Abstract: A unit for viewing and supplying light or radiant energy to the interior of a vessel that has a front fused glass window. The light and camera-viewing means see the interior of a vessel through this fused glass window which provides a substantially corrosion-proof seal across the entire distal portion of the unit. The light and camera-viewing means are pointed into the interior of the vessel in substantially the same direction.

Abstract: In using various vessels such as reaction vessels there must be provisions for adding materials to the vessels and for observing the vessel contents. The structure of this invention provides a vessel closure device that provides both of these conveniences. This closure device has an annular seal ring containing spring plungers each located outside areas of exposure to the contamination of the vessel. The seal ring also has two O-ring seals to ensure against leakage. There is also provided a sliding door with a viewing window that is aligned with all openings in the other closure device components in order to provide a clear viewing and addition path to the interior of the vessel.