Quartz tube sealing solution to the problem:
As long as a flange to flange and quartz tube, using O ring seal on it, the double O ring seal should be able to high vacuum. The effect of temperature, vacuum quartz tube can of course. General silicone ring can only be resistant to 100-200 degrees Celsius, so need to add water cooling device on the flange, of course if you heat away from the flange, a fan blowing can say these functions of any one annealing furnace are able to complete the simple.
In fact, quartz processing factories to cheaper just to find a long quartz tube can be, head set epithelial tube can vacuum. Quartz insulation or better working temperature was 500 degrees, the above method is expensive. Then the head end temperature can only 40-50 degrees, do not consider cooling.