Final answer:
Oxygen cylinders should be refilled when they fall to about 2/3 or 70% of their working pressure, with specific values depending on the system. It is crucial for safety and functionality to refill oxygen tanks before they are depleted to ensure adequate gas flow for their intended use.
Step-by-step explanation:
When to refill an oxygen cylinder is determined by its pressure gauge. Generally, medical oxygen cylinders should be refilled when they drop to about 2/3 or 70% of their working pressure; however, the specific refill pressure may vary depending on the system in use. For instance, for a cylinder with a working pressure rated at 2,200 psi, it should typically be refilled when the pressure gauge reads between 500 to 1,000 psi to ensure a safe margin. It's also critical to note that the handling and refilling of oxygen cylinders must comply with safety standards to prevent accidents and ensure the purity of the oxygen, particularly in medical contexts.
Low pressures in an oxygen tank can be dangerous and may not deliver sufficient gas flow to meet oxygen demands, depending on the application. In medical scenarios, inadequate oxygen supply can have serious or fatal consequences. Therefore, it is vital to monitor cylinder pressures and refill them accordingly.