Helium leak testing for switchgear, GIS & RMU tanks
Custom vacuum-based helium leak test systems for medium-voltage and HT switchgear enclosures, built to meet the strict leak-tightness norms for SF6-insulated equipment.
SF6 switchgear has to hold its gas for decades, so tank leak rates must be proven before dispatch. Our machines test large GIS and RMU tanks in a vacuum set-up and, once a tank passes, fills it with SF6 to the required pressure without disconnecting it from the circuit.
Key features
- Vacuum helium test sized for large GIS and RMU tanks
- Automatic SF6 filling at set pressure after a successful leak test
- Monitoring of filled SF6 gas: density, dew point and related parameters
- Recipe-based operation for different tank variants
- Test report for each tank with leak rate and pass/fail result
- Optional helium recovery to reuse test gas

Technical specifications
| Test method | Vacuum (hard vacuum) helium testing |
|---|---|
| Parts tested | MV/HT switchgear tanks, GIS enclosures, RMU tanks |
| Reject leak rate | 1.0 × 10⁻⁶ mbar·l/s |
| Maximum tank size | 2 m × 2 m × 1 m |
| Cycle time | 30 minutes |
| Helium leak detector | Pfeiffer Vacuum ASI 35 |
| SF6 filling | Automatic, to set pressure, after leak test pass |
| Gas quality checks | SF6 density, dew point |
| Controls | PLC with industrial PC (IPC) touchscreen |
| Data | PDF and CSV test reports; export by USB or to MES |
Specifications are configured for each order. Send your part details for a machine matched to your leak-rate limit and cycle time.
Gallery



Questions about this machine
Can the machine fill SF6 after testing?
Yes. After a tank passes the helium test, the machine evacuates it and fills SF6 to the set pressure while the tank is still connected, then checks gas density and dew point.
Which switchgear makers is this suited to?
Manufacturers of MV/HT gas-insulated switchgear, ring main units and similar SF6-filled enclosures. We adapt fixtures and tank connections to your designs.

