Following a bakeout the other day, I found this worrisome sight:
Under the high temperatures (130C) the Viton expanded and extruded itself through the narrow gap between the flanges. The four affected seals still held vacuum. However, this was not an unforeseeable problem. The 2.75" conflat Viton gaskets carried by LDS Vacuum changed sometime in the last few years, increasing in thickness and OD, but decreasing in ID (and quality). The change in volume is ~40%. The grooves in my chamber were designed for the old size, but I foolishly decided to proceed anyway... Lesson learned.
Bakeout - Fail
- Liam David
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- Richard Hull
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Re: Bakeout - Fail
Good to know, Thanks! I only use Cu gaskets. Expensive and sometimes cantankerous to install at odd angles or in tight spots, but solid.
Richard Hull
Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment
Fusion is the energy of the future....and it always will be
The more complex the idea put forward by the poor amateur, the more likely it will never see embodiment