What is the yoke on an anaesthetic circuit/trolley?

• A. A handle for moving the trolley
• B. A valve that controls gas flow to the patient
• C. The pressure relief device
• D. Where the cylinder is attached to either the anaesthetic machine or the cylinder manifold on the pipeline system

Answer: (D)

The yoke is the interface that attaches and seals a high‑pressure gas cylinder to the anesthesia machine or to the pipeline manifold. It is the mounting point where the cylinder sits, forming a gas-tight connection so the gas can flow from the cylinder into the regulator and down to the flow meters. Often it includes a safety feature set (pin‑index) to prevent connecting the wrong gas cylinder to the machine, helping to avoid dangerous cross‑connections. It is not a handle for moving the trolley, not the valve that controls gas flow, and not the pressure‑relief device—the yoke’s job is securing the cylinder and enabling a secure, sealed transfer of gas into the system.