In gas installations, what is a common method for checking leak-tightness?

The air pressure test is a widely accepted method for checking leak-tightness in gas installations. This procedure involves applying a controlled amount of pressurized air to the gas piping system and monitoring it for any drop in pressure over a specified duration. If there is a pressure drop, it indicates that there may be a leak in the system.

This method is particularly useful because air can easily be detected due to its characteristics, and specialized instruments can be used to identify even small leaks. Additionally, air pressure tests are typically less risky than using flammable gases like natural gas or propane, making them safer for the technician and the environment during the testing process.

While other methods like water pressure tests and vacuum tests do have their applications in various contexts, they are generally not standard practice for leak detection in gas installations. The fuel gas test is also not suitable for initial leak testing before a system is placed into service, as it involves using the actual fuel gas which carries inherent safety risks. Therefore, the air pressure test remains the preferred method for ensuring the integrity and safety of gas piping systems.