pressure vacuum relief valves
excess flow valves
safety relief valves
flame screens
第1题：
Which of the following problems could cause the high pressure cutout switch to shut down the compressor in a refrigeration system?
A.A shortage of liquid refrigerant.
B.Excessive frost on the evaporator.
C.Excessive condenser cooling water.
D.Insufficient condenser cooling water flow.
第2题：
If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably ______.
A.excessive pump speed
B.excessive suction head
C.worn wearing rings
D.gross pump misalignment
第3题：
To prevent excessive __ in the transverse girders, the tie bolts are positioned as close to the center of the crankshaft as possible
A.thermal stresses
B.bending moments
C.thermal loads
D.surface tensions
第4题：
gear
vane
screw
centrifugal
第5题：
When loading a cargo of taconite，proper sequencing of loading by hatch number is necessary to ______．
A.Provide the proper trim
B.Prevent negative stability from developing
C.Prevent excessive longitudinal stresses
D.Control list
第6题：
If a diesel engine turned over freely but failed to start, the cause could be ________.
A.water in the fuel
B.cold lube oil
C.excessive starting air pressure
D.excessive fuel pressure
第7题：
According to the regulations，what type of gauging is required for a cargo of butadiene?
A.Open
B.Restricted
C.Closed
D.None
第8题：
Low compressor head pressure in a refrigeration system can be caused by ___.
A.insufficient condenser cooling water
B.excessive condenser cooling water
C.air in the refrigeration system
D.excessive refrigerant in the system
第9题：
The Database Resource Manager is automatically enabled in the maintenance window that runs the Automated Maintenance Task. What is the reason for this？（）
第10题：
compression pressure
lube oil header pressure
scavenge air pressure
piston ring blow-by