RMGA Medical Gas Systems Design & Components 2 — Questions and Answers
Question 1: According to NFPA 99, what is the minimum pressure at which bulk liquid oxygen storage systems must be equipped with a pressure relief valve set to vent?
- 100 psig
- 125 psig
- 150 psig (Correct answer)
- 250 psig
Correct answer: 150 psig
Bulk liquid oxygen systems require pressure relief valves set no higher than 150 psig to protect the vessel from overpressure conditions.
Question 2: Which type of medical gas zone valve is specifically designed to allow isolation of a single patient room without affecting adjacent rooms?
- Area alarm valve
- Room isolation valve (Correct answer)
- Zone service valve
- Sector shutoff valve
Correct answer: Room isolation valve
Room isolation valves are installed to allow a single patient room to be shut off for maintenance or emergency without disrupting adjacent rooms.
Question 3: What is the primary function of a medical gas pressure-reducing valve (PRV) in a piped distribution system?
- Prevent backflow of gases into the supply source
- Reduce high source pressure to a safe, usable outlet pressure (Correct answer)
- Monitor gas purity levels at the point of use
- Automatically switch between primary and secondary supply sources
Correct answer: Reduce high source pressure to a safe, usable outlet pressure
A pressure-reducing valve steps down the high-pressure supply to the lower, regulated pressure required at outlets throughout the facility.
Question 4: NFPA 99 requires that medical gas outlets in patient care areas be installed at what minimum height above the finished floor?
- 36 inches
- 48 inches (Correct answer)
- 60 inches
- 72 inches
Correct answer: 48 inches
Medical gas outlets must be installed at a minimum of 48 inches above the finished floor to ensure accessibility and prevent contamination.
Question 5: In a medical compressed air system, what is the purpose of the aftercooler installed immediately downstream of the compressors?
- Remove oil vapors from the compressed air stream
- Reduce the temperature of compressed air to condense and remove moisture (Correct answer)
- Regulate outlet pressure to system requirements
- Filter particulate matter larger than 0.01 microns
Correct answer: Reduce the temperature of compressed air to condense and remove moisture
The aftercooler cools hot compressed air exiting the compressor, causing water vapor to condense so it can be removed before entering the distribution system.
Question 6: Which component in a medical gas piping system is used to prevent the transmission of vibration from compressors or pumps into the rigid piping?
- Expansion loop
- Flexible connector (Correct answer)
- Dielectric union
- Swing joint
Correct answer: Flexible connector
Flexible connectors isolate mechanical vibration from compressors and pumps, preventing it from being transmitted into and damaging the rigid piping system.
Question 7: Under NFPA 99, a medical gas master alarm panel must be located where?
- In the boiler room adjacent to the gas supply
- At the telephone switchboard or security location that is continuously staffed (Correct answer)
- Outside the main medical gas storage room
- In the facility administrator's office
Correct answer: At the telephone switchboard or security location that is continuously staffed
Master alarm panels must be at a continuously staffed location such as a telephone switchboard or security desk so that alarms are always monitored.
RMGA Medical Gas Systems Design & Components 2
According to NFPA 99, what is the minimum pressure at which bulk liquid oxygen storage systems must be equipped with a pressure relief valve set to vent?