Abstract: A manway lid gasket is an annular gasket that has top and bottom surfaces between the inside diameter and outside diameter of the gasket. Each of the top and bottom surfaces includes a concave, circumferential groove therein. Additionally, the gasket has a radial cut out that extends from the outside diameter face partway through the radial width of the gasket and has an annular corrugated metal insert positioned therein.

Abstract: A manway lid gasket is an annular gasket that has top and bottom surfaces between the inside diameter and outside diameter of the gasket. Each of the top and bottom surfaces includes a concave, circumferential groove therein. Additionally, the gasket has a radial cut out that extends from the outside diameter face partway through the radial width of the gasket and has an annular corrugated metal insert positioned therein.

Abstract: A cooperative antenna tracking system for use at both ends of a radio link employs conical-scanning-type tracking at each end of the radio link to point a directional antenna guided by a continuous radio signal transmitted from an antenna at the other end of the link. A cooperative system between the two stations avoids pollution of the tracking in each station which might be caused by conical scanning at the other end of the link. Tracking pollution is avoided by time multiplexing tracking intervals between the two stations or by employing a tracker drive signal as a reference signal in a synchronous detector in each station to demodulate its own scanning frequency while sharply discriminating against signal variations produced by a scanning frequency at the other end of the link.