Seal structure for metal vacuum joint

摘要

Each of a pair of annular, especially non-circular, apertured flanges for vacuum joints are formed by machining an outer groove spaced in from the outer edge, an inner groove extending inward from the inner margin of the joint and an outward slanted side interconnecting the two grooves resulting in a sharp corner on the inner edge of the inner groove. A flange spacer, apertured to receive the bolts which draw the flanges together is positioned in the outer groove of both flanges. A soft metal (e.g., copper) gasket overlies the inner grooves. When the bolts are tightened, the gasket deforms outwardly under the pressure of the sharp corners to seal against both slanted surfaces to form an ultra-high vacuum joint which is "bakeable." For temporary testing of joints a portion of the gasket immediately overlying the corners may be replaced with an elastomeric ring.