NYC RMO EXAM, CHAPTER 18 (Engine Indicators)
questions with verified answers
18.01.) When attempting to read the high pressure gauge on an operating
ammonia compressor, it is noted that the pointer "hunts" (has a wide and
relatively slow back and forth movement). This would most likely indicate that the
compressor? Ans✓✓-Valve action is sluggish
18.02.) Of the following statements, which one is correct regarding an engine
indicator diagram? Ans✓✓-An abnormal diagram indicates a mechanical problem
with the compressor
18.03.) What type of seal is likely to be used in a small compressor? Ans✓✓-
Sleeve type
18.04.) A multi-cylinder, single acting compressor is equipped with reed type
compressor valves, what type of force is used to actuate these values? Ans✓✓-
Differential pressure
18.05.) An engine indicator that is working perfectly indicates a pressure that is 20
psi below the reading of a gauge that has been installed in a system over an
extended period of time. What does the difference in readings indicate? Ans✓✓-
Discharge gauge is faulty
18.06.) The cylinder of a compressor is running hot at decreased capacity. Which
of the following is the most likely cause of this problem? Ans✓✓-Broken or
leaking piston rings
, 18.07.) In addition to malfunctioning compressor valves, what other component
of a compressor could affect the relative shape of an engine indicator diagram?
Ans✓✓-Leaking pistons
18.08.) Which of the following best describes how the atmospheric reference line
on an indicator diagram is used? Ans✓✓-Determine actual pressure at any point
in the diagram
18.09.) If the valve plate of a reciprocating compressor is to be replaced, what
other components should be replaced at the same time? Ans✓✓-Springs
18.10.) A system is cycling excessively, the crankcase temperature is high,
discharge pressure is low and suction pressure is high, what is a possible
explanation? Ans✓✓-Faulty compressor valves
18.11.) Compressor valves control the flow of vapor into and out of a
compressor's cylinders. Which of the following best describes how they are
located on the valve plate? Ans✓✓-Suction on the bottom, discharge on the top
(important)
18.12.) A decrease in the capacity of a reciprocating compressor may be due to?
Ans✓✓-Leaking compressor valves
18.13.) Which of the following is not a form of compressor valve? Ans✓✓-Disc
type
18.14.) A compressor's service valves are mounted externally (on the body of the
compressor), at the compressor's inlet and outlet. Where are the "compressor
valves" located? Ans✓✓-On the valve plate
questions with verified answers
18.01.) When attempting to read the high pressure gauge on an operating
ammonia compressor, it is noted that the pointer "hunts" (has a wide and
relatively slow back and forth movement). This would most likely indicate that the
compressor? Ans✓✓-Valve action is sluggish
18.02.) Of the following statements, which one is correct regarding an engine
indicator diagram? Ans✓✓-An abnormal diagram indicates a mechanical problem
with the compressor
18.03.) What type of seal is likely to be used in a small compressor? Ans✓✓-
Sleeve type
18.04.) A multi-cylinder, single acting compressor is equipped with reed type
compressor valves, what type of force is used to actuate these values? Ans✓✓-
Differential pressure
18.05.) An engine indicator that is working perfectly indicates a pressure that is 20
psi below the reading of a gauge that has been installed in a system over an
extended period of time. What does the difference in readings indicate? Ans✓✓-
Discharge gauge is faulty
18.06.) The cylinder of a compressor is running hot at decreased capacity. Which
of the following is the most likely cause of this problem? Ans✓✓-Broken or
leaking piston rings
, 18.07.) In addition to malfunctioning compressor valves, what other component
of a compressor could affect the relative shape of an engine indicator diagram?
Ans✓✓-Leaking pistons
18.08.) Which of the following best describes how the atmospheric reference line
on an indicator diagram is used? Ans✓✓-Determine actual pressure at any point
in the diagram
18.09.) If the valve plate of a reciprocating compressor is to be replaced, what
other components should be replaced at the same time? Ans✓✓-Springs
18.10.) A system is cycling excessively, the crankcase temperature is high,
discharge pressure is low and suction pressure is high, what is a possible
explanation? Ans✓✓-Faulty compressor valves
18.11.) Compressor valves control the flow of vapor into and out of a
compressor's cylinders. Which of the following best describes how they are
located on the valve plate? Ans✓✓-Suction on the bottom, discharge on the top
(important)
18.12.) A decrease in the capacity of a reciprocating compressor may be due to?
Ans✓✓-Leaking compressor valves
18.13.) Which of the following is not a form of compressor valve? Ans✓✓-Disc
type
18.14.) A compressor's service valves are mounted externally (on the body of the
compressor), at the compressor's inlet and outlet. Where are the "compressor
valves" located? Ans✓✓-On the valve plate
