When inspecting a removable rigid fuel tank for leaks, what procedure should be followed?

Pressurizing the tank with air and brushing with soapy water is a highly effective method for leak detection in removable rigid fuel tanks. When the tank is pressurized, any leaks will allow air to escape, and when this escaping air bubbles through the soapy water applied to the surface, it creates visible bubbles, indicating the presence of a leak.

This method provides a clear visual indication of leaks, making it straightforward to identify and locate any problem areas effectively. Additionally, because air is lighter than most liquids, this technique minimizes the risk associated with using potentially corrosive or hazardous substances that could be present in the tank when it is filled with fuel or other liquids.

In contrast, filling the tank with water can be impractical and can cause issues if debris or contaminants are present. Visual inspection alone may not reveal hidden issues, especially in welded or sealed areas where leaks may not be visible. Ultrasonic testing can be useful in some circumstances but is typically more involved and may not be necessary for initial leak inspections like the pressurization method. Hence, using air pressure with soapy water combines efficiency with effectiveness for leak detection in such tanks.