METAL SEALS FOR VACUUM VESSELS AT TEMPERATURES UP TO 350 DEG. C
At the 13th SOFT a report was given on KFA tests with different types of metallic seals for large circular and non- circular ports of the toroidal vacuum vessel of TEXTOR (Tokamak Experiment for Technology Oriented Research, Fig. 1). The vessel is built for bake-out temperatures of up to 350 degrees C and for a base pressure of 10-8 mbar. Several types of metallic seals for these flanges have been tested: wire seals of aluminium, silver coated copper and gold and silver jacketed Helicoflex seals. The tests were performed under thermocycling conditions and temperatures between 25 degrees C and 350 degrees C and temperature gradients of "TRIANGLE" T = 30K between the two flanges. Only Helicoflex seals have been found leak tight under these conditions whereas the wire seals failed after 4 to 8 cycles. In addition to these tests a new type of metal seal has been tested. This full metal sealing system of BALZERS consists of a special support-ring of stainless steel and two sealing rings of silver wire. The re-usable sealing system has been found leak tight under the same thermocycling conditions as above mentioned with a helium leak rate of < 3 x 10-10 mbar 1 s-1.
Bibliographic Reference: 14TH SOFT CONFERENCE, AVIGNON (FRANCE), SEPT. 8-12, 1986 VOL. 1, PP. 467-472 1895 P., 1986, VOL. 1 AND VOL. 2, ISBN 0 08 034935 8 WRITE TO PERGAMON PRESS, HEADINGTON HILL HALL, OXFORD, OX3 0BW (UK), PRICE: UKL 220 (FOR BOTH VOLS.)
Record Number: 1989126043601 / Last updated on: 1989-01-01
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