更多"Air cocks, usually positioned at th"的相关试题:
[单项选择]Under normal conditions, the quantity of air circulation becomes less and less.What is the reason?（）
A. dirty delivery ducts
B. too much refrigerant
C. the fouling filters
D. high temperature outside
[单项选择]（） usually helps to induce air movement to assist combustion.
A. Cylinder cover
B. Main bearing
C. The exhaust valve
D. The piston movement
[单项选择]The pressurized air is usually cooled to increase the charge air （）.
A. viscosity
B. density
C. velocity
D. electricity
[单项选择]The starting air system usually has （） to prevent starting if anything is not in order.
A. drain cocks
B. vent valves
C. counteracts
D. interlocks
[单项选择]Usually we take the cooling effect of the air flown through the cylinder during the overlap period as（）
A. inevitable
B. harmful
C. helpful
D. unacceptable
[单项选择]The pressure of pilot air is usually （） than that of starting air.
A. higher
B. lower
C. low
D. high
[单项选择]The projection on a shaft designed to change circular motion into up and down or back and fore motion is called （）.
A. wheel
B. crankshaft
C. running gear
D. cam
[单项选择]Air chambers are usually fitted to reciprocating pumps in order to （）.
A. increase discharge pressure
B. increase suction vacuum
C. develop pulsation flow
D. keep a steady rate of flow
[单项选择]Low pressure air is usually taken through （） or pressure regulators to a low pressure reservoir supplying a ring main through driers.
A. globe valves
B. butterfly valves
C. gate valves
D. reducing valves
[单项选择]Failure to open the diesel engine test cocks after a long period of shutdown, prior to starting may result in （）
A. an air bound fuel system
B. damage to cylinder heads and pistons
C. excessive fuel injection
D. excessive air valve lift
[单项选择]Diesel engine cylinder head test cocks are used to （）
A. check cylinder lubrication
B. connect the pressure indicator pressure
C. test cylinder heads
D. connect the exhaust gas pyrometers
[单项选择]A shallow dish positioned at the normal water level is connected to the（）This enables the blowing down or removal of scum and impurities from the water surface.
A. main stern stop valve
B. auxiliary steam stop valve
C. scum valve
D. blow down valve
[单项选择]A tug is best positioned for towing and maneuvering on rivers and other restricted waters where wave action is limited when（）.
A. directly astern and pushing the tow
B. towing on a hawser
C. towing alongside and parallel to the vessel it is towing
D. towing on the hip
[单项选择]Cocks and valves control or interrupt flow, and have internal passages arranged so that they can be restricted or closed: in cocks, by rotating the plug, and in valves, by lowering, raising or rotating a disc in relation to a seating surfaceAccording to the above sentence, which of the following statements is not true?（）
A. Flows of fluids can be restricted by both cocks and valves
B. There are seats in the internal passages of valves
C. A disc of valve only moves up and down
D. We can infer that there is a bore in cock ping
[单项选择]The outlet at a fire hydrant may be positioned anywhere from horizontal to pointing（）.
A. 45°upward
B. vertically upward
C. vertically downward
D. all of the above
[单项选择]Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.
A. a high suction head
B. rotating rings
C. badly worn bearings
D. a loose stuffing box gland
[单项选择]Air receivers installed in starting air systems are to be （）.
A. cylindrical in shape with service connections located at the top and bottom
B. opened and made available for inspection during biannual inspections provided
C. with automatic drain traps for the removal of moisture
D. so installed as to make the drain connections effective under extreme conditions of trim
