单项选择题
What is the purpose of pressure-vacuum relief valves? （）
A.Regulation of discharge pressure from cargo pumps
B.Maintaining constant velocity in cargo lines
C.Regulation of suction head on cargo pumps
D.To maintain a tank or void at atmospheric pressure
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相关考题
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单项选择题
What is the principle behind dynamic braking as used on an anchor windlass?（）
A.Electrical loading
B.Mechanical distribution
C.Compressibility of air
D.Mechanical friction -
单项选择题
What is the holding power ratio of an anchor? （）
A.Maximum mooring line tension divided by the anchor's weight in air
B.Anchor's weight in air divided by the maximum mooring line tension
C.Preloading tension divided by the anchor's weight in air
D.Operating tension divided by the anchor's weight in air -
单项选择题
What is the function of wearing rings found on some centrifugal pumps? （）
A.Absorb erosion of high velocity discharge stream
B.Seal pump shaft against entry of air
C.Isolate the outlet side from the inlet side
D.Dampen the turbulent discharge flow
