Hermeticity

One of the foremost quality characteristics of SCHOTT glass-to-metal seals is our hermeticity. Because of its importance to the functionality of components, the vacuum tightness of our glass-to-metal seals is constantly monitored through random sample inspections. Tightness tests are performed with helium leakage detectors that work according to the mass-spectrometer principle.

Using helium as a test medium, modern leakage detectors are capable of tracing minute leaks of 10-12 mbar l/s. However, this is only possible under laboratory conditions and requires long pumping and measurement cycles.

In tough everyday usage, leakage rates of up to 10-8 mbar l/s can realistically be measured. That is why SCHOTT glass-to-metal seals are generally guaranteed to a leakage rate of 10-8 mbar l/s; in this case, the pressure differential between the interior and the exterior is 1 bar. In special cases and upon agreement, leakage rates down to 10-11 mbar l/s can be confirmed and guaranteed, because, as a rule, SCHOTT glass-to-metal seals also meet these lower leakage requirements.

The leakage rate of SCHOTT glass-to-metal seals can also be tested under non-static conditions. For example, it is possible to conduct cap welding tests with increased welding stresses and then to determine the remaining leakage rate.
新闻,展会与活动
04.
April
展会 Gastech Japan 2017, Tokyo, 日本国, 04.04 - 07.04.2017
21.
March
展会 IDS 2017, Cologne, Deutschland, 21.03 - 25.03.2017