更多"One cause of high head pressure occ"的相关试题:
[单项选择]Which of the following would not cause high suction pressure?（）
A. insufficient refrigeration
B. leaky suction valves
C. expansion valve stuck open
D. suction valve not adjusted properly
[单项选择]The sudden reduction of pressure occurring within the crankcase of a refrigeration compressor during starting causes the （）.
A. sudden evaporation of wax crystals in the lubricant
B. sudden evaporation of entrapped air in the lubricant
C. release of refrigerant from the oil/refrigerant mixture
D. release of dissolved lubricant from the refrigerant
[单项选择]Excessively low air pressure occurring in the intercooler of a reciprocating air compressor is caused by（）.
A. leaky discharge valves on the LP cylinder
B. leaky discharge valves on the HP cylinder
C. insufficient intercooler cooling
D. low ambient air pressure
[单项选择]Which will cause the high pressure cutout to stop the compressor in a R-22 system?（）
A. Condenser leakage
B. A shortage of liquid refrigerant
C. Excessive frost on the evaporator
D. Not enough condenser cooling water
[单项选择]One cause of diesel engine surging can be a result of （）
A. injection pump plungers stuck or worn
B. low compression
C. solenoid stuck open
D. fuel tank too full
[单项选择]One of the reasons that cause oil flowed from sludge outlet of a self-cleaning separator is（）
A. seal water supply be cut off
B. make up water supply be cut off
C. oil outlet valve closed or not open sufficiently
D. the flow rate of oily water is too much
[单项选择]If the head pressure is too high,（）
A. the relief valve should open before the high-pressure cutout
B. the relief valve should open and let excess refrigerant go to receiver
C. the high-pressure cutout switch should operate before the relief valve opens
D. close in on the suction valve
[单项选择]A head-on situation at night is one in which you see dead ahead a vessel showing（）.
A. one sidelight
B. one sidelight and a masthead light
C. one sidelight and two masthead lights
D. both sidelights of a vessel and her masthead light(s)
[单项选择]One remedy for a high firing pressure, in addition to a high exhaust temperature in one cylinder of a diesel engine, is to （）
A. increase scavenge air pressure
B. reduce fuel booster pump pressure
C. adjust the fuel rack
D. retard fuel injector timing
[单项选择]A common rail engine has only one or two high pressure pumps in operation at the same（）time, and the injection into each cylinder.
A. can’t be controlled very precisely
B. can’t be controlled as flexibly as the separate pump system
C. can be controlled as flexibly as the separate pump system
D. can be controlled more precisely and flexibly
[单项选择]（）uses one or two high pressure pumps for all the cylinders with one more standby, while（）have a separate high-pressure pump for each cylinder.
A. A common rail engine；conventional engines
B. A conventional engine；common rail engines
C. A marine diesel engine；most other engines
D. A two-stroke engine；four-stroke engines
[单项选择]On the high seas，a fog signal consisting of one prolonged blast followed by four short blasts would indicate the presence of a（）.
A. vessel being towed
B. fishing vessel engaged in trawling
C. vessel at anchor warning you of her location
D. power-driven pilot vessel on station underway
[单项选择]One end of a cylinder for a medium or high-speed diesel engine is sealed by the piston and rings, the other end is sealed by the （）
A. crankcase
B. cylinder head
C. valve cover
D. engine frame
[单项选择]双喷嘴喷码机READY HEAD1，HEAD2恒亮表示意思是（）
A. 表示该喷头未启动或已关闭
B. 表示该喷头已启动但未准备就绪或有故障
C. 表示该喷头准备就绪，可以喷印
D. 表示该喷码机已关闭
[单项选择]双喷嘴喷码机READY HEAD1，HEAD2闪亮表示意思是（）
A. 表示该喷头未启动或已关闭
B. 表示该喷头已启动但未准备就绪或有故障
C. 表示该喷头准备就绪，可以喷印
D. 表示该喷码机已启动完成，可以进行任何操作
[单项选择]A whistle signal of one prolonged，one short，one prolonged and one short blast，is sounded by a vessel（）.
A. at anchor
B. towing a submerged object
C. being overtaken in a narrow channel
D. in distress
[单项选择]A signal of one prolonged，one short，one prolonged，and one short blast，in that order is given by a vessel（）.
A. engaged on pilotage duty
B. in distress
C. at anchor
D. being overtaken in a narrow channel
