Pipeline Installation Flashcards

According to NFPA 99, what is the minimum burial depth required for medical gas piping installed underground inside a healthcare facility?

Answer: 18 inches

NFPA 99 requires underground medical gas piping inside buildings to be buried at least 18 inches deep to protect against damage.

Which type of fitting is prohibited in medical gas pipeline systems according to NFPA 99?

Answer: Threaded fittings on copper tubing

Threaded fittings on copper tubing are prohibited in medical gas systems; all joints must use brazed or approved mechanical connections.

What is the required color coding for a nitrous oxide pipeline in the United States?

Answer: Blue

Nitrous oxide pipelines are coded blue per CGA and NFPA 99 standards for medical gas identification in the US.

When installing copper tubing for medical gas pipelines, which grade must be used?

Answer: Type ACR copper cleaned for oxygen service

Medical gas piping requires Type K or Type L hard-drawn copper tubing that has been cleaned for oxygen service and labeled accordingly.

In a medical gas pipeline system, what is the purpose of a zone valve box?

Answer: To isolate a section of the distribution system for maintenance or emergency

Zone valve boxes allow specific areas to be isolated from the pipeline system without shutting down the entire facility supply.

After brazing joints in a medical gas pipeline, what must be done before pressure testing?

Answer: Blown down with oil-free nitrogen to remove residual flux

After brazing, lines must be blown down with dry nitrogen to remove flux residue, which is corrosive and could contaminate the gas supply.

What is the maximum allowable pressure drop across a medical gas pipeline system during peak demand as specified by NFPA 99?

Answer: 5 psi

NFPA 99 requires that the pipeline system maintain pressures within ±5 psi (or ±10%) of the operating pressure under peak demand conditions.