A.radiation
B.conduction
C.convection
D.condo-radiation
您可能感興趣的試卷
你可能感興趣的試題
A.used in either the fully dosed or fully opened position
B.installed with the stem down
C.used for steam service only
D.used to throttle or regulate the flow of liquid
A.Radiation
B.Conduction
C.Natural convection
D.All of the above
A.A gate valve
B.A globe valve
C.Any check valve
D.Any needle valve
A.a shortage of compressor oil
B.warm food in the refrigerator
C.excessive condenser cooling water
D.a shortage of refrigerant
A.molecular fluid vibration
B.energy losses
C.wide pressure variations
D.mechanical damage to control valves
最新試題
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
Thermostatic expansion valves can be adjusted for （）.
If the relief valve on the discharge side of a hydraulic pump lifts, the cause could be （）.
A grease gun is generally used to lubricate a （）.
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
Who is responsible for ensuring that someone is assigned to close the watertight doors in an emergency?（）
The usual symptoms of cavitation in a centrifugal pump is （）.
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.