competence 4.7

50問 • 1年前

問題一覧

301. In which of the listed components of refrigeration system does a superheating of the refrigerant take place?

•Evaporator

302. How does the power transfer from the engines located deep inside the hull of a vessel to the propellers at the aft. The answer lies in an integral mechanical component known as

•the marine shaft or propeller shaft

303. An eccentric reducer, used as a transition piece between a centrifugal pump suction flange and the suction piping flange, must be installed with the eccentric portion below the suction pipe centerline to

•prevent the formation of air pockets

304. Faulty operation of diesel engine fuel injection nozzles can be caused by ?

•water in the fuel oil supply

305. Why cruise ship is one of the main candidates for gas turbine propulsion?

•The compactness of gas turbine machinery can be exploited to create extra accomodation

306. A boiler fuel burner that is equipped with a variable capacity pressure atomizing system functions to

•provide wide range of combustion

307. The cooling effect in a refrigeration system is produced by.

•lowering the pressure of the refrigerant.

308. In order to move the rudder, what must be created by steering gear?

•Torque

309. The ash content of a fuel oil is significant to the operating engineer because ?

•it is an indication of the amount of noncombustble material present in the oil

310. Fuel leakage in high-pressure fuel pipe between the injection pumps and the fuel nozzle needs immediate repair because of

•distortion of the spray pattern

311. The follow-up mechanism for any steering gear is to assure one rudder position for each corresponding position of the helm. Therefore, the follow-up mechanism should ?

•be returning the main pump variable stroke device gradually to neutral stroke just as rudder is achieving command angle

312. At what pressure should a cylinder relief valve of an internal combustion engine be set to relieve?

•The device should be set to relieve at a pressure not more than 40 percent in excess of the maximum firing pressure

313. What part of the steam assisted atomizer where the fuel/air mixtures take place ?

•mixing chamber

314. What component is used to thoroughly separate small particle contamination from hydraulic fluid?

•Filter

315. In most horizontally split centrifugal pump casings, wearing rings are prevented from rotating by

•using an extended lip formed on one half of the ring and using the upper casing half to trap the lip when the casing is reassembled

316. What can be found when subjecting a metal to an axial ?

•strength

317. Almost all solenoid valves are actuated by ?

•an electromagnet

318. In a centrifugal pump, the seal piping directs liquid from the discharge side of the pump to the

•lantern ring

319. The range of values around a setpoint of a measured variable where "no action" occurs in an automatic flow controller is called:

•Deadband

320. Component of an engine used to increase scavenging air is called

•turbocharger

321. Through which part of the air register assembly does the largest quantity of air passes through?

•Stationary air foil or bladed cone

322. If the moisture content of air increases, what could happens to the difference between the dry bulb and wet bulb temperature ?

•It decreases

323. Slag build up on boiler furnace refractory is undesirable because it causes

•peeling or spalling of the brickwork

324. Operating a rotary gear pump far below its rated speed when handling low viscosity liquids, will cause its volumetric efficiency to ?

•decrease to where the pump no longer develops flow

325. KPa is equivalent to ?

•7.5 mm of Hg

326. Why are air compressors equipped with unloading system?.

•removing all but the frictional load during starting

327. What is the most effective way of detecting any malfunction of machinery during their operation?

•Electric siren

328. Which metal is bolted to the ship's hull to preserve the steel against pitting?

•Zinc

329. Which of the following statement is true if the lube oil temperature is allowed to become 'excessively high in the heaters?

•The lubricant will carbonize and its lubricating ability will be reduced

330. What is the simplest method used for determining if a centrifugal pump is operating as designed? .

•close off the discharge valve, and watch for a rise in pressure

331. It refers to an internal combustion engine practice, where there is a necessity of heating the oil, to ensure easy flow and good atomization --------

•Pre-heating

332. Why should a boiler furnace be purged before the burner is lit off?

•To clear the furnace of any explosive gases

333. Maximum rated horsepower of a diesel engine is attained ?

•Â Â at rated engine RPM

334. An inadequate reciprocating bilge pump discharge is most often caused by ?

defective intake valves

335. When installing a new rotary pump, the suction piping should

•be at least one size larger than the pump suction connection

336. After the installation of new impeller wearing rings by pressing them onto the pump impeller hub, it is advisable to ?

•check the shaft and impeller assembly on centers to see if the ring surfaces are true

337. A diesel engine fails to start due to excessive water in the fuel. Before the engine can be started. the water should be removed from which of the following ?

•fuel lines

338. When a burner atomizer is improperly positioned in the distance piece, it may cause ?

•oil impingement in the furnace walls

339. Cylinder wear may take place as a product of mechanical wear,corrosion and combustion which is hard to remove?

•Adhesion

340. Why are burner registers to be left open for few minutes when securing burners ?

•To purge the furnace

341. In a large slow-speed propulsion diesel engine, the side thrust on the crosshead is the direct result of?

•the angularity of the connecting rod against the crosshead during the powr stroke

342. Refrigerant is circulated through a refrigeration systemb y the_

•compressor

343. Salinity cell is installed in the distilling unit to indicate the ?

•quality of water produced

344. A suitable location for the installation of an impulse type steam trap would be in the ?

•horizontal run of drain line from the lowest point at the outlet of the heat exchanger

345. In a refrigeration system how do you clean the oil filter ?

•pulling out and clean vwith chemical

346. Which type of pump is used in the steering gear of modern ships?

•Vane

347. In a flash type distilling unit, which of the following first absorb heat from the evaporator feed ?

•Distillate cooler

348. According to Regulations, a power driven auxiliary steering gear for a vessel capable of a 12 knot service speed, must be able to meet the rudder movement requirements at which of the minimum vessel speeds listed below?

•7 knots

349. Noise and vibration in a condensate pump would be caused by ?

•bent shaft

350. Provision is to be made for ventilation of an enclosed diesel engine crankcase by means of a small

•breather or by means of a slight suction not exceeding 1" of water

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