EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023, Exams of Nursing

Download EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 and more Exams Nursing in PDF only on Docsity! EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What are the typical uses of the center port of gauge set? - Correct Answer ✅Used during evacuation, charging and recovery procedures. What color are the gauges on a manifold gauge set? - Correct Answer ✅Low pressure is blue, High pressure is red. What are the typical ranges of pressure measurements used on the gauges of a manifold gauge set? - Correct Answer ✅High side is 0 to 500 PSIG; Low side is 0 to 350 PSIG and 0 to 30 in. Hg below atmospheric pressure. Is the refrigerant leaving a condenser at a high or low pressure? Is it a liquid or a gas? - Correct Answer ✅High pressure, liquid. Is the refrigerant entering the expansion valve (variable metering device) a liquid or gas? - Correct Answer ✅Liquid, high pressure. Is the pressure of the refrigerant entering the compressor high or low? - Correct Answer ✅Low pressure vapor. Where in a refrigerant circuit does a liquid boil to absorb heat? - Correct Answer ✅In the evaporator. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 The refrigerant in the suction line is a gas that has been heated above its saturation. What is this condition called? - Correct Answer ✅Superheated vapor. What can cause liquid refrigerant to migrate to a compressor crankcase? - Correct Answer ✅If the compressor is located in the coldest location in the circuit. List two conditions that can quickly damage a compressor that is starting to run? - Correct Answer ✅Operating while in a deep vacuum or when the service valves are closed. What system failures require taking an oil sample? - Correct Answer ✅A compressor burnout or if the unit has had a leak. Is flushing with refrigerant an acceptable tube cleaning method? - Correct Answer ✅No. In addition to preventing and repairing leaks what else should a technician do to conserve refrigerant? - Correct Answer ✅Recover and recycle used refrigerants. What factors affect the speed of an evacuation? - Correct Answer ✅Pump size, hose length, hose diameter, size of system to be EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What is Ozone Depletion Potential (ODP)? - Correct Answer ✅The ability of any chemical to deplete the ozone layer. What is CFC? - Correct Answer ✅Chlorofluorocarbon. Which refrigerants are CFC's? - Correct Answer ✅R-11,12,113,114. Which chemical in the CFC refrigerants does the most damage to the ozone layer? - Correct Answer ✅Chlorine. What is an HCFC? - Correct Answer ✅Hydrochlorofluorocarbons. Which refrigerants are HCFC's? - Correct Answer ✅R-22,123. Which is more harmful to the ozone layer a CFC or an HCFC? - Correct Answer ✅CFC's. What is it about CFC's that make them more harmful to the stratosphere? - Correct Answer ✅Chemical strength, they will not breakdown in the lower atmosphere. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What is an HFC? - Correct Answer ✅A fluorocarbon that contains no chlorine. Which refrigerants are HFC's? - Correct Answer ✅R- 134a,404a,407c,410a. What is the ODP of the HFC refrigerant? - Correct Answer ✅Zero. Which refrigerants contain chlorine? - Correct Answer ✅CFC's and HCFC's. Which refrigerants have high ODP? - Correct Answer ✅CFC's. Which refrigerants have low ODP? - Correct Answer ✅HCFC's, HFC's are zero. What is an azeotrope refrigerant? - Correct Answer ✅A mixture of two or more compounds where the mixture behaves like a single chemical. Is one of the components of R-500 a CFC? - Correct Answer ✅Yes Does stratospheric ozone help or hurt the work of the earth's protective shield? - Correct Answer ✅It helps. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What chemical in the stratosphere tells us ozone depletion is occurring? - Correct Answer ✅Chlorine-monoxide. How do we know the chlorine in the stratosphere is coming from CFC's? - Correct Answer ✅The increase in chlorine and fluorine present in the stratosphere, matches the increase in emissions of CFC's. How do we know CFC's get to the stratosphere? - Correct Answer ✅From high altitude air sampling measurements. What role does the ozone layer play in protecting the earth? - Correct Answer ✅It blocks much of the harmful ultraviolet radiation (uv-b). What are the effects on health from increased ultraviolet radiation? - Correct Answer ✅Skin cancer, cataracts, human immunity is reduced. What are the effects on the environment? - Correct Answer ✅Timber growth is reduced, crop yields lowered, marine life and the food chain are impaired. Is ozone depletion a problem for the United States only or a global problem? - Correct Answer ✅A global problem. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What releases of a CFC and HCFC are violations of the Clean Air Act? - Correct Answer ✅Any knowingly vented refrigerants. On what date did it become illegal to vent CFC and HCFC refrigerants? - Correct Answer ✅July 1, 1992. Which appliances are covered by Section 608? - Correct Answer ✅Any device which contains and uses a class 1 or class 2 substance as a refrigerant and is used for household or commercial purposes. What is the primary reason the EPA requires a service aperture or process stub on all appliances? - Correct Answer ✅For adding or removing refrigerant from the appliance. Who sets the regulations for recovery machines? - Correct Answer ✅EPA. What is a "self-contained" recovery machines? - Correct Answer ✅A recovery machine that has its own compressor to pump refrigerant out of the system. Is HCFC-123 a "low or "high" pressure refrigerant? - Correct Answer ✅Low pressure. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 Is CFC-12 a "low" or "high" pressure refrigerant? - Correct Answer ✅High pressure. What is the smallest container in which refrigerants may be sold to a Section 608 certified technicians. - Correct Answer ✅20 pounds. What must you do to the refrigerant in an appliance before disposing of the appliance? - Correct Answer ✅Recover refrigerant or verify that the refrigerant was previously recovered. Who is responsible for removing the refrigerant from household refrigerators prior to disposal? - Correct Answer ✅The final person in the disposal chain. (Scrap metal recyclers, landfill owner, etc) What is the penalty for violation of the Clean Air Act? - Correct Answer ✅Fines up to $27,500 per violation per day and possible loss of technician certification. How much is the bounty for information leading to a conviction? - Correct Answer ✅Up to $10,000. What can happen if a technician cannot demonstrate an ability to use recovery or recycling equipment? - Correct Answer ✅May result in revocation of the technician's certification. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What is the name of the process that removes refrigerant from a system and stores it without testing or processing? - Correct Answer ✅Recovery. What is the name for the process that removes moisture and acids from refrigerant but does not test the refrigerant? - Correct Answer ✅Recycling. What is the name for the process that removes moisture and acids from refrigerant and also chemically tests the refrigerant? - Correct Answer ✅Reclaim. What must be done with reclaimed refrigerant before it can be legally resold? - Correct Answer ✅Chemically tested to ARI Standard 700, the purity level of factory new refrigerant. What is the preferred instrument for detecting small leaks? - Correct Answer ✅Electronic leak detector and Ultrasonic detector. What is an inert gas typically used in leak detection? - Correct Answer ✅Dry nitrogen. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 Can ester based oils be mixed with other oils? - Correct Answer ✅No. What does "hygroscopic" mean? - Correct Answer ✅Oil that absorbs moisture easily. What lubricant is recommended for use with a ternary blend? - Correct Answer ✅Depends on the blend: For HCFC's-Alkylbenze, For HFC's- Ployolester. Safety glasses and butyl-lined gloves should be worn for what procedures? - Correct Answer ✅When operating recovery or recycling devices and when handling and refilling refrigerant cylinders. What safety component must be used whenever dry nitrogen is used to pressurize a system? - Correct Answer ✅Pressure regulator. Safety rules for technicians such as: no open flame or hot steam near a refrigerant never cutting or brazing a charged refrigerant line, and never using oxygen to purge or pressurize lines, are all important. Which one should a technician follow? - Correct Answer ✅All of them. What is a Material Safety Data Sheet? - Correct Answer ✅A sheet the states the safety ratings and precautions to be taken for use and handling of chemicals. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What safety classification within the ASHRAE standard is the most safe? - Correct Answer ✅A1. What is caused by tie inhaling of refrigerant vapors? - Correct Answer ✅Heart irregularities or Asphyxia. What is the major causes of death involving refrigerants? - Correct Answer ✅Oxygen deprivation. What breathing problem can be caused by CFC-12? - Correct Answer ✅Asphyxia. How can ice be removed from a sight glass? - Correct Answer ✅With alcohol spray. What must be done with a badly corroded relief valve? - Correct Answer ✅It must be replaced. Where can you find the allowable test pressure on a system? - Correct Answer ✅Unit data plate. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 Can oxygen be used to check for leaks? If not why not? - Correct Answer ✅No. Oxygen in the presence of oil under high pressure can be explosive. What is the likely result of heating a recovery cylinder with an open flame? - Correct Answer ✅Refrigerant will decompose into a toxic material, venting of refrigerant in the atmosphere or the tank may explode. What is the primary purpose of a disposable cylinder? - Correct Answer ✅For virgin refrigerant from the manufacturer. To what internal pressure should a disposable cylinder be reduced to for disposal? - Correct Answer ✅Reduced to at least 0 PSIG. Should you ever use a disposable cylinder for refrigerant recovery? - Correct Answer ✅No. To dispose of a cylinder you should be sure all refrigerant is recovered and the cylinder is no longer usable. What else should you do? - Correct Answer ✅Puncture the container before disposal. For safety refrigerant cylinders should not be rusted or damaged and always properly color coded. What additional step should also be EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What service aperture may be used on small appliance? - Correct Answer ✅Access tubes or process tubes. What is the name for a fitting used to connect a recovery device to an appliance, which can close to prevent loss of refrigerant form hoses? - Correct Answer ✅Low-loss fitting. (shut-off valve) What is the primary purpose for using hand valves or self-sealing hoses when using a gauge set? - Correct Answer ✅To prevent loss of refrigerant. Which refrigerants must be recovered under Section 608 of the EPA regulations? - Correct Answer ✅CFC, HCFC and HFC refrigerant. Is there a "drop-in" refrigerant for CFC-12? - Correct Answer ✅No. What is the replacement refrigerant for CFC-12 in household refrigerators? - Correct Answer ✅HFC-134a. What can be determined by taking an accurate temperature and pressure reading of a container holding a recovered refrigerant? - Correct Answer ✅Check for non-condensables and the type of refrigerant. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 When doing a non-condensables check, a recovery cylinder should stabilize in temperature before any readings are taken. Why? - Correct Answer ✅To find the correct pressure for that temperature on a T/P chart. What is the internal pressure of CFC-12 refrigerant stored at 75 deg. F? - Correct Answer ✅77 PSIG. What is the exception to the rule that says that someone servicing and appliance must have at least one self-contained recovery machine available at their place of business? - Correct Answer ✅Only when the person is working on a small appliance. Ammonia hydrogen, and water can be found in the refrigerators in some campers and other recreational vehicles. Should these compounds be recovered with EPA approved recovery equipment? - Correct Answer ✅No. May the nitrogen used for purging or pressurizing a system be vented to the atmosphere? - Correct Answer ✅Yes. When may a technician recover only 80% of the refrigerant in a small appliance? - Correct Answer ✅In a system dependent recovery with a non-operating compressor? EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 May a technician use a passive recovery machine for recovery from a domestic refrigerator? - Correct Answer ✅Yes. What requirements are placed on recovery machines built after November 15 1993? - Correct Answer ✅Must be able to recover 80% of the refrigerant if the compressor is inoperative or 90% if the compressor is operative. Must be EPA certified. When using a recovery machine manufactured after November 15 1993, what percentage of the refrigerant must be recovered in a household refrigerator with an operating compressor? What percentage if the compressor is NOT operating? - Correct Answer ✅80%, 90%. Is a certified technician responsible for future changes in EPA regulations? - Correct Answer ✅Yes. What type of certification is required to purchase CFC and HCFC refrigerants? - Correct Answer ✅Type 1. What must be done with any regulated refrigerant vented from a graduated charging cylinder? - Correct Answer ✅It must be recovered. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What does striking the appliance compressor do during a recovery? - Correct Answer ✅Helps to free refrigerant that may be trapped in the oil. A recovery machine should be checked daily for what? - Correct Answer ✅Refrigerant leaks. Can a standard vacuum pump be used as a recovery machine? - Correct Answer ✅In theory yes, but unlikely. First it would have to be certifiable, second it would have to be connected to a non-pressurized recovery container. Should technicians ever mix refrigerants in the field? - Correct Answer ✅No. How should you recover refrigerant that is different from the refrigerant you usually recover? - Correct Answer ✅Different refrigerants must be placed in recovery vessels containing the same type of refrigerant. What can a reclaimer do with any mixed refrigerant you ship to them? - Correct Answer ✅They may either refuse to process and return it at owner's expense or agree to destroy the refrigerant for a substantial fee. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 To ship recovered refrigerant you must label the container and complete all necessary paperwork. What else should you do? - Correct Answer ✅Use DOT approved cylinders. What federal agency sets the standards for portable refillable tanks or containers used to ship CFC or HCFC refrigerants? - Correct Answer ✅Department of Transportation (DOT). Safety glasses and butyl-lined gloves should be worn fro what procedures? - Correct Answer ✅When you are connecting and disconnecting hoses. Piercing valves are used for what purpose? - Correct Answer ✅To allow access to the sealed system for recovery. On what materials are piercing valves used? - Correct Answer ✅Copper or aluminum refrigerant lines. What should be done to a piercing type Schrader valve after it is installed on a charged system? - Correct Answer ✅It should be capped after any service procedure. Why should solder-less type piercing valves be removed after completion of repairs? - Correct Answer ✅To prevent leaks. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What are the critical maintenance checks done to a Schrader valve? - Correct Answer ✅Periodically checked for leaks and replaced if damaged. What does a pungent odor detected after opening a system mean? - Correct Answer ✅It might mean acids are present due to a compressor burnout. What do you do if the oil is contaminated? - Correct Answer ✅Tubing flushing might be required. What system pressure would indicate a recovery should not be performed? - Correct Answer ✅0 PSIG. What are the current methods used to monitor the 80% fill level in a recovery tank? - Correct Answer ✅Floats, thermistor-type sensors and weighing scales. Why do large refrigerant leaks cause suffocation? - Correct Answer ✅Refrigerants will replace air in a confined space leading to possible oxygen starvation. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 Where is a receiver typically installed on a system? - Correct Answer ✅At the outlet of the condenser. What will be the boiling temperature of HFC-134a be at 0 PSIG? - Correct Answer ✅-15 degrees F. Is it a requirement that recovery machines contain an oil separator? - Correct Answer ✅No. Which refrigerant is typically used on a residential split system air conditioner? - Correct Answer ✅HCFC-22. Is the refrigerant leaving a receiver a liquid or a gas? Is it at a high or low pressure? - Correct Answer ✅Liquid, high pressure. What is the initial charging method of a system when the charge is specified at 70 pounds? - Correct Answer ✅Charged in liquid state. Is the receiver on the high or low side of a system? - Correct Answer ✅High side. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What is the minimum recommended capability (measured in microns) of a vacuum pump used for evacuations? - Correct Answer ✅Should pull a vacuum of 500 microns. What is the pressure of a CFC-12 machine at 72 deg. F while the machine is idle? - Correct Answer ✅73 PSIG. What is the preferred unit of measurement for checking a deep vacuum? - Correct Answer ✅Microns. Where is an accumulator located in a refrigeration system? - Correct Answer ✅On the suction line before the compressor. To prevent freezing of any moisture in a CFC-12 system vapor should first be charged until the pressure is at what level? - Correct Answer ✅33 PSIG What gas should be used during an evacuation to increase pressure to prevent freezing? - Correct Answer ✅Dry nitrogen. What is the purpose of a compressor heater? - Correct Answer ✅To reduce the amount of refrigerant in the lubricating oil. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 How is moisture remaining from an evacuation removed from the refrigerant in a system? - Correct Answer ✅By the filter-drier. What is the preferred method of leak checking a built-up system prior to charging? - Correct Answer ✅Bubble solution. What would a technician initially look for during a visual inspection of a leaking hermetic system? - Correct Answer ✅Stains around tubing and fittings. What is typically indicated by excessive superheat on a high-pressure system? - Correct Answer ✅Undercharged system, possibly the result of a leaky system. Which refrigerant should be used for a trace charge during leak detection? - Correct Answer ✅R-22. How do you leak check an HFC-134a system with a partial charge (no HFC-134a detector available)? - Correct Answer ✅Recover remaining 134a, pressurize the system with nitrogen and a trace charge of R-22 so you can use an HCFC electronic leak detector. For what purpose are soap bubbles used in leak checking? - Correct Answer ✅For a visual check for leaks. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What access location should you use when recovering from an air cooled system with its condenser several feet above the evaporator? - Correct Answer ✅Suction line. What access location should you use when recovering from a system with its condenser below the evaporator? - Correct Answer ✅Liquid line. Before using a recovery unit - Correct Answer ✅the technician should check service valve positions and check the recovery unit oil level. What additional step must be taken?,All solenoid valves should be open. What is the primary purpose for using hand valves or self-sealing hoses when using a gauge set? - Correct Answer ✅To prevent loss of refrigerant when connecting and disconnecting hoses. What can cause recovery equipment with a hermetic compressor to overheat when drawing a deep vacuum? - Correct Answer ✅No airflow over the compressor body or no suction gas flow over the internal motors, or a combination of the two. What is the reason for not operating a hermetic refrigeration compressor while it is in a deep vacuum? - Correct Answer ✅To prevent overheating the compressor motor. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What is the reason for not starting a reciprocating compressor with its discharge service valve closed? - Correct Answer ✅To prevent overheating the compressor motor. When can a "system-dependent" recovery device be used? - Correct Answer ✅On small appliances as long as the device meets EPA standards and the technician adheres to the servicing procedures specified for the recovery equipment. Cannot be used on systems with more than 15 lbs. of refrigerant. What vacuum level must you reach when recovering from a system with 38 pounds of R-502 using a recovery machine manufactured in 1995? - Correct Answer ✅10 inches of Hg. What is EPA's definition of a "major repair"? - Correct Answer ✅Any repair that involves the removal of the compressor, evaporator, condenser, or any auxiliary heat exchanger coil. Prior to making a major repair what vacuum level must you pull when using recovery equipment manufactured in 1996 on a unit with 215 lbs. of CFC-12? - Correct Answer ✅15 inches of Hg. What vacuum level must you pull when using recovery equipment manufactured in 1992 when disposing of an appliance containing 12 lbs. of R-500? - Correct Answer ✅4 inches of Hg. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 Under what circumstances may a technician recover the CFC refrigerant in an appliance to atmospheric pressure only? - Correct Answer ✅If leaks are in the system or if recovery to target levels would contaminate the refrigerant. What procedure should be performed on an empty recovery cylinder before it is used for storing recovered refrigerant? - Correct Answer ✅It must be evacuated of all non-condensables. What may legally be done with the refrigerant recovered from a system in order to replace a condenser coil? - Correct Answer ✅Reused in the original system or transferred to another system with the same owner after it is checked so that it is free of non-condensables. When servicing an operating unit with a receiver where should the recovery hoses be attached to the unit? - Correct Answer ✅To the liquid line. In order to recover from a system with parallel compressors the individual compressors must be isolated. Why? - Correct Answer ✅It isolates the refrigerant that must be recovered from the rest of the system. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 What minimum saturation temperature needs to be achieved before liquid is charged into a chiller? - Correct Answer ✅Above freezing, typically 36 deg. F. To prevent freezing of water when charging a chiller what pressure should be reached with vapor before using liquid CFC-11? - Correct Answer ✅16.9 inches of Hg. What could result from liquid refrigerant being charged into a chiller that is holding a 29 inch Hg. vacuum? - Correct Answer ✅Can cause system water to freeze. What function is served by a purge unit on a chiller? - Correct Answer ✅Minimize the effects of contamination. To remove non-condensables. What is the most likely cause of air leaks into a chiller refrigerant circuit? - Correct Answer ✅Gaskets and fittings. How is a purge unit connected on a low pressure chiller? - Correct Answer ✅The inlet of the purge unit is typically connected to the top of the condenser. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 Where is the suction of a purge unit connected? - Correct Answer ✅The inlet of the purge unit is typically connected to the top of the condenser. What is a high efficiency purge unit? - Correct Answer ✅It removes non- condensables that contain a low percentage of refrigerant. This adds to the value of the purge drum in refrigerant containment. Shaft seals on an open type compressor are susceptible to what failures? - Correct Answer ✅Refrigerant leaks. Purge units work best when they are not needed. How can purge unit operating time be reduced? - Correct Answer ✅By regular leak checking and repairing any leaks on a regular schedule. What is the maximum pressure that can be used when leak checking a low pressure chiller? - Correct Answer ✅10 PSIG on low pressure equipment that utilizes a rupture disk. What is the preferred method of leak checking a charged low pressure chiller? - Correct Answer ✅By increasing the refrigerant pressure using an external heat source or running hot water through the chiller tubes not to exceed 10 PSIG. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 Where should you check for leaks between a chiller refrigerant tube and the water box? - Correct Answer ✅The chiller barrel can be emptied of all water and a leak check can be made at the drain valve with the water off. If the tubes themselves require a leak check, the check can be made with a hydrostatic tube test kit. What is a hydrostatic tube test kit used for? - Correct Answer ✅To check for leaks in a chiller tubes. What leak rate is permissible on industrial and process refrigeration? - Correct Answer ✅Effective 6/14/93, any annualized leak rate of 35% or more on equipment with 50 lbs. of charge or more must be repaired. Less than 35% is permissible. What leak rate is permissible on equipment other than industrial and process equipment? - Correct Answer ✅For appliances with 50 lbs. of charge or more an annual leak rate of 15% or more must be repaired. Less than 15% leak rate is permissible. According to ASHRAE 3-1990 what rise is permitted in vacuum level during a standing vacuum test? - Correct Answer ✅Starting at 1mm of Hg., after 12 hours the vacuum reading should not increase to more than 2.5 mm of Hg. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 Under what circumstances may the recovery from an appliance be stopped without reaching the prescribed level? - Correct Answer ✅If the recovery would contaminate the refrigerant being recovered. (this level cannot exceed 0 PSIG.) Is it a requirement that recycling and recovery equipment be capable of handling more than one refrigerant? - Correct Answer ✅No. Is it permissible to warm the refrigerant under EPA's regulations to pressurize a low pressure system to do a non-major repair? - Correct Answer ✅Yes. What final vacuum level is required for recovering refrigerant from a low pressure system if the technician is using recovery equipment manufactured BEFORE November 15 1993? AFTER November 15, 1993? - Correct Answer ✅25 inches of Hg, 25 mm of Hg. Absolute (equal to about 29 inches of Hg.) A vacuum pump that is too large for a particular system can cause what problem? - Correct Answer ✅It can cause moisture to freeze in the system. EPA Section 608 Technician Certification Study Guide Question And Answers 2024-2023 How can you prevent moisture from freezing during dehydration? - Correct Answer ✅You can raise the pressure with nitrogen and allow the ice to melt, then continue with the evacuation. Are multiple relief valves connected in series or parallel? - Correct Answer ✅Parallel. ASHRAE Standard 15 covers refrigerant level monitoring for what refrigerants? - Correct Answer ✅All refrigerants. According to ASHRAE Standard 15 what is the standard for refrigerant concentration for a machine room that must not be exceeded without activating an alarm and starting ventilation in the machine room? - Correct Answer ✅May not exceed the TLV-TWA. (Threshold limit value- Time weighted average.) List four safety procedures that should be followed when working with liquid low pressure refrigerant. - Correct Answer ✅1. Use refrigerant sensors in equipment room. 2. Avoid siphoning refrigerant by mouth. 3. Wear butyl-lined gloves. 4. Wear safety glasses. What is the toxicity and flammability rating of HCFC-123 per ASHRAE Standard 34? - Correct Answer ✅B1.