Which of the following ensures that gas flows only in one direction in the hanger yoke?

• A. The washer
• B. The retaining screw
• C. The floating valve
• D. The body

Answer: (C)

The floating valve is a crucial component in the hanger yoke of an anesthesia machine that ensures gas flows only in one direction. Its design allows it to move freely and seal off the flow from one side when gas is entering from the opposite side. This mechanism prevents backflow, ensuring that the gases supplied to the patient are consistent and not contaminated by any return flow or leakage from other sources.

In the context of the other components: the washer is primarily involved in creating a seal to prevent gas leaks at connection points; the retaining screw provides mechanical stability to the assembly but does not influence gas flow direction; and the body of the hanger yoke itself serves as a structural component without intrinsic properties that guide or control the flow of gas. Therefore, the floating valve is specifically designed to maintain unidirectional flow, making it the correct answer.