Marposs In-Line Leak Test Machines for High-Precision HVAC Applications

Marposs In-Line Leak Test Machines are advanced end-of-line (EOL) testing systems designed for heat pump assemblies in the White Goods and HVAC industry. The solution ensures the highest standards of quality, reliability, and energy efficiency while maintaining the productivity required in modern manufacturing environments.

The system uses hard vacuum helium leak detection to test the entire finished assembly. Helium, used as a 100 percent tracer gas, is analyzed through a mass spectrometer inside a vacuum chamber. This method is recognized as one of the most accurate leak detection technologies available, capable of identifying extremely small leak rates down to 10⁻⁵ mbar*l/s. In comparison, traditional nitrogen leak tests performed in water tanks typically detect leaks around 10⁻² mbar*l/s (one bubble with a radius of 2 mm in 1 second), and rely heavily on visual inspection, which may allow smaller leaks to go unnoticed.

The critical issue in automatic testing is the large manufacturing tolerances in all directions of the coolant tubes. To overcome this, a highly flexible coupling design has been developed by Marposs. This specially developed coupling design compensates for alignment variations and enables automatic connection to the inlet pipe, even when significant positional uncertainty exists. The solution converts what was traditionally a manual operation into a fully automated and reliable process.

The modular architecture allows configurations ranging from a single station to multiple leak test stations, supporting various production capacities.

In addition to fine helium leak testing, the system includes a preliminary gross leak test using the air pressure decay method. This step identifies major defects early, eliminating unnecessary fine leak tests on non-conforming parts, saving time, improving overall cycle efficiency, and providing quality data management for production process adjustment.

A manual sniffing system is also integrated to support maintenance, troubleshooting, and leak localization for corrective action. Additional functional tests for electro-pneumatic components can be performed within the same test station, with full traceability for warranty and quality documentation.

To enhance operational efficiency, Marposs offers an integrated helium recovery system with an efficiency of 85–95 percent. The closed-loop system recovers and recycles helium used during each test cycle, analyzes gas purity, and restores the required test pressure. This integrated approach improves accuracy, reduces operating costs, and ensures reliable detection performance.

Image Source: Marposs