Permanent High Temperature Vacuum Tubing Joints

摘要

A new method has been developed for producing permanent tube joints exhibiting decreasing leak rate with increasing service temperature. This allows leak testing of vacuum connections at room temperature with the confidence that leak rates will not increase at elevated temperatures. A uniform internal cross-sectional area and smooth outer surfaces may also be readily provided. The process involves diffusion bonding of dissimilar metal sealing surfaces and lends itself to such problem materials as titanium and zirconium alloys. Splices and joints to dissimilar metal tubes, elbow, valves, and other fittings may be fabricated easily and reliably. Dimensional tolerances become less critical with increasing tube diameter. Joint strength is limited by the strength of the base metals. Experimental procedures for joint design, assembly, and testing are reported. (Author)