GCAP Operator 2 Practice Exam

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• How much superheat is found on the outlet of a DX evaporator if the suction header temperature is 37°F?
• What is the primary benefit of a soft start in gas defrost systems?
• What is a basic definition of Enthalpy?
• What is the superheat of the compressor inlet given a suction pressure of 33 PSIG and a suction temperature of 34°F?
• What could indicate a problem if the only change on a CRO Screen is an increase in room temperature?
• What happens to the un-evaporated liquid in the evaporator of a flooded system during operation?
• What initiates the soft start phase in a gas defrost cycle?
• In a pump overfeed design, what would be the correct name for the vessel that feeds liquid to the heat exchangers?
• In gas defrost, what is the role of the re-freeze phase?
• What is unique to the traditional intercooler vessel?
• In refrigeration systems, how is the term "flooded" typically defined?
• What is the Relative Humidity when the Dry Bulb Temperature is 80°F and the Wet Bulb Temperature is 70°F?
• The flooded evaporator has fluctuating recirculation rates due to?
• Any service valve that does not have an instrument such as a gauge in its port, what must an operator consider?
• True or False: At any given constant, as Dry Bulb Temperature and Relative Humidity go up, all other variables will increase as well.
• What does Mechanical Integrity ensure in engineering applications?
• What is the Dew Point when the Dry Bulb Temperature is 70°F and the Relative Humidity is 40%?
• Intercooler vessels?
• When does a TXV respond to changes in load conditions?
• What is the Dew Point for a Dry Bulb Temperature of 70°F with 40% Relative Humidity?
• How does an increase in water percentage in ammonia affect the refrigeration cycle?
• What does a smaller diameter impeller in a pump affect?
• How is motor efficiency expressed in percentage terms?
• What is a likely cause of high discharge temperatures in a compressor?
• What dictates the maximum NPSH available for a liquid Ammonia pump?
• Given a suction header pressure of 38 PSIG and a suction header temperature of 37°F, how much superheat is found at the outlet of the evaporator?
• When dealing with compressors, what does the term "suction header" refer to?
• What does CUI stand for in mechanical integrity?
• What is true about most industrial solenoids?
• What type of pressure differential is needed to properly adjust an overfeed evaporator in a recirculated system?
• What is the purpose of the soft stop design in a gas defrost process?
• What is the temperature condition of the gas entering the evaporator during the gas defrost cycle?
• If a flooded system is operating with a suction pressure of 8 PSIG, what return line temperature would be concerning?
• What is the significance of the specific heat of a carrot in cooling calculations?
• How is Enthalpy best defined?
• When one drum is filling from the LPR in a pumper drum system, what is the operational function of the opposite drum?
• Which factor influences thermal conductivity the least?
• What is NOT a characteristic of a true accumulator vessel?
• What is the suggested minimum height of NPSH needed for gravity supply to a liquid Ammonia pump?
• What is the typical sequence of steps in a gas defrost process?
• How do the temperature lines run within the SAT region of an Enthalpy diagram?
• What is the theoretical discharge temperature of the compressor including suction superheat given the following conditions: Suction Pressure - 33 PSIG, Discharge Pressure - 152 PSIG, Suction Temp - 34°F?
• What is NOT a symptom of an overfed evaporator that is over-adjusted?
• For a flooded system to operate correctly, it must be?
• Which three regions are identified in an Enthalpy diagram?
• What is one common term for the desirable properties in an engineering practice that RAGAGEP refers to?
• Which defrost design is recognized as the most efficient but also poses significant risks if not executed correctly?
• Which one is NOT a category within the isolation valves?
• What condition can indicate a liquid level issue in the surge drum of a flooded system?
• Which of the following best represents the concept of heat transfer resistance?
• If the liquid drain temperature of an ammonia condenser is 80°F and the high side pressure is 156 PSIG, how many PSI of non-condensables are present?
• What might be an effective solution for a system struggling with ice buildup?
• What is the typical function of a surge drum in refrigeration systems?
• What occurs when the thermostat's set temperature is lower than the liquid refrigerant supply SAT temperature?
• What does the term "eutectic point" refer to?
• In the context of gas defrost, what does "soft stop" refer to?
• How many BTUs are required to cool 7,000 lbs. of carrots from 95°F to 36°F?
• What is the primary function of a compressor in a refrigeration system?
• Which of the following is NOT considered a name for a flooded system?
• What is NOT considered part of Mechanical Integrity?
• What is the state of ammonia at -32°F and 3" Hg?
• What is true about the three forces of the TXV?
• In a pumper drum system, how is the liquid refrigerant removed into the recirculation header?
• When an operator finds insufficient differential between the metering valve inlet and evaporator outlet, what can they do to correct this?
• What does the acronym RAGAGEP stand for?
• Which substance is primarily affected by the concept of Corrosion Under Insulation?
• Which statement about suction line accumulators is NOT true?
• Which part of the refrigeration cycle is primarily responsible for heat absorption?
• What does an Enthalpy diagram illustrate within a refrigeration system?
• In the case of excessive liquid feed supply to the evaporator, what action should be taken?
• What is one unique feed design to all flooded evaporator designs?
• How many control valves are required for the most basic gas defrost to function properly?
• How is the Flash/Tax gas percentage calculated given the condensing and evaporation temperatures?
• In a 4-pipe gas defrost system, defrost condensate liquid is returned to?
• What is the theoretical discharge temperature considering the following conditions: Suction Pressure 33 PSIG, Suction Temperature 34°F, and Discharge Pressure 151 PSIG?
• What is the thermosyphon action?
• How many PSI of non-condensables gases are present when the condenser outlet pressure is 151 PSIG?
• During a manual air defrost, operators must ensure they do NOT?
• What is a simple method to determine if a particular overfeed evaporator is over-adjusted?
• What does a rise in SAT temperature indicate when water increases in Ammonia?
• What is another term for dew point?
• What is the effect of high-pressure gas in a refrigeration system?
• What happens to the refrigerant in the defrost cycle when it changes state back into a liquid?
• When is a refrigerant considered 'superheated'?
• What would the Wet Bulb Temperature be at a Dry Bulb Temperature of 90°F with 30% Relative Humidity?
• Which evaporator design must include the 4-pipe defrost if using hot gas defrost?
• An increase in superheat on the bulb of a TXV causes what to happen?
• How do the temperature lines run in the Sub-Cooled and Superheated regions of the enthalpy diagram?
• Which parameter would be considered close to exceeding critical levels in this DX system?
• What is the Dry Bulb Temperature when the Wet Bulb Temperature is 75°F and the Relative Humidity is 100%?
• To maintain a flooded oil pot design continuously, what must be applied to the pot?
• What is the PSI of non-condensables in a system with a liquid drain temperature of 80°F and high side pressure of 138 PSIG?
• How many variables of air and water does the naked psychrometric chart typically show?
• What type of heat is released during the condensation process?
• What is a potential consequence of not adequately pinching down metering valves on a feed supply?
• What is the primary function of the soft start in a gas defrost?
• For an air unit with tubes and fins, what should be considered when designing with colder application temperatures?
• Which variables can be measured by instruments on most psychrometric charts?
• What is the most likely cause of the low recirculator liquid level?
• What does the "K" value of a material indicate?
• Hunting and surging can be indicative of what issue in a DX system?
• What is the significance of the saturation temperature in a refrigeration system?
• Water defrost can only be effectively incorporated at application temperatures above?
• Which aspect is critical for a DX system to function correctly in terms of overfeeding?
• What is a primary function of an intercooler vessel?
• Which of the following does NOT occur when the load is increased on a DX evaporator using a TXV?
• What is the Humidity Ratio with a Dry Bulb Temperature of 100°F and Relative Humidity of 60%?
• Which aspect makes gas defrost systems relatively dangerous during operation?
• What is a concern with a recirculated system if you lose the compressors that draw gas off of the LPR and a pump stays running?
• What is the name of the pipe that connects the evaporator back to the LPR in a recirculated system?
• When is a 3-way valve with dual relief valves needed for pressure protection?
• How many forces are incorporated in a thermostatic expansion valve (TXV)?
• True or False: ASME requires 3-way with dual relief valves on a vessel or heat exchanger greater than 10ft³ internal volume?
• What does the Power Factor (PF) measure in a motor's performance?
• Which of the following is a true statement regarding DX systems?
• When does the majority of heat delivery occur during the gas defrost process?
• What is the latent heat of evaporation at -20°F as stated in an Enthalpy Chart?
• What type of feed design is used with a shell and tube evaporator when using refrigerant in the shell?
• In a basic theory of general superheat measurement, what is the superheat measurement if a DX system's evaporator is 75% saturated and 25% superheated?
• Which aspect of a flooded evaporator is most influenced by heat load changes?
• What critical feature does a high-pressure receiver vessel possess?
• What measurement is used for determining superheat?
• How much pipe loss is acceptable before IIAR suggests a subjective analysis?
• Is a dynamic pump defined as a liquid pump that physically traps and tries to reduce the volume of the liquid?
• What is the state of ammonia at 115°F and 251 PSIG?
• When adjusting a flooded evaporator, which parameter should primarily be manipulated to achieve optimal performance?
• Which defrost process converts the evaporator into a condenser?
• What is the main purpose of a suction line accumulator?
• What is the superheat at the inlet of a compressor with a suction pressure of 33 PSIG and suction temperature of 34°F?
• The acronyms BPR and DSR refer to what type of valves?
• What is the name of the vessel that hydraulically feeds liquid to heat exchangers in a pump overfeed design?
• What is the latent heat of evaporation at 10°F SAT conditions?
• As the percentage of water increases in an ammonia charge, what happens to the SAT boiling temperature at various pressures?
• How much superheat is calculated at the outlet of the evaporator under the given conditions?
• For a flooded system to work properly in operation, it must be?
• What would NOT be a recommended distribution in an overfeed evaporator?
• Given the following, what would be the PSI build of this NH3 centrifugal pump running within its pump curve?
• What system configuration avoids flooding in a recirculated system?
• An increase in heat (superheat) on the bulb of a TXV causes what effect?
• How do you determine the actual superheat in a system?
• Which material is the best resistor to heat transfer?
• What happens to flash gas in a flooded system?
• True or False? Vessels can be fabricated and welded on in house without unique credentials?
• What describes the unique design characteristic of all flooded evaporators?
• What is the typical recirculation rate (RR) for most DX systems?
• What is the thermosyphon action?
• Which statement is true regarding isolation valves and refrigerant flow?
• Which factor is NOT involved in heat transfer?
• In a gravity feed system, which term describes the vessel that supplies heat exchangers?
• In a properly functioning system, which temperature is commonly expected at the evaporator outlet?
• From where does Cool Gas Defrost deliver gas to the evaporator?
• What does Entropy measure in thermodynamics?
• Which of the following can lead to flooding out the plant in a recirculated system?
• How many turns open should hand expansion or metering valves be for optimized efficiency?
• Under full load conditions, how much time should the solenoid be open when feeding makeup liquid to another vessel?
• What happens when the load increases on a DX evaporator using a TXV?
• What happens to Enthalpy during vertical changes in the sub-cooled or SAT region?
• How many BTU's must be removed from 1,000 lbs. of tomatoes to cool from 85°F to 34°F, given a specific heat of 0.96 BTU/lb.?
• What is the purpose of understanding the "U" Factor in operation?
• What is a common attribute of most semi-hermetic pumps?
• Which type of valve is typically used for on/off applications without throttling?
• For optimal performance, a flooded evaporator should be designed with what flow configuration?
• What is the main function of a low-side vessel in a refrigeration system?
• What is the superheat on the inlet of both compressors in a system?
• Which factor is critical in the design of a refrigeration system when considering energy efficiency?
• What is NOT a purpose for a true accumulator vessel?
• What is the main reason for using hot gas defrost in a refrigeration system?
• What needs to be corrected in a gravity flooded system to resolve changing conditions?
• What condition might lead to liquid standing in the suction line?
• What role do compressors typically play in a refrigeration cycle?
• What is the most common recirculation rate for an overfeed evaporator?
• What happens to the refrigerant state during compression in a refrigeration cycle?
• Why is it important to monitor the gas pressure entering the evaporator?
• What is the suggested minimum height of NPSH needed for gravity supply to a liquid ammonia pump?
• Which of the following actions is critical when a compressor is subjected to too much liquid feed from the evaporator?
• Where does the flash/tax gas go after the expansion valve in all DX systems?
• What characteristic defines a properly functioning flooded evaporator design?
• What is a way to stop pump slugs?
• What is the definition of psychometrics?
• In a properly operating flooded system, what is the superheat leaving the surge drum?
• What is the primary purpose of the surge drum in a flooded system?
• Operators with a flooded system should consider?
• How is the BHP of a 3-phase motor calculated?
• What is one potential consequence of a low liquid level in a refrigeration system?
• What is the Specific Volume when the Dry Bulb Temperature is 120°F and the Relative Humidity is 25%?
• Which of the following is NOT one of the three types of isolation valves?
• During full load conditions, how long should the solenoid valve remain open while feeding makeup liquid to another vessel?
• What are refrigerant strains produced during phase changes called?
• What is the formula used to calculate BHP for a 3-phase motor?
• What does a higher mesh count in a strainer basket indicate?
• What effect does high compressor discharge temperature have on a refrigeration system?
• At what state is ammonia when it is at 85°F and 140 PSIG?
• Which statement is NOT true regarding DX systems?
• Which metering device could NOT be used with a slightly overfed DX evaporator incorporating a suction line accumulator?
• What should be incorporated with a top fed DX air evaporator?
• What type of pressure differential is suggested to have to properly adjust an overfeed evaporator?
• What percentage of ammonia purity would most industry advocates begin to find concerning based on test results?
• Approximately how much superheat should one expect on a properly operating flooded design evaporator?
• What is an undesirable result of having higher water content in Ammonia?
• If an evaporator's defrost design method fails, what is the next best method for defrosting?
• A recirculation rate (RR) of 3:1 means what in terms of liquid and gas generation in the evaporator?
• How should a properly designed electric defrost operate to melt ice?
• What is the Dry Bulb Temperature when the Wet Bulb Temperature is 85°F and the Relative Humidity is 40%?
• What is CUPL an acronym for?
• What is the most likely cause of the changes observed in the DX system regarding the suction and compressor pressures and temperatures?
• When adjusting a valve in an ammonia liquid line, what is the name of the valve if the temperature is -25°F and pressure is 1 PSIG after the adjustment?
• When removing the packing nut from most gate or globe valves, the valve must be?
• A properly designed DX system facilitates which type of flow?
• What does psychometrics study?
• What is typically the first step in the gas defrost process?
• What must be considered when determining the operational capacity of a refrigeration system?
• Transferring liquid refrigerant using pneumatics instead of hydraulics can also be known as what other names?
• What is the purpose of performing mechanical integrity tests?
• What is the Humidity Ratio when the Dry Bulb Temperature is 100°F and the Relative Humidity is 60%?
• When water concentration increases in Ammonia, what effect does it have on the SAT temperature?
• Mechanical Integrity inspections and tests should be based on which of the following?
• Which method is used to facilitate a gas defrost cycle efficiently?
• What is the approximate pump pressure established under the provided conditions?
• What is meant by compound compression in a refrigeration system?
• In industrial refrigeration, the type of heat transfer often utilized involves?
• What two variables are considered to create a basic vapor pressure curve?
• Which type of refrigerant would typically be used with a TXV?
• What describes partially flooded systems?
• In a gravity feed design, what would be the correct name for the vessel that feeds the heat exchangers by gravity?
• Given a suction header pressure of 38 PSIG and a suction header temperature of 50°F, how much superheat is found at the outlet of the evaporator?
• What is the typical sequence of steps in a gas defrost cycle?
• When discharge pressure rises while suction pressure stays constant in a refrigeration system, what happens to the heat of compression triangles?
• Which of the following is NOT a type of defrost design used in industrial refrigeration?
• What is the approximate pressure for ammonia before reaching the trans-critical phase?
• What is the primary purpose of a bypass line in a pump system?
• Why is there no flash or tax gas across a metering valve?
• What is Wet Bulb Temperature?
• What is the Vapor Pressure when the Dry Bulb Temperature is 90°F and the Humidity Ratio is 106 grains?
• Which evaporator design must utilize a four-pipe system when employing gas defrost?
• In a two-stage system, how do the sizes of compressors typically compare?
• In thermodynamics, what change occurs when a substance undergoes condensation?
• True or False: Oils pots will have no oil in them if ice is still accumulated on the outside of the pot.
• What is NOT a concern with oil accumulation in level columns?
• How much pump pressure is being built by this system from the provided information?
• What is the main difference between the thermosyphon flooded system and the traditional gravity flooded system?
• Which organization governs the National Boiler Pressure Vessel Code for the safe design and build of pressure vessels?
• Which of the following is NOT a disadvantage of the flooded design?
• What does the term "superheat" refer to in refrigeration?
• Which organization oversees the National Boiler Pressure Vessel Code for pressure vessels?
• During which phase of gas defrost does the evaporator experience the highest risk for damage?
• What is the relationship between temperature difference and heat transfer?
• What is a possible symptom of a liquid pump cavitating?
• In a flooded system, what is the role of gravity in the operation of the evaporator?
• What is the Enthalpy when the Dry Bulb Temperature is 90°F, Humidity Ratio is 106 grains, and Relative Humidity is 50%?
• Are all isolation valves required to flow the refrigerant in the direction indicated by the flow arrow on the valve body?
• What is the refrigerant state of ammonia at -30°F and 6" Hg?
• How much pump pressure is being established with a suction header of 10" Hg and pump header of 22 PSIG?
• What does a refrigeration system plotted within an Enthalpy diagram illustrate?
• What is the Enthalpy when the Dry Bulb Temperature is 50°F and the Relative Humidity is 30%?
• When moving center horizontally on a psychrometric chart, what type of heat exchange occurs?
• If an Ammonia refrigeration system is concerned about water entrained within the Ammonia, what type of vessel could be used to help separate the water from the Ammonia?
• Why might a refrigeration system require a receiver?
• What is the orientation of temperature lines within the SAT region of an enthalpy diagram?
• What do hunting and surging in a DX system indicate?
• What does thermal conductivity, or "K" value, measure?
• What happens to pressure and temperature of a refrigerant as it passes through an expansion valve?
• Which of the following indicates proper refrigerant management practices?
• Which of the following will NOT lead to flooding out the plant in a recirculated system?
• What happens if liquid enters the evaporator during the gas defrost process?
• Which statement is true about a suction line accumulator?
• What must an operator consider for a service valve that does not have an instrument in its port?
• What is the "K" value in thermal conductivity?
• Calculate the superheat at the outlet of the compressor with a discharge temperature of 175°F and discharge pressure of 152 PSIG.
• The flooded evaporator has fluctuating recirculation rates due to?
• What do the flooded and recirculated system have in common?
• What does total heat rejection in a refrigeration system refer to?
• What is the maximum water concentration allowed in Ammonia for it to be classified as anhydrous or refrigeration grade?
• What should be considered in design and incorporated into all recirculators?
• How many unique angles are represented for the variables in a naked psychrometric chart?
• What type of expansion valve is typically used in DX systems?
• What occurs to the pressure in the suction pipe when the load on a DX evaporator is increased and the compressor cannot move the extra gas?
• How much superheat is leaving the evaporator when the suction header pressure is 33 PSIG and temperature is 38°F?
• When does the majority of heat used in the gas defrost get delivered to the evaporator?
• What is the correct sequence for pumping down a valve group to service the strainer?
• Which of the following is NOT a name for a recirculated system?
• A recirculation rate (RR) of 4:1 indicates what about the evaporation process?
• As the load decreases on a flooded evaporator, what happens to the amount of liquid refrigerant by volume in the evaporator?
• How many forces are incorporated in a TXV (Thermostatic Expansion Valve)?
• Approximately how much superheat is expected in a properly operating flooded design evaporator?
• In which phase does the evaporator release heat back into the system?
• If liquid carryover is a concern in a refrigeration system, which vessel should be included?
• According to enthalpy graphs, how does superheating affect compressor discharge temperature?
• What does Mechanical Integrity involve?
• What is the usual recirculation rate (RR) for most DX systems?
• What condition must the gas be in when entering the evaporator for optimal heat exchange?
• What role does a condenser play in a refrigeration cycle?
• Which indication would suggest improper adjustment of a thermal expansion valve?
• What characteristic of a DX evaporator enhances its compatibility with gas defrost?
• What is causing the given changes in the DX system where the compressor discharge temperature decreases significantly?
• When water freezes into ice, it can swell or expand by how much?
• Which of the following is NOT a factor of heat transfer?
• What is the effect of increasing the load on a DX evaporator using a TXV?
• What do the two boundary lines separating the SAT region from the superheat and subcooled represent?
• Which of the following is NOT one of the Non-Destructive Techniques used in Mechanical Integrity Inspections?
• What effects can high levels of non-condensables have in a refrigeration system?
• True or False: A DX system incorporating a TXV allows for overfeeding the unit if the valve is properly adjusted.
• What is the purpose of a pressure gauge in a refrigeration system?
• Where is low pressure re-established after a pump creates differential pressure in a refrigeration recirculated system?
• If a condenser pressure is 151 PSIG with a liquid temperature of 79°F, how many PSI of non-condensables are present?
• In a 3-pipe gas defrost system, where is the defrost condensate liquid returned to?