What is an appropriate test medium for testing gas systems?

Using air as the test medium for gas systems is appropriate as it allows for a practical assessment of any leaks or failures within the system. Air is abundant and can easily fill the system, facilitating the detection of issues through methods like soap solution testing. When air is used under pressure, any leakage will become apparent through bubbling or an audible hiss, making it a straightforward method for identifying problems.

In contrast, while water could be used theoretically, it is not suitable for testing gas systems primarily because it can cause corrosion and other damage to metal components over time. Argon, though an inert gas, does not provide the same ease of leak detection as air since it doesn’t readily indicate the presence of a leak. Similarly, sulfur hexafluoride could be used in specific applications due to its non-toxic, non-flammable properties, but it is typically not practical due to its high cost and environmental considerations.