RMGA Inspection, Testing & Maintenance Procedures 4 — Questions and Answers
Question 1: An RMGA is verifying outlet flow rates and finds that a medical air outlet delivers only 60% of its rated flow. Which of the following is the MOST likely cause?
- The outlet DISS fitting has a partial internal obstruction or damaged check valve (Correct answer)
- The zone valve for that area is fully open
- The compressor is operating normally at rated capacity
- The outlet label is incorrect
Correct answer: The outlet DISS fitting has a partial internal obstruction or damaged check valve
Partial obstruction or a damaged check valve inside the DISS fitting is the most common cause of reduced outlet flow rate.
Question 2: What is the purpose of performing a 24-hour standing pressure test on a newly installed medical gas piping system?
- To verify that gas purity meets NFPA 99 requirements
- To confirm there are no leaks in the system before connecting to the source (Correct answer)
- To measure the flow capacity at all terminal outlets
- To calibrate the master alarm panel thresholds
Correct answer: To confirm there are no leaks in the system before connecting to the source
A 24-hour standing pressure test identifies leaks in newly installed piping by pressurizing the system and monitoring for pressure loss over time.
Question 3: During maintenance of a medical oxygen manifold, a technician finds a cracked yoke on a cylinder connection. What is the correct action?
- Wrap the crack with thread seal tape and continue operation
- Remove the cylinder from service, tag the yoke as defective, and replace it before returning to service (Correct answer)
- Tighten the yoke connection to close the crack
- Monitor the yoke for growth of the crack before taking action
Correct answer: Remove the cylinder from service, tag the yoke as defective, and replace it before returning to service
A cracked yoke on a high-pressure oxygen cylinder connection is a safety hazard that requires immediate removal from service and replacement.
Question 4: When performing a purity test on a medical oxygen pipeline system, what minimum purity level must be achieved per USP standards?
- 93.0%
- 95.0%
- 99.0% (Correct answer)
- 99.5%
Correct answer: 99.0%
USP Oxygen specifies a minimum purity of 99.0% oxygen by volume for medical oxygen distributed through pipeline systems.
Question 5: An inspector finds that the automatic changeover on an oxygen manifold does not switch from the depleted primary bank to the reserve bank. What immediate risk does this create?
- Increased pressure in the reserve bank cylinders
- Loss of oxygen supply to patients if the primary bank is not manually switched (Correct answer)
- Over-pressurization of the distribution system
- False activation of the low-pressure alarm only
Correct answer: Loss of oxygen supply to patients if the primary bank is not manually switched
If automatic changeover fails, the oxygen supply will be interrupted when the primary bank empties unless clinical or facilities staff manually switch to the reserve bank.
Question 6: What is the recommended approach for leak testing brazed joints in a newly installed medical gas copper piping system?
- Use an open flame to heat the joint and check for color change
- Apply an approved liquid leak detection solution with the system pressurized with inert gas or the process gas (Correct answer)
- Pressure test with water and inspect for drips
- Rely solely on the 24-hour standing pressure test result
Correct answer: Apply an approved liquid leak detection solution with the system pressurized with inert gas or the process gas
Brazed joints should be individually tested using approved non-flammable leak detection solution while the system is pressurized, to pinpoint any leaks at the joint.
Question 7: Which of the following deficiencies found during a medical gas inspection would require the system to be immediately taken out of service?
- A zone valve label that is faded but still legible
- A confirmed cross-connection between oxygen and nitrous oxide piping (Correct answer)
- A master alarm panel indicator lamp that is burned out
- A compressor oil change that is 2 weeks overdue
Correct answer: A confirmed cross-connection between oxygen and nitrous oxide piping
A confirmed cross-connection between gas species is an immediately life-threatening condition that requires the system to be shut down and corrected before any patient use.
RMGA Inspection, Testing & Maintenance Procedures 4
An RMGA is verifying outlet flow rates and finds that a medical air outlet delivers only 60% of its rated flow.
Which of the following is the MOST likely cause?