The stainessless thin shell shall be filled with SF6 gas. As there might be welding defects, it is necessary to do leak testing before the SF6 fill. The normal solution is the auto helium leak test system.

As the stainessless thin shell can only bear limited pressure, the helium leak test, dryness test and SF6 fill process are completed inside an integrated system.

Test Concept
Evacuate the vacuum chamber.
Check the pressure drop inside the product for gross leak test.
Evacuate the product and charge helium into the product.
Test the helium signal from the vacuum chamber by the leak detector for fine leak testing.
Recover helium from the product.
Charge SF6 into the product.
Vent vacuum chamber.

Technical Specification
Cycle time:1hour/pcs.
Leak rate:1×10-6mbar.l/s
Test pressure:0.5bar

Main Parts of System
Vacuum pump: Leybold
Vacuum sensor: Inficon
Helium leak detector: Inficon
Pressure sensor: GE
Solenoid valve: Burkert
PLC: Omron
HMI: Omron