Saving Helium in Vacuum Chamber Leak Testing
A diminishing supply of helium has many companies looking for ways to minimize the amount of helium used in their processes. The following chart provides you with helpful guidelines for saving helium during vacuum chamber leak testing and at the same time, helping to save the precious reserve we have.
| Means | Description | Achievable Saving | Recommended for | Limitations | Ease of Implantation |
|---|---|---|---|---|---|
| Helium reclaiming | ~ 90% | Large parts |
Capital cost for reclaiming system loss of helium / dilution over time -> backfilling required |
Easy/Medium | |
| Diluting of helium | 10% helium = 10% leak rate | ~ 90 – 95% | Large parts medium leak rates |
Cost for mixing equipment loss of sensitivity -> Leak detector must have sufficient sensitivity |
Medium |
| Lower helium fill pressure | 50% fill pressure = 25% leak rate | ~ 50% | Large parts medium leak rates |
Loss of sensitivity -> Leak detector must have sufficient sensitivity testing pressure ≠ operating pressure |
Medium |
| Check helium supply lines for leaks | ~ 5 – 10% | All |
Maintenance effort |
Easy | |
| Switch off partial flow during measuring | = higher sensitivity = less helium needed (booster pump needed for decent response times) | ~ 90% | Large chambers |
Booster pump needed (Capital investment cost) |
Medium/Hard |
| Filling / venting valve close to part under test | = low volume of supply lines | ~ 10 – 80% | All (larger effect on smaller parts) |
Difficult to retrofit |
Hard |
| Minimize volume of chamber | = pump with lower pumping speed = better partial flow factor = higher sensitivity = less helium needed | ~ 10 – 50% | Large chambers |
May be difficult to retrofit |
Medium/Hard |
| Decide on leaking based on signal extrapolation | Move closer to detection limit = less helium needed | ~ 50% | All (larger effect on large parts) |
High reproducibility required |
Medium but application limited |
The items in the table above are all suggestions to improve your leak testing system. Not all of these suggestions will apply to all applications. The effort for implementing these suggestions will vary significantly.
For all changes to a leak testing system close cooperation of the end customer, the system integrator and INFICON is needed. Contact your nearest sales representative for expert advice on how to optimize your system.