Abstract: A buoyant float including a body having an interior defined in part by a side wall and a bottom extending inward from the side wall. The side wall has an upper edge defining an open top of the body. The float includes a cover sized and shaped for covering the top of the body. The cover attaches to the body to maintain the cover in position relative to the body to cover the open top. The cover has a tubular skirt extending downward and around the upper edge of the body side wall when the cover is in position covering the top of the body. An air pocket is created at an interface between the cover and the body when the float is positioned in liquid to isolate the interface from the liquid and prevent liquid from entering the hollow interior of the body through the interface.

Abstract: A buoyant float including a body having an interior defined in part by a side wall and a bottom extending inward from the side wall. The side wall has an upper edge defining an open top of the body. The float includes a cover sized and shaped for covering the top of the body. The cover attaches to the body to maintain the cover in position relative to the body to cover the open top. The cover has a tubular skirt extending downward and around the upper edge of the body side wall when the cover is in position covering the top of the body. An air pocket is created at an interface between the cover and the body when the float is positioned in liquid to isolate the interface from the liquid and prevent liquid from entering the hollow interior of the body through the interface.

Abstract: An apparatus includes a valve housing having an inlet port, a first chamber with a first outlet port, and a second chamber with a second outlet port. A first valve opens between the inlet port and the first chamber under a first level of pneumatic pressure at the inlet port. A second valve opens between the first chamber and the second chamber under a second, greater level of pneumatic pressure in the first chamber. A third valve opens between the second chamber and the first chamber under a third level of pneumatic pressure in the second chamber, with the third level being less than the first level.

Abstract: An apparatus includes a valve housing having an inlet port, a first chamber with a first outlet port, and a second chamber with a second outlet port. A first valve opens between the inlet port and the first chamber under a first level of pneumatic pressure at the inlet port. A second valve opens between the first chamber and the second chamber under a second, greater level of pneumatic pressure in the first chamber. A third valve opens between the second chamber and the first chamber under a third level of pneumatic pressure in the second chamber, with the third level being less than the first level.