Pressure Decay Test
Definition - What does Pressure Decay Test mean?
A pressure decay test is a technique used to detect leaks by measuring a pressure change in a vessel over a desired timeframe. This test works by first using a pressure leak tester unit to fill the test specimen with air until it reaches a target pressure. Next, the pressure source is cut off to isolate the specimen from the supply. The testing apparatus then monitors the vessel for any drops in pressure during the specified test time.
Among other causes, a leak may indicate the presence of pitting corrosion or a pinhole.
Corrosionpedia explains Pressure Decay Test
Pressure decay tests are especially useful in applications where parts or components are susceptible to pitting corrosion. Pitting corrosion can cause the formation of pinholes, which may sometimes be invisible to the naked eye. This test can easily detect minute pinhole leaks by calculating the change in pressure (delta) over a fixed period of time.
The sensitivity of the pressure decay test is affected by several factors including the test part’s size and the testing time. While most tests can be performed relatively quickly, larger components may require longer test times to obtain accurate results.