Floating lid for liquid vat - has conical cover with rim seal and central venting valve

摘要

The floating cover (4) on a vat (7) of liquid (6) e.g. wine has a conical shape with a central venting orifice (3) at the apex of the cover. The cover is either sealed around its periphery by a layer of special oil (5) or by an annular lipseal. The venting orifice is fitted with either a solid plug (2) or a valve (10). The valve may be a simple flexible tube flattened to provide a sealing surface or a membrane (12) on top of a cylindrical plug with a narrow centre bore (11). ADVANTAGE -The floating lid has a venting valvewhich allows entrapped gases to escape thus preventing the lid from tipping and eliminating the contamination of the vat contents with the sealing oil.