RMGA Equipment Operation 2 — Questions and Answers
Question 1: What is the primary function of a pressure relief valve on a medical gas cylinder?
- To regulate flow rate to the patient
- To prevent cylinder pressure from exceeding safe limits (Correct answer)
- To indicate when the cylinder is nearly empty
- To prevent backflow of gas into the cylinder
Correct answer: To prevent cylinder pressure from exceeding safe limits
Pressure relief valves are safety devices designed to vent gas if internal pressure exceeds the cylinder's rated safe working pressure.
Question 2: Which type of medical gas regulator is most appropriate when a precise, constant flow rate is required regardless of cylinder pressure changes?
- Single-stage regulator
- Two-stage regulator (Correct answer)
- Demand-flow regulator
- High-pressure regulator
Correct answer: Two-stage regulator
Two-stage regulators provide more stable outlet pressure as cylinder pressure drops, making them preferred for applications requiring consistent flow.
Question 3: When a flowmeter on a medical gas system reads zero but gas is flowing, the most likely cause is:
- The cylinder is empty
- The float is stuck or the tube is dirty (Correct answer)
- The regulator has failed
- The outlet valve is closed
Correct answer: The float is stuck or the tube is dirty
A stuck float or contaminated flowmeter tube can prevent accurate reading even when gas is actually flowing through the device.
Question 4: A Thorpe tube flowmeter must be positioned in what orientation to provide accurate readings?
- Horizontal
- At a 45-degree angle
- Vertical and upright (Correct answer)
- Inverted
Correct answer: Vertical and upright
Thorpe tube flowmeters rely on gravity acting on the float, requiring a perfectly vertical position for accurate flow measurement.
Question 5: Which component in a pipeline medical gas system is responsible for maintaining distribution pressure after the source equipment?
- Zone valve
- Area alarm
- Line pressure regulator (Correct answer)
- Outlet valve
Correct answer: Line pressure regulator
Line pressure regulators reduce and maintain the pipeline distribution pressure at the correct level throughout the facility.
Question 6: What is the standard pipeline distribution pressure for medical oxygen in a US healthcare facility?
- 25–35 psig
- 50–55 psig (Correct answer)
- 75–80 psig
- 100–110 psig
Correct answer: 50–55 psig
NFPA 99 specifies that medical oxygen pipeline systems operate at 50–55 psig at the point of use.
Question 7: During cylinder changeout, why should the valve be opened slightly before connecting the regulator?
- To check the gas purity
- To blow out any debris or moisture from the valve outlet (Correct answer)
- To reduce cylinder pressure for safe handling
- To activate the cylinder's built-in safety mechanism
Correct answer: To blow out any debris or moisture from the valve outlet
Briefly cracking the valve clears dust and particulates from the outlet that could damage the regulator or contaminate the gas supply.
RMGA Equipment Operation 2
What is the primary function of a pressure relief valve on a medical gas cylinder?