The purpose of leak testing is to detect discontinuity in the materials across the inspected piece, i.e. to discover leaks.
For leak testing, we use:
- Penetration method;
- Bubble leak testing method.
Penetration leak testing consists of applying penetrant on one side of the test specimen and developer on the other side. If there is leakage in the specimen, color indications present on the developer application side.
Bubble leak testing uses the penetration of gas from a higher pressure medium to a lower pressure medium. Welds are leak tested in atmospheric air, with negative pressure forming in the chamber put on the examined section. The tested weld is covered with foaming liquid and if a leak is present, a bubble will form in the position of the leak, as a result of a pressure difference. The bubble leak testing method will not replace a pressure test.
Leak testing is performed in conformity with the following standards:
PN-EN 1779:2002/A1:2006 - Non-destructive testing - Leak testing - Criteria for method and technique selection
PN-EN 1593:2004 - Non-destructive testing - Bubble emission techniques
PN-EN ISO 3452-1:2021-12 - Non-destructive testing. Penetrant testing. General principles
