NDTnet 1998 Aug, Vol.3 No.8

Full-Text - Abstract

Leaktesting is a non destructive examination method which is used for detection and localisation of leaks and for measurement of leakage's in systems or equipment which is under vacuum or pressure.

Leaks are special types of defects which can have a major importance in systems where they have influence on safety and performance. Many objects will have a reduced reliability if they contain leaks.

Four basic reasons to carry out leak test are:

1. to prevent material outslip, which can disturb the operation
2. to prevent dangerous or unpleasant pollution of the environment due to accidental leaks
3. to detect unreliable objects and objects at which the leak rate exceed what is acceptable according to the standards
4. to avoid financial lostes

Basically is leak testing at method where a pressure difference between the outer and the inner side of the object to be examined is produced. Subsequently the amount of gas or liquid which is passing through is measured.

Helium leak test is a test method where helium is used as a search gas. When the "Vacuum method" is applied the object to be examined for leaks is evacuated and sprayed from the outside with a search gas, Helium. The gas enters through any leaks present in the object and is detected by a sensor connected to the leak test instrument. When the "Overpressure method" is applied the object to be examined for leaks is filled with a search gas, Helium, under slight overpressure. The search gas escapes through any leaks present to the outside and is detected there by a sensor. This sensor is in most cases a so-called "sniffer" acting as a gas sampling probe.

This paper will present the helium leaktest method and a range of industrial applications in which the helium leaktest can be applied.

Abstract Source:
Book of Abstracts, 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN: 87-986898-0-00

Full-Text Source:
Proceedings of the 7th European Conference on Non-Destructive Testing, 26-29 May 1998, ISBN:

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