Abstract: A device for the automatic regulation of fluid flows through an aperture for use with immiscible liquids having differring densities, wherein the volume, weight and shape of a floatable plug are selected to provide a negative buoyancy with respect to the less dense liquid and a positive buoyancy with respect to the denser liquid, and with the buoyancy of the plug in the various liquids determining whether the fluids will be permitted to flow through the aperture.

Abstract: An inverted bucket-type steam trap has a completely sealed casing of uniform wall thickness and preferably made of stainless steel. The casing is comprised of an upper part and a lower part. The lower part and the upper part both have a cylindrical wall portion which is open at one end and closed at the other end by a spherical segment-shaped bottom wall. The upper part and the lower part are affixed to each other by welding. The upper part has sidewardly extending outlet and inlet fitting means welded thereto. A valve is provided in association with the outlet fitting means. An inverted bucket is movable vertically inside the casing in response to the presence of condensate therein to operate the valve between opened and closed positions. An inlet tube is provided inside the casing and it extends from the inlet fitting means into the lower end of the bucket.