keep the gas pass of a gas turbine clean, the following must be done:

1. inspect and clean air intake filters ducts

2. water wash the compressor blades

3. inspect and clean air intake

4. use good quality fuel

A. 1, 2

B. 1, 3

C. 1, 2, 3

D. 2, 3, 4

E. 1, 2, 3, 4

Answer: E

23. In a dual shaft gas turbine the load is driven by a:

A. generator

B. low pressure turbine

C. high pressure turbine

D. smaller starting motor

E. combination of low and high pressure turbines

Answer: B

24. A gas turbine would be chosen where these characteristics are advantageous:

1. little or no water requirements

2. best efficiency and maximum output.

3. low installation cost

4. high power to mass ratio

A. 1, 2 and 3

B. 2, 3 and 4

C. 1, 3 and 4

D. 1, 2 and 4

E. 1, 2, 3 and 4

Answer: C

25. The free piston gas generator in a gas turbine cycle will take the place of:

A. the turbine and combustor

B. the compressor and combustor

C. the compressor and turbine

D. the compressor and regenerator

E. the fuel pumping/supply system

Answer: B

26. The disadvantages of a gas turbine include:

1. fuel costs are high

2. the operating noise level is high

3. low thermal efficiency

4. a large amount of auxiliary equipment is required

A. 1, 2, 3

B. 2, 3, 4

C. 1, 2, 4

D. 1, 3, 4

E. 1, 2, 3, 4

Answer: A

27. Rough running of a diesel engine is caused by:

A. imperfect injection

B. injection timed too early

C. improper grade of fuel

D. worn injectors

E. all of the above

Answer: E

28. In the internal combustion engine, the purpose of the rocker arm is to operate:

A. the camshaft

B. the push rods

C. the oil pump

D. the inlet valves

E. the throttle

Answer: D

29. In the common rail system used for injection of fuel into the diesel engine cylinder:

A. the fuel is injected into the cylinder by the fuel pump

B. the fuel is injected into the cylinder by the injector

C. the system requires two pumps

D. the system does not require a return from the injector

E. the timing of the fuel injection is done by the fuel pump

Answer: B

30. Connecting rods are usually made of:

A. wrought iron

B. forged steel

C. aluminum

D. cast iron

E. stainless steel

Answer: B

31. Compressed air is not used for:

A. starting motors of large diesel engines

B. soot blowing for boiler furnaces

C. mixing or agitating materials for a process

D. cooling and aerating the steam in a steam condenser

E. sand blast cleaning

Answer: D

32. Of all the positive displacement air compressors, the ______ compressor can deliver the highest discharge pressure.

A. sliding vane

B. reciprocating

C. rotary lobe

D. rotary screw

E. centrifugal

Answer: B

33. For a particular air sample, wet and dry bulb temperatures when plotted on a psychometric chart will help determine:

1. what the relative humidity is.

2. what the dew point is.

3. how much moisture is in the air.

4. what the dryness factor is.

A. 1, 2 and 3

B. 1, 2 and 4

C. 2, 3 and 4

D. 1, 2, 3 and 4

E. 1, 3 and 4

Answer: D

34. Three different designs of rotary compressors are:

1. sliding vane

2. rotary screw

3. axial flow

4. volute centrifugal

5. rotary lobe

6. diffuser vane centrifugal

A. 2, 4, 6

B. 1, 2, 5

C. 3, 4, 6

D. 1, 3, 5

E. 1, 3, 6

Answer: B

35. Surging of dynamic air compressors can produce severe shock to the system and may be violent enough to damage the:

A. driver and casing

B. blading , shaft, and seals

C. dummy piston

D. discharge piping

E. foundations

Answer: B

36. The inlet pipe to the compressor must be:

A. larger than the compressor intake

B. twice as large as the compressor intake

C. smaller than the compressor intake

D. at least as large as the compressor intake

E. a minimum of 2″ NPS

Answer: D

37. Refrigeration may be defined as:

A. a method of absorbing heat in the cooling water

B. a way of maintaining the relative humidity

C. a system to help raise the dew point of air

D. a controlled process of removing heat from a substance

E. a method of increasing the heat level of a substance

Answer: D

38. Ammonia refrigerant will:

A. mix easily with vegetable oils

B. not mix with mineral oils

C. mix with oils when heated

D. not mix with water

E. react with fatty oils

Answer: B

39. The component that allows for the switching from heating to cooling mode on an air heat pump is called a/an __________ valve?

A. expansion

B. reversing

C. charging

D. king

E. port

Answer: B

40. Brine used in ammonia indirect systems is usually made with:

A. lithium bromide

B. calcium chloride

C. sodium chloride

D. sodium bicarbonate

E. calcium sulfate

Answer: B

41. The evaporator is where:

A. the liquid refrigerant is stored

B. the liquid refrigerant absorbs heat and boils

C. the refrigerant vapour condenses

D. most of the refrigerant is stored

E. the brine absorbs heat

Answer: B

42. The main components of an lithium bromide absorption refrigeration system are:

A. evaporator, expansion valve, compressor, receiver, absorber, condenser, aqua pump.

B. condenser, receiver, expansion valve, evaporator

C. generator, condenser, receiver, expansion valve, evaporator, absorber, aqua pump.

D. generator, evaporator, condenser, absorber.

E. generator, evaporator, condenser, compressor, expansion valve.

Answer: C

43. NH3 (R-717) refrigerant:

A. will not cause corrosion to metals

B. is non-toxic

C. is corrosive to non-ferrous metals in the presence of water

D. is very expensive

E. is flammable in weak concentrations

Answer: C

44. CSA B-52 applies to:

1. design, construction and installation of refrigerating systems

2. operation and inspection of refrigerating systems

3. Systems using air as the refrigerant

4. refrigeration systems in motor vehicles

5. refrigeration systems in private residences

A. 1, 2, 3, 4, 5

B. 1, 2, 3, 4

C. 2, 3, 4, 5

D. 1, 2, 4, 5

E. 1, 2

Answer: E

45. Ammonia (R-717) is classified in Safety Group:

A. A1

B. A2

C. A3

D. B1

E. B2

Answer: E

46. The purpose of the expansion valve is to:

A. isolate the high and low sides of the system

B. regulate the flow of refrigerant to the evaporator

C. expand the refrigerant gas for better refrigeration effect

D. control the brine flow

E. regulate the amount of vapour entering the compressor

Answer: B

47. Condenser cooling water is usually controlled by:

A. level controls

B. cooling tower demands

C. solenoid valves

D. hand operated gate valves

E. pump speed

Answer: C

48. Refrigeration systems are purged:

A. to release excess refrigerant

B. to rid the system of non-condensable gases

C. to rid the system of moisture

D. to reduce the evaporator pressure

E. to increase the condenser pressure

Answer: B

49. Solid lubricants are used for:

1. low load application

2. high temperature application

3. where chemical contamination is possible

4. on electrical equipment

A. 1, 2

B. 1, 3

C. 2, 3

D. 2, 3, 4

E. 1, 2, 3

Answer: D

50. The purpose of a thrust bearing is to:

A. prevent the shaft from moving axially with the thrust

B. prevent the shaft from rotation backwards due to thrust

C. prevent the shaft from moving in the opposite direction from

D. create thrust in the shaft

E. maintain shaft radial clearance

Answer: A