RMGA System Testing 5 — Questions and Answers
Question 1: What is the primary purpose of the 'operational pressure test' conducted at medical gas outlet stations during final system verification?
- To determine if the pipeline is leak-free at construction pressure
- To confirm the system delivers gas at the correct pressure range under simulated use conditions (Correct answer)
- To identify cross-connections between gas types
- To verify that alarm panels annunciate at the correct setpoints
Correct answer: To confirm the system delivers gas at the correct pressure range under simulated use conditions
The operational pressure test simulates actual use conditions to confirm that pipeline pressure at the outlet station stays within the required 50–55 psig range during flow.
Question 2: When verifying a medical air system produced by a compressor, what parameter must be measured and documented to confirm the air meets medical grade purity requirements?
- Carbon monoxide and dew point (Correct answer)
- Total hydrocarbon content only
- Oxygen percentage only
- Particulate count only
Correct answer: Carbon monoxide and dew point
Medical air purity requires testing for carbon monoxide (≤10 ppm) and dew point (≤−26°C at line pressure) as primary purity indicators per NFPA 99 and USP standards.
Question 3: During system testing, an RMGA observes that the master alarm panel does not annunciate when pipeline pressure drops below the low-pressure setpoint. What is the required response?
- Document the finding and inform the facility after testing is complete
- Fail the system and require repair and retest of the alarm system before certification (Correct answer)
- Bypass the alarm panel and continue testing other components
- Adjust the setpoint to match the observed pressure and continue
Correct answer: Fail the system and require repair and retest of the alarm system before certification
A non-functional master alarm is a critical safety failure; the system cannot be certified until the alarm is repaired and successfully retested to function correctly.
Question 4: What is the correct sequence for conducting a cross-connection test on a newly installed multi-gas medical pipeline system?
- Pressurize all gases simultaneously and test all outlets at once
- Pressurize one gas at a time with nitrogen while all other lines remain unpressurized, then test every outlet (Correct answer)
- Test only the oxygen and nitrous oxide lines since they are the highest risk
- Use color-coded inspectors at each outlet while all gases are flowing simultaneously
Correct answer: Pressurize one gas at a time with nitrogen while all other lines remain unpressurized, then test every outlet
NFPA 99 requires testing one gas line at a time with a test gas while all other lines remain depressurized, then confirming at every outlet that only the correct gas is present.
Question 5: Why must all system testing of medical gas piping be performed BEFORE any gas-powered medical equipment is connected to the outlets?
- To prevent damage to expensive equipment from high test pressures
- To ensure test results accurately reflect the piping system and are not influenced by connected equipment (Correct answer)
- Because NFPA 99 requires equipment to be tested separately by biomedical engineering
- To allow the piping to cure and off-gas before clinical use
Correct answer: To ensure test results accurately reflect the piping system and are not influenced by connected equipment
Connected equipment can mask leaks, affect flow readings, or introduce contaminants, so testing must be done on the bare piping system to obtain accurate, unambiguous results.
Question 6: During verification of a medical gas system addition (new wing), an RMGA must test the interface between the new and existing piping. Which test is most critical at this junction?
- Dew point measurement
- Cross-connection test at the tie-in point and downstream outlets (Correct answer)
- Standing pressure test only at the tie-in valve
- Purity test at the source equipment
Correct answer: Cross-connection test at the tie-in point and downstream outlets
The tie-in between new and existing piping is the highest-risk point for cross-connections or mislabeled connections, so cross-connection testing at and downstream of the junction is essential.
Question 7: According to NFPA 99, which of the following parties is prohibited from performing the final system verification of a medical gas pipeline?
- A certified ASSE 6010 verifier from another region
- The contractor who installed the piping system (Correct answer)
- A hospital-employed RMGA who was not involved in the installation
- A third-party inspection agency hired by the owner
Correct answer: The contractor who installed the piping system
NFPA 99 requires that verification be performed by a party independent from the installing contractor to avoid conflicts of interest and ensure objective results.
RMGA System Testing 5
What is the primary purpose of the 'operational pressure test' conducted at medical gas outlet stations during final system verification?