What is the purpose of a zone valve in a medical gas system?

• A. To isolate segments and control flow
• B. To relieve pressure
• C. To monitor flow rate
• D. To vent waste gas

Answer: (A)

Zone valves are used to isolate sections of a medical gas distribution system and regulate flow to different areas. By closing a valve, you can perform maintenance on a portion of the piping without shutting down the entire system, and you can direct gas supply to specific zones as needed for normal operation or emergencies. They are not meant to relieve pressure—that function comes from regulators or relief valves—nor are they for monitoring flow rate (that’s done by flow meters and gauges), nor for venting waste gas (that’s handled by scavenging/vent systems).