Which feature is essential in medical air receivers?

A three-valve bypass is essential in medical air receivers because it provides a way to maintain continuous supply under various conditions, ensuring that there is no interruption in the availability of medical air for patient care. This design allows for easier maintenance and inspection of the system without shutting down the entire air supply.

The three-valve configuration typically includes valves for isolation, allowing maintenance to occur without risking the loss of medical air pressure, thereby safeguarding the health and safety of patients relying on these gas systems. This is critical in medical environments where reliability is paramount.

While other options might suggest potential components or configurations, they do not offer the same level of reliability and operational flexibility that a three-valve bypass provides in a medical air system.