大管轮轮机英语综合(33-48期)(15)

A. to repair/renewing B. repairing/renewing C. to repair/ be renewed D. repairing/be renewed

6. The tendency for lubricating oil to thin out at high temperature and thicken at low temperature

will be characterized by a ______.

A. low viscosity index B. high viscosity index

C. high neutralization number D. low demulsibility((抗乳化性) quality 7. The centrifuge, settling tanks and ______are used to clean fuel oil.

A. balance tank B. storage tank C. service tank D. filters

8. Which of the following actions should be taken if during a routine maintenance inspection of a

centrifugal pump, localized scoring on a pump shaft sleeve is detected?

A. Correct the cause of the scoring and repair the sleeve or replace with a new one. B. Reassemble the unit and provide more water leak off for proper lubrication. C. Check for parallel alignment of the sleeve radial faces to the sleeve bores. D. Reassemble the unit and adjust the governor to obtain a slower speed. 9. A hot air start pipe indicates that there is ______.

A. inefficient cooling B. a leaking air start valve C. a clogged drain valve D. a leaking air bottle

10.

A restricted air intake to a diesel engine may result in the engine ______. A. failing to reach rated speed B. knocking under maximum load C. hunting or surging under light load D. overspeeding and running away

11. The turbo-blower comprises a gas turbine and a ______.

A. condenser B. blower C. soot blower D. air receiver

12.

Some vessels are equipped with a water lubricated stern tube. When at sea, operating under

normal conditions, the water service valve from the ship's saltwater system to the bearing should be ______.

A. closed, and no leakage permitted across the shaft packing

B. closed, and only slight leakage permitted across the shaft packing C. opened, and no leakage permitted across the shaft packing

D. opened, and only slight leakage permitted across the shaft packing

13.

Although lube oils used in the main lubricating service systems should have a relatively high flash point to avoid ignition, they can create smoke and fire hazards when they ______. A. are exposed to a vacuum

B. come in contact with extremely hot surfaces

C. are reduced in temperature to just above the pour point

D. become extremely agitated（激动的） or aerated (充气、通风)

14. An increase in load on a diesel engine results in ______of speed of the crankshaft. A. a reduction B. an increase C. an outing D. a downwards

15. We can control the speed of the engine by ______the quantity of oil supplied. A. exchanging B. regulating C. adjusting D. differing from

16. Wear in parts of exhaust valve operation gear will tend to ______the tappet clearance. A. increase B. reduce C. rise D. reduction.

17. The most suitable pump for oily water separator feed duties is______. A. a reciprocating pump B. a vane pump

C. a centrifugal pump D. a triple screw pump

18.

A centrifugal pump vibrates excessively during operation. Upon disassembling the pump it is found that the impeller is out of balance. Without an available spare, you should ______. A. drill holes through the heavy side of the impeller until it balances B. weld counterweights（平衡物） to the light side of the impeller C. remove metal from the heavy side by machining in a lathe D. acid wash and scrape the heavy side until it balances

19.

Improper maintenance of an automatic auxiliary boiler oil burner could result in ______. A. fuel pump failure B. fan motor failure