Pressure & Vacuum Tube Leak test and Tube sheet soap leak test = Pressure & Vacuum Tube Leak Test Academic Definition The Pressure & Vacuum Tube Leak Test is a class of non-destructive testing (NDT) methods used to verify the leak-tightness of industrial components-mainly in piping, vessels, and heat exchanger tubes--by subjecting them to either internal overpressure (pressure test) or underpressure (vacuum test) and observing for pressure changes over time. It ensures that the tested object can