Leak Testing is a non-destructive testing method for detection and localisation of leakages in pressure and vaccum systems.
„Leakage“ means liquid or gas passage through a leak independent from its physical size. A leak can be a crack, breakthrough, groove or hole which leaves or embeds a gas (e.g. air) or liquid (e.g. water) into/out of the construction.
Leakages could endanger the operation safety of vaccum or pressure systems, such as pressure vessels, significantly. Dangerous gases or liquids might emerge.
Leak testing is also applied for pyrotechnical facilities, electronic parts, air condition equipment, food packaging etc.
| Evidence of vessel decompression
using fluorescent concentrate H 849
The following table shows the relation of leakage rate, size of leakage and the leakage thus resulting :
|Diameter of leaks
||Leakage through leak at
Δp = 1 bar
|10¹||1.0 mm||Water runs out|
|10-1||0.1 mm||Water drops|
|10-3||0.03 mm||Watertight, but permeable to gas|
|10-5||≈ 3 µm||1 air bubble ( ≈ 1 mm³) in 10 seconds|
|10-7||≈ 0.1 µm||approx. 1 cm³ gas losses in 12 days|
|10-9||--||approx. 3 cm³ gas losses in 1 year|
|10-11||--||approx. 1 cm³ gas losses in 300 years|