問題一覧
1
136. What is the cause of excessively low air pressure occurring in the intercooler of a reciprocating air compressor?
•leaky discharge valves on the LP cylinder
2
137. While overhauling a jerk-type pump and the pump plunger must be replaced. What other part must also be replaced?
•Pump barrel
3
138. During injection, the cam nose of the camshaft will push up the plunger of the pump, forcing the fuel to the ?
•fuel injector
4
139. Increasing the speed of a centrifugal pump will result in an increase in the pump capacity. Another means of increasing the total head pressure of a centrifugal pump is to increase the ?
•diameter of the impeller
5
140. Which of the following component is the primary shaft emerging out of the engine?lt directly receives the rotational motion from the crankshaft and rotates at the maximum velocity in high speed engines.
•thrust shaft
6
141. The greatest decrease in the temperature of a refrigerant is at the
•expansion valve.
7
142. How does a quick closing valve operate?
•the valve bridge is collapse remotely allowing the valve to close
8
143. If the boiler fires are extinguished by water contamination in the fuel oil, you should FIRST?
•secure the burner valves
9
144. How is viscosity of fuel in the atomizer can be reduced ?
•increasing the fuel oil heater steam supply
10
145. In an engine operation what is the effect called that describes the unstable operation of the governor that will not maintain a steady state condition ?
•Hunting
11
146. The possible cause why lube oil pumps fail to build up discharge pressure could be that the ?
•suction valve is closed
12
147. Which of the following statement is correct relative to distillation plant operation?
•Distillation is the process of boiling seawater to produce vapor which is condensed into fresh Water
13
148. How many fuel oil heaters are required for main engine operation ?
•at least two heaters of approximately equal size are to be installed
14
149. Some engines are using auxiliary electrically driven blowers which is continuously running during maneuvering and automatically cut-off if the scavenge air pressure reaches load.
•50%
15
150. What type of pump is used in the steering gear of modern ship?
•Vane
16
151. What is the possible cause of fuel oil accumulation in boiler casing is ?
•dripping atomizers
17
152. Gas turbine uses a cycle that includes intake, compression, expansion and exhaust. Which of the following are you going to use to best explain the complete cycle.
•Pressure volume diagram
18
153. Which of the following determines the measured gap between the face of the burner atomizer tip nut and the dfifuser plate ?
•Distance piece
19
154. Most of the fuel injection pumps will then closed after injection because they are fitted with a ?
•spring loaded discharge check valve
20
155. Why is thin tipping design procedure is used in modern reaction turbines ?.
•reduce tip leakage
21
156. In a refrigeration system, the amount of superheat absorbed by the refrigerant is adjusted at the
•expansion valve
22
157. If turbine rotor shafts extend through the casing, what external source of sealing steam is used in conjunction with labrynith packing ?.
•seal the casing during periods of low casing pressure
23
158. Labyrinth seals used to reduce leakage around a turbine shaft are constructed of
•machined packing strips or fins
24
159. Visual inspection of a fuel injector valve, removed during overhaul, shows heat discoloration of the lower end of the valve. This is an indication of
•valve leakage
25
160. An internally mixed steam atomizer requires which of the following compared to a return flow oil burner system?
•Less excess air
26
161. What is the reason why fuel is heated before atomizing is to ?
•decrease its viscosity
27
162. Which of the listed conditions is responsible for causing the gland leak off steam from a propulsion turbine to pass through the gland exhaust condenser?
•The use of a gland exhauster fan
28
163. Parts of the pump used to maintain the alignment of the pump are ?
•bearings
29
164. A squeaking sound occurring from within an operating reciprocating air compressor is an indication of ?
•tight compressor bearings
30
165. The function of seal cages, or lantern rings installed in the centrifugal pump stuffing boxes, is to
•distribute the sealing liquid within the stuffing box
31
166. An oil mist detector is used to detect an oil mist formation in the diesel engine crankcase. Which of the following causes oil mist formation ?
•overheating of Oil
32
167. The bore of a diesel engine describes the ?
•AA diameter of the cylinder
33
168. How is constant steam pressure maintained?
•By controlling the amount of heat supplied to the boiler
34
169. How will you know the firing rate of boiler using steam atomization indicated?
•By the fuel oil pressure
35
170. Which of the following is the result of excessively high fuel oil temperature ?
•Fouling of the heaters
36
171. Which equipment must be tested NOT more than 12 hours prior to getting underway from a port when the voyage is to be of 48 hours or greater duration?
•Steering gear
37
172. In the boilerás combustion control system, when the demand for steam is increased
•air supply increases before fuel supply increases
38
173. The purpose of the diffuser in a boiler burner assembly is to
•allow some mixing of fuel and air
39
174. What is the purpose of the dehydrator in refrigeration?
•Remove refrigerant moisture
40
175. Main component of the engine to regulate speed is the ?
•governor
41
176. Movement of the pump control rack in a fuel injection system having individual plunger-type pumps
•changes the length of the pump stroke
42
177. Most fuel injection nozzles are opened by ?
•fuel oil pressure
43
178. One of the routine tasks onboard maintenance for Gas Turbine is mainly of daily visual checks of the running engine. What are you going to execute after a fix number of operating hours to remove any salt deposits on the compressor?
•Internal water wash
44
179. Boiler safety valves are set not to go above maximum operating pressure of higher than ?.
•0.1
45
180. Why should hydraulic cranes be properly warmed-up before they are used?
•Hydraulic fluid must be at the proper viscosity
46
181. In a main propulsion turbine installation, the condensate pump initially discharges to the
•air ejector condenser
47
182. If a reciprocating air compressor has a knock occurring in frequency with its operating RPM, the cause is probably
•misalignment or worn main bearings
48
183. The range of values around a set point of a measured variable where "no action"occurs in an automatic flow controller is called:
•Deadband
49
184. Passages are drilled at the diesel engine crankshaft in order to provide lubricating oil in the ?.
•piston rod bearings
50
185. If you hear a crackling sound coming from a salt water centrifugal pump casing, the most probable cause of the noise would be ?
•excessive suction lift
51
186. The capacity of a rotary pump, delivering a constant viscosity fluid, will decrease when the discharge pressure is increased, due to ?
•increased slippage
52
187. The measure of the amount of salt present in water is called ?
•Salinity Specific Gravity.
53
188. Which of the following statement is correct when a piston is said to be at top dead center?
•nearest to the cylinder head
54
189. The purpose of the six-way valve used in an electro-hydraulic steering system is to,
•redirect hydraulic fluid flow when changing over pumps
55
190. Main engine lube oil sump tank is located ?
•at the bottom of the engine
56
191. What is the most important rule for the safe operation of a boiler?
•Maintain the proper water level at all times
57
192. When turbine rotor shafts extend through the casing, an external source of sealing steam is used in conjunction with labyrinth packing to.
•seal the casing during periods of low casing pressure
58
193. Why diesel engine lubricating oil need more purification compare with the lubricating oil in a gas turbine?
•gas turbine lubricant does not come into contact with the combustion process
59
194. Which of the following is the reason for installing settling tanks in the fuel oil system?
•To heat, allowing sediments and water to settle down
60
195. Why is it necessary to transfer fuel oil to the settling tanks ?
•allow the sediments and water to settle
61
196. Part of centrifugal disc purifier use to hold discs in place and directs the flow of dirty liquid to the bottom then to the discs as the oil flows upward is called
•distributor
62
197. Which of the items listed below is normally describe a ventilating fan?
•Axial flow
63
198. Which of the following terms is used to identify the pressure of the liquid ?
•Suction head
64
199. If you were operating a centrifugal water service pump with worn wearing rings, the
•pump would develop insufficient flow
65
200. Irregular feeding or surging of the feedwater supply to a low pressure distilling plant may be attributed to
•A dirty strainer in the saltwater feed pump suction line
66
201. Which of the following admits air to the piston of a cylinder relay valves in a correct sequence for engine starting?
•Starting Air Distributor
67
202. A twin-screw, rotary, positive displacement pump is provided with timing gears. If it were possible to change the lead (pitch) of the screws, which of the following statements would represent the true effect on the pump characteristics?
•The shorter the lead, the higher the pressure potential
68
203. Excessive vibrations created by the main propulsion machinery are detrimental to which equipment listed below-----------?
•navigation
69
204. How is dissolved oxygen in boiler feed water minimized?
•Maintain high feed water temperature
70
205. When fuel viscosity in the service tank needs to be reduced before the atomizer, what should be done ?
•increase the heater steam supply
71
206. What is known as an air motion induced in a four-cycle diesel engine cylinder to improve air fuel mixing?
•Turbulence
72
207. Dirty condenser in a refrigeration system would indicate ?
•high pressure discharge
73
208. The rotary motion of a diesel engine crankshaft is obtained from the up and down motion of the piston via the?
•connecting rod or piston rod
74
209. What part of an engine transmits the reciprocating motion of the piston to the driven unit in the form of rotary motion?
•crankshaft
75
210. How is the pressure and temperature affected in a diesel engine cylinder during compression?
•Pressure and temperature increase
76
211. If condensate is accumulated in the steam side of a fuel oil heater, it could result in ?
•corrosion
77
212. Why should the boiler fire side be kept free from soot accumulations ?
•soot insulates the boiler heating surfaces
78
213. What is the use of follow-up gear on an electro-hydraulic steering gear?
•Takes the pump off stroke when the desired rudder angle is attained
79
214. The most common diesel engine fuel system problems are caused by ?
•dirty fuel
80
215. When a fuel injection nozzle overheated which of the problems listed below can be expected?
•The fuel metering will vary.
81
216. An incinerator is a waste disposal unit that will burn ?
•solid material and all types of liquid waste
82
217. Reduced capacity, vibration and noise at the centrifugal pump suction due to vapor pockets in the fluid being pumped is caused by
•cavitation
83
218. What will be the result if carbon deposits accomulates in the burner throat and diffuser rings of boiler?
•decrease boiler efficiency
84
219. Rapid fluctuations of absolute pressure in the last effect of a multi-effect submerged tube distilling, plant will tend to cause ?
•Priming with increased salinity of distillate
85
220. Why are relief valves of fuel service pump for boiler burners installed ?
•To protect the pump from high discharge pressure
86
221. Which operating condition of a diesel engine is indicated by excessive firing pressures?
•Overload
87
222. What will happen if the needle valve in a fuel injection nozzle sticks open ?
•The nozzle will overheat
88
223. Which of the listed turbocharger component increases air density and helps improve engineoperating efficiency?
•Air cooler
89
224. In addition to a nozzle, a fuel oil atomizer uses which of the listed parts?
•Burner cone
90
225. When an engine coupled with the large vibrational shocks that act on the shafts, there could be a permanent damage to the propeller shafts.Why.?
•Because of the intermediate shaft weight
91
226. What does an unusual or new vibration in the hull or propeller shafting indicate?
•Propeller unbalance
92
227. What happens when oil is heated up ?
•Its viscosity will increase
93
228. Schedule of soot blowing for economizers is done for at least ?
•Three times a day
94
229. Which items on the list could reduce high salinity in a steaming boiler?
•using the continuous blowdown
95
230. In the water tube boiler, the fire in the furnace is located at the ?
•outside the tubes
96
231. On a medium pressure, differential piston, reciprocating air compressor, lubrication of the pistons/cylinders is usually accomplished,
•with metering type cylinder lubricators
97
232. A badly leaking refrigeration compressor discharge valves will cause ?
•constant running of the compressor
98
233. A change in the degree of fuel atomization in a diesel engine cylinder has the greatest effect on the_ _.?
•combustion in that cylinder
99
234. Which of the following is the purpose of the diffuser in a burner assembly?
•To shield the flame from the incoming air blast while allowing mixing of fuel and air
100
235. If the discharge valve is closed before the drive motor is stopped, which type of pump will most likely be damaged?
•Gear pump