英语2期末考

Both relief valves and reducing valves are pressure control valves. The basic difference between them is that(　　) is closed by a spring, and(　　)opened by a spring. A the latter后者; the former前者 B the former; the latter C the reducing valves; the relief valves D reducing valves; the later

In a general cargo crane,(　　)is fitted to lift the cargo load. Athe slewing motor Bthe luffing motor Cthe hoisting motor Dthe fan motor

Which problem can occur if the brake band lining of a wildcat brake becomes excessively worn?(　　) AThe driving engine will over-speed. BThe anchor will immediately drop. CThe clutch will overheat. DThe brake' s effectiveness will be reduced.

Centrifugal separators can be arranged(　　)to attain a higher throughput. Ain series Bin parallel Cindependently Din series or parallel

Which of the following factors determines the interval between discharges of a self-cleaning separator?(　　) AThe separating temperature. BThe rated throughput. CThe content of impurities in the fuel oil. DThe volume of the bowl.

If sludge had packed between the bowl discs it may be necessary to stop the machine for (　　)of the bowl. Aself-cleaning Bmanual cleaning Cautomatic cleaning Dself or automatic cleaning

Before the sludge in a purifier is ejected,(　　) Athe oil feeding is stopped and replaced by admitting flushing water Bthe flushing water feeding is stopped and replaced by admitting oil Cthe feeding of dirty oil and flushing water is stopped Dthe feeding of dirty oil and flushing water is admitted

When separating lube oil in purifier, the optimal separating quantity is (　　) of the rated quantity on nameplate. A100% B1/2 C1/5 D1/3

When two oil separators are working in series, they should work(　　) Aboth for removing impurity Bfirst stage for removing impurity, second stage for removing water Cboth for removing water Dfirst stage for removing water, second stage for removing impurity

Amore sealing water is needed Bthe cover clamp needs tightening Cthe purifier has a bad vibration when started Dwater is discharged from the overflow line

The factors influencing the interface position in the purifier are: oil viscosity and density, throughput and back pressure and (　　). Aconical discs Bcatch plate Cgravity disc Dwater content

Where 15 ppm purity is necessary,(　　)to provide warning of the level of discharge is in excess of 15 ppm. Aalarm unit Bmonitoring unit Cheating unit Dcooling unit

The safe rate of bunkering heavy fuel oil is directly related to the(　　) Atype of fuel transfer pump aboard Btemperature of the heavy fuel oil being received Csize of the fuel storage tanks ashore Ddistance from the fuel oil storage tanks ashore

Which of the following fuel oil characteristics establishes the danger point when transferring. pumping, and firing procedures are concerned?(　　) AFire point. BFlash point. CSpecific gravity. DViscosity.