RMGA Pipeline Installation 5 — Questions and Answers
Question 1: What is the purpose of the 'blow-down' procedure performed on medical gas pipelines after installation?
- To test the system for leaks under pressure
- To purge construction debris, flux residue, and moisture from the interior (Correct answer)
- To balance flow between branches
- To verify that all outlets are open
Correct answer: To purge construction debris, flux residue, and moisture from the interior
The blow-down procedure uses high-velocity nitrogen to remove particulates, flux residue, and moisture that could contaminate medical gases or harm patients.
Question 2: In a medical gas pipeline system, what is a 'riser'?
- A pressure regulator that increases supply pressure
- A vertical section of piping connecting different floor levels (Correct answer)
- A check valve that prevents reverse gas flow
- A manifold that distributes gas to multiple outlets
Correct answer: A vertical section of piping connecting different floor levels
A riser is a vertical run of piping that carries medical gas between floors of a multi-story healthcare facility.
Question 3: Which of the following conditions requires a pipeline installer to stop work and notify the RMGA immediately?
- A minor cosmetic scratch on copper tubing
- Discovery of an unlabeled pipeline of unknown content (Correct answer)
- A 1-inch change in the planned routing to avoid a structural beam
- Use of a new brand of approved brazing flux
Correct answer: Discovery of an unlabeled pipeline of unknown content
An unlabeled pipeline of unknown content represents a potential cross-connection or contamination hazard that must be investigated before work continues.
Question 4: Medical vacuum systems serving patient care areas must maintain a minimum vacuum level of:
- -12 in Hg
- -15 in Hg
- -19 in Hg (Correct answer)
- -25 in Hg
Correct answer: -19 in Hg
NFPA 99 requires medical vacuum systems in patient care areas to maintain at least -19 in Hg (inches of mercury) at the point of use.
Question 5: When a medical gas pipeline must cross another utility line, which arrangement is preferred?
- The medical gas pipe should always pass below the other utility
- The medical gas pipe should pass above the other utility (Correct answer)
- Either arrangement is acceptable if the pipes are in contact
- The pipes must be separated by a minimum of 3 feet
Correct answer: The medical gas pipe should pass above the other utility
Medical gas piping should pass above other utilities to reduce contamination risk from leaks in water or drain piping and to maintain easier access for inspection.
Question 6: Which documentation must be provided to the owner upon completion of a medical gas pipeline installation per NFPA 99?
- Only the pressure test results
- Installer certification number only
- As-built drawings, test reports, certifications, and training records (Correct answer)
- A verbal summary of the installation findings
Correct answer: As-built drawings, test reports, certifications, and training records
NFPA 99 requires a complete documentation package including as-built drawings, all test results, installer/verifier certifications, and training records at project closeout.
Question 7: What is the maximum operating pressure for a standard medical oxygen distribution pipeline system?
- 25–35 psi
- 50–55 psi (Correct answer)
- 100–110 psi
- 150–175 psi
Correct answer: 50–55 psi
Standard medical oxygen (and most medical gas) distribution systems operate at 50–55 psi at the point of use per NFPA 99 design requirements.
RMGA Pipeline Installation 5
What is the purpose of the 'blow-down' procedure performed on medical gas pipelines after installation?