During pneumatic testing, which substance is commonly used to identify pressure leaks?

Using soapy water during pneumatic testing is a well-established method to identify pressure leaks. The soap forms bubbles when it comes into contact with escaping air, making it easy to detect even small leaks. As air escapes through any openings or cracks in the system under test, the pressure causes the soapy water to produce visible bubbles, indicating the precise location of the leak.

While other methods may also be employed in certain contexts, they do not provide the same clarity and immediacy in leak detection as soapy water does. Hydrostatic testing involves using water under pressure, which isn’t suitable for identifying leaks in gas systems. Shaving cream, while it can create lather, is not as effective or commonly used in industry for this purpose. An audio decibel meter can measure sound levels but cannot specifically detect escaping air in a manner that is as direct as soapy water. Therefore, soapy water remains the preferred choice for its effectiveness and simplicity.