2
CIRO OP 2 Exam with accurate detailed solutions || || || || || || ||
What was the main disadvantage of hand expansion valves in early refrigeration systems
|| || || || || || || || || || || ||
A. They were big and bulky
|| || || || ||
B. They always required service because they had many moving parts
|| || || || || || || || || ||
C. They did not automatically adjust to changing loads so an operator had to frequently
|| || || || || || || || || || || || || || ||
check and adjust them
|| || ||
C. They did not automatically adjust to changing loads so an operator had to frequently
|| || || || || || || || || || || || || || ||
check and adjust them
|| || ||
What is the advantage of a thermostatic expansion valve
|| || || || || || || ||
A. They will automatically adjust themselves to match varying load conditions
|| || || || || || || || || ||
B. They create fully wetted coil surface with coil capacity equal to a gravity flooded system
|| || || || || || || || || || || || || || ||
C. They can be used on gravity, flooded, recirculated over-feed and DX systems
|| || || || || || || || || || || ||
D. One size fits all evaporators
|| || || || ||
A. They will automatically adjust themselves to match varying load conditions
|| || || || || || || || || ||
How many forces are involved in operating a thermostatic expansion valve?
|| || || || || || || || || ||
A. One - only bulb pressure
|| || || || ||
B. Two - only the bulb and spring pressure
|| || || || || || || ||
C. Three - The bulb, spring, and evaporator pressure
|| || || || || || || ||
D. Four - The bulb, spring, evaporator, and atmospheric pressure
|| || || || || || || || ||
C. Three - The bulb, spring, and evaporator pressure
|| || || || || || || ||
,2
Which of the following best describes the term 'flash gas'?
|| || || || || || || || ||
A. The vapor in the last 25% of travel in a DX coil
|| || || || || || || || || || || ||
B. The gas that is discharged out of the compressor
|| || || || || || || || ||
C. The gas that is generated at the orifice of the expansion device
|| || || || || || || || || || || ||
D. The gas that is traveling down the suction line toward the compressor
|| || || || || || || || || || || ||
C. The gas that is generated at the orifice of the expansion device
|| || || || || || || || || || || ||
What is the average starting point for setting superheat at the outlet of a DX coil?
|| || || || || || || || || || || || || || ||
A. 5F
||
B. 10F
||
C. 25F
||
D. 1F
||
B. 10F
||
Level adjustment of an "LL" type float switch assembly is accomplished by
|| || || || || || || || || || ||
A. Adjusting the activation screw on the switch mechanism
|| || || || || || || ||
B. Re-piping or re-attaching the float at a different level
|| || || || || || || || ||
C. Re-calibrating the switch height on the float assembly
|| || || || || || || ||
D. Entering new level parameters in the float controller
|| || || || || || || ||
B. Re-piping or re-attaching the float at a different level
|| || || || || || || || ||
When servicing a DX air unit
|| || || || ||
,2
A. It is acceptable to use the TXV as an isolation valve as the warm temperature will result
|| || || || || || || || || || || || || || || || || ||
in a complete closing of the valve
|| || || || || ||
B. A separate isolation valve must always be used to isolate the coil
|| || || || || || || || || || || ||
C. The TXV can be used to isolate the coil if the superheat adjustment is turned completely
|| || || || || || || || || || || || || || || || ||
in to the "manual off" position
|| || || || ||
D. The TXV can be used to isolate the coil if the superheat adjustment is turned completely
|| || || || || || || || || || || || || || || || ||
out to the "manual off" position
|| || || || ||
B. A separate isolation valve must always be used to isolate the coil
|| || || || || || || || || || || ||
Which of the following is a typical function of a low side vessel?
|| || || || || || || || || || || ||
A. Oil cooling
|| ||
B. Phase separation
|| ||
C. Thermosiphon refrigerant storage
|| || ||
D. Subcooling liquid for low side use
|| || || || || ||
B. Phase separation
|| ||
If a power element of a TXV lost its charge
|| || || || || || || || ||
A. The evaporator would starve
|| || || ||
B. The evaporator would hunt
|| || || ||
C. There would be low superheat at the coil outlet
|| || || || || || || || ||
D. The evaporator would flood
|| || || ||
A. The evaporator would starve
|| || || ||
Hand expansion valves are || || ||
, 2
A. Seldom used in newer systems
|| || || || ||
B. Only used to feed gravity flooded evaporators
|| || || || || || ||
C. Not used in series with another feed control device
|| || || || || || || || ||
D. Commonly used in series with another feed control device
|| || || || || || || || ||
D. Commonly used in series with another feed control device
|| || || || || || || || ||
The thermostatic expansion valve is opened by forces coming from
|| || || || || || || || ||
A. Evaporator pressure only
|| || ||
B. Evaporator temperature only
|| || ||
C. Compressor pressure only
|| || ||
D. Sensing bulb pressure
|| || ||
D. Sensing bulb pressure
|| || ||
A hand expansion valve can control the flow of refrigerant into an evaporator better than a
|| || || || || || || || || || || || || || || ||
typical stop valve because
|| || ||
A. It is larger than the liquid line pipe size feeding it
|| || || || || || || || || || ||
B. It has an adjustable orifice designed to control flow
|| || || || || || || || ||
C. It is made of special alloy metal that expands and contracts with temperature change
|| || || || || || || || || || || || || ||
D. Pointers can be attached to the hand wheel
|| || || || || || || ||
B. It has an adjustable orifice designed to control flow
|| || || || || || || || ||
Where may hand expansion valves be found in modern industrial refrigeration systems
|| || || || || || || || || || ||
A. They are not used
|| || || ||
CIRO OP 2 Exam with accurate detailed solutions || || || || || || ||
What was the main disadvantage of hand expansion valves in early refrigeration systems
|| || || || || || || || || || || ||
A. They were big and bulky
|| || || || ||
B. They always required service because they had many moving parts
|| || || || || || || || || ||
C. They did not automatically adjust to changing loads so an operator had to frequently
|| || || || || || || || || || || || || || ||
check and adjust them
|| || ||
C. They did not automatically adjust to changing loads so an operator had to frequently
|| || || || || || || || || || || || || || ||
check and adjust them
|| || ||
What is the advantage of a thermostatic expansion valve
|| || || || || || || ||
A. They will automatically adjust themselves to match varying load conditions
|| || || || || || || || || ||
B. They create fully wetted coil surface with coil capacity equal to a gravity flooded system
|| || || || || || || || || || || || || || ||
C. They can be used on gravity, flooded, recirculated over-feed and DX systems
|| || || || || || || || || || || ||
D. One size fits all evaporators
|| || || || ||
A. They will automatically adjust themselves to match varying load conditions
|| || || || || || || || || ||
How many forces are involved in operating a thermostatic expansion valve?
|| || || || || || || || || ||
A. One - only bulb pressure
|| || || || ||
B. Two - only the bulb and spring pressure
|| || || || || || || ||
C. Three - The bulb, spring, and evaporator pressure
|| || || || || || || ||
D. Four - The bulb, spring, evaporator, and atmospheric pressure
|| || || || || || || || ||
C. Three - The bulb, spring, and evaporator pressure
|| || || || || || || ||
,2
Which of the following best describes the term 'flash gas'?
|| || || || || || || || ||
A. The vapor in the last 25% of travel in a DX coil
|| || || || || || || || || || || ||
B. The gas that is discharged out of the compressor
|| || || || || || || || ||
C. The gas that is generated at the orifice of the expansion device
|| || || || || || || || || || || ||
D. The gas that is traveling down the suction line toward the compressor
|| || || || || || || || || || || ||
C. The gas that is generated at the orifice of the expansion device
|| || || || || || || || || || || ||
What is the average starting point for setting superheat at the outlet of a DX coil?
|| || || || || || || || || || || || || || ||
A. 5F
||
B. 10F
||
C. 25F
||
D. 1F
||
B. 10F
||
Level adjustment of an "LL" type float switch assembly is accomplished by
|| || || || || || || || || || ||
A. Adjusting the activation screw on the switch mechanism
|| || || || || || || ||
B. Re-piping or re-attaching the float at a different level
|| || || || || || || || ||
C. Re-calibrating the switch height on the float assembly
|| || || || || || || ||
D. Entering new level parameters in the float controller
|| || || || || || || ||
B. Re-piping or re-attaching the float at a different level
|| || || || || || || || ||
When servicing a DX air unit
|| || || || ||
,2
A. It is acceptable to use the TXV as an isolation valve as the warm temperature will result
|| || || || || || || || || || || || || || || || || ||
in a complete closing of the valve
|| || || || || ||
B. A separate isolation valve must always be used to isolate the coil
|| || || || || || || || || || || ||
C. The TXV can be used to isolate the coil if the superheat adjustment is turned completely
|| || || || || || || || || || || || || || || || ||
in to the "manual off" position
|| || || || ||
D. The TXV can be used to isolate the coil if the superheat adjustment is turned completely
|| || || || || || || || || || || || || || || || ||
out to the "manual off" position
|| || || || ||
B. A separate isolation valve must always be used to isolate the coil
|| || || || || || || || || || || ||
Which of the following is a typical function of a low side vessel?
|| || || || || || || || || || || ||
A. Oil cooling
|| ||
B. Phase separation
|| ||
C. Thermosiphon refrigerant storage
|| || ||
D. Subcooling liquid for low side use
|| || || || || ||
B. Phase separation
|| ||
If a power element of a TXV lost its charge
|| || || || || || || || ||
A. The evaporator would starve
|| || || ||
B. The evaporator would hunt
|| || || ||
C. There would be low superheat at the coil outlet
|| || || || || || || || ||
D. The evaporator would flood
|| || || ||
A. The evaporator would starve
|| || || ||
Hand expansion valves are || || ||
, 2
A. Seldom used in newer systems
|| || || || ||
B. Only used to feed gravity flooded evaporators
|| || || || || || ||
C. Not used in series with another feed control device
|| || || || || || || || ||
D. Commonly used in series with another feed control device
|| || || || || || || || ||
D. Commonly used in series with another feed control device
|| || || || || || || || ||
The thermostatic expansion valve is opened by forces coming from
|| || || || || || || || ||
A. Evaporator pressure only
|| || ||
B. Evaporator temperature only
|| || ||
C. Compressor pressure only
|| || ||
D. Sensing bulb pressure
|| || ||
D. Sensing bulb pressure
|| || ||
A hand expansion valve can control the flow of refrigerant into an evaporator better than a
|| || || || || || || || || || || || || || || ||
typical stop valve because
|| || ||
A. It is larger than the liquid line pipe size feeding it
|| || || || || || || || || || ||
B. It has an adjustable orifice designed to control flow
|| || || || || || || || ||
C. It is made of special alloy metal that expands and contracts with temperature change
|| || || || || || || || || || || || || ||
D. Pointers can be attached to the hand wheel
|| || || || || || || ||
B. It has an adjustable orifice designed to control flow
|| || || || || || || || ||
Where may hand expansion valves be found in modern industrial refrigeration systems
|| || || || || || || || || || ||
A. They are not used
|| || || ||
