Leak Test

Bubble Leak Testing, as the name implies, relies on the visual detection of a gas (usually air) leaking from a pressurized system.  Small parts can be pressurized and immersed in a tank of liquid and larger vessels can be pressurized and inspected by spraying a soap solution that creates fine bubbles to the area being tested.  For flat surfaces, the soap solution can be applied to the surface and a vacuum box can be used to create a negative pressure from the inspection side.  If there are through leaks, bubbles will form, showing the location of the leak.