competence 4.5

50問 • 1年前

問題一覧

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

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

203. Excessive vibrations created by the main propulsion machinery are detrimental to which equipment listed below-----------?

•navigation

204. How is dissolved oxygen in boiler feed water minimized?

•Maintain high feed water temperature

205. When fuel viscosity in the service tank needs to be reduced before the atomizer, what should be done ?

•increase the heater steam supply

206. What is known as an air motion induced in a four-cycle diesel engine cylinder to improve air fuel mixing?

•Turbulence

207. Dirty condenser in a refrigeration system would indicate ?

•high pressure discharge

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

209. What part of an engine transmits the reciprocating motion of the piston to the driven unit in the form of rotary motion?

•crankshaft

210. How is the pressure and temperature affected in a diesel engine cylinder during compression?

•Pressure and temperature increase

211. If condensate is accumulated in the steam side of a fuel oil heater, it could result in ?

•corrosion

212. Why should the boiler fire side be kept free from soot accumulations ?

•soot insulates the boiler heating surfaces

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

214. The most common diesel engine fuel system problems are caused by ?

•dirty fuel

215. When a fuel injection nozzle overheated which of the problems listed below can be expected?

•The fuel metering will vary.

216. An incinerator is a waste disposal unit that will burn ?

•solid material and all types of liquid waste

217. Reduced capacity, vibration and noise at the centrifugal pump suction due to vapor pockets in the fluid being pumped is caused by

•cavitation

218. What will be the result if carbon deposits accomulates in the burner throat and diffuser rings of boiler?

•decrease boiler efficiency

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

220. Why are relief valves of fuel service pump for boiler burners installed ?

•To protect the pump from high discharge pressure

221. Which operating condition of a diesel engine is indicated by excessive firing pressures?

•Overload

222. What will happen if the needle valve in a fuel injection nozzle sticks open ?

•The nozzle will overheat

223. Which of the listed turbocharger component increases air density and helps improve engineoperating efficiency?

•Air cooler

224. In addition to a nozzle, a fuel oil atomizer uses which of the listed parts?

•Burner cone

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

226. What does an unusual or new vibration in the hull or propeller shafting indicate?

•Propeller unbalance

227.If a centrifugal pump gradually develops insufficient discharge pressure as a result of worn wearing rings, which of the following corrective actions is required?

replace the rings

228. Schedule of soot blowing for economizers is done for at least ?

•Three times a day

229. Which items on the list could reduce high salinity in a steaming boiler?

•using the continuous blowdown

230. In the water tube boiler, the fire in the furnace is located at the ?

•outside the tubes

231. On a medium pressure, differential piston, reciprocating air compressor, lubrication of the pistons/cylinders is usually accomplished,

•with metering type cylinder lubricators

232. A badly leaking refrigeration compressor discharge valves will cause ?

•constant running of the compressor

233. A change in the degree of fuel atomization in a diesel engine cylinder has the greatest effect on the_ _.?

•combustion in that cylinder

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

235. If the discharge valve is closed before the drive motor is stopped, which type of pump will most likely be damaged?

•Gear pump

236. Diesel engine crankcase oil mist detectors are designed to analyze ?

•the concentration of oil vapours in the crankcase

237. Burned gas from each cylinder is directed to the exhaust manifold which is part of ?

•2-stroke engine

238. When chemical energy of the fuel is converted to thermal energy during boiler operation, the conversion process occurs where ?

•furnace

239. In bunker tanks, which of the following tanks is used in storing fuel ready for immediate use for starting up the diesel engine?

•Sercvice tank

240. The boiler water having a pH reading of 7.0 is said to be ?

•neutral

241. What is a practical way of checking for excessive fuel injection in one cylinder of an operating diesel engine?

•Check the cylinder exhaust temperature frequently,

242. Positive displacement helical gear pumps are well suited for pumping oil because ?

•they are self-priming and produce high suction lift

243. The measured temperature indicates the ?

•level of heat intensity

244. Which of the following components is directly connected to the propellers and lies mainly encased in the stern tube?

•Tail shaft

245. In a mechanical compression refrigerating system, what is the main cause of a very low discharge pressure?

•Insufficient refrigerant in the system

246. In air conditioning system, which part of the system where the refrigerant begins to boil and flash into gas?

•Evaporator

247. Purging air from a hydraulic oil system is necessary when ?

•system has been drained and filled with new oil

248. Regarding the low pressure evaporator steam control orifice in the live steam supply line, the steam at the outlet of the orifice if not properly conditioned will be developed as ?

•superheated steam

249. In a large slow-speed propulsion diesel engine, the force applied to the piston is

•against the crosshead during the power and compression strokes

250. Why is it important to apply proper filtering and straining of diesel fuel oil ?

•fuel injectors may be damaged by foreign particles in the fuel oil

competence 4.1

ERNO ENRIQUE JOMENTO · 50問 · 1年前

competence 4.1