Field installed brazed thermocouple feedthroughs for high vacuum experiments

Conference · Thu Dec 01 00:00:00 EST 1983

OSTI ID:6730801

Anderson, P M; Messick, C

In order to reduce the occurrence of vacuum leaks and to increase the availability of the DIII vacuum vessel for experimental operation, effort was applied to developing a vacuum-tight brazed feedthrough system for sheathed thermocouples, stainless steel sheathed conductor cables and tubes for cooling fluids. This brazed technique is a replacement for elastomer O ring sealed feedthroughs that have proven vulnerable to leaks caused by thermal cycling, etc. To date, about 200 feedthroughs have been used. Up to 91 were grouped on a single conflat flange mounted in a bulkhead connector configuration which facilitates installation and removal. Investigation was required to select a suitable braze alloy, flux and installation procedure. Braze alloy selection was challenging since the alloy was required to have: (1) Melting temperature in excess of the 250/sup 0/C (482/sup 0/F) bakeout temperature. (2) No high vapor pressure elements. (3) Good wetting properties when used in air with acceptable flux. (4) Good wettability to 300 series stainless steel and Inconel.

• Research Organization: GA Technologies, Inc., San Diego, CA (USA)
• DOE Contract Number: AT03-76ET51011
• OSTI ID: 6730801
• Report Number(s): GA-A-17225; CONF-831203-165; ON: DE84013556
• Resource Relation: Conference: 10. symposium on fusion engineering, Philadelphia, PA, USA, 5 Dec 1983; Other Information: Portions are illegible in microfiche products
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
DOUBLET REACTORS
PRESSURE VESSELS
BRAZING
LANGMUIR PROBE
THERMAL CYCLING
THERMOCOUPLES
WIRES
CONTAINERS
ELECTRIC PROBES
FABRICATION
JOINING
MEASURING INSTRUMENTS
PROBES
THERMONUCLEAR REACTORS
TOKAMAK TYPE REACTORS
WELDING
700209* - Fusion Power Plant Technology- Component Development & Materials Testing