Technical Concept

The tightness of the pipeline can be determined by applying the HCNA Pressure-Step test methodology. The testing is conducted and a tightness factor is determined by the evaluation of the measurement results. The tightness factor is the leaking liquid volume in gallons per hour of the checked volume usually based on 145 psi (10 bar).

Evaluation of Test Results

In any pressure based test, the determination of a leak is most influenced by temperature and pressure changes during testing. The Pressure-Step method is based on the physical fact that given a defined leak size, the leak rate would be proportionately larger at higher pressure than at lower pressure. Because the leak rate is directly related to a change in pressure, it can be determined from the pressure gradients during the test, whether the system is or is not tight.

The leak rate sensitivity is primarily determined by the volume of the test section. In special cases (e.g. air inclusions in the fuel system), the detection accuracy may be impacted if the volume of the air inclusions is significant relative to the test section volume.

The HCNA Pressure-Step program is able to determine the leak rate on the basis of the specific properties of the material and geometry of the piping system being tested. The evaluated tightness factors are recorded in a statistical database. The reliability of the HCNA Pressure-Step method can be proven anytime by means of controlled, manually created leaks.